Taking Marine Mammals Incidental to Specified Activities; Port Sutton Navigation Channel, Tampa Bay, FL, 48541-48545 [05-16392]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 70, Number 159 (Thursday, August 18, 2005)]
[Notices]
[Pages 48541-48545]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-16392]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 061405A]


Taking Marine Mammals Incidental to Specified Activities; Port 
Sutton Navigation Channel, Tampa Bay, FL

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

ACTION: Notice of receipt of application and proposed authorization for 
an incidental take authorization; request for comments.

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SUMMARY: NMFS has received a request from the U.S. Army Corps of 
Engineers-Jacksonville District (Corps) for authorizations to take 
marine mammals, by harassment, incidental to expanding and deepening 
the Port Sutton Navigation Channel in Tampa Harbor, FL (Port Sutton 
project). Under the Marine Mammal Protection Act (MMPA), NMFS is 
requesting comments on its proposal to issue a 1-year Incidental 
Harassment Authorization (IHA) to the Corps to incidentally take, by 
harassment, bottlenose dolphins (Tursiops truncatus) as a result of 
conducting this activity and the Corps' application for regulations.

DATES: Comments and information must be received no later than 
September 19, 2005.

ADDRESSES: Comments on the application should be addressed to Steve 
Leathery, Chief, Permits, Conservation and Education Division, Office 
of Protected Species, National Marine Fisheries Service, 1315 East-West 
Highway, Silver Spring, Md 20910. The mailbox address for providing e-
mail comments on this action is PR1.061405A@noaa.gov. Comments sent via 
email, including all attachments, must not exceed a 10-megabyte file 
size. A copy of the application containing a list of references used in 
this document may be obtained by writing to the address

[[Page 48542]]

provided or by telephoning the contact listed under the heading FOR 
FURTHER INFORMATION CONTACT. Publications referenced in this document 
are available for viewing, by appointment during regular business 
hours, at the address provided here during this comment period.

FOR FURTHER INFORMATION CONTACT: Layne Bolen, NMFS, (301) 713-2289, ext 
117.

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 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 may 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, and provided that the permissible 
methods of taking and requirements pertaining to the 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 the species or stock through effects on 
annual rates of recruitment or survival.''
    Subsection 101(a)(5)(D) of the MMPA established an expedited 
process by which citizens of the United States can apply for an 
authorization to incidentally take small numbers of marine mammals by 
harassment. Except with respect to certain activities not pertinent 
here, the MMPA now 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].
    Subsection 101(a)(5)(D) establishes a 45-day time limit for NMFS 
review of an application followed by a 30-day public notice and comment 
period on any proposed authorizations for the incidental harassment of 
small numbers of marine mammals.

