Endangered and Threatened Species; Critical Habitat for Threatened Elkhorn and Staghorn Corals, 6895-6919 [08-497]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 73, Number 25 (Wednesday, February 6, 2008)]
[Proposed Rules]
[Pages 6895-6919]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 08-497]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Parts 223 and 226

[Docket No. 070801431-7787-01]
RIN 0648-AV35


Endangered and Threatened Species; Critical Habitat for 
Threatened Elkhorn and Staghorn Corals

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

ACTION: Proposed rule; request for comments.

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SUMMARY: We, the National Marine Fisheries Service (NMFS), propose to 
designate critical habitat for elkhorn (Acropora palmata) and staghorn 
(A. cervicornis) corals, which we listed as threatened under the 
Endangered Species Act of 1973, as amended (ESA), on May 9, 2006. Four 
specific areas are proposed for designation: the Florida unit, which 
comprises approximately 3,301 square miles (8,671 sq km) of marine 
habitat; the Puerto Rico unit, which comprises approximately 1,383 
square miles (3,582 sq km) of marine habitat; the St. John/St. Thomas 
unit, which comprises approximately 121 square miles (313 sq km) of 
marine habitat; and the St. Croix unit, which comprises approximately 
126 square miles (326 sq km) of marine habitat. We propose to exclude 
one military site, comprising approximately 47 square miles (123 sq 
km), because of national security impacts.
    We are soliciting comments from the public on all aspects of the 
proposal, including our identification and consideration of the 
positive and negative economic, national security, and other relevant 
impacts of the proposed designation, and the areas we propose to 
exclude from the designation. A draft impacts report prepared pursuant 
to section 4(b)(2) of the ESA in support of this proposal is also 
available for public review and comment.

DATES: Comments on this proposal must be received by May 6, 2008. 
Public hearings will be held; see SUPPLEMENTARY INFORMATION for dates 
and locations.

ADDRESSES: You may submit comments, identified by the Regulation 
Identifier Number (RIN) 0648-AV35, by any of the following methods:
    Electronic Submissions: Submit all electronic public comments via 
the

[[Page 6896]]

Federal eRulemaking Portal: https://www.regulations.gov.
    Mail: Assistant Regional Administrator, Protected Resources 
Division, NMFS, Southeast Regional Office, 263 13th Ave. South, St. 
Petersburg, FL 33701.
    Facsimile (fax) : 727-824-5309.
    Instructions: All comments received are a part of the public record 
and will generally be posted to https://www.regulations.gov without 
change. All Personal Identifying Information (for example, name, 
address, etc.) voluntarily submitted by the commenter may be publicly 
accessible. Do not submit Confidential Business Information or 
otherwise sensitive or protected information.
    NMFS will accept anonymous comments. Attachments to electronic 
comments will be accepted in Microsoft Word, Excel, WordPerfect, or 
Adobe PDF file formats only.
    Public Hearing: See SUPPLEMENTARY INFORMATION for hearing dates and 
locations.

FOR FURTHER INFORMATION CONTACT: Jennifer Moore or Sarah Heberling, 
NMFS, at the address above or at 727-824-5312; or Marta Nammack, NMFS, 
at 301-713-1401.

SUPPLEMENTARY INFORMATION:

Background

    On May 9, 2006, we listed elkhorn and staghorn corals as threatened 
under the ESA (71 FR 26852; May 9, 2006). At the time of listing, we 
also announced our intention to propose critical habitat for elkhorn 
and staghorn corals. We are proposing to designate critical habitat for 
both species through one rule; due to their similar life histories, 
distribution, threats, and conservation requirements, critical habitat 
for these coral species is overlapping.

