Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Boost-Back and Landing of Falcon 9 Rockets, 49332-49354 [2017-23134]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 82, Number 205 (Wednesday, October 25, 2017)]
[Notices]
[Pages 49332-49354]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-23134]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XF507


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Boost-Back and Landing of Falcon 9 
Rockets

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Notice; proposed incidental harassment authorization; request 
for comments.

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SUMMARY:  NMFS has received a request from Space Exploration Technology 
Corporation (SpaceX) for authorization to take marine mammals 
incidental to boost-back and landing of Falcon 9 rockets at Vandenberg 
Air Force Base in California, and at contingency landing locations in 
the Pacific Ocean. Pursuant to the Marine Mammal Protection Act (MMPA), 
NMFS is requesting comments on its proposal to issue an incidental 
harassment authorization (IHA) to SpaceX to incidentally take marine 
mammals, by Level B harassment only, during the specified activity. 
NMFS will consider public comments prior to making any final decision 
on the issuance of the requested MMPA authorizations and agency 
responses will be summarized in the final notice of our decision.

DATES: Comments and information must be received no later than November 
24, 2017.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service. Physical comments should be sent to 
1315 East-West Highway, Silver Spring, MD 20910 and electronic comments 
should be sent to [email protected].
    Instructions: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Comments received electronically, including 
all attachments, must not exceed a 25-megabyte file size. Attachments 
to electronic comments will be accepted in Microsoft Word or Excel or 
Adobe PDF file formats only. All comments received are a part of the 
public record and will generally be posted online at www.nmfs.noaa.gov/pr/permits/incidental/research.htm without change. All personal 
identifying information (e.g., name, address) voluntarily submitted by 
the commenter may be publicly accessible. Do not submit confidential 
business information or otherwise sensitive or protected information.

FOR FURTHER INFORMATION CONTACT: Jordan Carduner, Office of Protected 
Resources, NMFS, (301) 427-8401. Electronic copies of the application 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at: www.nmfs.noaa.gov/pr/permits/incidental/research.htm. In case of problems accessing these documents, 
please call the contact listed above.

SUPPLEMENTARY INFORMATION:

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce to allow, upon request, the 
incidental, but not intentional, taking of small numbers of marine 
mammals by U.S. citizens who engage in a specified activity (other than 
commercial fishing) within a specified geographical region if certain 
findings are made and either regulations are issued or, if the taking 
is limited to harassment, a notice of a proposed authorization is 
provided to the public for review.
    An authorization for incidental takings shall be granted if NMFS 
finds that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth.
    NMFS has defined ``negligible impact'' in 50 CFR 216.103 as an 
impact resulting from the specified activity that cannot be reasonably 
expected to, and is not reasonably likely to, adversely affect

[[Page 49333]]

the species or stock through effects on annual rates of recruitment or 
survival.
    The MMPA states that the term ``take'' means to harass, hunt, 
capture, kill or attempt to harass, hunt, capture, or kill any marine 
mammal.
    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: Any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild (Level A harassment); or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering (Level B harassment).

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action with respect to potential impacts 
on the human environment.
    This action is consistent with categories of activities identified 
in CE B4 of the Companion Manual for NAO 216-6A, which do not 
individually or cumulatively have the potential for significant impacts 
on the quality of the human environment and for which we have not 
identified any extraordinary circumstances that would preclude this 
categorical exclusion. Accordingly, NMFS has preliminarily determined 
that the issuance of the proposed IHA qualifies to be categorically 
excluded from further NEPA review.
    We will review all comments submitted in response to this notice 
prior to concluding our NEPA process in making a final decision on the 
IHA request.

Summary of Request

    NMFS received a request from SpaceX for an IHA to take marine 
mammals incidental to Falcon 9 First Stage recovery activities, 
including in-air boost-back maneuvers and landings of the First Stage 
of the Falcon 9 rocket at Vandenberg Air Force Base (VAFB) in 
California, and at contingency landing locations offshore. SpaceX's 
request was for harassment only and NMFS concurs that mortality is not 
expected to result from this activity. Therefore, an IHA is 
appropriate.
    SpaceX's application for incidental take authorization was received 
on July 11, 2017. SpaceX submitted a revised version of the request on 
October 13, 2017. This revised version of the application was deemed 
adequate and complete. The planned activity may exceed one year, hence 
subsequent MMPA incidental harassment authorizations may be requested 
for this particular activity.
    The planned activities include in-air boost-back maneuvers and 
landings of the First Stage of the Falcon 9 rocket. The action may 
occur as many as 12 times and may occur at any time of year. Species 
that are expected to be taken by the planned activity include harbor 
seal, California sea lion, Steller sea lion, northern elephant seal, 
northern fur seal, and Guadalupe fur seal. SpaceX's activities are 
expected to produce noise, in the form of sonic booms, that are 
expected to result in harassment of marine mammals that are hauled out 
of the water. Take by Level B harassment only is expected; no injury or 
mortality of marine mammals is expected to result from the proposed 
activity.
    If issued, this would be the second IHA issued for this activity. 
SpaceX applied for, and was granted, an IHA in 2016 that was valid from 
June 30, 2016 through June 29, 2017 (81 FR 34984, June 30, 2016). 
SpaceX complied with all the requirements (e.g., mitigation, 
monitoring, and reporting) of the previous IHA.

Description of Proposed Activity

Overview

    The Falcon 9 is a two-stage rocket designed and manufactured by 
SpaceX for transport of satellites and SpaceX's Dragon spacecraft into 
orbit. SpaceX currently operates the Falcon Launch Vehicle Program at 
Space Launch Complex 4E (SLC-4E) at VAFB. SpaceX proposes regular 
employment of First Stage recovery by returning the Falcon 9 First 
Stage to SLC-4 West (SLC-4W) at VAFB for potential reuse, up to twelve 
times per year. This includes performing boost-back maneuvers (in-air) 
and landings of the Falcon 9 First Stage on the pad at SLC-4W. The 
reuse of the Falcon 9 First Stage enables SpaceX to efficiently conduct 
lower cost launch missions from VAFB in support of commercial and 
government clients.
    Although SLC-4W is the preferred landing location, SpaceX has 
identified the need for contingency landing locations should it not be 
feasible to land the First Stage at SLC-4W. The first contingency 
landing option is on a barge located at least 27 nautical miles (nm) 
(50 kilometers (km) offshore of VAFB. The second contingency landing 
option is on a barge within the Iridium Landing Area, an area 
approximately 33,153 square kilometers (km\2\) area that is located 
approximately 122 nm (225 km) southwest of San Nicolas Island and 133 
nm (245 km) southwest of San Clemente Island (see Figure 1-3 in the IHA 
application).
    During descent, a sonic boom (overpressure of high-energy impulsive 
sound) would be generated when the First Stage reaches a rate of travel 
that exceeds the speed of sound. Sonic booms would occur in proximity 
to the landing areas and may be heard during or briefly after the 
boost-back and landing, depending on the location of the observer. 
Sound from the sonic boom would have the potential to result in 
harassment of marine mammals, either on the mainland at or near VAFB, 
or at the Northern Channel Islands (NCI), as described in more detail 
later in this document.

Dates and Duration

    The planned project would occur from December 1, 2017 through 
November 30, 2018. Up to twelve Falcon 9 First Stage recovery 
activities would occur per year. Precise dates of Falcon 9 First Stage 
recovery activities are not known. Falcon 9 First Stage recovery 
activities may take place at any time of year and at any time of day. 
The IHA, if issued, would be valid from December 1, 2017 through 
November 30, 2018.

Specified Geographic Region

    Falcon 9 First Stage recovery activities will originate at VAFB. 
Areas potentially affected include VAFB, areas on the coastline 
surrounding VAFB and the NCI. VAFB operates as a missile test base and 
aerospace center, supporting west coast space launch activities for the 
U.S. Air Force (USAF), Department of Defense, National Aeronautics and 
Space Administration, and commercial contractors. VAFB is the main west 
coast launch facility for placing commercial, government, and military 
satellites into polar orbit on expendable (unmanned) launch vehicles, 
and for testing and evaluating intercontinental ballistic missiles and 
sub-orbital target and interceptor missiles.
    VAFB occupies approximately 99,100 acres of central Santa Barbara 
County, California. VAFB is divided by the Santa Ynez River and State 
Highway 246 into two distinct parts: North Base and South Base. SLC-4W 
is located on South Base, approximately 0.5 mile (0.8 km) inland from 
the Pacific Ocean (see Figure 1-2 in SpaceX's IHA application). SLC-4E, 
the launch facility for SpaceX's Falcon 9 program, is located 
approximately 427 meters (m) to the east of SLC-4W, the proposed 
landing site for the Falcon 9 First Stage

[[Page 49334]]

(see Figure 1-2 in SpaceX's IHA application).
    Although SLC-4W is the preferred landing location, SpaceX has 
identified the need for a contingency landing option. As described 
above, a contingency landing would occur on a barge located either at a 
pre-determined location at least 27 nautical miles (nm) (50 km) 
offshore of VAFB (see Figure 1-7 in the IHA application) or within the 
Iridium Landing Area located approximately 122 nm (225 km) southwest of 
San Nicolas Island and 133 nm (245 km) southwest of San Clemente Island 
(see Figure 1-8 in the IHA application). The NCI are also considered 
part of the project area for the purposes of this proposed 
authorization, as landings at VAFB could result in sonic booms that 
impact the NCI. The NCI are four islands (San Miguel, Santa Rosa, Santa 
Cruz, and Anacapa) located approximately 50 km south of Point 
Conception, which is located on the mainland approximately 6.5 km south 
of the southern border of VAFB. The closest part of the NCI to VAFB 
(Harris Point on San Miguel Island (SMI)) is located more than 55 km 
south-southeast of SLC-4E, the launch facility for the Falcon 9 rocket.

Detailed Description of Specific Activities

    The Falcon 9 is a two-stage rocket designed and manufactured by 
SpaceX for transport of satellites and SpaceX's Dragon spacecraft into 
orbit. The First Stage of the Falcon 9 is designed to be reusable, 
while the second stage is not reusable. The Falcon 9 First Stage is 12 
feet (ft.) in diameter and 160 ft. in height, including the interstage 
that would remain attached during landing. The proposed action includes 
up to twelve Falcon 9 First Stage recoveries, including in-air boost-
back maneuvers and landings of the First Stage, at VAFB or at a 
contingency landing location as described above.
    After launch of the Falcon 9, the boost-back and landing sequence 
begins when the rocket's First Stage separates from the second stage 
and the Merlin engines of the First Stage cut off. After First Stage 
engine cutoff, rather than dropping the First Stage in the Pacific 
Ocean, exoatmospheric cold gas thrusters would be triggered to flip the 
First Stage into position for retrograde burn. Three of the nine First 
Stage Merlin engines would be restarted to conduct the retrograde burn 
in order to reduce the velocity of the First Stage and to place the 
First Stage in the correct angle to land. Once the First Stage is in 
position and approaching its landing target, the three engines would 
cut off to end the boost-back burn. The First Stage would then perform 
a controlled descent using atmospheric resistance to slow the stage 
down and guide it to the landing pad target. The First Stage is 
outfitted with grid fins that allow cross range corrections as needed. 
The landing legs on the First Stage would then deploy in preparation 
for a final single engine burn that would slow the First Stage to a 
velocity of zero before landing on the landing pad at SLC-4W.
    During descent, a sonic boom (overpressure of high-energy impulsive 
sound) would be generated when the First Stage reaches a rate of travel 
that exceeds the speed of sound. Sonic booms would occur in proximity 
to the landing area with the highest sound levels generated from sonic 
booms generally focused in the direction of the landing area, and may 
be heard during or briefly after the boost-back and landing, depending 
on the location of the observer. Sound from the sonic booms would have 
the potential to result in harassment of marine mammals, as described 
in greater detail later in this document. Based on model results, a 
boost-back and landing of the Falcon 9 First Stage at SLC-4W would 
produce sonic booms with overpressures that would potentially be as 
high as 8.5 pounds per square foot (psf) at VAFB and potentially as 
high as 3.1 psf at the NCI. Sonic boom modeling indicates that landings 
that occur at either of the proposed contingency landing locations 
offshore would result in sonic booms below 1.0 psf. Take of marine 
mammals that are hauled out of the water are expected to occur only 
when those hauled out marine mammals experience sonic booms greater 
than 1.0 psf (this is discussed in greater detail below in the section 
on Estimated Take by Incidental Harassment). Therefore, take of marine 
mammals may occur as a result of landings that occur at VAFB; however, 
take of marine mammals is not expected to occur as a result of landings 
that occur at either of the proposed contingency landing locations 
offshore. Please see Figure 1-4 in the IHA application for a graphical 
depiction of the boost-back and landing sequence, and see Figure 1-5 in 
the IHA application for an example of the boost-back trajectory of the 
First Stage and the second stage trajectory.
    As a contingency action to landing the Falcon 9 First Stage on the 
SLC-4W pad at VAFB, SpaceX proposes to return the Falcon 9 First Stage 
booster to a barge in the Pacific Ocean (Figure 1-6 in the IHA 
application). The barge is specifically designed to be used as a First 
Stage landing platform and would be located at least 27 nm (50 km) 
offshore of VAFB (Figure 1-7 in the IHA application) or within the 
Iridium Landing Area (Figure 1-8 in the IHA application). These 
contingency landing locations would be used when landing at SLC-4W 
would not be feasible. The maneuvering and landing process described 
above for a pad landing would be the same for a barge landing. Three 
vessels would be required to support a barge landing, if it were 
required: A barge/landing platform (300 ft long and 150 ft wide); a 
support vessel (165 ft long research vessel); and an ocean tug (120 ft 
long open water commercial tug).

Landing Noise

    Landing noise would be generated during each boost-back event. 
SpaceX proposes to use a three-engine burn during landing. This engine 
burn, lasting approximately 17 seconds, would generate noise between 70 
and 110 decibels (dB) re 20 [micro]Pa (non-pulse, in-air noise) 
centered on SLC-4W, but affecting an area up to 15 nm (27.8 km) 
offshore of VAFB (Figure 2-10 in the IHA application). This landing 
noise event would be of short duration (approximately 17 seconds). 
Although, during a landing event at SLC-4W, landing noise between 70 
and 90 dB would be expected to overlap pinniped haulout areas at and 
near Point Arguello and Purisima Point, no pinniped haulouts would 
experience landing noises of 90 dB or greater (see Figure 2-10 in the 
IHA application).
    NMFS's recommended acoustic thresholds for in-air acoustic impacts 
assume that Level B harassment of harbor seals occurs at 90 dB rms re 
20 [micro]Pa and Level B harassment of all other pinnipeds occurs at 
100 dB rms re 20 [micro]Pa (Table 1). Therefore, harassment of marine 
mammals hauled out at VAFB from engine noise generated during landings 
is not expected to occur. Engine noise would also be produced during a 
contingency barge landing of the Falcon 9 First Stage. Engine noise 
during a barge landing is expected to be between 70 and 110 dB re 20 
[micro]Pa affecting a radial area up to 15 nm (27.8 km) around the 
contingency landing location (Figure 2-11 in the IHA application) and 
the Iridium 38 Landing Area (Figure 2-12 in the IHA application). No 
pinniped haulouts are located within the areas predicted to experience 
engine noise of 90 dB and above during Falcon 9 First Stage landings at 
contingency landing locations and the Iridium Landing Area (Figures 2-
11 and 2-12 in the IHA application). Therefore, the likelihood

[[Page 49335]]

of engine noise associated with the landing of the Falcon 9 First Stage 
resulting in take of marine mammals is considered so low as to be 
discountable, and landing noise is therefore not discussed further in 
this document.