Summary of Request

    On February 26, 2004, NMFS received a request from the Corps for an 
authorization to take bottlenose dolphins incidental to using blasting 
during enlargement of the Port Sutton Navigation Channel, a part of the 
Tampa Harbor Federal Navigation Project, in the northern portion of 
Tampa Bay, Hillsborough County, Florida. The purpose of the project is 
to enlarge the navigation channel to accommodate larger vessels and 
incorporate an additional channel segment into the Federal channel. 
Completion of the dredging project may employ blasting and/or a 
clamshell or cutterhead dredge. The dredging will remove approximately 
900,000 cubic yards of material from the existing navigation channel 
and extension. The Corps proposes to widen the 3,930-ft (1,198-m) long 
navigation channel to 290 feet (88 m) bottom-width, deepen to 42 feet 
(13 m) at mean low-low water (mllw), and lengthen the channel to 6,195 
ft (1,888 m) in length with the previously discussed dimensions. 
Material removed from the dredging will be placed in the existing 
upland dredged material management area CMDA-2D. The project is 
proposed to start in March, 2006 and last approximately 18 months.
    The Corps expects the contractor to employ underwater confined 
blasting and dredging to construct the project. Blasting may have 
adverse impacts on bottlenose dolphins and manatees (Trichechus manatus 
latirostris) inhabiting the area near or utilizing the northern portion 
of Tampa Bay. Dolphins and other marine mammals have not been 
documented to be directly affected by dredging activities other than 
blasting.
    While the Corps does not presently have a blasting plan from the 
contractor, which will specifically identify the number of holes that 
will be drilled, the amount of explosives that will be used for each 
hole, the number of blasts per day (usually no more than 3/day), or the 
number of days the construction is anticipated to take to complete, the 
Corps submitted a description of a completed project in San Juan 
Harbor, Puerto Rico as an example. For that project, the maximum weight 
of the explosives used for each event was 375 lbs (170 kg) and the 
contractors detonated explosives once or twice daily from July 16 to 
September 9, for a total of 38 individual detonations. Normal practice 
is for each charge to be placed approximately 5 - 10 ft (1.5 - 3 m) 
deep within the rock substrate, depending on how much rock needs to be 
broken and how deep a channel depth is authorized. The charges are 
placed in the holes and tamped with rock. Therefore, if the total 
explosive weight needed is 375 lbs (170 kg) and they have 10 holes, 
they would average 37.5 lbs (17.0 kgs)/hole. However, a more likely 
weight for this project may be only 90 lbs (41 kgs) total and, 
therefore, 9 lbs (4.1 kg)/hole. Charge weight and other determinations 
are expected to be made by the Corps and the contractor approximately 
30-60 days prior to commencement of the construction project. Because 
the charge weight and other information is not presently available, 
NMFS will require the Corps to provide this information to NMFS, 
including calculations for impact/mitigation zones to protect marine 
mammals from injury, prior to commencing work. However, as described 
later in this document, mitigation measures will require the Corps to 
limit detonations to the minimum level necessary to accomplish the task 
and the larger the charge weight, the greater the safety zone that will 
be required to protect marine mammals.

Summary of Request for Regulations

    While the Corps was coordinating with NMFS on the application and 
issuance of an IHA for the Miami Turning Basin in early 2003 (see 68 FR 
32016, May 29, 2003), the Corps identified several additional Federal 
navigation projects that might need similar MMPA authorizations within 
the next few years, if confined blasting is used as a construction 
technique. To ensure consistency across MMPA authorizations for these 
dredging projects, and efficiency for both agencies, NMFS recommended 
that the Corps apply for these authorizations under section 
101(a)(5)(A) of the MMPA, instead of individually under section 
101(a)(5)(D) of the MMPA. This request was received on December 1, 
2003. At this time the Miami Turning Basin project, the Alafia River 
project (see 69 FR 29693, May 25, 2004) and this project are proposed 
to be covered by the section 101(a)(5)(A) rulemaking. This rule, if 
implemented, and Letters of Authorization (LOA) issued under that rule, 
would replace the IHA process for these activities in the Jacksonville 
District. Each application for an LOA for additional projects within 
the Jacksonville District for confined blasting within the District 
would require separate public review and comment, prior to issuance of 
an LOA.

[[Page 48543]]

NMFS expects to start this rulemaking shortly.