Elkhorn and Staghorn Coral Natural History

    The following discussion of the life history and reproductive 
biology of threatened corals is based on the best scientific data 
available, including the Atlantic Acropora Status Review Report 
(Acropora Biological Review Team, 2005), and additional information, 
particularly concerning the genetics of these corals.
    Acropora spp. are widely distributed throughout the Caribbean 
(U.S.--Florida, Puerto Rico, U.S. Virgin Islands (U.S.V.I.), Navassa; 
and Antigua and Barbuda, Aruba, Bahamas, Barbados, Belize, British 
Virgin Islands, Colombia, Costa Rica, Cuba, Dominica, Dominican 
Republic, Grenada, Guadeloupe, Haiti, Honduras, Jamaica, Martinique, 
Mexico, Netherlands Antilles, Nicaragua, Panama, St. Kitts and Nevis, 
St. Lucia, St. Vincent and the Grenadines, Trinidad and Tobago, and 
Venezuela). In general, elkhorn and staghorn corals have the same 
geographic distribution, with few exceptions. The northern extent (Palm 
Beach County, Florida) of staghorn coral occurrence is farther north 
than that of elkhorn coral (Broward County, Florida). Staghorn coral 
commonly grows in more protected, deeper water ranging from 5 to 20 m 
in depth and has been found in rare instances to 60 m. Elkhorn coral 
commonly grows in turbulent shallow water on the seaward face of reefs 
in water ranging from 1 to 5 m in depth but has been found to 30 m 
depth.
    Elkhorn and staghorn corals were once the most abundant and most 
important species on Caribbean coral reefs in terms of accretion of 
reef structure. Relative to other corals, elkhorn and staghorn corals 
have high growth rates that have allowed reef growth to keep pace with 
past changes in sea level. Both species exhibit branching morphologies 
that provide important habitat for other reef organisms. Environmental 
influences (e.g., wave action, currents) result in morphological 
variation (e.g., length, shape of branches) in both species.
    Staghorn coral is characterized by staghorn antler-like colonies 
with cylindrical, straight, or slightly curved branches. The diameter 
of staghorn coral branches ranges from 1 to 4 cm, and tissue color 
ranges from golden yellow to medium brown. The growing tips of staghorn 
coral tend to be lighter or lack color. The linear growth rate for 
staghorn coral has been reported to range from 3 to 11.5 cm/year. 
Today, staghorn coral colonies typically exist as isolated branches and 
small thickets, 0.5 to 1 m across in size, unlike the vast fields 
(thickets) of staghorn found commonly during the 1970s.
    Elkhorn coral is the larger species of Acropora found in the 
Atlantic. Colonies are flattened to near round with frond-like 
branches. Branches are up to 50 cm across and range in thickness from 2 
to 10 cm, tapering towards the branch terminal. Like staghorn coral, 
branches are white near the growing tip, and brown to tan away from the 
growing area. The linear growth rate for elkhorn coral is reported to 
range from 4 to 11 cm/year. Individual colonies can grow to at least 2 
m in height and 4 m in diameter.
    Elkhorn and staghorn corals require relatively clear, well-
circulated water and are almost entirely dependent upon sunlight for 
nourishment. Unlike other coral species, neither acroporid species is 
likely to compensate for long-term reductions in water clarity with 
alternate food sources, such as zooplankton and suspended particulate 
matter. Typical water temperatures in which Acropora spp. occur from 21 
to 29 [deg]C, with the species being able to tolerate temperatures 
higher than the seasonal maximum for a brief period of time (days to 
weeks depending on the magnitude of the temperature elevation). The 
species' response to temperature perturbations is dependent on the 
duration and intensity of the event. Both acroporids are susceptible to 
bleaching (loss of symbiotic algae) under adverse environmental 
conditions.
    Acropora spp. reproduce both sexually and asexually. Elkhorn and 
staghorn corals do not differ substantially in their sexual 
reproductive biology. Both species are broadcast spawners: male and 
female gametes are released into the water column where fertilization 
takes place. Additionally, both species are simultaneous 
hermaphrodites, meaning that a given colony will contain both male and 
female reproductive parts during the spawning season; however, an 
individual colony or clone will not produce viable offspring. The 
spawning season for elkhorn and staghorn corals is relatively short, 
with gametes released on only a few nights during July, August, and/or 
September. In most populations, spawning is synchronous after the full 
moon during any of these 3 months. Larger colonies of elkhorn and 
staghorn corals have much higher fecundity rates (Soong and Lang, 
1992).
    In elkhorn and staghorn corals, fertilization and development are 
exclusively external. Embryonic development culminates with the 
development of planktonic larvae called planulae. Little is known 
concerning the settlement patterns of planula of elkhorn and staghorn 
corals. In general, upon proper stimulation, coral larvae, whether 
released from parental colonies or developed in the water column 
external to the parental colonies (like Acropora spp.), settle and 
metamorphose on appropriate substrates. Like most corals, elkhorn and 
staghorn corals require hard, consolidated substrate, including 
attached, dead coral skeleton, for their larvae to settle. Unlike most 
other coral larvae, elkhorn (and presumably staghorn) planulae appear 
to prefer settling on upper, exposed surfaces, rather than in dark, 
cryptic ones, at least in a laboratory setting (Szmant and Miller, 
2005).
    Coral planula larvae experience considerable mortality (90 percent 
or

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more) from predation or other factors prior to settlement and 
metamorphosis (Goreau, et al., 1981). Because newly settled corals 
barely protrude above the substrate, juveniles need to reach a certain 
size to reduce damage or mortality from impacts such as grazing, 
sediment burial, and algal overgrowth. Recent studies examining early 
survivorship indicated that lab cultured elkhorn coral settled onto 
experimental limestone plates and placed in the field had substantially 
higher survivorship than another spawning coral species, Montastraea 
faveolata, and similar survivorship to brooding coral species (species 
that retain developing larvae within the parent polyp until an advanced 
stage) over the first 9 months following settlement (Szmant and Miller, 
2005). This pattern corresponds to the size of planulae; elkhorn coral 
eggs and larvae are much larger than those of Montastraea spp. Overall, 
older recruits (i.e., those that survive to a size where they are 
visible to the human eye, probably 1 to 2 years post-settlement) of 
Acropora spp. appear to have similar growth and post-settlement 
mortality rates observed in other coral species.
    Studies of Acropora spp. from across the Caribbean confirm two 
overall patterns of sexual recruitment: (1) Low juvenile densities 
relative to other coral species; and (2) low juvenile densities 
relative to the commonness of adults (Porter, 1987). This pattern 
suggests that the composition of the adult population is based upon 
variable recruitment. To date, the settlement rates for Acropora spp. 
have not been quantified.
    Few data on the genetic population structure of elkhorn and 
staghorn corals exist; however, due to recent advances in technology, 
the genetic population structure of the current, depleted population is 
beginning to be characterized. Baums, et al. (2005) examined the 
genetic exchange in elkhorn coral by sampling and genotyping colonies 
from 11 locations throughout its geographic range using microsatellite 
markers. Results indicate that elkhorn populations in the eastern 
Caribbean (St. Vincent and the Grenadines, U.S.V.I., Curacao, and 
Bonaire) have experienced little or no genetic exchange with 
populations in the western Caribbean (Bahamas, Florida, Mexico, Panama, 
Navassa, and Mona Island). Mainland Puerto Rico is an area of mixing 
where elkhorn populations show genetic contribution from both regions, 
though it is more closely connected with the western Caribbean. Within 
these regions, the degree of larval exchange appears to be 
asymmetrical, with some locations being entirely self-recruiting and 
some receiving immigrants from other locations within their region.
    Vollmer and Palumbi (2007) examined multilocus sequence data from 
276 colonies of staghorn coral spread across 22 populations from 9 
regions in the Caribbean, Florida, and the Bahamas. Their data were 
consistent with the Western-Eastern Caribbean subdivision observed in 
elkhorn coral populations by Baums, et al. (2005). Additionally, the 
data indicated that regional populations of staghorn separated by 
greater than 500 km are genetically differentiated and that gene flow 
across the greater Caribbean is low in staghorn coral. This is 
consistent with studies conducted on other Caribbean corals showing 
that gene flow is restricted at spatial scales over 500 km (Fukami, et 
al., 2004; Baums, et al., 2005; Brazeau, et al., 2005). Furthermore, 
fine-scale genetic differences were observed among reefs separated by 
as little as 2 km, suggesting that gene flow in staghorn corals may be 
limited over much smaller spatial scales (Vollmer and Palumbi, 2007).
    Both acroporid population studies suggest that no population is 
more or less significant to the status of the species. Staghorn coral 
populations on one reef exhibit limited ability to seed another 
population separated by large distances. Elkhorn coral populations are 
genetically related over larger geographic distances; however, because 
sexual recruitment levels are extremely low, re-seeding potential is 
also minimal. This regional population structure suggests that 
conservation should be implemented at local to regional scales because 
relying on long-distance larval dispersal as a means of recovery may be 
unreliable and infeasible. Therefore, protecting source populations, in 
relatively close proximity to each other (<500 km), is likely the more 
effective conservation alternative (Vollmer and Palumbi, 2007).
    Elkhorn and staghorn corals, like most coral species, also 
reproduce asexually. Asexual reproduction involves fragmentation, 
wherein colony pieces or fragments break from a larger colony and re-
attach to hard, consolidated substrate to form a new colony. 
Reattachment occurs when: (1) Live coral tissue on the fragment 
overgrows suitable substrate where it touches after falling; or (2) 
encrusting organisms settle on the dead basal areas of the fragment and 
cement it to the adjacent substrate (Tunnicliffe, 1981). Fragmentation 
results in multiple colonies (ramets) that are genetically identical, 
while sexual reproduction results in the creation of new genotypes 
(genets). Fragmentation is the most common means of forming new elkhorn 
and staghorn coral colonies in most populations and plays a major role 
in maintaining local populations when sexual recruitment is limited. 
The larger size of fragments compared to planulae may result in higher 
survivorship after recruitment (Jackson, 1977, as cited by Lirman, 
2000). Also unlike sexual reproduction, which is restricted seasonally 
for elkhorn coral (Szmant, 1986, as cited by Lirman, 2000), 
fragmentation can take place year-round.