 Table 1--Recommended Criteria for Pinniped Harassment From Exposure to
                             Airborne Sound
------------------------------------------------------------------------
                  Species                   Level B harassment threshold
------------------------------------------------------------------------
Harbor seals..............................  90 dB re 20 [micro]Pa.
All other pinniped species................  100 dB re 20 [micro]Pa.
------------------------------------------------------------------------

Unsuccessful Barge Landing

    In the event of an unsuccessful barge landing, the First Stage 
would explode upon impact with the barge. The direct sound from an 
explosion would last less than a second. Furthermore, the proposed 
activities would be dispersed in time, with maximum of twelve barge 
landing attempts occurring within a twelve month time period. If an 
explosion occurred on the barge, as in the case of an unsuccessful 
barge landing attempt, some amount of the explosive energy would be 
transferred through the ship's structure and would enter the water and 
propagate away from the ship.
    There is very little published literature on the ratio of explosive 
energy that is absorbed by a ship's hull versus the amount of energy 
that is transferred through the ship into the water. However, based on 
the best available information, we have determined that exceptionally 
little of the acoustic energy from the explosion would transmit into 
the water (Yagla and Stiegler, 2003). An explosion on the barge would 
create an in-air blast that propagates away in all directions, 
including toward the water's surface; however the barge's deck would 
act as a barrier that would attenuate the energy directed downward 
toward the water (Yagla and Stiegler, 2003). Most sound enters the 
water in a narrow cone beneath the sound source (within 13 degrees of 
vertical). Since the explosion would occur on the barge, most of this 
sound would be reflected by the barge's surface, and sound waves would 
approach the water's surface at angles higher than 13 degrees, 
minimizing transmission into the ocean. An explosion on the barge would 
also send energy through the barge's structure, into the water, and 
away from the barge. This effect was investigated in conjunction with 
the measurements described in Yagla and Steigler (2003). Yagla and 
Steigler (2003) reported that the energy transmitted through a ship to 
the water for the firing of a typical 5-inch round was approximately 
six percent of that from the air blast impinging on the water (Yagla 
and Stiegler, 2003). Therefore, sound transmitted from the blast 
through the hull into the water was a minimal component of overall 
firing noise, and would likewise be expected to be a minimal component 
of an explosion occurring on the surface of the barge.
    Depending on the amount of fuel remaining in the booster at the 
time of the explosion, the intensity of the explosion would likely 
vary. Based on previous Falcon 9 boost-back and landing activities, the 
explosive equivalence of the First Stage with maximum fuel and oxidizer 
would be expected to be approximately 500 lb. of trinitrotoluene (TNT). 
Explosion shock theory has proposed specific relationships for the peak 
pressure and time constant in terms of the charge weight and range from 
the detonation position (Pater 1981; Plotkin et al. 2012). For an in-
air explosion equivalent to 500 lb. of TNT, at 0.5 feet the explosion 
would be approximately 250 dB re 20 [micro]Pa. Based on the assumption 
that the structure of the barge would absorb and reflect approximately 
94 percent of this energy, with approximately six percent of the energy 
from the explosion transmitted into the water (Yagla and Stiegler, 
2003), the amount of energy that would be transmitted into the water 
would be far less than the lowest threshold for Level B harassment for 
both pinnipeds and cetaceans based on NMFS's current acoustic criteria 
for in-water explosive noise (160 dB re 1 [micro]pa). As a result, the 
likelihood of in-water sound generated by an explosion of the Falcon 9 
First Stage during an unsuccessful barge landing attempt resulting in 
take of marine mammals is considered so low as to be discountable and 
is therefore not discussed further in this document.
    As discussed above, in the event of an unsuccessful contingency 
landing attempt, the First Stage would be expected to explode upon 
impact with the barge. SpaceX has experience performing recovery 
operations after water and unsuccessful barge landings for previous 
Falcon 9 First Stage landing attempts. This experience, in addition to 
the debris catalog that identifies all floating debris, has revealed 
that approximately 25 pieces of debris remain floating after an 
unsuccessful barge landing. The approximately 25 pieces of debris would 
primarily be made of Carbon Over Pressure Vessels (COPVs), the liquid 
oxygen fill line, and carbon fiber constructed legs. The vast majority 
of debris would be recovered. All other debris is expected to sink to 
the bottom of the ocean. Denser debris that would not float on the 
surface would sink relatively quickly and is composed of inert 
materials which would not affect water quality or bottom substrate 
potentially used by marine mammals. The rate of deposition would vary 
with the type of debris; however, none of the debris is so dense or 
large that benthic habitat would be degraded.
    The surface area potentially impacted with debris would be less 
than 0.46 km\2\. Since the area impacted by debris is very small, the 
likelihood of adverse effects to marine mammals is very low. During 
previous landing attempts in other locations, SpaceX has performed 
successful debris recovery. All of the recovered debris would be 
transported back to Long Beach Harbor for proper disposal. Most of the 
fuel remaining in the First Stage would be released onto the barge deck 
at the location of impact. Therefore, the likelihood of take of marine 
mammals as a result of contact with exploded First Stage materials is 
considered so low as to be discountable, and explosion of the Falcon 9 
First Stage is therefore not discussed further in this document.
    In the event that a contingency landing action is required, there 
is the potential that the Falcon 9 First Stage would miss the barge 
entirely and land instead in the ocean. However, the likelihood of the 
First Stage missing the barge entirely and landing in the Pacific Ocean 
is considered so unlikely as to be discountable. This is supported by 
several previous attempts by SpaceX at Falcon 9 First Stage barge 
landings, none of which have missed the barge. Therefore, the 
likelihood of take of marine mammals associated with a Falcon 9 First 
Stage landing in the ocean is considered so low as to be discountable, 
and landing of the Falcon 9 First Stage in the ocean is not considered 
further in this document.
    NMFS has previously issued regulations and Letters of Authorization 
(LOA) that authorize the take of marine mammals, by Level B harassment, 
incidental to launches of up to 50 rockets per year (including the 
Falcon 9) from VAFB (79 FR 10016, February 24, 2014). The regulations, 
titled ``Taking of Marine Mammals Incidental to U.S. Air Force 
Launches, Aircraft and Helicopter Operations, and Harbor Activities 
Related to Vehicles from Vandenberg Air Force Base, California,'' 
published February 24, 2014, are effective from March 2014 to March 
2019. The activities proposed by SpaceX are limited to Falcon 9 First 
Stage recovery events (Falcon 9 boost-back maneuvers

[[Page 49336]]

and landings); launches of the Falcon 9 rocket are not part of the 
proposed activities, and incidental take (Level B harassment) resulting 
from Falcon 9 rocket launches from VAFB is already authorized in the 
above referenced LOA. As such, NMFS does not propose to authorize take 
of marine mammals incidental to launches of the Falcon 9 rocket; 
incidental take resulting from Falcon 9 rocket launches is therefore 
not analyzed further in this document. The LOA application (USAF 
2013a), and links to the Federal Register notice of the final rule (79 
FR 10016, February 24, 2014) and the Federal Register notice of 
issuance of the LOA (79 FR 18528, April 2, 2014), can be found on the 
NMFS Web site at: https://www.nmfs.noaa.gov/pr/permits/incidental/research.
    Proposed mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see ``Proposed 
Mitigation'' and ``Proposed Monitoring and Reporting'').

Description of Marine Mammals in the Area of Specified Activities

    There are six marine mammal species with expected occurrence in the 
project area (including at VAFB, on the NCI, and in the waters 
surrounding VAFB, the NCI and the contingency landing location) that 
are expected to be affected by the specified activities. These include 
the Steller sea lion (Eumetopias jubatus), northern fur seal 
(Callorhinus ursinus), northern elephant seal (Mirounga 
angustirostris), Guadalupe fur seal (Arctocephalus philippii 
townsendi), California sea lion (Zalophus californianus), and Pacific 
harbor seal (Phoca vitulina richardii). This section provides summary 
information regarding local occurrence of these species. We have 
reviewed SpaceX's detailed species descriptions, including life history 
information, for accuracy and completeness and refer the reader to 
Section 3 of SpaceX's IHA application, as well as to NMFS's Stock 
Assessment Reports (SAR; www.nmfs.noaa.gov/pr/sars/), rather than 
reprinting all of the information here. Additional general information 
about these species (e.g., physical and behavioral descriptions) may be 
found on NMFS's Web site (www.nmfs.noaa.gov/pr/species/mammals/).
    There are an additional 28 species of cetaceans with expected or 
possible occurrence in the project area. However, we have determined 
that the only potential stressor associated with the activity that 
could result in take of marine mammals (sonic booms) only has the 
potential to result in harassment of marine mammals that are hauled out 
of the water. Therefore, we have concluded that the likelihood of the 
proposed activities resulting in the harassment of any cetacean to be 
so low as to be discountable. As we have concluded that the likelihood 
of any cetacean being taken incidentally as a result of SpaceX's 
proposed activities to be so low as to be discountable, cetaceans are 
not considered further in this proposed authorization. Please see Table 
3-1 in SpaceX's IHA application for a complete list of species with 
expected or potential occurrence in the project area.
    Table 2 lists the marine mammal species with expected potential for 
occurrence in the vicinity of the project during the project timeframe 
that are likely to be affected by the specified activities, and 
summarizes information related to the population or stock, including 
PBR, where known. For taxonomy, we follow Committee on Taxonomy (2016). 
For status of species, we provide information regarding U.S. regulatory 
status under the MMPA and ESA. Abundance estimates presented here 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study area. NMFS's stock 
abundance estimates for most species represent the total estimate of 
individuals within the geographic area, if known, that comprises that 
stock. For some species, this geographic area may extend beyond U.S. 
waters. PBR, defined by the MMPA as the maximum number of animals, not 
including natural mortalities, that may be removed from a marine mammal 
stock while allowing that stock to reach or maintain its optimum 
sustainable population, is considered in concert with known sources of 
ongoing anthropogenic mortality to assess the population-level effects 
of the anticipated mortality from a specific project (as described in 
NMFS's SARs). While no mortality is anticipated or authorized here, PBR 
and annual serious injury and mortality are included here as gross 
indicators of the status of the species and other threats.
    All values presented in Table 2 are the most recent available at 
the time of publication and are available in NMFS's SARs (e.g., 
Carretta et al., 2017; Muto et al., 2017). Please see the SARs, 
available at www.nmfs.noaa.gov/pr/sars, for more detailed accounts of 
these stocks' status and abundance.

                                         Table 2--Marine Mammal Species Potentially Present in the Project Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                  Stock abundance                                    Relative occurrence
                                                            ESA/MMPA status;      (CV, Nmin, most                     Annual  M/SI     in project area;
             Species                       Stock          Strategic  (Y/N) \1\   recent  abundance       PBR \3\           \4\            season of
                                                                                    survey) \2\                                           occurrence
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                      Family Otariidae (eared seals and sea lions)
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion..............  U.S.................  -; N                   296,750 (n/a;                 9,200             389  Abundant; year-
                                                                                 153,337; 2011).                                      round.
Northern fur seal................  California..........  -; N                   14,050 (n/a; 7,524;             451             1.8  Abundant; year-
                                                                                 2013).                                               round; peak
                                                                                                                                      occurrence during
                                                                                                                                      summer.
Guadalupe fur seal...............  n/a.................  T/D; Y                 20,000 (n/a;                    542             3.2  Rare; slightly more
                                                                                 15,830; 2010).                                       common in summer.
Steller sea lion.................  Eastern U.S.........  -; N                   71,562 (n/a;                  2,498             108  Rare; year-round.
                                                                                 41,638; 2015).
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 49337]]

 
                                                             Family Phocidae (earless seals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor seal......................  California..........  -; N                   30,968 (n/a;                  1,641              43  Abundant; year-
                                                                                 27,348; 2012).                                       round.
Northern elephant seal...........  California breeding.  -; N                   179,000 (n/a;                 4,882             8.8  Abundant; year-
                                                                                 81,368; 2010).                                       round; peak
                                                                                                                                      occurrence during
                                                                                                                                      winter.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of
  stock abundance. In some cases, CV is not applicable.
\3\ Potential biological removal, defined by the MMPA as the maximum number of animals, not including natural mortalities, that may be removed from a
  marine mammal stock while allowing that stock to reach or maintain its optimum sustainable population size (OSP).
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual mortality/serious injury (M/SI) often cannot be determined precisely and is in some cases presented as a
  minimum value or range. A CV associated with estimated mortality due to commercial fisheries is presented in some cases.

Pacific Harbor Seal

    Harbor seals inhabit coastal and estuarine waters and shoreline 
areas of the northern hemisphere from temperate to polar regions. The 
eastern North Pacific subspecies is found from Baja California north to 
the Aleutian Islands and into the Bering Sea. Multiple lines of 
evidence support the existence of geographic structure among harbor 
seal populations from California to Alaska (Carretta et al., 2016). 
However, because stock boundaries are difficult to meaningfully draw 
from a biological perspective, three separate harbor seal stocks are 
recognized for management purposes along the west coast of the 
continental United States: (1) Washington inland waters, (2) Oregon and 
Washington coast, and (3) California (Carretta et al., 2016). In 
addition, harbor seals may occur in Mexican waters, but these animals 
are not considered part of the California stock. Only the California 
stock is considered in this proposed authorization due to the 
distribution of the stock and the geographic scope of the proposed 
activities. Although the need for stock boundaries for management is 
real and is supported by biological information, it should be noted 
that the exact placement of a boundary between California and Oregon 
for stock delineation purposes was largely a political/jurisdictional 
convenience (Carretta et al. 2015).
    Pacific harbor seals are nonmigratory, with local movements 
associated with such factors as tides, weather, season, food 
availability, and reproduction (Scheffer and Slipp 1944, Fisher 1952, 
Bigg 1969, 1981, Hastings et al. 2004). In California, over 500 harbor 
seal haulout sites are widely distributed along the mainland and 
offshore islands, and include rocky shores, beaches and intertidal 
sandbars (Lowry et al. 2005). Harbor seals mate at sea and females give 
birth during the spring and summer, though the pupping season varies 
with latitude. Harbor seal pupping takes place at many locations and 
rookery size varies from a few pups to many hundreds of pups.
    Harbor seals are the most common marine mammal inhabiting VAFB, 
congregating on multiple rocky haulout sites along the VAFB coastline. 
They are local to the area, rarely traveling more than 50 km from haul-
out sites. There are 12 harbor seal haulout sites on south VAFB; of 
these, 10 sites represent an almost continuous haulout area which is 
used by the same animals. Virtually all of the haulout sites at VAFB 
are used during low tides and are wave-washed or submerged during high 
tides. Additionally, the harbor seal is the only species that regularly 
hauls out near the VAFB harbor. The main harbor seal haulouts on VAFB 
are near Purisima Point and at Lion's Head (approximately 0.6 km south 
of Point Sal) on north VAFB and between the VAFB harbor north to South 
Rocky Point Beach on south VAFB (ManTech 2009).
    Pups are generally present in the region from March through July. 
Within the affected area on VAFB, a total of up to 332 adults and 34 
pups have been recorded, at all haulouts combined, in monthly counts 
from 2013 to 2015 (ManTech 2015). Harbor seals also haul out, breed, 
and pup in isolated beaches and coves throughout the coasts of San 
Miguel, Santa Rosa, and Santa Cruz Islands (Lowry 2002). During aerial 
surveys conducted by NMFS in May 2002 and May and June of 2004, between 
521 and 1,004 harbors seals were recorded at SMI, between 605 and 972 
at Santa Rosa Island, and between 599 and 1,102 Santa Cruz Island (M. 
Lowry, NOAA Fisheries, unpubl. data).
    The harbor seal population at VAFB has undergone an apparent 
decline in recent years (USAF 2013b). This decline has been attributed 
to a series of natural landslides at south VAFB, resulting in the 
abandonment of many haulout sites. These slides have also resulted in 
extensive down-current sediment deposition, making these sites 
accessible to coyotes, which are now regularly seen in the area. Some 
of the displaced seals have moved to other sites at south VAFB, while 
others likely have moved to Point Conception, about 6.5 km south of the 
southern boundary of VAFB.
    Pacific harbor seals frequently use haul-out sites on the NCI, 
including San Miguel, Santa Rosa, Santa Cruz; and Anacapa. On SMI, they 
occur along the north coast at Tyler Bight and from Crook Point to 
Cardwell Point. Additionally, they regularly breed on SMI. On Santa 
Cruz Island, they inhabit small coves and rocky ledges along much of 
the coast. Harbor seals are scattered throughout Santa Rosa Island and 
also are observed in small numbers on Anacapa Island.