Description of the Marine Mammals Affected by the Activity

    General information on marine mammal species found off the east 
coast of the United States can be found in Waring et al. (2001, 2002). 
These reports are available on the Internet at the following location: 
https://www.nmfs.noaa.gov/prot_res/PR2/Stock_Assessment_Program/
sars.html
    Bottlenose dolphins and West Indian manatees are the only marine 
mammal species expected in the activity area. However, take 
authorizations for manatees are issued by the U.S. Fish and Wildlife 
Service (USFWS) and are not covered by this proposed IHA or any future 
rulemaking for LOAs issued by NMFS. Wang et al. (2002) provides the 
following minimum population estimates for the Gulf of Mexico 
bottlenose dolphin stocks: outer shelf, 43,233; shelf and slope, 4,530; 
western Gulf, 2,938; northern Gulf, 3,518; eastern Gulf, 8,953; and 
Bay, Sound & Estuarine waters, 3,933.
    The best estimate is that the Tampa Bay bottlenose dolphin 
population (which includes any dolphins within the Port Sutton project 
area) consists of 559 individuals (Wang et al., 2002). Previous 
population estimates for Tampa Bay include Wells et al. (1996), Weigle 
(1990), Scott et al. (1989) Wells (1986), Thompson (1981), and O'Dell 
and Reynolds (1980). A monitoring study of bottlenose dolphins in Tampa 
Bay was conducted from 1988-1993. The results of that study were 
published in Wells et al. (1996). It is the most recent study of those 
animals currently available (R. Wells, pers. comm. to T. Jordan, Corps, 
2004). The study identified a population size ranging between 437 and 
728 individuals utilizing three different survey and population 
estimation techniques. Some of these animals have been shown to be in 
the vicinity of the Port Sutton channel. In a subsequent examination of 
the data, Urian (2002) identified five populations of bottlenose 
dolphins in Tampa Bay. Neither the Corps nor NMFS has determined if 
bottlenose dolphins in the Tampa Bay area utilize the Port Sutton 
channel directly. Wells et al. (1996), shows animals in the vicinity of 
the project area, but no detailed information is provided regarding 
area usage. The bottom of the basin is rock and sand, and the walls of 
the turning basin are vertical rock. The Corps recognizes that while 
the Port Sutton area may not be suitable habitat for dolphins in Tampa 
Bay, based on Urian's (2002) findings it is likely that animals may 
enter the vicinity of the channel.

Potential Effects on Marine Mammals

    According to the Corps, bottlenose dolphins and other marine 
mammals have not been documented to be directly affected by dredging 
activities and therefore the Corps does not anticipate any incidental 
harassment of bottlenose dolphins by dredging. However, potential 
impacts to marine mammals from explosive detonations include both 
lethal and non-lethal injury, as well as Level B harassment. Marine 
mammals may be killed or injured as a result of an explosive detonation 
due to the response of air cavities in the body, such as the lungs and 
bubbles in the intestines. Effects are likely to be most severe in 
near-surface waters where the reflected shock wave creates a region of 
negative pressure called ``cavitation.'' This is a region of near total 
physical trauma within which no animals would be expected to survive. A 
second possible cause of mortality or lethal injury is the onset of 
extensive lung hemorrhage. Extensive lung hemorrhage is considered 
debilitating and potentially fatal. Suffocation caused by lung 
hemorrhage is likely to be the major cause of marine mammal death from 
underwater shock waves. The onset of extensive lung hemorrhage for 
marine mammals will vary depending upon the animal's weight, with the 
smallest mammals having the greatest potential hazard range.
    NMFS has also established criteria for determining non-lethal 
injury (Level A harassment)and non-injurious harassment (Level B 
harassment) from underwater explosions (see 66 FR 22450, May 4, 2001). 
For non-lethal injury from explosives the criteria are established as 
the peak pressure that will result in: (1) the onset of slight lung 
hemorrhage, or (2) a 50-percent probability level for a rupture of the 
tympanic membrane. These are injuries from which animals would be 
expected to recover on their own.
    Although each of the tamped charges are fairly small (probably less 
than the 37 lbs (16.8 kg) per drilled hole used in Puerto Rico) and 
detonation staggered to reduce total pressure, the maximum horizontal 
extent for mortality/lethal injury and non-lethal injury (Level A 
harassment), estimated based on the total charge weight (375 lbs in the 
case of Puerto Rico) would be less than 1875 ft (571 m) and 3750 ft 
(1143 m) respectively. As these distances are based on an open-water 
charge calculation, and as stemmed/confined blasts result in a 
significant decrease in the strength of the pressure wave released as 
compared to an open water blast, the zones for mortality and non-
serious injury would be significantly less than these distances. As a 
result of these small impact zones, the relatively shallow waters for 
blasting, and the nature of bottlenose dolphins to remain in surface 
waters, the biological monitoring (aerial- and vessel-based) is 
expected to be effective in locating all marine mammals prior to them 
entering an area where injury or mortality might result and thereby 
preventing any takes by injury or mortality.
    NMFS has also established dual criteria for what constitutes Level 
B acoustic harassment for all marine mammals by large scale 
detonations: (1) an energy-based temporary threshold shift (TTS) from 
received sound levels of 182 dB re 1 microPa\2\-sec cumulative energy 
flux in any 1/3 octave band above 100 Hz for odontocetes (derived from 
experiments with bottlenose dolphins (Ridgway et al., 1997; Schlundt et 
al., 2000); and (2) 12 psi peak pressure (cited by Ketten (1995) as 
associated with a safe outer limit for minimal, recoverable auditory 
trauma (i.e., TTS)). Recently, Finneran et al. (2002) found that TTS 
can be induced from single impulses at a peak pressure level of 160 kPa 
(23 psi), pk-pk pressures of 226 dB re 1 microPa, and total energy flux 
density of 186 dB re 1 mPa\2\-s (as tested in belugas). Thresholds 
returned to within 2 dB of the pre-exposure value approximately 4 
minutes post exposure. However, no masked TTS was observed in the 
single bottlenose dolphin tested at the highest exposure conditions: 
peak pressure of 207 kPa (30 psi), 228 dB re 1 microPa pk-pk pressure, 
and 188 dB re 1 mPa\2\-s total energy flux. NMFS considers this 
conservative since a 23-psi pressure level was below the level that 
induced TTS in bottlenose dolphins. The Level B harassment zone, 
therefore, is the distance from the mortality/serious injury zone to 
the radius where neither of these criteria is exceeded.