Critical Habitat Identification and Designation

    Critical habitat is defined by section 3 of the ESA (and further by 
50 CFR 424.02(d)) as ``(i) the specific areas within the geographical 
area occupied by the species, at the time it is listed in accordance 
with the provisions of section 4 of this Act, on which are found those 
physical or biological features (I) essential to the conservation of 
the species and (II) which may require special management 
considerations or protection; and (ii) specific areas outside the 
geographical area occupied by the species at the time it is listed in 
accordance with the provisions of section 4 of this Act, upon a 
determination by the Secretary that such areas are essential for the 
conservation of the species.'' This definition provides a step-wise 
approach to identifying areas that may be designated as critical 
habitat for listed corals.

Geographical Areas Occupied by the Species

    The best scientific data available show the current geographical 
area occupied by both elkhorn and staghorn corals has remained 
unchanged from their historical ranges. In other words, there is no 
evidence of range constriction for either species. ``Geographical areas 
occupied'' in the definition of critical habitat is interpreted to mean 
the current range of the species and not every discrete location on 
which individuals of the species physically are located (45 FR 13011; 
February 27, 1980). In general, elkhorn and staghorn corals have the 
same distribution, with few exceptions, and are widely distributed 
throughout the Caribbean. The Status of Coral Reefs in the Western 
Atlantic: Results of Initial Surveys, Atlantic and Gulf Rapid Reef 
Assessment (AGRRA) Program (Lang, 2003) provides results (1997-2004) of 
a regional systematic survey of corals, including Acropora spp., from 
many locations throughout the

[[Page 6898]]