California Sea Lion

    California sea lions range from the Gulf of California north to the 
Gulf of Alaska, with breeding areas located in the Gulf of California, 
western Baja California, and southern California. Five

[[Page 49338]]

genetically distinct geographic populations have been identified: (1) 
Pacific Temperate, (2) Pacific Subtropical, (3) Southern Gulf of 
California, (4) Central Gulf of California and (5) Northern Gulf of 
California (Schramm et al., 2009). Rookeries for the Pacific Temperate 
population are found within U.S. waters and just south of the U.S.-
Mexico border, and animals belonging to this population may be found 
from the Gulf of Alaska to Mexican waters off Baja California. Animals 
belonging to other populations (e.g., Pacific Subtropical) may range 
into U.S. waters during non-breeding periods. For management purposes, 
a stock of California sea lions comprising those animals at rookeries 
within the United States is defined (i.e., the U.S. stock of California 
sea lions) (Carretta et al., 2017). There are indications that the 
California sea lion may have reached or is approaching carrying 
capacity, although more data are needed to confirm that leveling in 
growth persists (Carretta et al., 2017).
    Beginning in January 2013, elevated strandings of California sea 
lion pups were observed in southern California, with live sea lion 
strandings nearly three times higher than the historical average. 
Findings to date indicate that a likely contributor to the large number 
of stranded, malnourished pups was a change in the availability of sea 
lion prey for nursing mothers, especially sardines. The Working Group 
on Marine Mammal Unusual Mortality Events determined that the ongoing 
stranding event meets the criteria for an Unusual Mortality Event (UME) 
and declared California sea lion strandings from 2013 through 2017 to 
be one continuous UME. The causes and mechanisms of this event remain 
under investigation. For more information on the UME, see: 
www.nmfs.noaa.gov/pr/health/mmume/californiasealions2013.htm.
    Rookery sites in southern California are limited to SMI and the 
southerly Channel Islands of San Nicolas, Santa Barbara, and San 
Clemente (Carretta et al., 2015). Males establish breeding territories 
during May through July on both land and in the water. Females come 
ashore in mid-May and June where they give birth to a single pup 
approximately four to five days after arrival and will nurse pups for 
about a week before going on their first feeding trip. Adult and 
juvenile males will migrate as far north as British Columbia, Canada 
while females and pups remain in southern California waters in the non-
breeding season. In warm water (El Ni[ntilde]o) years, some females are 
found as far north as Washington and Oregon, presumably following prey.
    California sea lions are common offshore of VAFB and haul out on 
rocks and beaches along the coastline of VAFB. At south VAFB, 
California sea lions haul out on north Rocky Point, with numbers often 
peaking in spring. They have been reported at Point Arguello and Point 
Pedernales (both on south VAFB) in the past, although none have been 
noted there over the past several years. Individual sea lions have been 
noted hauled out throughout the VAFB coast; these were transient or 
stranded specimens. They regularly haul out on Lion Rock, north of VAFB 
and immediately south of Point Sal, and occasionally haul out on Point 
Conception, south of VAFB. In 2014, counts of California sea lions at 
haulouts on VAFB increased substantially, ranging from 47 to 416 during 
monthly counts. Despite their prevalence at haulout sites at VAFB, 
California sea lions rarely pup on the VAFB coastline (ManTech 2015); 
no pups were observed in 2013 or 2014 (ManTech 2015) and 1 pup was 
observed in 2015 (VAFB, unpubl. data).
    Pupping occurs in large numbers on SMI at the rookeries found at 
Point Bennett on the west end of the island and at Cardwell Point on 
the east end of the island (Lowry 2002). Sea lions haul out at the west 
end of Santa Rosa Island at Ford Point and Carrington Point. A few 
California sea lions have been born on Santa Rosa Island, but no 
rookery has been established. On Santa Cruz Island, California sea 
lions haul out from Painted Cave almost to Fraser Point, on the west 
end. Fair numbers haul out at Gull Island, off the south shore near 
Punta Arena. Pupping appears to be increasing there. Sea lions also 
haul out near Potato Harbor, on the northeast end of Santa Cruz. 
California sea lions haul out by the hundreds on the south side of East 
Anacapa Island.
    During aerial surveys conducted by NMFS in February 2010 of the 
NCI, 21,192 total California sea lions (14,802 pups) were observed at 
haulouts on SMI and 8,237 total (5,712 pups) at Santa Rosa Island (M. 
Lowry, NOAA Fisheries, unpubl. data). During aerial surveys in July 
2012, 65,660 total California sea lions (28,289 pups) were recorded at 
haulouts on SMI, 1,584 total (3 pups) at Santa Rosa Island, and 1,571 
total (zero pups) at Santa Cruz Island (M. Lowry, NOAA Fisheries, 
unpubl. data).

Northern Elephant Seal

    Northern elephant seals range in the eastern and central North 
Pacific Ocean, from as far north as Alaska and as far south as Mexico. 
They spend much of the year, generally about nine months, in the ocean. 
They spend much of their lives underwater, diving to depths of about 
1,000 to 2,500 ft (330-800 m) for 20- to 30-minute intervals with only 
short breaks at the surface, and are rarely seen at sea for this 
reason. Northern elephant seals breed and give birth in California and 
Baja California (Mexico), primarily on offshore islands, from December 
to March (Stewart et al. 1994). Adults return to land between March and 
August to molt, with males returning later than females. Adults return 
to their feeding areas again between their spring/summer molting and 
their winter breeding seasons.
    Populations of northern elephant seals in the U.S. and Mexico are 
derived from a few tens or hundreds of individuals surviving in Mexico 
after being nearly hunted to extinction (Stewart et al., 1994). Given 
the recent derivation of most rookeries, no genetic differentiation 
would be expected. Although movement and genetic exchange continues 
between rookeries, most elephant seals return to their natal rookeries 
when they start breeding (Huber et al., 1991). The California breeding 
population is now demographically isolated from the Baja California 
population and is considered to be a separate stock.
    Northern elephant seals haul out sporadically on rocks and beaches 
along the coastline of VAFB; monthly counts in 2013 and 2014 recorded 
between 0 and 191 elephant seals within the affected area (ManTech 
2015) and northern elephant seal pupping at VAFB was documented for the 
first time in January 2017 (Pers. comm., R. Evans, United States Air 
Force, to J. Carduner, NMFS, February 1, 2017). The nearest regularly 
used haul-out site on the mainland coast is at Point Conception. Eleven 
northern elephant seals were observed during aerial surveys of the 
Point Conception area by NMFS in February of 2010 (M. Lowry, NOAA 
Fisheries, unpubl. data).
    Point Bennett on the west end of SMI is the primary northern 
elephant seal rookery in the NCI, with another rookery at Cardwell 
Point on the east end of SMI (Lowry 2002). They also pup and breed on 
Santa Rosa Island, mostly on the west end. Northern elephant seals are 
rarely seen on Santa Cruz and Anacapa Islands. During aerial surveys of 
the NCI conducted by NMFS in February 2010, 21,192 total northern 
elephant seals (14,802 pups) were recorded at haulouts on SMI and 8,237 
total (5,712 pups) were observed at Santa Rosa Island (M. Lowry, NOAA 
Fisheries, unpubl. data). None were observed at Santa Cruz Island (M. 
Lowry, NOAA Fisheries, unpubl. data).

[[Page 49339]]

Steller Sea Lion

    Steller sea lions are distributed mainly around the coasts to the 
outer continental shelf along the North Pacific rim from northern 
Hokkaido, Japan through the Kuril Islands and Okhotsk Sea, Aleutian 
Islands and central Bering Sea, southern coast of Alaska and south to 
California (Loughlin et al., 1984). The species as a whole was ESA-
listed as threatened in 1990 (55 FR 49204, November 26, 1990). In 1997, 
the species was divided into western and eastern distinct population 
segments (DPS), with the western DPS reclassified as endangered under 
the ESA and the eastern DPS retaining its threatened listing (62 FR 
24345, May 5, 2997). On October 23, 2013, NMFS found that the eastern 
DPS has recovered; as a result of the finding, NMFS removed the eastern 
DPS from ESA listing. Only the eastern DPS is considered in this 
proposed authorization due to its distribution and the geographic scope 
of the action.
    Prior to 2012, there were no records of Steller sea lions observed 
at VAFB. In April and May 2012, Steller sea lions were observed hauled 
out at North Rocky Point on VAFB, representing the first time the 
species had been observed on VAFB during launch monitoring and monthly 
surveys conducted over the past two decades (Marine Mammal Consulting 
Group and Science Applications International Corporation 2013). Since 
2012, Steller sea lions have been observed frequently in routine 
monthly surveys, with as many as 16 individuals recorded. In 2014, up 
to five Steller sea lions were observed in the affected area during 
monthly marine mammal counts (ManTech 2015) and a maximum of 12 
individuals were observed during monthly counts in 2015 (VAFB, 
unpublished data). However, up to 16 individuals were observed in 2012 
(SAIC 2012). Steller sea lions once had two small rookeries on SMI, but 
these were abandoned after the 1982-1983 El Ni[ntilde]o event (DeLong 
and Melin 2000; Lowry 2002); these rookeries were once the southernmost 
colonies of the eastern stock of this species. In recent years, between 
two to four juvenile and adult males have been observed on a somewhat 
regular basis on SMI (pers. comm. Sharon Melin, NMFS Alaska Fisheries 
Science Center, to J. Carduner, NMFS, Feb 11, 2016). Steller sea lions 
are not observed on the other NCI.

Northern Fur Seal

    Northern fur seals occur from southern California north to the 
Bering Sea and west to the Okhotsk Sea and Honshu Island, Japan. Due to 
differing requirements during the annual reproductive season, adult 
males and females typically occur ashore at different, though 
overlapping, times. Adult males occur ashore and defend reproductive 
territories during a three month period from June through August, 
though some may be present until November (well after giving up their 
territories). Adult females are found ashore for as long as six months 
(June-November). After their respective times ashore, fur seals of both 
sexes spend the next seven to eight months at sea (Roppel 1984). Peak 
pupping is in early July and pups are weaned at three to four months. 
Some juveniles are present year-round, but most juveniles and adults 
head for the open ocean and a pelagic existence until the next year. 
Northern fur seals exhibit high site fidelity to their natal rookeries. 
Two stocks of northern fur seals are recognized in U.S. waters: An 
eastern Pacific stock and a California stock (formerly referred to as 
the San Miguel Island stock). Only the California stock is considered 
in this proposed authorization due to its geographic distribution.
    Northern fur seals have rookeries on SMI at Point Bennett and on 
Castle Rock. Comprehensive count data for northern fur seals on SMI are 
not available. SMI is the only island in the NCI on which northern fur 
seals have been observed. Although the population at SMI was 
established by individuals from Alaska and Russian Islands during the 
late 1960s, most individuals currently found on San Miguel are 
considered resident to the island. No haulout or rookery sites exist 
for northern fur seals on the mainland coast. The only individuals that 
appear on mainland beaches are stranded animals.

Guadalupe Fur Seal

    Guadalupe fur seals are found along the west coast of the United 
States. They were abundant prior to seal exploitation, when they were 
likely the most abundant pinniped species on the Channel Islands, but 
are considered uncommon in Southern California. They are typically 
found on shores with abundant large rocks, often at the base of large 
cliffs (Belcher and Lee 2002). Increased strandings of Guadalupe fur 
seals started occurring along the entire coast of California in early 
2015. This event was declared a marine mammal UME. Strandings were 
eight times higher than the historical average, peaking from April 
through June 2015, and have since lessened but continue at a rate that 
is well above average. Most stranded individuals have been weaned pups 
and juveniles (1-2 years old). For more information on this UME, see: 
https://www.nmfs.noaa.gov/pr/health/mmume/guadalupefurseals2015.html.
    Comprehensive survey data on Guadalupe fur seals in the NCI is not 
readily available. On SMI, one to several male Guadalupe fur seals had 
been observed annually between 1969 and 2000 (DeLong and Melin 2000) 
and juvenile animals of both sexes have been seen occasionally over the 
years (Stewart et al. 1987). The first adult female at SMI was seen in 
1997. In June 1997, she gave birth to a pup in rocky habitat along the 
south side of the island and, over the next year, reared the pup to 
weaning age. This was apparently the first pup born in the Channel 
Islands in at least 150 years. Since 2008, individual adult females, 
subadult males, and between one and three pups have been observed 
annually on SMI. There are estimated to be approximately 20-25 
individuals that have fidelity to San Miguel, mostly inhabiting the 
southwest and northwest ends of the island. A total of 14 pups have 
been born on the island since 2009, with no more than 3 born in any 
single season (pers. comm., S. Melin, NMFS National Marine Mammal 
Laboratory, to J. Carduner, NMFS, Aug. 28, 2015). Thirteen individuals 
and two pups were observed in 2015 (NMFS 2016). No haulout or rookery 
sites exist for Guadalupe fur seals on the mainland coast, including 
VAFB. The only individuals that do appear on mainland beaches are 
stranded animals.
    Marine Mammal Hearing--Hearing is the most important sensory 
modality for marine mammals underwater, and exposure to anthropogenic 
sound can have deleterious effects. To appropriately assess the 
potential effects of exposure to sound, it is necessary to understand 
the frequency ranges marine mammals are able to hear. Current data 
indicate that not all marine mammal species have equal hearing 
capabilities (e.g., Richardson et al., 1995; Wartzok and Ketten, 1999; 
Au and Hastings, 2008). To reflect this, Southall et al. (2007) 
recommended that marine mammals be divided into functional hearing 
groups based on directly measured or estimated hearing ranges on the 
basis of available behavioral response data, audiograms derived using 
auditory evoked potential techniques, anatomical modeling, and other 
data. Subsequently, NMFS (2016) described generalized hearing ranges 
for these marine mammal hearing groups. Generalized hearing ranges were 
chosen based on the approximately 65 dB threshold from the normalized 
composite audiograms. The relevant functional groups and the associated

[[Page 49340]]

frequencies are indicated below (note that these frequency ranges 
correspond to the range for the composite group, with the entire range 
not necessarily reflecting the capabilities of every species within 
that group):
     Pinnipeds in water; Phocidae (true seals): Generalized 
hearing is estimated to occur between approximately 50 hertz (Hz) to 86 
kilohertz (kHz), with best hearing between 1-50 kHz;
     Pinnipeds in water; Otariidae (eared seals): Generalized 
hearing is estimated to occur between 60 Hz and 39 kHz, with best 
hearing between 2-48 kHz.
    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).

   Table 3--Relevant Marine Mammal Functional Hearing Groups and Their
                       Generalized Hearing Ranges
------------------------------------------------------------------------
             Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Phocid pinnipeds (PW) (underwater)      50 Hz to 86 kHz.
 (true seals).
Otariid pinnipeds (OW) (underwater)     60 Hz to 39 kHz.
 (sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al., 2007) and PW pinniped (approximation).