Mitigation

    The Corps proposes to establish and monitor caution- and safety-
zone radii to ensure that bottlenose dolphins will not be injured or 
killed during blasting and that impacts will be at the lowest level 
practicable. In the absence of acoustic measurements of the shock and 
pressure waves emanating from the detonations (due to the high cost and 
complex instrumentation needed), the following equations have been 
proposed by the Corps for blasting projects to determine zones for 
injury or mortality from an open water explosion and to

[[Page 48544]]

assist the Corps in establishing mitigation to reduce impacts to the 
lowest level practicable. The equations, based on Young (1991), are:
Caution Zone Radius (R) = 260 (W)\1/3\
Safety Zone Radius (R) = 520 (W)\1/3\
    with radius (R) = 260 times or 520 times the cube root of the 
weight (W) of the explosive charge where R = radius of the zone in feet 
and W = weight of the explosive charge in lbs/delay. The Caution Zone 
represents the radius in feet from the detonation beyond which 
mortality would not be expected from an open-water blast. The Safety 
Zone is the approximate distance in feet beyond which injury (Level A 
harassment) is unlikely from an open-water explosion. These zones will 
be used for implementing mitigation measures to protect both marine 
mammals and sea turtles, although this activity area apparently does 
not include known sea turtle habitat.
    These equations are believed to be conservative because they are 
based on (1) humans, who are more sensitive to the effects from the 
pressure wave of the detonation than are dolphins, and (2) unconfined 
charges while the proposed blasts in the Port Sutton channel will be 
confined (stemmed) charges (i.e., placed in a hole drilled in rock and 
tamped with rock). Studies (e.g., Nedwell and Thandavamoorthy, 1992) 
have shown that stemmed/confined blasts have a greater than 90 percent 
decrease in the strength of the pressure wave released as compared to 
an open water blast.
    In the area where explosives are required to obtain channel design 
depth for each explosive charge, the Corps proposes that detonation 
will not occur if a marine mammal is sighted within the Safety Zone by 
a member of the marine mammal observer program.
    Although the Caution Zone is considered to be an area for potential 
mortality, the Corps and NMFS believe that because all explosive 
charges will be stemmed, the true areas for potential mortality and 
injury will be significantly smaller than this area and, therefore, for 
reasons mentioned previously, it is unlikely that even non-serious 
injury will occur. This is particularly true in this case, since 
bottlenose dolphins are commonly found on the surface of the water and 
implementation of a mitigation/ monitoring program is unlikely to miss 
bottlenose dolphins in such a small area.
    Additional mitigation measures that will significantly lower 
potential impacts to marine mammals (and sea turtles) include: (1) 
confining the explosives in a hole with drill patterns restricted to a 
minimum of 8 ft (2.44 m) separation from any other loaded hole; (2) 
restricting the hours of detonation from 2 hours after sunrise to 1 
hour before sunset to ensure adequate observation of marine mammals in 
the safety zone; (3) staggering the detonation for each explosive hole 
in order to spread the explosive's total overpressure over time, which 
in turn will reduce the radius of the caution zone; (4) capping the 
hole containing explosives with rock in order to reduce the outward 
potential of the blast, thereby reducing the chance of injuring a 
dolphin or manatee; (5) matching, to the extent possible, the energy 
needed in the ``work effort'' of the borehole to the rock mass to 
minimize excess energy vented into the water column; and (6) conducting 
a marine mammal watch with no less than two qualified observers from a 
small water craft and/or an elevated platform on the explosives barge, 
at least 30 minutes before and continuing for 30 minutes after each 
detonation to ensure that there are no dolphins, manatees or sea 
turtles in the area at the time of detonation.