Caribbean. AGRRA data (1997-2004) indicate that the historic range of 
both species remains intact; staghorn coral is rare throughout the 
range (including areas of previously known dense occurrence); and 
elkhorn coral occurs in moderation. We also collected data and 
information pertaining to the geographical area occupied by these 
species at the time of listing by partnering with our Southeast 
Fisheries Science Center (SEFSC), NOAA National Centers for Coastal 
Ocean Science Biogeography Team, and the U.S. Geological Survey of the 
Department of the Interior. These partnerships resulted in the 
collection of geographic information system (GIS) and remote sensing 
data (e.g., benthic habitat data, water depth, and presence/absence 
location data for Acropora spp. colonies), which we supplemented with 
relevant information collected from the public during comment periods 
and workshops held throughout the ESA listing process.
    In Southeast Florida, staghorn coral has been documented along the 
east coast as far north as Palm Beach County in deeper (16 to 30 m) 
water (Goldberg, 1973) and is distributed south and west throughout the 
coral and hardbottom habitats of the Florida Keys (Jaap, 1984), through 
Tortugas Bank. Elkhorn coral has been reported as far north as Broward 
and Miami-Dade Counties, with significant reef development and 
framework construction by this species beginning at Ball Buoy Reef in 
Biscayne National Park, extending discontinuously southward to the Dry 
Tortugas.
    In Puerto Rico, elkhorn and staghorn corals have been reported in 
patchy abundance around the main island and isolated offshore 
locations. In the late 1970s, both elkhorn and staghorn corals occurred 
in dense and well developed thickets on many reefs off the northeast, 
east, south, west and northwest coast, and also the offshore islands of 
Mona, Vieques and Culebra (Weil, et al., unpublished data). Dense, high 
profile, monospecific thickets of elkhorn and staghorn corals have been 
documented in only a few reefs along the southwest shore of the main 
island and isolated offshore locations (Weil, et al., unpublished data) 
though recent monitoring data for the presence of coral are incomplete 
in coverage around the islands. Further, the species have been recently 
documented along the west (e.g., Rincon) and northeast coasts (e.g., La 
Cordillera). Additionally, large stands of dead elkhorn currently exist 
on the fringing coral reefs along the south shoreline (e.g., Punta 
Pic[uacute]a, Punta Miquillo, R[iacute]o Grande, Gu[aacute]nica, La 
Parguera, Mayaguez). It appears that elkhorn and staghorn are rare on 
the north shore of Puerto Rico; however, there is a thin strip of 
hardbottom substrate on that shore, which may be supporting additional 
unrecorded colonies of elkhorn or staghorn.
    The U.S.V.I. also supports populations of elkhorn and staghorn 
corals, particularly at Buck Island Reef National Monument. St. Croix 
has coral reef and colonized hardbottom surrounding the entire island. 
Data from the 1980's indicate that the species were present along the 
north, eastern, and western shores at that time. The GIS data we 
compiled indicate the presence of elkhorn and staghorn currently along 
the north, northeastern, south, and southeastern shores of St. Croix. 
Monitoring data are incomplete, and it is possible that unrecorded 
colonies are present along the western, northwestern, or southwestern 
shores. For the islands of St. Thomas and St. John, there are limited 
GIS presence data available for elkhorn and staghorn corals. However, 
Grober-Dunsmore, et al. (2006) show that from 2001-2003, elkhorn 
colonies were distributed in many locations around the island of St. 
John. Additionally, the data we have indicate coral reef and coral-
colonized hard bottom surrounding each of these islands as well as the 
smaller offshore islands. Again, it is possible that unrecorded 
colonies are present in these areas.
    Navassa Island is a small, uninhabited, oceanic island 
approximately 50 km off the southwest tip of Haiti managed by U.S. Fish 
and Wildlife Service (FWS) as one component of the Caribbean Islands 
National Wildlife Refuge (NWR). Both acroporid species are known from 
Navassa, with elkhorn apparently increasing in abundance and staghorn 
rare (Miller and Gerstner, 2002).
    Last, there are two known colonies of elkhorn at the Flower Garden 
Banks National Marine Sanctuary (FGBNMS), located 100 mi (161 km) off 
the coast of Texas in the Gulf of Mexico. The FGBNMS is a group of 
three areas of salt domes that rise to approximately 15 m water depth 
and are surrounded by depths from 60 to 120 m. The FGBNMS is regularly 
surveyed, and the two known colonies, which were only recently 
discovered and are considered to be a potential range expansion, are 
constantly monitored.
    Our regulations at 50 CFR 424.12(h) state: ``Critical habitat shall 
not be designated within foreign countries or in other areas outside of 
United States jurisdiction.'' Although the geographical area occupied 
by elkhorn and staghorn corals includes coastal waters of many 
Caribbean and Central and South American nations, we are not proposing 
these areas for designation. The geographical area occupied by listed 
coral species which is within the jurisdiction of the United States is 
therefore limited to four counties in the State of Florida (Palm Beach 
County, Broward County, Miami-Dade County, and Monroe County), FGBNMS, 
and the U.S. territories of Puerto Rico, U.S.V.I, and Navassa Island.

Physical or Biological Features Essential for Conservation (Primary 
Constituent Elements)

    Within the geographical area occupied, critical habitat consists of 
specific areas on which are found those physical or biological features 
essential to the conservation of the species (hereafter also referred 
to as essential features or ``Primary Constituent Elements'' or 
``PCEs''). Section 3 of the ESA (16 U.S.C. 1532(3)) defines the terms 
``conserve,'' ``conserving,'' and ``conservation'' to mean: ``To use, 
and the use of, all methods and procedures which are necessary to bring 
any endangered species or threatened species to the point at which the 
measures provided pursuant to this chapter are no longer necessary.'' 
Further, our regulations at 50 CFR 424.12(b) for designating critical 
habitat state that physical and biological features that are essential 
to the conservation of a given species and that may require special 
management considerations or protection may include, but are not 
limited to: (1) Space for individual and population growth, and for 
normal behavior; (2) food, water, air, light, minerals, or other 
nutritional or physiological requirements; (3) cover or shelter; (4) 
sites for breeding, reproduction, rearing of offspring, germination, or 
seed dispersal; and generally, (5) habitats that are protected from 
disturbance or are representative of the historic geographical and 
ecological distributions of a species. These regulations state that we 
shall focus on essential features within the specific areas considered 
for designation.
    As stated in the Atlantic Acropora Status Review Report (Acropora 
Biological Review Team, 2005),

there are several implications of the current low population sizes 
of Acropora spp. throughout much of the wider Caribbean. First, the 
number of sexual recruits to a population will be most influenced by 
larval availability, recruitment, and early juvenile mortality. 
Because corals cannot move and are dependent upon external 
fertilization in order to produce larvae, fertilization success 
declines greatly as adult density declines;

[[Page 6899]]

this is termed an Allee effect (Levitan 1991). To compound the 
impact, Acropora spp., although hermaphroditic, do not effectively 
self-fertilize; gametes must be outcrossed with a different genotype 
to form viable offspring. Thus, in populations where fragmentation 
is prevalent, the effective density (of genetically distinct adults) 
will be even lower than colony density. It is highly likely that 
this type of recruitment limitation (Allee effect) is occurring in 
some local elkhorn and staghorn populations, given their state of 
drastically reduced abundance/density. Simultaneously, when adult 
abundances of elkhorn and staghorn corals are reduced, the source 
for fragments (to provide for asexual recruitment) is also 
compromised. These conditions imply that once a threshold level of 
population decline has been reached (i.e., a density where 
fertilization success becomes negligible) the chances for recovery 
are low.