    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2016) for a review of available information. 
Of the six marine mammal species that may be affected by the proposed 
activities, four are classified as otariids and two are classified as 
phocids.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section includes a summary and discussion of the ways that 
components of the specified activity may impact marine mammals and 
their habitat. The ``Estimated Take by Incidental Harassment'' section 
later in this document will include a quantitative analysis of the 
number of individuals that are expected to be taken by this activity. 
The ``Negligible Impact Analysis and Determination'' section will 
consider the content of this section, the ``Estimated Take by 
Incidental Harassment'' section, and the ``Proposed Mitigation'' 
section, to draw conclusions regarding the likely impacts of these 
activities on the reproductive success or survivorship of individuals 
and how those impacts on individuals are likely to impact marine mammal 
species or stocks. Potential effects of the proposed action include 
acoustic effects as well as visual stimuli.

Acoustic Effects

    This section contains a brief technical background on sound, the 
characteristics of certain sound types, and on metrics used in this 
proposal inasmuch as the information is relevant to the specified 
activity and to a discussion of the potential effects of the specified 
activity on marine mammals found later in this document.
    Sound travels in waves, the basic components of which are 
frequency, wavelength, velocity, and amplitude. Frequency is the number 
of pressure waves that pass by a reference point per unit of time and 
is measured in Hz or cycles per second. Wavelength is the distance 
between two peaks or corresponding points of a sound wave (length of 
one cycle). Higher frequency sounds have shorter wavelengths than lower 
frequency sounds, and typically attenuate (decrease) more rapidly, 
except in certain cases in shallower water. Amplitude is the height of 
the sound pressure wave or the ``loudness'' of a sound and is typically 
described using the relative unit of the dB. A sound pressure level 
(SPL) in dB is described as the ratio between a measured pressure and a 
reference pressure and is a logarithmic unit that accounts for large 
variations in amplitude; therefore, a relatively small change in dB 
corresponds to large changes in sound pressure. The source level (SL) 
represents the SPL referenced at a distance of 1 m from the source 
while the received level is the SPL at the listener's position. Note 
that all airborne sound levels in this document are referenced to a 
pressure of 20 [micro]Pa.
    Root mean square (rms) is the quadratic mean sound pressure over 
the duration of an impulse. Root mean square is calculated by squaring 
all of the sound amplitudes, averaging the squares, and then taking the 
square root of the average (Urick, 1983). Root mean square accounts for 
both positive and negative values; squaring the pressures makes all 
values positive so that they may be accounted for in the summation of 
pressure levels (Hastings and Popper, 2005). This measurement is often 
used in the context of discussing behavioral effects, in part because 
behavioral effects, which often result from auditory cues, may be 
better expressed through averaged units than by peak pressures.
    Sound exposure level (SEL; represented as dB re 1 [mu]Pa\2\-s) 
represents the total energy contained within a pulse and considers both 
intensity and duration of exposure. Peak sound pressure (also referred 
to as zero-to-peak sound pressure or 0-p) is the maximum instantaneous 
sound pressure measurable in the water at a specified distance from the 
source and is represented in the same units as the rms sound pressure. 
Another common metric is peak-to-peak sound pressure (pk-pk), which is 
the algebraic difference between the peak positive and peak negative 
sound pressures. Peak-to-peak pressure is typically approximately 6 dB 
higher than peak pressure (Southall et al., 2007).
    A-weighting is applied to instrument-measured sound levels in an 
effort to account for the relative loudness perceived by the human ear, 
as the ear is less sensitive to low audio frequencies, and is commonly 
used in measuring airborne noise. The relative sensitivity of pinnipeds 
listening in air to different frequencies is more-or-less similar to 
that of humans (Richardson et al. 1995), so A-weighting may, as a first 
approximation, be relevant to pinnipeds listening to moderate-level 
sounds.
    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' or 
``background'' sound--depends not only on the source levels (as 
determined by current weather conditions and levels of biological and 
human activity) but also on the ability of sound to propagate through 
the environment. In turn, sound propagation is dependent on the 
spatially and temporally varying properties of the water column and sea 
floor, and is frequency-dependent. As a result of the dependence on a 
large number of varying factors, ambient sound levels can be expected 
to vary widely over both coarse and fine spatial and temporal scales. 
Sound levels at a given frequency and location can vary by 10-20 dB 
from day to day (Richardson et al., 1995). The result is that, 
depending on the source type and its intensity, sound from a given 
activity may be a negligible addition to the local environment or could 
form a distinctive signal that may affect marine mammals. Details of 
source types are described in the following text.
    Sounds are often considered to fall into one of two general types: 
Pulsed and non-pulsed (defined in the following). The distinction 
between

[[Page 49341]]

these two sound types is important because they have differing 
potential to cause physical effects, particularly with regard to 
hearing (e.g., Ward, 1997 in Southall et al., 2007). Please see 
Southall et al. (2007) for an in-depth discussion of these concepts.
    Pulsed sound sources (e.g., airguns, explosions, gunshots, sonic 
booms, impact pile driving) produce signals that are brief (typically 
considered to be less than one second), broadband, atonal transients 
(ANSI, 1986, 2005; Harris, 1998; NIOSH, 1998; ISO, 2003) and occur 
either as isolated events or repeated in some succession. Pulsed sounds 
are all characterized by a relatively rapid rise from ambient pressure 
to a maximal pressure value followed by a rapid decay period that may 
include a period of diminishing, oscillating maximal and minimal 
pressures, and generally have an increased capacity to induce physical 
injury as compared with sounds that lack these features.
    Non-pulsed sounds can be tonal, narrowband, or broadband, brief or 
prolonged, and may be either continuous or non-continuous (ANSI, 1995; 
NIOSH, 1998). Some of these non-pulsed sounds can be transient signals 
of short duration but without the essential properties of pulses (e.g., 
rapid rise time). Examples of non-pulsed sounds include those produced 
by vessels, aircraft, machinery operations such as drilling or 
dredging, vibratory pile driving, and active sonar systems (such as 
those used by the U.S. Navy). The duration of such sounds, as received 
at a distance, can be greatly extended in a highly reverberant 
environment.
    The effects of sounds on marine mammals are dependent on several 
factors, including the species, size, behavior (feeding, nursing, 
resting, etc.), and, if underwater, depth of the animal; the intensity 
and duration of the sound; and the sound propagation properties of the 
environment. Impacts to marine species can result from physiological 
and behavioral responses to both the type and strength of the acoustic 
signature (Viada et al., 2008). The type and severity of behavioral 
impacts are more difficult to define due to limited studies addressing 
the behavioral effects of sounds on marine mammals. Potential effects 
from impulsive sound sources can range in severity from effects such as 
behavioral disturbance or tactile perception to physical discomfort, 
slight injury of the internal organs and the auditory system, or 
mortality (Yelverton et al., 1973).
    The effects of sounds from the proposed activities are expected to 
result in behavioral disturbance of marine mammals. Due to the expected 
sound levels of the activities proposed and the distance of the 
activity from marine mammal habitat, the effects of sounds from the 
proposed activities are not expected to result in temporary or 
permanent hearing impairment (TTS and PTS, respectively), non-auditory 
physical or physiological effects, or masking in marine mammals. Data 
from monitoring reports associated with IHAs issued previously for 
similar activities in the same location as the planned activities 
provides further support for the assertion that TTS, PTS, non-auditory 
physical or physiological effects, and masking are not likely to occur 
(USAF 2013b; SAIC 2012). Therefore, TTS, PTS, non-auditory physical or 
physiological effects, and masking are not discussed further in this 
section.

Disturbance Reactions

    Disturbance includes a variety of effects, including subtle changes 
in behavior, more conspicuous changes in activities, and displacement. 
Behavioral responses to sound are highly variable and context-specific 
and reactions, if any, depend on species, state of maturity, 
experience, current activity, reproductive state, auditory sensitivity, 
time of day, and many other factors (Richardson et al., 1995; Wartzok 
et al., 2003; Southall et al., 2007).
    Habituation can occur when an animal's response to a stimulus wanes 
with repeated exposure, usually in the absence of unpleasant associated 
events (Wartzok et al., 2003). Animals are most likely to habituate to 
sounds that are predictable and unvarying. The opposite process is 
sensitization, when an unpleasant experience leads to subsequent 
responses, often in the form of avoidance, at a lower level of 
exposure. Behavioral state may affect the type of response as well. For 
example, animals that are resting may show greater behavioral change in 
response to disturbing sound levels than animals that are highly 
motivated to remain in an area for feeding (Richardson et al., 1995; 
NRC, 2003; Wartzok et al., 2003).
    Controlled experiments with captive marine mammals have shown 
pronounced behavioral reactions, including avoidance of loud underwater 
sound sources (Ridgway et al., 1997; Finneran et al., 2003). Observed 
responses of wild marine mammals to loud pulsed sound sources 
(typically seismic guns or acoustic harassment devices) have been 
varied but often consist of avoidance behavior or other behavioral 
changes suggesting discomfort (Morton and Symonds, 2002; Thorson and 
Reyff, 2006; see also Gordon et al., 2004; Wartzok et al., 2003; 
Nowacek et al., 2007).
    The onset of noise can result in temporary, short term changes in 
an animal's typical behavior and/or avoidance of the affected area. 
These behavioral changes may include: Reduced/increased vocal 
activities; changing/cessation of certain behavioral activities (such 
as socializing or feeding); visible startle response or aggressive 
behavior; avoidance of areas where sound sources are located; and/or 
flight responses (Richardson et al., 1995).
    The biological significance of many of these behavioral 
disturbances is difficult to predict, especially if the detected 
disturbances appear minor. However, the consequences of behavioral 
modification could potentially be biologically significant if the 
change affects growth, survival, or reproduction. The onset of 
behavioral disturbance from anthropogenic sound depends on both 
external factors (characteristics of sound sources and their paths) and 
the specific characteristics of the receiving animals (hearing, 
motivation, experience, demography) and is difficult to predict 
(Southall et al., 2007).
    Marine mammals that occur in the project area could be exposed to 
airborne sounds associated with Falcon 9 boost-back and landing 
activities that have the potential to result in behavioral harassment, 
depending on an animal's distance from the sound. Airborne sound could 
potentially affect pinnipeds that are hauled out. Most likely, airborne 
sound would cause behavioral responses similar to those discussed above 
in relation to underwater sound. For instance, anthropogenic sound 
could cause hauled out pinnipeds to exhibit changes in their normal 
behavior, such as reduction in vocalizations, or cause them to 
temporarily abandon their habitat and move further from the source. 
Hauled out pinnipeds may flush from a haulout into the water. Though 
pup abandonment could theoretically result from these reactions, site-
specific monitoring data (described below) indicate that pup 
abandonment is not likely to occur as a result of the specified 
activity.

Description of Effects From the Specified Activity

    This section includes a discussion of the active acoustic sound 
sources associated with SpaceX's proposed activity and the likelihood 
for these sources to result in harassment of

[[Page 49342]]

marine mammals. Potential acoustic sources associated with SpaceX's 
proposed activity include sonic booms, Falcon 9 First Stage landings, 
and potential explosions as a result of unsuccessful Falcon 9 First 
Stage landing attempts. Sounds produced by the proposed activities may 
be impulsive, due to sonic booms, and non-pulse (but short-duration) 
noise, due to combustion effects of the Falcon 9 First Stage. As 
described above, sounds associated with Falcon 9 First Stage landings 
and potential explosions as a result of unsuccessful Falcon 9 First 
Stage landing attempts are not expected to result in take of marine 
mammals and are therefore not addressed here.

Sonic Boom

    As described above, during descent when the First Stage is 
supersonic, a sonic boom would be generated. The USAF has monitored 
pinniped responses to rocket launches from VAFB for nearly 20 years. 
Though rocket launches are not part of the proposed activities (as 
described above), the acoustic stimuli (sonic booms) associated with 
launches is expected to be substantially similar to those expected to 
occur with Falcon 9 boost-backs and landings; therefore, we rely on 
observational data on responses of pinnipeds to sonic booms associated 
with rocket launches from VAFB in making assumptions about expected 
pinniped responses to sonic booms associated with Falcon 9 boost-backs 
and landings.
    Observed reactions of pinnipeds at the NCI to sonic booms have 
ranged from no response to heads-up alerts, from startle responses to 
some movements on land, and from some movements into the water to 
occasional stampedes (especially involving California sea lions on the 
NCI). We therefore assume sonic booms generated during the return 
flight of the Falcon 9 First Stage may elicit an alerting or other 
short-term behavioral reaction, including flushing into the water if 
hauled out.
    Data from launch monitoring by the USAF on the NCI has shown that 
pinniped reactions to sonic booms are correlated with the level of the 
sonic boom. Low energy sonic booms (<1.0 psf have resulted in little to 
no behavioral responses, including head raising and briefly alerting 
but returning to normal behavior shortly after the stimulus (Table 5). 
More powerful sonic booms have resulted in pinnipeds flushing from 
haulouts. No pinniped mortalities have been associated with sonic 
booms. No sustained decreases in numbers of animals observed at 
haulouts have been observed after the stimulus. Table 5 presents a 
summary of monitoring efforts at the NCI from 1999 to 2014. These data 
show that reactions to sonic booms tend to be insignificant below 1.0 
psf and that, even above 1.0 psf, only a portion of the animals present 
have reacted to the sonic boom. Time-lapse video photography during 
four launch events revealed that harbor seals that reacted to the 
rocket launch noise but did not leave the haul-out were all adults.
    Data from previous monitoring also suggests that for those 
pinnipeds that flush from haulouts in response to sonic booms, the 
amount of time it takes for those animals to begin returning to the 
haulout site, and for numbers of animals to return to pre-launch 
levels, is correlated with sonic boom sound levels. Pinnipeds may begin 
to return to the haul-out site within 2-55 min of the launch 
disturbance, and the haulout site usually returned to pre-launch levels 
within 45-120 min. Monitoring data from launches of the Athena IKONOS 
rocket from VAFB, with 107.3 and 107.8 dB (A-weighted SEL) recorded at 
the closest haul-out site, showed seals that flushed to the water on 
exposure to the sonic boom began to return to the haul-out 
approximately 16-55 minutes post-launch (Thorson et al., 1999a; 1999b). 
In contrast, in the cases of Atlas rocket launches and several Titan II 
rocket launches with SELs (A-weighted) ranging from 86.7 to 95.7 dB 
recorded at the closest haul-out, seals began to return to the haul-out 
site within 2-8 minutes post-launch (Thorson and Francine, 1997; 
Thorson et al., 2000).
    Monitoring data has consistently shown that reactions among 
pinnipeds vary between species, with harbor seals and California sea 
lions tending to be more sensitive to disturbance than northern 
elephant seals and northern fur seals (Table 5). Because Steller sea 
lions and Guadalupe fur seals occur in the project area relatively 
infrequently, no data has been recorded on their reactions to sonic 
booms). At VAFB, harbor seals generally alert to nearby launch noises, 
with some or all of the animals going into the water. Usually the 
animals haul out again from within minutes to two hours or so of the 
launch, provided rising tides or breakers have not submerged the haul-
out sites. Post-launch surveys often indicate as many or more animals 
hauled out than were present at the time of the launch, unless rising 
tides, breakers or other disturbances are involved (SAIC 2012). When 
launches occurred during high tides at VAFB, no impacts have been 
recorded because virtually all haul-out sites were submerged.
    At the Channel Islands, California sea lions have been observed to 
react more strongly to sonic booms than other species present there. 
Pups sometimes react more than adults, either because they are more 
easily frightened or because their hearing is more acute. Harbor seals 
generally appear to be more sensitive to sonic booms than most other 
pinnipeds, often startling and fleeing into the water. Northern fur 
seals generally show little or no reaction. Northern elephant seals 
generally exhibit no reaction at all, except perhaps a heads-up 
response or some stirring, especially if sea lions in the same area or 
mingled with the elephant seals react strongly to the boom. Post-launch 
monitoring generally reveals a return to normal patterns within minutes 
up to an hour or two of each launch, regardless of species (SAIC 2012).
    Table 5 summarizes monitoring efforts at San Miguel Island during 
which acoustic measurements were successfully recorded and during which 
pinnipeds were observed. During more recent launches, night vision 
equipment was used. The table shows only launches during which sonic 
booms were heard and recorded. The table shows that little or no 
reaction from the four species usually occurs when overpressures are 
below 1.0 psf. In general, as described above, elephant seals do not 
react unless other animals around them react strongly or if the sonic 
boom is extremely loud, and northern fur seals seem to react similarly. 
Not enough data exist to draw conclusions about harbor seals, but 
considering their reactions to launch noise at VAFB, it is likely that 
they are also sensitive to sonic booms (SAIC 2012).