Monitoring Program

    The Corps proposes to implement aerial and vessel-based observer 
monitoring programs. The vessel-based observer program will take place 
in a circular area at least three times the radius of the above 
described Caution Zone (called the watch zone). Detonation will not 
occur if a marine mammal or sea turtle is sighted within the safety 
zone and will be delayed until the animal(s) move(s) out of the safety 
zone on its own volition. The aerial and vessel-based marine mammal 
watch is proposed to be conducted for at least a half hour before and 
after the time of each detonation.

Reporting

    NMFS proposes to require the Corps to submit a report of activities 
120 days before the expiration of the proposed IHA if the proposed work 
has started. This report will include the status of the work being 
undertaken, marine mammals sighted during the monitoring period, any 
behavioral observations conducted on bottlenose dolphins and any delays 
in detonation due to marine mammals being within the safety zone.
    In the unlikely event a marine mammal or sea turtle is injured or 
killed during blasting, the Contractor shall immediately notify the 
NMFS Southeast Regional Office.

Endangered Species Act

    Under section 7 of the ESA, the Corps has determined that the Port 
Sutton blasting activities will have no effect on listed species. This 
finding is supported by documentation provided in the Corps' Port 
Sutton Environmental Assessment (EA).

National Environmental Policy Act

    The Corps prepared an EA on the Navigation Study for Tampa Harbor-
Port Sutton Channel, Florida in September 2000 and made a finding of no 
significant impact (FONSI)on October 11, 2000. In addition, NMFS 
completed an EA and made a FONSI on the impacts of blasting activities 
in Florida waters on marine life, particularly bottlenose dolphins. 
Therefore, preparation of an EIS on this action is not required by 
section 102(2) of the NEPA or its implementing regulations. A copy of 
the NMFS EA and FONSI are available upon request (see ADDRESSES).

Preliminary Conclusions

    NMFS has preliminarily determined that the Corps' proposed action, 
including mitigation measures to protect marine mammals, should result, 
at worst, in the temporary modification in behavior by small numbers of 
bottlenose dolphins including temporarily vacating the Port Sutton 
Channel area to avoid the blasting activity and the potential for minor 
visual and acoustic disturbance from dredging and detonations. This 
action is expected to have a negligible impact on the affected species 
or stock of marine mammals. In addition, no take by injury or death is 
anticipated, and harassment takes will be at the lowest level 
practicable due to incorporation of the mitigation measures described 
in this document.

Proposed Authorization

    NMFS proposes to issue an IHA to the Corps for the harassment of 
small numbers of bottlenose dolphins incidental to expanding and 
deepening the Port Sutton Channel in Tampa Harbor, FL, provided the 
previously mentioned mitigation, monitoring, and reporting requirements 
are incorporated. NMFS has preliminarily determined that the proposed 
activity would result in the harassment of only small numbers of 
bottlenose dolphins and will have no more than a negligible impact on 
this marine mammal stock.

Information Solicited

    NMFS requests interested persons to submit comments and information 
concerning this proposed IHA and the application for regulations 
request (see ADDRESSES).


[[Page 48545]]


    Dated: August 12, 2005.
P. Michael Payne,
Acting Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 05-16392 Filed 8-17-05; 8:45 am]
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