Thus, we determined that based on available information, facilitating 
increased incidence of successful sexual and asexual reproduction is 
the key objective to the conservation of these species. We then turned 
to determining the physical or biological features essential to this 
conservation objective.
    Currently, sexual recruitment of elkhorn and staghorn corals is 
limited in some areas and absent in most. Compounding the difficulty of 
documenting sexual recruitment is the difficulty of visually 
distinguishing some sexual recruits from asexual recruits (Miller, et 
al., 2007). Settlement of larvae or attachment of fragments is often 
unsuccessful, given limited amounts of appropriate habitat due to the 
shift in benthic community structure from coral-dominated to algae-
dominated that has been documented since the 1980s (Hughes and Connell, 
1999). Appropriate habitat for elkhorn and staghorn coral recruits to 
attach and grow consists of hard, consolidated substrate. In addition 
to being limited, the availability of appropriate habitat for 
successful sexual and asexual reproduction is susceptible to becoming 
reduced further because of such factors as fleshy macroalgae 
overgrowing and preempting the space available for larval settlement, 
recruitment, and fragment reattachment. Similarly, sediment 
accumulating on suitable substrate impedes sexual and asexual 
reproductive success by preempting available substrate and smothering 
coral recruits. Exacerbating the effect of sedimentation is the 
presence of turf algae, which traps the sediment, leading to greater 
amounts of accumulations as compared to bare substrate alone. As 
described above, features that will facilitate successful larval 
settlement and recruitment, and reattachment of asexual fragments, are 
essential to the conservation of elkhorn and staghorn corals. Without 
successful recruits, the species will not increase in abundance, 
distribution, and genetic diversity.
    Elkhorn and staghorn corals, like most corals, require hard, 
consolidated substrate (i.e., attached, dead coral skeleton or 
hardbottom) for their larvae to settle or fragments to reattach. The 
type of substrate available directly influences settlement success and 
fragment survivorship. Lirman (2000) demonstrated this in a transplant 
experiment using elkhorn coral fragments created by a ship grounding. 
Fifty fragments were collected within 24 hours of fragmentation and 
assigned to one of the following four types of substrate: (1) 
Hardbottom (consolidated carbonate framework), (2) rubble (loose, dead 
pieces of elkhorn and staghorn corals), (3) sand, and (4) live coral. 
The results showed that the survivorship of transplanted fragments was 
significantly affected by the type of substrate, with fragment 
mortality being the greatest for those transplanted to sandy bottom (58 
percent loss within the first month and 71 percent after 4 months). 
Fragments placed on live adult elkhorn coral colonies fused to the 
underlying tissue and did not experience any tissue loss; and fragments 
placed on rubble and hardbottom substrates showed high survivorship.
    Unlike fragments, coral larvae cannot attach to living coral 
(Connell, et al., 1997). Larvae can settle and attach to dead coral 
skeleton (Jordan-Dahlgren, 1992; Bonito and Grober-Dunsmore, 2006) and 
may settle in particular areas in response to chemical cues from 
certain species of crustose coralline algae (CCA) (Morse, et al., 1996; 
Heyward and Negri, 1999; Harrington and Fabricius, 2004). While algae, 
including CCA and fleshy macroalgae, is a natural component of healthy 
reef ecosystems, the recent increase in the dominance of fleshy 
macroalgae as major space-occupiers on many Caribbean coral reefs 
impedes the recruitment of new corals. This shift in benthic community 
structure (from the dominance of stony corals to that of fleshy algae) 
on Caribbean coral reefs is generally attributed to the greater 
persistence of fleshy macroalgae under reduced grazing regimes due to 
human overexploitation of herbivorous fishes (Hughes, 1994) and the 
regional mass mortality of the herbivorous long-spined sea urchin in 
1983-84. Further, impacts to water quality (principally nutrient input) 
coupled with low herbivore grazing are also believed to enhance fleshy 
macroalgal productivity. Fleshy macroalgae are able to colonize dead 
coral skeleton and other available substrate, preempting space 
available for coral recruitment.
    The persistence of fleshy macroalgae under reduced grazing regimes 
has impacts on CCA growth, which may reduce settlement of coral larvae 
as CCA is thought to provide chemical cues for settlement. Most CCA are 
susceptible to fouling by fleshy algae, particularly when herbivores 
are absent (Steneck, 1986). Patterns observed in St. Croix, U.S.V.I., 
also indicate a strong positive correlation between CCA abundance and 
herbivory (Steneck, 1997). A study in which Miller, et al. (1999) used 
cages to exclude large herbivores from the study site resulted in 
increased cover of both turf algae and macroalgae, and cover of CCA 
decreased. The response of CCA to the experimental treatment persisted 
for 2 months following cage removal (Miller, et al., 1999). 
Additionally, following the mass mortality of the urchin Diadema 
antillarum, significant increases in cover of fleshy and filamentous 
algae occurred with parallel decreases in cover of CCA (de Ruyter van 
Steveninck and Bak, 1986; Liddel and Ohlhorst, 1986). The ability of 
fleshy macroalgae to affect growth and survival of CCA has indirect, 
yet important, impacts on the ability of coral larvae to successfully 
settle and recruit.
    Several studies show that coral recruitment tends to be greater 
when algal biomass is low (Rogers, et al., 1984; Hughes, 1985; Connell, 
et al., 1997; Edmunds, et al., 2004; Birrell, et al., 2005; Vermeij, 
2006). In addition to preempting space for coral larvae settlement, 
many fleshy macroalgae produce secondary metabolites with generalized 
toxicity, which also may inhibit settlement of coral larvae (Kuffner 
and Paul, 2004). Furthermore, algal turfs can trap sediments (Eckman, 
et al., 1989; Kendrik, 1991; Steneck, 1997; Purcell, 2000; Nugues and 
Roberts, 2003; Wilson, et al., 2003; Purcell and Bellwood, 2001), which 
then creates the potential for algal turfs and sediments to act in 
combination to hinder coral settlement (Nugues and Roberts, 2003; 
Birrell, et al., 2005). These turf algae sediment mats also can 
suppress coral growth under high sediment conditions (Nugues and 
Roberts, 2003) and may gradually kill the marginal tissues of stony 
corals with which they come into contact (Dustan, 1977, 1999, as cited 
by Roy, 2004).
    Sediments enter the reef environment through many processes that 
are natural or anthropogenic in origin, including erosion of coastline, 
resuspension of bottom sediments, terrestrial run-off, and nearshore 
dredging for coastal construction projects and navigation