[[Page 49343]]



                                        Table 5--Observed Pinniped Responses to Sonic Booms at San Miguel Island
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Sonic boom
                     Launch event                        level (psf)       Monitoring location                Species and associated reactions
--------------------------------------------------------------------------------------------------------------------------------------------------------
Athena II (April 27, 1999)...........................             1.0  Adams Cove.................  California sea lion--866 alerted; 232 (27%) flushed
                                                                                                     into water, Northern elephant seal--alerted but did
                                                                                                     not flush, Northern fur seal--alerted but did not
                                                                                                     flush.
Athena II (September 24, 1999).......................            0.95  Point Bennett..............  California sea lion--12 of 600 (2%) flushed into
                                                                                                     water, Northern elephant seal--alerted but did not
                                                                                                     flush, Northern fur seal--alerted but did not
                                                                                                     flush.
Delta II 20 (November 20, 2000)......................             0.4  Point Bennett..............  California sea lion--60 pups flushed into water; no
                                                                                                     reaction from focal group, Northern elephant seal--
                                                                                                     no reaction.
Atlas II (September 8, 2001).........................            0.75  Cardwell Point.............  California sea lion (Group 1)--no reaction (1,200
                                                                                                     animals), California sea lion (Group 2)--no
                                                                                                     reaction (247 animals), Northern elephant seal--no
                                                                                                     reaction, Harbor seal--2 of 4 flushed into water.
Delta II (February 11, 2002).........................            0.64  Point Bennett..............  California sea lion and northern fur seal--no
                                                                                                     reaction among 485 animals in 3 groups, Northern
                                                                                                     elephant seal--no reaction among 424 animals in 2
                                                                                                     groups.
Atlas II (December 2, 2003)..........................            0.88  Point Bennett..............  California sea lion--approximately 40% alerted;
                                                                                                     several flushed to water (number unknown--night
                                                                                                     launch), Northern elephant seal--no reaction.
Delta II (July 15, 2004).............................            1.34  Adams Cove.................  California sea lion--10% alerted (number unknown--
                                                                                                     night launch).
Atlas V (March 13, 2008).............................            1.24  Cardwell Point.............  Northern elephant seal--no reaction (109 pups).
Delta II (May 5, 2009)...............................            0.76  West of Judith Rock........  California sea lion--no reaction (784 animals).
Atlas V (April 14, 2011).............................            1.01  Cuyler Harbor..............  Northern elephant seal--no reaction (445 animals).
Atlas V (September 13, 2012).........................            2.10  Cardwell Point.............  California sea lion--no reaction (460 animals),
                                                                                                     Northern elephant seal--no reaction (68 animals),
                                                                                                     Harbor seal--20 of 36 (56%) flushed into water.
Atlas V (April 3, 2014)..............................            0.74  Cardwell Point.............  Harbor seal--1 of ~25 flushed into water; no
                                                                                                     reaction, from others.
Atlas V (December 12, 2014)..........................            1.16  Point Bennett..............  Calif. sea lion--5 of ~225 alerted; none flushed.
--------------------------------------------------------------------------------------------------------------------------------------------------------

Physiological Responses to Sonic Booms

    To determine if harbor seals experience changes in their hearing 
sensitivity as a result of sounds associated with rocket launches 
(including sonic booms), Auditory Brainstem Response (ABR) testing was 
conducted on 14 harbor seals following four launches of the Titan IV 
rocket, one launch of the Taurus rocket, and two launches of the Delta 
IV rocket from VAFB, in accordance with NMFS scientific research 
permits. ABR tests have not yet been performed following Falcon 9 
rocket landings nor launches, however results of ABR tests that 
followed launches of other rockets from VAFB are nonetheless 
informative as the sound source (sonic boom) is expected to be the same 
as that associated with the activities proposed by SpaceX.
    Following standard ABR testing protocol, the ABR was measured from 
one ear of each seal using sterile, sub-dermal, stainless steel 
electrodes. A conventional electrode array was used, and low-level 
white noise was presented to the non-tested ear to reduce any 
electrical potentials generated by the non-tested ear. A computer was 
used to produce the click and an eight kHz tone burst stimuli, through 
standard audiometric headphones. Over 1,000 ABR waveforms were 
collected and averaged per trial. Initially the stimuli were presented 
at SPLs loud enough to obtain a clean reliable waveform, and then 
decreased in 10 dB steps until the response was no longer reliably 
observed. Once response was no longer reliably observed, the stimuli 
were then increased in 10 dB steps to the original SPL. By obtaining 
two ABR waveforms at each SPL, it was possible to quantify the 
variability in the measurements.
    Good replicable responses were measured from most of the seals, 
with waveforms following the expected pattern of an increase in latency 
and decrease in amplitude of the peaks, as the stimulus level was 
lowered. Detailed analysis of the changes in waveform latency and 
waveform replication of the ABR measurements for the 14 seals showed no 
detectable changes in the seals' hearing sensitivity as a result of 
exposure to the launch noise. The delayed start (1.75 to 3.5 hours 
after the launches) for ABR testing allows for the possibility that the 
seals may have recovered from a TTS before testing began. However, it 
can be said with confidence that the post-launch tested animals did not 
have permanent hearing changes due to exposure to the launch noise from 
the sonic booms associated with launches of the rockets from VAFB (SAIC 
2013).
    We also note that stress from long-term cumulative sound exposures 
can result in physiological effects on reproduction, metabolism, and 
general health, or on the animals' resistance to disease. However, this 
is not likely to occur as a result of the proposed activities because 
of the infrequent nature and short duration of the noise (up to twelve 
sonic booms annually). Research indicates that population levels at 
these haul-out sites have remained constant in recent years (with 
decreases only noted in some areas because of the increased presence of 
coyotes), giving support to this conclusion.
    In conclusion, based on data from numerous years of monitoring of 
similar activities to the activities proposed by SpaceX, in the same 
geographic area as the geographic area of the SpaceX's proposed 
activities, we expect that any behavioral responses by pinnipeds to 
sonic booms resulting from the proposed activities would range from no 
response to heads-up alerts, startle responses, some movements on land, 
and some movements into the water (flushing).

Non-Acoustic Effects of the Proposed Activity

    This section includes a discussion of potential effects of SpaceX's 
proposed activity other than those related to sound.

Visual Stimuli

    Visual stimuli resulting from Falcon 9 First Stage landings would 
have the

[[Page 49344]]

potential to cause pinnipeds to lift their heads, move towards the 
water, or enter the water. However, SpaceX has determined that the 
trajectory of the return flight includes a nearly vertical descent to 
the SLC-4W landing pad (see Figure 1-7 and 1-8 in the IHA application) 
and the contingency landing location (see Figure 1-5 in the IHA 
application). As a result, the descending Falcon 9 First Stage would 
either be shielded by coastal bluffs (for a SLC-4W landing) or would be 
too far away from any pinniped haulouts to result in significant 
stimuli (in the case of a barge landing). Further, the visual stimulus 
of the Falcon 9 First Stage would not be coupled with the sonic boom, 
since the First Stage would be at significant altitude when the 
overpressure is produced, further decreasing the likelihood of a 
behavioral response. Therefore, the likelihood of takes of marine 
mammals resulting from visual stimuli associated with the proposed 
activity is so low as to be considered discountable. As such, visual 
stimuli associated with the proposed activity is not discussed further 
in this document.

Effects on Marine Mammal Habitat

    We do not anticipate that the proposed activities would result in 
any temporary or permanent effects on the habitats used by the marine 
mammals in the proposed area, including the food sources they use (i.e. 
fish and invertebrates). Behavioral disturbance caused by in-air 
acoustic stimuli may result in marine mammals temporarily moving away 
from or avoiding the exposure area but are not expected to have long 
term impacts, as supported by over two decades of launch monitoring 
studies on the NCI by the U.S. Air Force (MMCG and SAIC 2012).
    The proposed activities would not result in in-water acoustic 
stimuli that would cause significant injury or mortality to prey 
species and would not create barriers to movement for marine mammal 
prey. As described above, in the event of an unsuccessful barge landing 
and a resulting explosion of the Falcon 9 First Stage, up to 25 pieces 
of debris would likely remain floating. SpaceX would recover all 
floating debris. Denser debris that would not float on the surface is 
anticipated to sink relatively quickly and would be composed of inert 
materials. The area of benthic habitat impacted by falling debris would 
be very small (approximately 0.000706 km\2\) (ManTech 2015) and all 
debris that would sink are composed of inert materials that would not 
affect water quality or bottom substrate potentially used by marine 
mammals. None of the debris would be so dense or large that benthic 
habitat would be degraded. As a result, debris from an unsuccessful 
barge landing that enters the ocean environment approximately 50 km 
offshore of VAFB would not have a significant effect on marine mammal 
habitat.
    In summary, since the acoustic impacts associated with the proposed 
activities are of short duration and infrequent (up to twelve events 
annually), the associated behavioral responses in marine mammals are 
expected to be temporary. Therefore, the proposed activities are 
unlikely to result in long term or permanent avoidance of the exposure 
areas or loss of habitat. The proposed activities are also not expected 
to result in any reduction in foraging habitat or adverse impacts to 
marine mammal prey. Thus, any impacts to marine mammal habitat are not 
expected to cause significant or long-term consequences for individual 
marine mammals or their populations.

Estimated Take by Incidental Harassment

    This section provides an estimate of the number of incidental takes 
proposed for authorization through this IHA, which will inform both 
NMFS' consideration of whether the number of takes is ``small'' and the 
negligible impact determination.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as: Any act of 
pursuit, torment, or annoyance which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    All authorized takes would be by Level B harassment only, in the 
form of disruption of behavioral patterns for individual marine mammals 
resulting from exposure to sounds associated with the planned 
activities. Based on the nature of the activity, Level A harassment, 
serious injury, and mortality are neither anticipated nor proposed to 
be authorized.
    Described in the most basic way, we estimate take by considering: 
(1) Acoustic thresholds above which NMFS believes the best available 
science indicates marine mammals will be behaviorally harassed; (2) the 
area that will be ensonified above these levels in a day; (3) the 
density or occurrence of marine mammals within these ensonified areas; 
and (4) and number of days of activities. Below, we describe these 
components in more detail and present the proposed take estimate.

Acoustic Thresholds

    Using the best available science, NMFS has developed acoustic 
thresholds that identify the received level of sound above which 
exposed marine mammals would be reasonably expected to be behaviorally 
harassed (equated to Level B harassment) or to incur PTS of some degree 
(equated to Level A harassment). As described above, Level A harassment 
is not expected to occur as a result of the proposed activities and we 
do not propose to authorize take by Level A harassment, thus criteria 
and thresholds for Level A harassment are not discussed further. 
Thresholds have been developed identifying the received level of in-air 
sound above which exposed pinnipeds would likely be behaviorally 
harassed. In this case, we are concerned only with in-air sound as the 
proposed activities are not expected to result in harassment of marine 
mammals that are underwater. Thus only in-air thresholds are discussed 
further.

Level B Harassment for Non-Explosive Sources

    Though significantly driven by received level, the onset of 
behavioral disturbance from anthropogenic noise exposure is also 
informed to varying degrees by other factors related to the source 
(e.g., frequency, predictability, duty cycle), the environment, and the 
receiving animals (hearing, motivation, experience, demography, 
behavioral context) and can be difficult to predict (Southall et al., 
2007, Ellison et al., 2011). Based on what the available science 
indicates and the practical need to use a threshold based on a factor 
that is both predictable and measurable for most activities, NMFS 
typically uses a generalized acoustic threshold based on received level 
to estimate the onset of behavioral harassment. As described above, for 
in-air sounds, NMFS expects that harbor seals exposed to sound above 
received levels of 90 dB re 20 [mu]Pa (rms) will be behaviorally 
harassed, and all other species of pinnipeds exposed to sound above 
received levels of 100 dB re 20 [mu]Pa (rms) will be behaviorally 
harassed (Table 1).
    Typically, NMFS relies on the acoustic criteria shown in Table 1 to 
estimate take as a result of exposure to airborne sound from a given 
activity. However, in this case we have the

[[Page 49345]]

benefit of more than 20 years of observational data on pinniped 
responses to the stimuli associated with the proposed activity that we 
expect to result in harassment (sonic booms) in the particular 
geographic area of the proposed activity (VAFB and the NCI). Therefore, 
we consider these data to be the best available information in regard 
to estimating take based on modeled exposures among pinnipeds to sounds 
associated with the proposed activities. These data suggest that 
pinniped reactions to sonic booms are dependent on the species and the 
intensity of the sonic boom (Table 5).
    As described above, data from launch monitoring by the USAF on the 
NCI and at VAFB have shown that pinniped reactions to sonic booms are 
correlated to the level of the sonic boom. Low energy sonic booms (<1.0 
psf) have typically resulted in little to no behavioral responses, 
including head raising and briefly alerting but returning to normal 
behavior shortly after the stimulus. More powerful sonic booms have 
flushed animals from haulouts (but not resulted in any mortality or 
sustained decreased in numbers after the stimulus). Table 5 presents a 
summary of monitoring efforts at the NCI from 1999 to 2014. These data 
show that reactions to sonic booms tend to be insignificant below 1.0 
psf and that, even above 1.0 psf, only a portion of the animals present 
react to the sonic boom. Therefore, for the purposes of estimating the 
extent of take that is likely to occur as a result of the proposed 
activities, we assume that Level B harassment occurs when a pinniped 
(on land) is exposed to a sonic boom at or above 1.0 psf. Therefore the 
number of expected takes by Level B harassment is based on estimates of 
the numbers of animals that would be within the areas exposed to sonic 
booms at levels at or above 1.0 psf.
    The data recorded by USAF at VAFB and the NCI over the past 20 
years has also shown that pinniped reactions to sonic booms vary 
between species. As described above, little or no reaction has been 
observed in northern fur seals and northern elephant seals when 
overpressures were below 1.0 psf. At the NCI sea lions have reacted 
more strongly to sonic booms than most other species. Harbor seals also 
appear to be more sensitive to sonic booms than most other pinnipeds, 
often resulting in startling and fleeing into the water. Northern fur 
seals generally show little or no reaction, and northern elephant seals 
generally exhibit no reaction at all, except perhaps a heads-up 
response or some stirring, especially if sea lions in the same area 
mingled with the elephant seals react strongly to the boom. No data is 
available on Steller sea lion or Guadalupe fur seal responses to sonic 
booms.