[[Page 6900]]

purposes. The rate of sedimentation affects reef distribution, 
community structure, growth rates, and coral recruitment (Dutra, et 
al., 2003). Accumulation of sediment can smother living corals, dead 
coral skeleton, and exposed hardbottom. Sediment accumulation on dead 
coral skeletons and exposed hardbottom reduces the amount of available 
substrate suitable for coral larvae settlement and fragment 
reattachment (Rogers, 1990; Babcock and Smith, 2002). Accumulation of 
sediments is also a major cause of mortality in coral recruits 
(Fabricius, et al., 2003). In some instances, if mortality of coral 
recruits does not occur under heavy sediment conditions, then settled 
coral planulae may undergo reverse metamorphosis and not survive (Te, 
1992). Sedimentation, therefore, impacts the health and survivorship of 
all life stages (i.e., fecund adults, fragments, larvae, and recruits) 
of elkhorn and staghorn corals.
    Based on the key conservation objective we have identified to date, 
the natural history of elkhorn and staghorn corals, and their habitat 
needs, the physical or biological feature of elkhorn and staghorn 
corals' habitat essential to their conservation is substrate of 
suitable quality and availability, in water depths from the mean high 
water (MHW) line to 30 m, to support successful larval settlement, 
recruitment, and reattachment of fragments. For purposes of this 
definition, ``substrate of suitable quality and availability'' means 
consolidated hardbottom or dead coral skeleton that is free from fleshy 
macroalgae cover and sediment cover. This feature is essential to the 
conservation of these two species due to the extremely limited 
recruitment currently being observed.
    We determined that no other environmental features are appropriate 
or necessary for defining critical habitat for the two corals. Other 
than the substrate PCE, we cannot conclude that any other sufficiently 
definable feature of the environment is essential to the corals' 
conservation. Other features of the corals' environment, such as water 
temperature, are more appropriately viewed as sources of impacts or 
stressors that can harm the corals, rather than habitat features that 
provide a conservation function. Therefore, these stressors would not 
be analyzed as factors that may contribute to a determination whether 
the corals' critical habitat is likely to be destroyed or adversely 
modified. Some environmental features are also subsumed within the 
definition of the substrate PCE; for instance, substrate free from 
macroalgal cover would encompass water quality sufficiently free of 
nutrients.

Specific Areas Within the Geographical Area Occupied by the Species

    The definition of critical habitat further instructs us to identify 
specific areas on which are found the physical or biological features 
essential to the species' conservation. Our regulations state that 
critical habitat will be defined by specific limits using reference 
points and lines on standard topographic maps of the area, and 
referencing each area by the State, county, or other local governmental 
unit in which it is located (50 CFR 424.12(c)). As discussed below, we 
determined that specific areas in FGBNMS and Navassa National Wildlife 
Refuge that contain the PCE do not otherwise meet the definition of 
critical habitat. Hence, in this section we only describe our 
identification of the specific areas we are proposing to include in 
this designation.
    In addition to information obtained from the public, we partnered 
with SEFSC, NOAA Biogeography Team, and U.S. Geological Survey to 
obtain GIS and remote sensing data (e.g., benthic habitat data, water 
depth) to compile existing data to identify and map areas that may 
contain the identified PCE. The following are the major datasets upon 
which we relied. NOAA's National Ocean Service (NOS) and the Florida 
Fish and Wildlife Research Institute completed The Benthic Habitat 
Mapping of Florida Coral Reef Ecosystems using a series of 450 aerial 
photographs collected in 1991-1992. For this mapping effort, coral 
ecosystem ecologists outlined the boundaries of specific habitat types 
by interpreting color patterns on the photographs. Benthic habitats 
were classified into four major categories--corals, seagrasses, 
hardbottom, and bare substrate--and 24 subcategories, such as sparse 
seagrass and patch reef. Each habitat type was groundtruthed in the 
field by divers to validate the photo-interpretation of the aerial 
photography. Habitat boundaries were georeferenced and digitized to 
create computer maps. A similar method was followed by NOS using 1999 
aerial imagery in developing the Benthic Habitat Mapping of Puerto Rico 
and the U.S.V.I.
    Using GIS software, we extracted all areas that could be considered 
potential recruitment habitat, including hardbottom and coral. The 
benthic habitat information assisted in identifying any major gaps in 
the distribution of the substrate PCE. Given uncertainties in the age 
and resolution of the data, we were unable to identify smaller, 
discrete specific areas that contained the PCE rather than large, 
continuous areas. Thus, we concluded that, based upon the best 
available information, although the PCE is unevenly dispersed 
throughout the ranges of the species, no major gaps existed in the 
distribution. We further limited the specific areas to the maximum 
depth of occurrence of the two corals (i.e., 30 m). The 30-m contour 
was extracted from the National Geophysical Data Center Coastal Relief 
Model for Puerto Rico & Virgin Islands, and Florida. Because Puerto 
Rico and the U.S.V.I. are islands, the contours yielded continuous 
closed polygons. However, because the two species only occur off 
specific counties in Florida, we used additional boundaries to close 
the polygons. The Florida Area consists of all waters contained by the 
boundary beginning at the MHW line at the north boundary of Palm Beach 
County; then due east to the 30-m contour; then following the 30-m 
contour to the intersection with the FKNMS boundary northeast of the 
Dry Tortugas; then following the FKNMS boundary to the intersection 
with the COLREGS line (see 33 CFR 80.727, 730, 735, and 740) for 
Florida Bay; then following the COLREGS line southeast to the 
intersection with Long Key; then following the COLREGS line and MHW 
line returning to the beginning point. The COLREGS line separates 
inland waters from marine waters. Also included are the waters in two 
shoals southwest of the Dry Tortugas bounded by the 30-m contour.
    Using the above procedure and consistent with our regulations (50 
CFR 424.12(c)), we identified four ``specific areas'' and a few small 
adjacent areas (separated from main areas by water depth greater than 
30 m) within the geographical area occupied by the species, at the time 
of listing, that contain the PCE. These areas comprise all waters in 
the depths of 30 m and shallower to the MHW or COLREG line off: (1) 
Palm Beach, Broward, Miami-Dade, and Monroe Counties, including the 
Marquesas Keys and the Dry Tortugas, Florida; (2) Puerto Rico and 
associated Islands; (3) St. John/St. Thomas, U.S.V.I.; and (4) St. 
Croix, U.S.V.I.) (see maps). Within these specific areas, the PCE 
consists of consolidated hardbottom or dead coral skeleton that are 
free from fleshy macroalgae cover and sediment cover. The PCE can be 
found unevenly dispersed throughout these four areas due to trends in 
macroalgae coverage, and naturally occurring unconsolidated sediment 
and seagrasses dispersed within the reef ecosystem. A larger

[[Page 6901]]

number of smaller specific areas could not be identified because the 
submerged nature of the PCE, the limits of available information on the 
distribution of the PCE, and limits on mapping methodologies make it 
infeasible to define the specific areas containing the PCE more finely 
than described herein. Further, based on data about their historical 
distributions, the corals are capable of successfully recruiting and 
attaching to available substrate anywhere within the boundaries of the 
four specific areas. Given these species' reduced abundances, the four 
specific areas were identified to include all available potential 
settling substrate within the 30 m contour to maximize the potential 
for successful recruitment and population growth.
    The PCE is not likely to be present in natural sites covered with 
loose sediment, fleshy macroalgal covered hardbottom, or seagrasses. 
Additionally, existing man-made structures such as aids-to-navigation 
(ATONs), artificial reefs, boat ramps, docks, pilings, maintained 
channels or marinas do not provide the PCE that is essential to the 
species' conservation. Substrate within the proposed critical habitat 
boundaries that do not contain the PCE are not part of the designation. 
Federal actions, or the effects thereof, limited to these areas would 
not trigger section 7 consultation under the ESA, unless they may 
affect the species and/or the PCE in adjacent critical habitat. As 
discussed here and in the supporting impacts analysis, given the 
precise definition of the proposed PCE, determining whether an action 
may affect the feature can be accomplished without entering into an ESA 
section 7 consultation.

Unoccupied Areas

    ESA section 3(5)(A)(ii) further defines critical habitat to include 
specific areas outside the geographical area occupied if the areas are 
determined by the Secretary to be essential for the conservation of the 
species. Regulations at 50 CFR 424.12(e) specify that we shall 
designate as critical habitat areas outside the geographical area 
presently occupied by a species only when a designation limited to its 
present range would be inadequate to ensure the conservation of the 
species. At the present time, the range of these species has not been 
constricted, and we have not identified any areas outside the 
geographical area occupied by the species that are essential for their 
conservation. Therefore, we are not proposing to designate any 
unoccupied areas for elkhorn and staghorn corals.

Special Management Considerations or Protection

    Specific areas within the geographical area occupied by a species 
may be designated as critical habitat only if they contain physical or 
biological features that ``may require special management 
considerations or protection.'' A few courts have interpreted aspects 
of this statutory requirement, and the plain language aids in its 
interpretation. For instance, the language clearly indicates the 
features, not the specific area containing the features, are the focus 
of the ``may require'' provision. Use of the disjunctive ``or'' also 
suggests the need to give distinct meaning to the terms ``special 
management considerations'' and ``protection.'' Generally speaking, 
``protection'' suggests actions to address a negative impact or threat 
of a negative impact. ``Management'' seems plainly broader than 
protection, and could include active manipulation of a feature or 
aspects of the environment. Two Federal district courts, focusing on 
the term ``may,'' ruled that features can meet this provision based on 
either present requirements for special management considerations or 
protections, or on possible future requirements. See, Center for Biol. 
Diversity v. Norton, 240 F. Supp. 2d 1090 (D. Ariz. 2003); Cape 
Hatteras Access Preservation Alliance v. DOI, 344 F. Supp. 108 (D.D.C. 
2004). The Arizona district court ruled that the provision cannot be 
interpreted to mean that features already covered by an existing 
management plan must be determined to require ``additional'' special 
management, because the term ``additional'' is not in the statute. 
Rather, the court ruled that the existence of management plans may be 
evidence that the features in fact require special management. Center 
for Biol. Diversity v. Norton, 1096-1100. NMFS' regulations define 
``special management considerations or protections'' to mean ``any 
methods or procedures useful in protecting physical and biological 
features of the environment for the conservation of listed species'' 
(50 CFR 424.02(j)).
    Based on the above, we evaluated whether the PCE proposed in this 
document may require special management considerations or protections 
by evaluating four criteria:
    (a) Whether there is presently a need to manage the feature;
    (b) Whether there is the possibility of a need to manage the 
feature;
    (c) Whether there is presently a negative impact on the feature; or
    (d) Whether there is the possibility of a negative impact on the 
feature.
    In evaluating present or possible future management needs for the 
PCE, we recognized that the feature in its present condition must be 
the basis for a finding that it is essential to the corals' 
conservation. In addition, the needs for management evaluated in (a) 
and (b) were limited to managing the feature for the conservation of 
the species. In evaluating whether the PCE meets either criterion (c) 
or (d), we evaluated direct and indirect negative impacts from any 
source (e.g., human or natural). However, we only considered the 
criteria to be met if impacts affect or have the potential to affect 
the aspect of the feature that makes it essential to the conservation 
of the species. We then evaluated whether the PCE met the ``may 
require'' provision separately for each of the four ``specific areas'' 
proposed for designation, as well as Navassa Island and FGBNMS 
(discussed later), as management and protection requirements can vary 
from area to area based on such factors as the legal authorities 
applicable to areas and the location of the area within the occupied 
range.
    Suitable habitat available for larval settlement and recruitment, 
and asexual fragment reattachment, of these coral species, is 
particularly susceptible to impacts from human activity because of the 
shallow water depth range (MHW to 30 m) in which elkhorn and staghorn 
corals commonly grow. The proximity of this habitat to coastal areas 
subject this feature to impacts from multiple activities including, but 
not limited to, dredging and disposal activities, stormwater run-off, 
coastal and maritime construction, land development, wastewater and 
sewage outflow discharges, point and non-point source pollutant 
discharges, fishing, placement of large vessel anchorages, and 
installation of submerged pipelines or cables. The impacts from these 
activities, combined with those from natural factors (e.g., major storm 
events), significantly affect the quality and quantity of available 
substrate for these threatened species to successfully sexually and 
asexually reproduce. We concluded that the PCE is currently and will 
likely continue to be negatively impacted by some or all of these 
factors in all four specific areas.
    Overfishing of herbivorous fishes and the mass die-off of long-
spined sea urchin Diadema antillarum are considered two of the primary 
contributing factors to the recent shift in benthic community structure 
from the dominance of stony corals to that of fleshy macroalgae on 
Caribbean coral reefs. In the absence of fish and urchin grazing or at 
very low grazing pressures,