Ensonified Area

    As described above, modeling was performed to estimate overpressure 
levels that would be created during the return flight of the Falcon 9 
First Stage. The predicted acoustic footprint of the sonic boom was 
computed using the computer program PCBoom (Plotkin and Grandi 2002; 
Page et al. 2010). As described above, the highest sound generated by a 
sonic boom would generally be focused on the area where the Falcon 9 
ultimately lands. Based on model results, a boost-back and landing of 
the Falcon 9 First Stage at SLC-4W would produce a sonic boom with 
overpressures as high as 8.5 psf at SLC-4W, which would attenuate to 
levels below 1.0 psf at approximately 15.90 mi. (25.59 km) from the 
landing area (Figure 2-2 in the IHA application). This estimate is 
based, in part, on actual observations from Falcon 9 boost-back and 
landing activities at Cape Canaveral, Florida. A boost-back and landing 
of the Falcon 9 First Stage at SLC-4W would produce a sonic boom with 
overpressures up to 3.1 psf on the NCI (San Miguel Island, Santa Rosa 
Island, and Santa Cruz Island) based on model results.
    During a contingency barge landing event, sonic boom overpressure 
would be directed at the ocean surface while the first-stage booster is 
supersonic. Model results indicate that sonic booms would not exceed 
1.0 psf on any part of the NCI during a boost-back and landing of the 
Falcon 9 First Stage at the contingency landing location at least 27 nm 
(50 km) offshore (Figure 2-6 and Figure 2-7 in the IHA application). 
Additionally, First Stage boost-backs and landings within the Iridium 
Landing Area would not likely produce measurable overpressures at any 
land surface (Figure 2-8 and Figure 2-9 in the IHA application). 
Therefore, take of marine mammals is not expected to occur as a result 
of boost-back and landing activities at the contingency landing 
location at least 27 nm (50 km) offshore, nor within the Iridium 
Landing Area. Estimated takes are therefore based on the possibility of 
boost-back and landing activities occurring at SLC-4W.

Marine Mammal Occurrence

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations. Data collected from marine mammal surveys, including 
monthly marine mammal surveys conducted by the USAF at VAFB as well as 
data collected by NMFS, represent the best available information on the 
occurrence of the six pinniped species expected to occur in the project 
area. The quality and amount of information available on pinnipeds in 
the project area varies depending on species; some species are surveyed 
regularly at VAFB and the NCI (e.g., California sea lion), while other 
species are surveyed less frequently (e.g., northern fur seals and 
Guadalupe fur seals). However, the best available data was used to 
estimate take numbers. Take estimates for all species are shown in 
Table 6.
    Harbor Seal--Pacific harbor seals are the most common marine mammal 
inhabiting VAFB, congregating on several rocky haulout sites along the 
VAFB coastline. They also haul out, breed, and pup in isolated beaches 
and coves throughout the coasts of the NCI. Harbor seals may be exposed 
to sonic booms above 1.0 psf on the mainland and the NCI. Take of 
harbor seals at VAFB was estimated based on the maximum count totals 
from monthly surveys of VAFB haulout sites from 2013-2016 (ManTech SRS 
Technologies, Inc., 2014, 2015, 2016; VAFB, unpubl. data). Take of 
harbor seals at the NCI and at Point Conception was estimated based on 
the maximum count totals from aerial survey data collected from 2002 to 
2012 by the NMFS SWFSC (M. Lowry, NMFS SWFSC, unpubl. data).
    California sea lion--California sea lions are common offshore of 
VAFB and haul out on rocks and beaches along the coastline of VAFB, 
though pupping rarely occurs on the VAFB coastline. They haul out in 
large numbers on the NCI and rookeries exist on San Miguel and Santa 
Cruz islands. California sea lions may be exposed to sonic booms above 
1.0 psf on the mainland and the NCI. Take of California sea lions at 
VAFB was estimated based on the maximum count totals from monthly 
surveys of VAFB haulout sites from 2013-2016 (ManTech SRS Technologies, 
Inc., 2014, 2015, 2016; VAFB, unpubl. data). Take of California sea 
lions at the NCI was estimated based on the maximum count totals from 
aerial survey data collected from 2002 to 2012 by the NMFS Southwest 
Fisheries Science Center (SWFSC) (M. Lowry, NMFS SWFSC, unpubl. data).
    Steller Sea Lion--Steller sea lions occur in small numbers at VAFB 
and on San Miguel Island. They have not been observed on the Channel 
Islands other than at San Miguel Island and they do not currently have 
rookeries at VAFB or the NCI. Steller sea lions may be

[[Page 49346]]

exposed to sonic booms above 1.0 psf on the mainland and the NCI. Take 
of Steller sea lions at VAFB was estimated based on the largest count 
totals from monthly surveys of VAFB haulout sites from 2013-2016 
(ManTech SRS Technologies, Inc., 2014, 2015, 2016; VAFB, unpubl. data). 
Steller sea lions haul out in very small numbers on the NCI, and 
comprehensive survey data for Steller sea lions in the NCI is not 
available. Take of Steller sea lions at the NCI was estimated based on 
subject matter expert input suggesting that as many as four Steller sea 
lions have been observed on San Miguel Island at a time (pers. comm., 
S. Melin, NMFS Marine Mammal Laboratory (MML), to J. Carduner, NMFS, 
Feb 11, 2016).
    Northern elephant seal--Northern elephant seals haul out 
sporadically on rocks and beaches along the coastline of VAFB and at 
Point Conception and have rookeries on San Miguel Island and Santa Rosa 
Island and at one location at VAFB. Northern elephant seals may be 
exposed to sonic booms above 1.0 psf on the mainland and the NCI. Take 
of northern elephant seals at VAFB was estimated based on the largest 
count totals from monthly surveys of VAFB haulout sites from 2013-2016 
(ManTech SRS Technologies, Inc., 2014, 2015, 2016; VAFB, unpubl. data). 
Take of northern elephant seals at the NCI and at Point Conception was 
estimated based on the maximum count totals from aerial survey data 
collected from 2002 to 2012 by the NMFS Southwest Fisheries Science 
Center (SWFSC) (M. Lowry, NMFS SWFSC, unpubl. data).
    Northern fur seal--Northern fur seals have rookeries on San Miguel 
Island, the only island in the NCI on which they have been observed. No 
haulouts or rookeries exist for northern fur seals on the mainland 
coast, including VAFB, thus they may be exposed to sonic booms above 
1.0 psf at the NCI but not on the mainland. Comprehensive survey data 
for northern fur seals in the project area is not available. Estimated 
take of northern fur seals was based on subject matter expert input 
which suggested a maximum of approximately 6,000-8,000 northern fur 
seals may be present on San Miguel Island at the height of breeding/
pupping season (early July). After the height of the breeding/pupping 
season, numbers fluctuate but decrease as females go on foraging trips 
and males begin to migrate in late July/August. Numbers continue to 
decrease until November when most of the population is absent from the 
island until the following breeding/pupping period (starting the 
following June) (pers. comm., T. Orr, NMFS NMML, to J. Carduner, NMFS 
OPR, February 27, 2016). It was therefore conservatively estimated that 
numbers peak at 8,000 animals hauled out at any given time in July and 
decrease to a minimum of 2,000 animals hauled out at any given time in 
the winter, then increase again until the following July. This results 
in an average estimate of 5,000 northern fur seals hauled out at San 
Miguel Island at any given time over the course of the entire year.
    Guadalupe fur seal--There are estimated to be approximately 20-25 
individual Guadalupe fur seals that have fidelity to San Miguel Island 
(pers. comm. S. Mellin, NMFS NMML, to J. Carduner, NMFS OPR, February 
11, 2016). No haulouts or rookeries exist for Guadalupe fur seals on 
the mainland coast, including VAFB, thus they may be exposed to sonic 
booms above 1.0 psf at the NCI but not on the mainland. Comprehensive 
survey data on Guadalupe fur seals in the project area is not readily 
available. Estimated take of Guadalupe fur seals was based on the 
maximum number of Guadalupe fur seals observed at any one time on San 
Miguel Island (13) (pers. comm., J. LaBonte, ManTech SRS Technologies 
Inc., to J. Carduner, NMFS, Feb. 29, 2016); it was therefore 
conservatively assumed that 13 Guadalupe fur seals may be hauled out at 
San Miguel Island at any given time.

Take Calculation and Estimation

    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate.
    NMFS currently uses a three-tiered scale to determine whether the 
response of a pinniped on land to acoustic or visual stimuli is 
considered an alert, a movement, or a flush. NMFS considers the 
behaviors that meet the definitions of both movements and flushes to 
qualify as behavioral harassment. Thus a pinniped on land is considered 
by NMFS to have been behaviorally harassed if it moves greater than two 
times its body length, or if the animal is already moving and changes 
direction and/or speed, or if the animal flushes from land into the 
water. Animals that become alert without such movements are not 
considered harassed. See Table 4 for a summary of the pinniped 
disturbance scale.

                           Table 4--Levels of Pinniped Behavioral Disturbance on Land
----------------------------------------------------------------------------------------------------------------
                                                                                     Characterized as behavioral
      Level          Type of response                    Definition                       harassment by NMFS
----------------------------------------------------------------------------------------------------------------
1................  Alert..............  Seal head orientation or brief movement in   No.
                                         response to disturbance, which may include
                                         turning head towards the disturbance,
                                         craning head and neck while holding the
                                         body rigid in a u-shaped position,
                                         changing from a lying to a sitting
                                         position, or brief movement of less than
                                         twice the animal's body length.
2................  Movement...........  Movements away from the source of            Yes.
                                         disturbance, ranging from short
                                         withdrawals at least twice the animal's
                                         body length to longer retreats over the
                                         beach, or if already moving a change of
                                         direction of greater than 90 degrees.
3................  Flush..............  All retreats (flushes) to the water........  Yes.
----------------------------------------------------------------------------------------------------------------

    As described above, the likelihood of pinnipeds exhibiting 
responses to sonic booms that would be considered behavioral harassment 
(based on the levels of pinniped disturbance as shown in Table 4) is 
dependent on both the species and on the intensity of the sonic boom. 
Data from rocket launch monitoring by the USAF at VAFB and the NCI show 
that pinniped reactions to sonic booms are correlated to the level of 
the sonic boom, with low energy sonic booms (<1.0 psf) typically 
resulting in little to no behavioral responses, and higher energy sonic 
booms resulting in responses ranging from no response to heads-up 
alerts, startle responses, some movements on land, and some movements 
into the water (flushing). Based on model results, a boost-back and 
landing of the Falcon 9 First Stage at SLC-4W would produce a sonic 
boom with greater intensity at VAFB (overpressures potentially as high 
as 8.5 psf) than at the NCI (overpressures potentially as high as 3.1 
psf). Responses of pinnipeds to

[[Page 49347]]

sonic booms are also highly dependent on species, with harbor seals, 
California sea lions and Steller sea lions generally displaying greater 
sensitivity to sonic booms than northern elephant seals and northern 
fur seals (Table 5). We are not aware of any data on Guadalupe fur seal 
responses to sonic booms, but we assume responses by Guadalupe fur seal 
responses to be similar to those observed in northern fur seals as the 
two species are physiologically and behaviorally very similar.
    Take estimates were calculated by overlaying the modeled acoustic 
footprints of sonic booms from boost-back and landing events at SLC-4W 
with known pinniped haulouts on the mainland (including those at VAFB) 
and the NCI to determine the pinniped haulouts that would potentially 
be affected by sonic booms with overpressures of 1.0 psf and above. 
Only haulouts along northeastern San Miguel Island, northern and 
northwestern Santa Rosa Island, and northwestern Santa Cruz Island 
would be expected to experience overpressures greater than 1.0 psf 
during a boost-back and landing at SLC-4W (Figure 2-3, 2-4, 2-5 and 2-6 
in the IHA application). Take estimates also account for the likely 
intensity of the sonic boom as well as the relative sensitivity of the 
marine mammal species present, based on monitoring data as described 
above.
    A boost-back and landing of the Falcon 9 First Stage at SLC-4W that 
results in a sonic boom of 1.0 psf and above at VAFB was conservatively 
estimated to result in behavioral harassment of 100 percent of all 
species hauled out at or near VAFB and Point Conception (Table 6). A 
boost-back and landing of the Falcon 9 First Stage at SLC-4W that 
results in a sonic boom of 1.0 psf and above at the NCI was estimated 
to result in the behavioral harassment of 100 percent of California sea 
lions, harbor seals, and Steller sea lions that are hauled out at the 
NCI and of five percent of northern elephant seals, northern fur seals, 
and Guadalupe fur seals that are hauled out at the NCI. The five 
percent adjustment in the take estimates for these species at the NCI 
is also considered conservative, as launch monitoring data shows that 
elephant seals and fur seals sometimes alert to sonic booms but have 
never been observed flushing to the water or responding in a manner 
that would be classified as behavioral harassment even when sonic booms 
were measured at >1.0 psf (see Table 5 for a summary of launch 
monitoring data).
    The take calculations presented in Table 6 are based on the best 
available information on marine mammal populations in the project 
location and responses among marine mammals to the stimuli associated 
with the proposed activities.

   Table 6--Estimated Numbers of Marine Mammals, and Percentage of Marine Mammal Populations, Potentially Taken as a Result of the Proposed Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                               Estimated number      Estimated       Total number of    Takes by Level B
                                                                                  of Level B      combined number    takes by Level B      harassment
                                                                                  harassment         of Level B         harassment        proposed for
                   Species                          Geographic location         exposures per        harassment        proposed for     authorization as
                                                                                  event, by        exposures per      authorization     a percentage of
                                                                                   location            event            [supcaret]         population
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pacific Harbor Seal.........................  VAFB..........................                366              1,384              1,384                4.4
                                              Pt. Conception................                516
                                              San Miguel Island.............                310
                                              Santa Rosa Island.............                192
                                              Santa Cruz Island.............                  0
California Sea Lion.........................  VAFB..........................                416              4,561             54,732               18.4
                                              Pt. Conception................                N/A
                                              San Miguel Island.............              2,134
                                              Santa Rosa Island.............              1,200
                                              Santa Cruz Island.............                811
Northern Elephant Seal......................  VAFB..........................                190                227              2,724                1.5
                                              Pt. Conception................                 11
                                              San Miguel Island *...........                 18
                                              Santa Rosa Island *...........                  8
                                              Santa Cruz Island.............                  0
Steller Sea Lion............................  VAFB..........................                 16                 20                240                0.3
                                              Pt. Conception................                N/A
                                              San Miguel Island.............                  4
                                              Santa Rosa Island.............                N/A
                                              Santa Cruz Island.............                N/A
Northern Fur Seal...........................  VAFB..........................                N/A                250              3,000               21.4
                                              Pt. Conception................                N/A
                                              San Miguel Island *...........                250
                                              Santa Rosa Island.............                N/A
                                              Santa Cruz Island.............                N/A
Guadalupe Fur Seal..........................  VAFB..........................                N/A                  1                 12                0.1
                                              Pt. Conception................                N/A
                                              San Miguel Island *...........                  1
                                              Santa Rosa Island.............                N/A
                                              Santa Cruz Island.............                N/A
--------------------------------------------------------------------------------------------------------------------------------------------------------
[supcaret] Based on twelve boost-back and landing events.
* Number shown reflects five percent of total number of predicted potential exposures, i.e., five percent of animals exposed to sonic booms above 1.0
  psf at these locations are assumed to experience Level B harassment.


[[Page 49348]]

    Take estimates are believed to be conservative based on the 
assumption that all twelve Falcon 9 First Stage recovery actions would 
result in landings at SLC-4W, with no landings occurring at the 
contingency barge landing location. However, some or all actual landing 
events may ultimately occur at the contingency landing location or 
within the Iridium Landing Area; as described above, landings at the 
contingency landing location or within the Iridium Landing Area would 
be expected to result in no takes of marine mammals. However, the 
number of landings at each location is not known in advance, therefore 
we assume all landings would occur at SLC-4W. In addition, as described 
above, it is conservatively assumed that 100 percent of all any species 
of pinnipeds hauled out on the mainland (VAFB and Point Conception) and 
100 percent of harbor seals, California sea lions and Steller sea lions 
hauled out at the NCI would be harassed (Level B harassment only) by a 
Falcon 9 boost-back and landing events at SLC-4W that result in a psf 
of <1.0. However, it is possible that less than this percentage of 
hauled out pinnipeds will be behaviorally harassed by a Falcon 9 boost-
back and landing at SLC-4W. While there may be some limited behavioral 
harassment of pinnipeds that occurs at psf levels <1.0, we account for 
that in the overall conservativeness of the total take number, as 
described above.
    Given the many uncertainties in predicting the quantity and types 
of impacts of sound on marine mammals, it is common practice to 
estimate how many animals are likely to be present within a particular 
distance of a given activity, or exposed to a particular level of 
sound. In practice, depending on the amount of information available to 
characterize daily and seasonal movement and distribution of affected 
marine mammals, it can be difficult to distinguish between the number 
of individuals harassed and the instances of harassment and, when 
duration of the activity is considered, it can result in a take 
estimate that overestimates the number of individuals harassed. For 
instance, an individual animal may accrue a number of incidences of 
harassment over the duration of a project, as opposed to each incident 
of harassment accruing to a new individual. This is especially likely 
if individual animals display some degree of residency or site fidelity 
and the impetus to use the site is stronger than the deterrence 
presented by the harassing activity.
    Take estimates shown in Table 6 are considered reasonable estimates 
of the number of instances of marine mammal exposures to sound 
resulting in Level B harassment that are likely to occur as a result of 
the proposed activities, and not necessarily the number of individual 
animals exposed.

Proposed Mitigation

    In order to issue an IHA under Section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to such 
activity, and other means of effecting the least practicable impact on 
such species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of such species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting such 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable impact on species or stocks and their 
habitat, as well as subsistence uses where applicable, we carefully 
balance two primary factors: (1) The manner in which, and the degree to 
which, the successful implementation of the measure(s) is expected to 
reduce impacts to marine mammals, marine mammal species or stocks, and 
their habitat--which considers the nature of the potential adverse 
impact being mitigated (likelihood, scope, range), as well as the 
likelihood that the measure will be effective if implemented; and the 
likelihood of effective implementation, and; (2) the practicability of 
the measures for applicant implementation, which may consider such 
things as cost, impact on operations, and, in the case of a military 
readiness activity, personnel safety, practicality of implementation, 
and impact on the effectiveness of the military readiness activity.
    Any mitigation measure(s) prescribed by NMFS should be able to 
accomplish, have a reasonable likelihood of accomplishing (based on 
current science), or contribute to the accomplishment of one or more of 
the general goals listed below:
    1. Avoidance or minimization of injury or death of marine mammals 
wherever possible (goals 2, 3, and 4 may contribute to this goal).
    2. A reduction in the numbers of marine mammals (total number or 
number at biologically important time or location) exposed to 
activities expected to result in the take of marine mammals (this goal 
may contribute to 1, above, or to reducing harassment takes only).
    3. A reduction in the number of times (total number or number at 
biologically important time or location) individuals would be exposed 
to activities expected to result in the take of marine mammals (this 
goal may contribute to 1, above, or to reducing harassment takes only).
    4. A reduction in the intensity of exposures (either total number 
or number at biologically important time or location) to activities 
expected to result in the take of marine mammals (this goal may 
contribute to 1, above, or to reducing the severity of harassment takes 
only).
    5. Avoidance or minimization of adverse effects to marine mammal 
habitat, paying special attention to the food base, activities that 
block or limit passage to or from biologically important areas, 
permanent destruction of habitat, or temporary destruction/disturbance 
of habitat during a biologically important time.
    6. For monitoring directly related to mitigation--an increase in 
the probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation.

Mitigation for Marine Mammals and Their Habitat

    SpaceX's IHA application contains descriptions of the mitigation 
measures proposed to be implemented during the specified activities in 
order to effect the least practicable adverse impact on the affected 
marine mammal species and stocks and their habitats.
    It should be noted that it would not be feasible to stop or divert 
an inbound Falcon 9 First Stage booster. Once the boost-back and 
landing sequence is underway, there would be no way for SpaceX to 
change the trajectory of the Falcon 9 First Stage to avoid potential 
impacts to marine mammals. The proposed mitigation measures include the 
following:

     Unless constrained by other factors including human 
safety or national security concerns, launches would be scheduled to 
avoid boost-backs and landings during the harbor seal pupping season 
of March through June, when practicable.

    Based on our evaluation of SpaceX's proposed mitigation measures, 
NMFS has preliminarily determined that the proposed mitigation measures 
provide the means effecting the least practicable

[[Page 49349]]

impact on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance.

Proposed Monitoring and Reporting

    In order to issue an IHA for an activity, Section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth, requirements pertaining to 
the monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
proposed action area. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density).
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas).
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors.
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks.
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat).
     Mitigation and monitoring effectiveness.

Proposed Monitoring

    SpaceX submitted a monitoring plan as part of their IHA 
application. SpaceX's proposed marine mammal monitoring plan was 
created with input from NMFS and was based on similar plans that have 
been successfully implemented by other action proponents under previous 
authorizations for similar projects, specifically the USAF's monitoring 
of rocket launches from VAFB. The plan may be modified or supplemented 
based on comments or new information received from the public during 
the public comment period.

Marine Mammal Monitoring

    SpaceX would determine a monitoring location for each boost-back 
and landing activity, taking into consideration predictions of the 
areas likely to receive the greatest sonic boom intensity as well as 
current haulout locations and the distribution of pinniped species and 
their behavior. The selection of the monitoring location would also be 
based on what species (if any) have pups at haulouts and which of those 
species would be expected to be the most reactive to sonic booms. 
SpaceX prioritizes the selection of rookery locations if they are 
expected to be impacted by a sonic boom and prioritizes the most 
reactive species if there are multiple species that are expected to be 
hauled out in the modeled sonic boom impact area. For instance, if 
harbor seals were pupping, SpaceX would tend to select a harbor seal 
rookery for monitoring because they tend to be the most reactive 
species to sonic booms. There is also thought given to the geography 
and wind exposure of the specific beaches that are predicted to be 
impacted, to avoid inadvertently selecting a portion of a beach that 
tends to be abandoned by pinnipeds every afternoon as a result high 
winds. As VAFB is an active military base, the selection of appropriate 
monitoring locations must also take into account security restrictions 
and human safety as unexploded ordnance is present in some areas.
    Marine mammal monitoring protocols would vary based on modeled 
sonic boom intensity, the location and the season. As described above, 
sonic boom modeling would be performed prior to all boost-back and 
landing activities. Although the same rockets would be used, other 
parameters specific to each launch would be incorporated into each 
model. These include direction and trajectory, weight, length, engine 
thrust, engine plume drag, position versus time from initiating boost-
back to additional engine burns, among other aspects. Various weather 
scenarios would be analyzed from NOAA weather records for the region, 
then run through the model. Among other factors, these would include 
the presence or absence of the jet stream, and if present, its 
direction, altitude and velocity. The type, altitude, and density of 
clouds would also be considered. From these data, the models would 
predict peak amplitudes and impact locations. As described above, 
impacts to pinnipeds on the NCI, including pups, have been shown 
through more than two decades of monitoring reports to be minimal and 
temporary (MMCG and SAIC 2012a). Therefore monitoring requirements at 
the NCI would be dependent on modeled sonic boom intensity and would be 
based on the harbor seal pupping season, such that monitoring 
requirements would be greater when pups would be expected to be 
present. At the height of the pupping season (between March 1 and June 
30) monitoring is required if sonic boom model results indicate a peak 
overpressure of 1.0 psf or greater is likely to impact one of the NCI. 
Between July 1 and September 30 monitoring is required if sonic boom 
model results indicate a peak overpressure of 1.5 psf or greater is 
likely to impact one of the NCI. Between October 1 and February 28, 
monitoring is required if sonic boom model results indicate a peak 
overpressure of 2.0 psf or greater is likely to impact one of the NCI.
    Marine mammal monitoring procedures would consist of the following:
     To conduct monitoring of Falcon 9 First Stage boost-back 
and landing activities, SpaceX would designate qualified, on-site 
observers that would be approved in advance by NMFS;
     If sonic boom model results indicate a peak overpressure 
of 1.0 psf or greater is likely to impact VAFB, then acoustic and 
biological monitoring at VAFB would be implemented;
     If sonic boom model results indicate a peak overpressure 
of 1.0 psf or greater is likely to impact one of the NCI between March 
1 and June 30; a peak overpressure of greater than 1.5 psf is likely to 
impact one of the NCI between July 1 and September 30, or a peak 
overpressure of greater than 2.0 psf is likely to impact one of the NCI 
between October 1 and February 28, then monitoring of haulout sites on 
the NCI would be implemented.
     Monitoring would be conducted at the haulout site closest 
to the predicted sonic boom impact area;
     Monitoring would commence at least 72 hours prior to the 
boost-back and continue until at least 48 hours after the event;

[[Page 49350]]

     Monitoring would include multiple surveys each day that 
record the species; number of animals; general behavior; presence of 
pups; age class; gender; and reaction to noise associated with Falcon 9 
First Stage recovery activities, sonic booms or other natural or human 
caused disturbances, in addition to recording environmental conditions 
such as tide, wind speed, air temperature, and swell;
     If the boost-back and landing is scheduled during 
daylight, time lapse photography or video recording would be used to 
document the behavior of marine mammals during Falcon 9 First Stage 
recovery activities;
     For Falcon 9 First Stage recovery activities scheduled 
during harbor seal pupping season (March through June), follow-up 
surveys would be conducted within two weeks of the boost-back and 
landing;
     New northern elephant seal pupping location(s) at VAFB 
would be prioritized for monitoring when landings occur at SLC-4W 
during northern elephant seal pupping season (January through February) 
when practicable.

Acoustic Monitoring

    Acoustic measurements of the sonic boom created during boost-back 
at the monitoring location would be recorded to determine the 
overpressure level. Typically this would entail use of a digital audio 
tape (DAT) recorder and a high quality microphone to monitor the sound 
environment and measure the sonic boom. This system would be specially 
tailored for recording the low frequency sound associated with rocket 
launches and sonic booms. The DAT system would record the launch noise 
and sonic boom digitally to tape, which would allow for detailed 
post[hyphen]analysis of the frequency content, and the calculation of 
other acoustic metrics, and would record the ambient noise and sonic 
boom. The DAT recorder would be placed near the marine mammal 
monitoring site when practicable.

Proposed Reporting

    SpaceX would report data collected during marine mammal monitoring 
and acoustic monitoring as described above. The monitoring report would 
include a description of project related activities, counts of marine 
mammals by species, sex and age class, a summary of marine mammal 
species/count data, and a summary of observed marine mammal responses 
to project-related activities.
    A launch monitoring report would be submitted by SpaceX to the NMFS 
Office of Protected Resources and the NMFS West Coast Region within 60 
days after each Falcon 9 First Stage recovery action. This report would 
contain information on the date(s) and time(s) of the Falcon 9 First 
Stage recovery action, the design of the monitoring program; and 
results of the monitoring program, including, but not necessarily 
limited to the following:
     Numbers of pinnipeds present on the monitored haulout 
prior to the Falcon 9 First Stage recovery;
     Numbers of pinnipeds that may have been harassed (based on 
observations of pinniped responses and the pinniped disturbance scale 
as shown in Table 4);
     The length of time pinnipeds remained off the haulout or 
rookery for pinnipeds estimated to have entered the water as a result 
of Falcon 9 First Stage recovery noise;
     Any other observed behavioral modifications by pinnipeds 
that were likely the result of Falcon 9 First Stage recovery 
activities, including sonic boom; and
     Results of acoustic monitoring including comparisons of 
modeled sonic booms with actual acoustic recordings of sonic booms.
    In addition, a final monitoring report would be submitted by SpaceX 
to the NMFS Office of Protected Resources. A draft of the report would 
be submitted within 90 days of the expiration of the IHA, or, within 45 
days of the requested renewal of the IHA (if applicable). A final 
version of the report would be submitted within 30 days following 
resolution of comments on the draft report from NMFS. The report would 
summarize the information from the 60-day post-activity reports (as 
described above), including but not necessarily limited to the 
following:
     Date(s) and time(s) of the Falcon 9 First Stage recovery 
actions;
     Design of the monitoring program; and
     Results of the monitoring program, including the 
information components contained in the 60-day launch reports, as well 
as any documented cumulative impacts on marine mammals as a result of 
the activities, such as long term reductions in the number of pinnipeds 
at haulouts as a result of the activities.
    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner not authorized by the 
proposed IHA (if issued), such as a Level A harassment, or a take of a 
marine mammal species other than those proposed for authorization, 
SpaceX would immediately cease the specified activities and immediately 
report the incident to the NMFS Office of Protected Resources. The 
report would include the following information:
     Time, date, and location (latitude/longitude) of the 
incident;
     Description of the incident;
     Status of all Falcon 9 First Stage recovery activities in 
the 48 hours preceding the incident;
     Description of all marine mammal observations in the 48 
hours preceding the incident;
     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities would not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS would work with SpaceX to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. SpaceX would not be able to 
resume their activities until notified by NMFS via letter, email, or 
telephone.
    In the event that SpaceX discovers an injured or dead marine 
mammal, and the lead observer determines the cause of the injury or 
death is unknown and the death is relatively recent (i.e., in less than 
a moderate state of decomposition), SpaceX would immediately report the 
incident to the NMFS Office of Protected Resources and the NMFS West 
Coast Region Stranding Coordinator. The report would include the same 
information identified in the paragraph above. Authorized activities 
would be able to continue while NMFS reviews the circumstances of the 
incident. NMFS would work with SpaceX to determine whether 
modifications in the activities are appropriate.
    In the event that SpaceX discovers an injured or dead marine 
mammal, and the lead MMO determines the injury or death is not 
associated with or related to the activities authorized in the IHA 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), SpaceX would report the incident 
to the NMFS Office of Protected Resources and NMFS West Coast Region 
Stranding Coordinator, within 24 hours of the discovery. SpaceX would 
provide photographs or video footage (if available) or other 
documentation of the stranded animal sighting to NMFS and the Marine 
Mammal Stranding Network.
    If issued, this would be the second IHA issued to SpaceX for the 
proposed activity. SpaceX did not perform any Falcon 9 boost-back and 
landing activities that resulted in return flights to VAFB nor that 
generated sonic booms that impacted the NCI. SpaceX did

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perform boost-back and landing activities at a contingency landing 
location located offshore during the period of validity for the prior 
IHA, however the contingency landing location was located so far 
offshore that there were no impacts predicted to marine mammals by 
sonic boom modeling, thus marine mammal monitoring was not required.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS's implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    To avoid repetition, the discussion of our analyses applies to all 
the species listed in Table 2, given that the anticipated effects of 
this activity on these different marine mammal species are expected to 
be similar. Activities associated with the proposed Falcon 9 First 
Stage recovery project, as outlined previously, have the potential to 
disturb or displace marine mammals. Specifically, the specified 
activities may result in take, in the form of Level B harassment 
(behavioral disturbance) only, from airborne sounds of sonic booms. 
Potential takes could occur if marine mammals are hauled out in areas 
where a sonic boom above 1.0 psf occurs, which is considered likely 
given the modeled sonic booms of the proposed activities and the 
occurrence of pinnipeds in the project area. Based on the best 
available information, including monitoring reports from similar 
activities that have been authorized by NMFS, behavioral responses will 
likely be limited to reactions such as alerting to the noise, with some 
animals possibly moving toward or entering the water, depending on the 
species and the intensity of the sonic boom. Repeated exposures of 
individuals to levels of sound that may cause Level B harassment are 
unlikely to result in hearing impairment or to significantly disrupt 
foraging behavior. Thus, even repeated Level B harassment of some small 
subset of an overall stock is unlikely to result in any significant 
realized decrease in fitness to those individuals, and thus would not 
result in any adverse impact to the stock as a whole. Level B 
harassment would be reduced to the level of least practicable impact 
through use of mitigation measures described above.
    If a marine mammal responds to a stimulus by changing its behavior 
(e.g., through relatively minor changes in locomotion direction/speed), 
the response may or may not constitute taking at the individual level, 
and is unlikely to affect the stock or the species as a whole. However, 
if a sound source displaces marine mammals from an important feeding or 
breeding area for a prolonged period, impacts on animals or on the 
stock or species could potentially be significant (e.g., Lusseau and 
Bejder, 2007; Weilgart, 2007). Flushing of pinnipeds into the water has 
the potential to result in mother-pup separation, or could result in a 
stampede, either of which could potentially result in serious injury or 
mortality and thereby could potentially impact the stock or species. 
However, based on the best available information, including reports 
from over 20 years of launch monitoring at VAFB and the NCI, no serious 
injury or mortality of marine mammals is anticipated as a result of the 
proposed activities.
    Even in the instances of pinnipeds being behaviorally disturbed by 
sonic booms from rocket launches at VAFB, no evidence has been 
presented of abnormal behavior, injuries or mortalities, or pup 
abandonment as a result of sonic booms (SAIC 2013). These findings came 
as a result of more than two decades of surveys at VAFB and the NCI 
(MMCG and SAIC, 2012). Post-launch monitoring generally reveals a 
return to normal behavioral patterns within minutes up to an hour or 
two of each launch, regardless of species. For instance, a total of 
eight Delta II and Taurus space vehicle launches occurred from north 
VAFB, near the Spur Road and Purisima Point haulout sites, from 
February, 2009 through February, 2014. Of these eight launches, three 
occurred during the harbor seal pupping season. The continued use by 
harbor seals of the Spur Road and Purisima Point haulout sites 
indicates that it is unlikely that these rocket launches (and 
associated sonic booms) resulted in long-term disturbances of pinnipeds 
using the haulout sites. San Miguel Island represents the most 
important pinniped rookery in the lower 48 states, and as such 
extensive research has been conducted there for decades. From this 
research, as well as stock assessment reports, it is clear that VAFB 
operations (including associated sonic booms) have not had any 
significant impacts on San Miguel Island rookeries and haulouts (SAIC 
2012).
    In summary, this negligible impact analysis is founded on the 
following factors:
     No injury, serious injury, or mortality are anticipated or 
authorized;
     The anticipated incidences of Level B harassment are 
expected to consist of, at worst, temporary modifications in behavior 
(i.e., short distance movements and occasional flushing into the water 
with return to haulouts within at most two days), which are not 
expected to adversely affect the fitness of any individuals;
     The proposed activities are expected to result in no long-
term changes in the use by pinnipeds of rookeries and haulouts in the 
project area, based on over 20 years of monitoring data; and
     The presumed efficacy of planned mitigation measures in 
reducing the effects of the specified activity to the level of least 
practicable impact.
    In combination, we believe that these factors, as well as the 
available body of evidence from other similar activities, demonstrate 
that the potential effects of the specified activity will be short-term 
on individual animals. The specified activity is not expected to impact 
rates of recruitment or survival and will therefore not result in 
population-level impacts. Based on the analysis contained herein of the 
likely effects of the specified activity on marine mammals and their 
habitat, and taking into consideration the implementation of the 
proposed monitoring and mitigation measures, NMFS preliminarily finds 
that the total marine mammal take from the proposed activity will have 
a negligible impact on the

[[Page 49352]]

affected marine mammal species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under Section 101(a)(5)(D) of the MMPA for specified 
activities other than military readiness activities. The MMPA does not 
define small numbers and so, in practice, NMFS compares the number of 
individuals taken to the most appropriate estimation of abundance of 
the relevant species or stock in our determination of whether an 
authorization is limited to small numbers of marine mammals. 
Additionally, other qualitative factors may be considered in the 
analysis, such as the temporal or spatial scale of the activities.
    The numbers of proposed authorized takes would be considered small 
relative to the relevant stocks or populations (less than 22 percent 
for all species and stocks). It is important to note that the number of 
expected takes does not necessarily represent of the number of 
individual animals expected to be taken. Our small numbers analysis 
accounts for this fact. Multiple exposures to Level B harassment can 
accrue to the same individual animals over the course of an activity 
that occurs multiple times in the same area (such as SpaceX's proposed 
activity). This is especially likely in the case of species that have 
limited ranges and that have site fidelity to a location within the 
project area, as is the case with Pacific harbor seals.
    As described above, harbor seals are non-migratory, rarely 
traveling more than 50 km from their haul-out sites. Thus, while the 
estimated abundance of the California stock of Pacific harbor seals is 
30,968 (Carretta et al. 2017), a substantially smaller number of 
individual harbor seals is expected to occur within the project area. 
We expect that, because of harbor seals' documented site fidelity to 
haulout locations at VAFB and the NCI, and because of their limited 
ranges, the same individuals are likely to be taken repeatedly over the 
course of the proposed activities (maximum of twelve Falcon 9 First 
Stage recovery actions). Therefore, the proposed number of instances of 
Level B harassment among harbor seals over the course of the proposed 
authorization (i.e., the total number of takes shown in Table 6) is 
expected to accrue to a much smaller number of individuals encompassing 
a small portion of the overall regional stock. Thus while we propose to 
authorize the instances of incidental take of harbor seals shown in 
Table 6, we believe that the number of individual harbor seals that 
would be incidentally taken by the proposed activities would, in fact, 
be substantially lower than this numbers. The maximum number of harbor 
seals expected to be taken by Level B harassment, per Falcon 9 First 
Stage recovery action, is 1,384. As we believe the same individuals are 
likely to be taken repeatedly over the duration of the proposed 
activities, we use the estimate of 1,165 individual animals taken per 
Falcon 9 First Stage recovery activity for the purposes of estimating 
the percentage of the stock abundance likely to be taken.
    Based on the analysis contained herein of the proposed activity 
(including the proposed mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS preliminarily finds that small 
numbers of marine mammals will be taken relative to the population size 
of the affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    There are no relevant subsistence uses of the affected marine 
mammal stocks or species implicated by this action. Therefore, NMFS has 
determined that the total taking of affected species or stocks would 
not have an unmitigable adverse impact on the availability of such 
species or stocks for taking for subsistence purposes.

Endangered Species Act (ESA)

    There is one marine mammal species (Guadalupe fur seal) listed 
under the ESA with confirmed occurrence in the area expected to be 
impacted by the proposed activities. The NMFS West Coast Region has 
determined that the NMFS OPR's proposed authorization of SpaceX's 
Falcon 9 First Stage recovery activities is not likely to adversely 
affect the Guadalupe fur seal. Therefore, formal ESA section 7 
consultation on this proposed authorization is not required.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to SpaceX, to conduct Falcon 9 First Stage recovery 
activities at Vandenberg Air Force Base, in the Pacific Ocean offshore 
Vandenberg Air Force Base, and at the Northern Channel Islands, 
California, from December 1, 2017 through November 30, 2018, provided 
the previously mentioned mitigation, monitoring, and reporting 
requirements are incorporated. The proposed IHA language is provided 
next.
    This section contains a draft of the IHA itself. The wording 
contained in this section is proposed for inclusion in the IHA (if 
issued).
    1. This Incidental Harassment Authorization (IHA) is valid from 
December 1, 2017 through November 30, 2018.
    (a) This IHA is valid only for Falcon 9 First Stage recovery 
activities at Vandenberg Air Force Base, California, and at auxiliary 
landing sites offshore.
    2. General Conditions.
    (a) A copy of this IHA must be in the possession of SpaceX, its 
designees, and work crew personnel operating under the authority of 
this IHA.
    (b) The species authorized for taking are the Pacific harbor seal 
(Phoca vitulina richardii), California sea lion (Zalophus 
californianus), Steller sea lion (Eumetopias jubatus), northern 
elephant seal (Mirounga angustirostris), northern fur seal (Callorhinus 
ursinus), and Guadalupe fur seal (Arctocephalus philippii townsendi).
    (c) The taking, by Level B harassment only, is limited to the 
species listed in condition 2(b). See Table 6 for numbers of take 
authorized.
    (d) The taking by injury (Level A harassment), serious injury, or 
death of any of the species listed in condition 2(b) of the 
Authorization or any taking of any other species of marine mammal is 
prohibited and may result in the modification, suspension, or 
revocation of this IHA.
    3. Mitigation Measures.
    The holder of this Authorization must implement the following 
mitigation measure: Unless constrained by other factors including human 
safety or national security concerns, launches must be scheduled to 
avoid, whenever possible, boost-backs and landings during the harbor 
seal pupping season of March through June.
    4. Monitoring.
    The holder of this Authorization mustconduct marine mammal and 
acoustic monitoring as described below.
    (a) SpaceX must notify the Administrator, West Coast Region, NMFS, 
by letter or telephone, at least two weeks prior to activities possibly 
involving the taking of marine mammals;
    (b) To conduct monitoring of Falcon 9 First Stage recovery 
activities, SpaceX must designate qualified, on-site individuals 
approved in advance by NMFS;
    (c) If sonic boom model results indicate that a peak overpressure 
of 1.0 psf or greater is likely to impact VAFB, then acoustic and 
biological monitoring at VAFB must be implemented;

[[Page 49353]]

    (d) If sonic boom model results indicate a peak overpressure of 1.0 
psf or greater is likely to impact VAFB during January and February, 
then acoustic and biological monitoring must be implemented at northern 
elephant seal rookeries at VAFB, when practicable;
    (e) If sonic boom model results indicate that a peak overpressure 
of 1.0 psf or greater is predicted to impact the Channel Islands 
between March 1 and June 30, greater than 1.5 psf between July 1 and 
September 30, and greater than 2.0 psf between October 1 and February 
28, monitoring of haulout sites on the Channel Islands must be 
implemented. Monitoring will be conducted at the haulout site closest 
to the predicted sonic boom impact area;
    (f) Monitoring will be conducted for at least 72 hours prior to any 
planned Falcon 9 First Stage recovery and continue until at least 48 
hours after the event;
    (g) For Falcon 9 First Stage recovery activities that occur during 
March through June, follow-up surveys of harbor seal haulouts will be 
conducted within two weeks of the Falcon 9 First Stage recovery;
    (h) If Falcon 9 First Stage recovery activities are scheduled 
during daylight, time-lapse photography or video recording must be used 
to document the behavior of marine mammals during Falcon 9 First Stage 
recovery activities;
    (i) Monitoring will include multiple surveys each day that record 
the species, number of animals, general behavior, presence of pups, age 
class, gender and reaction to noise associated with Falcon 9 First 
Stage recovery, sonic booms or other natural or human caused 
disturbances, in addition to recording environmental conditions such as 
tide, wind speed, air temperature, and swell; and
    (j) Acoustic measurements of the sonic boom created during boost-
back at the monitoring location must be recorded to determine the 
overpressure level.
    5. Reporting.
    The holder of this Authorization is required to:
    (a) Submit a report to the Office of Protected Resources, NMFS, and 
the West Coast Regional Administrator, NMFS, within 60 days after each 
Falcon 9 First Stage recovery action. This report must contain the 
following information:
    (1) Date(s) and time(s) of the Falcon 9 First Stage recovery 
action;
    (2) Design of the monitoring program; and
    (3) Results of the monitoring program, including, but not 
necessarily limited to:
    (i) Numbers of pinnipeds present on the haulout prior to the Falcon 
9 First Stage recovery;
    (ii) Numbers of pinnipeds that may have been harassed as a result 
of Falcon 9 First Stage recovery activities;
    (iii) For pinnipeds estimated to have been harassed as a result of 
Falcon 9 First Stage recovery noise, the length of time pinnipeds 
remained off the haulout or rookery;
    (iv) Any other observed behavioral modifications by pinnipeds that 
were likely the result of Falcon 9 First Stage recovery activities, 
including sonic boom; and
    (v) Results of acoustic monitoring including comparisons of modeled 
sonic booms with actual acoustic recordings of sonic booms.
    (b) Submit an annual report on all monitoring conducted under the 
IHA. A draft of the annual report must be submitted within 90 calendar 
days of the expiration of this IHA, or, within 45 calendar days of the 
requested renewal of the IHA (if applicable). A final annual report 
must be prepared and submitted within 30 days following resolution of 
comments on the draft report from NMFS. The annual report will 
summarize the information from the 60-day post-activity reports, 
including but not necessarily limited to:
    (1) Date(s) and time(s) of the Falcon 9 First Stage recovery 
action;
    (2) Design of the monitoring program; and
    (3) Results of the monitoring program, including, but not 
necessarily limited to:
    (i) Numbers of pinnipeds present on the haulout prior to the Falcon 
9 First Stage recovery;
    (ii) Numbers of pinnipeds estimated to have been harassed as a 
result of Falcon 9 First Stage recovery activities at the monitoring 
location;
    (iii) For pinnipeds estimated to have been harassed as a result of 
Falcon 9 First Stage recovery noise, the length of time pinnipeds 
remained off the haulout or rookery;
    (iv) Any other observed behavioral modifications by pinnipeds that 
were likely the result of Falcon 9 First Stage recovery activities, 
including sonic boom;
    (v) Any cumulative impacts on marine mammals as a result of the 
activities, such as long term reductions in the number of pinnipeds at 
haulouts as a result of the activities; and
    (vi) Results of acoustic monitoring including comparisons of 
modeled sonic booms with actual acoustic recordings of sonic booms.
    (c) Reporting injured or dead marine mammals:
    (1) In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by this IHA 
(as determined by the lead marine mammal observer), such as an injury 
(Level A harassment), serious injury, or mortality, SpaceX will 
immediately cease the specified activities and report the incident to 
the NMFS Office of Protected Resources and the NMFS West Coast Region 
Stranding Coordinator. The report must include the following 
information:
    A. Time and date of the incident;
    B. Description of the incident;
    C. Status of all Falcon 9 First Stage recovery activities in the 48 
hours preceding the incident;
    D. Description of all marine mammal observations in the 48 hours 
preceding the incident;
    E. Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
    F. Species identification or description of the animal(s) involved;
    G. Fate of the animal(s); and
    H. Photographs or video footage of the animal(s).
    Activities will not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS will work with SpaceX to 
determine what measures are necessary to minimize the likelihood of 
further prohibited take and ensure MMPA compliance. SpaceX may not 
resume their activities until notified by NMFS via letter, email, or 
telephone.
    (2) In the event that SpaceX discovers an injured or dead marine 
mammal, and the lead observer determines that the cause of the injury 
or death is unknown and the death is relatively recent (e.g., in less 
than a moderate state of decomposition), SpaceX will immediately report 
the incident to the NMFS Office of Protected Resources and the NMFS 
West Coast Region Stranding Coordinator. The report must include the 
same information identified in 5(c)(1) of this IHA. Activities may 
continue while NMFS reviews the circumstances of the incident and makes 
a final determination on the cause of the reported injury or death. 
NMFS will work with SpaceX to determine whether additional mitigation 
measures or modifications to the activities are appropriate.
    (3) In the event that SpaceX discovers an injured or dead marine 
mammal, and the lead observer determines that the injury or death is 
not associated with or related to the activities authorized in the IHA 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, scavenger damage), SpaceX will report the incident to 
the NMFS Office of Protected Resources and

[[Page 49354]]

the NMFS West Coast Region Stranding Coordinator, within 24 hours of 
the discovery. SpaceX will provide photographs or video footage or 
other documentation of the stranded animal sighting to NMFS. The cause 
of injury or death may be subject to review and a final determination 
by NMFS.
    6. Modification and suspension.
    (a) This IHA may be modified, suspended or withdrawn if the holder 
fails to abide by the conditions prescribed herein, or if NMFS 
determines that the authorized taking is having more than a negligible 
impact on the species or stock of affected marine mammals.

Request for Public Comments

    We request comment on our analysis, the draft authorization, and 
any other aspect of this Notice of Proposed IHA for SpaceX Falcon 9 
First Stage recovery activities. Please include with your comments any 
supporting data or literature citations to help inform our final 
decision on SpaceX's request for an MMPA authorization.

    Dated: October 19, 2017.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2017-23134 Filed 10-24-17; 8:45 am]
 BILLING CODE 3510-22-P