[[Page 6902]]

coral larvae, algae, and numerous other epibenthic organisms settle in 
high numbers, but most young, developing coral larvae are rapidly 
outcompeted for space, and their mortality levels are high (Sammarco, 
1985). The weight of evidence suggests that competition between algae 
and corals is widespread on coral reefs and is largely mediated by 
herbivory (McCook, et al., 2001).
    An additional factor contributing to the dominance of fleshy 
macroalgae as major space-occupiers on many Caribbean coral reefs is 
nutrient enrichment. Nutrients are added to coral reefs from both point 
sources (readily identifiable inputs where pollutants are discharged to 
receiving surface waters from a pipe or drain) and non-point sources 
(inputs that occur over a wide area and are associated with particular 
land uses). Anthropogenic sources of nutrients include sewage, 
stormwater and agricultural runoff, river discharge, and groundwater; 
however, natural oceanographic sources like internal waves and 
upwelling also distribute nutrients on coral reefs. Coral reefs have 
been considered to be generally nutrient-limited systems, meaning that 
levels of accessible nitrogen and phosphorus limit the rates of 
macroalgae growth. When nutrient levels are raised in such a system, 
growth rates of fleshy macroalgae can be expected to increase, and this 
can yield imbalance and changes in community structure.
    The anthropogenic source routes for nutrients may also bring 
additional sediments into the coral reef environment. Sources of 
sediment include erosion of coastline, resuspension of bottom 
sediments, terrestrial run-off (following clearing of mangroves and 
deforestation of hillsides), beach renourishment, and nearshore 
dredging and disposal for coastal construction projects and for 
navigation purposes. Sediment deposition and accumulation affect the 
overall amount of suitable substrate available for larval settlement, 
recruitment, and fragment reattachment (Babcock and Davies, 1991), and 
both sediment composition and deposition affect the survival of 
juvenile corals (Fabricius, et al., 2003).
    The major category of habitat-related activities that may affect 
the PCE for the two listed corals is water quality management. 
Activities within this category have the potential to negatively affect 
the PCE for elkhorn and staghorn corals by altering the quality and 
availability of suitable substrate for larval settlement, recruitment, 
and fragment reattachment. Nutrient enrichment, via sewage, stormwater 
and agricultural runoff, river discharge, and groundwater, is a major 
factor contributing to this shift in benthic community structure and 
preemption of available substrate suitable for larval settlement, 
recruitment, and asexual fragment reattachment. Additionally, 
sedimentation resulting from land-use practices and from dredging and 
disposal activities in all four specific areas reduces the overall 
availability and quality of substrate suitable for successful sexual 
and asexual reproduction by the two acroporid corals. Thus, the PCE 
currently needs and will likely continue to need special management or 
protection.
    Although they fall within U.S. jurisdiction and may contain the 
PCE, we are not proposing to include FGBNMS and Navassa National 
Wildlife Refuge in our critical habitat designation, because we do not 
believe the PCE in these areas requires special management 
considerations or protections. Both FGBNMS and Navassa Island are 
remote marine protected areas and are not currently exposed to the 
negative impacts and conditions needing management discussed for the 
other areas above. Additionally, based on available information, we do 
not expect the PCE found within these two protected areas to experience 
negative impacts from human or natural sources that would diminish the 
feature's conservation value to the two coral species.

Activities That May Be Affected

    Section 4(b)(8) of the ESA requires that we describe briefly and 
evaluate, in any proposed or final regulation to designate critical 
habitat, those activities that may destroy or adversely modify such 
habitat or that may be affected by such designation. A wide variety of 
activities may affect critical habitat and, when carried out, funded, 
or authorized by a Federal agency, will require an ESA section 7 
consultation. Such activities include, but are not limited to, dredging 
and disposal, beach renourishment, large vessel anchorages, submarine 
cable/pipeline installation and repair, oil and gas exploration, 
pollutant discharge, and oil spill prevention and response. Notably, 
all the activities identified that may affect the critical habitat may 
also affect the species themselves, if present within the action area 
of a proposed Federal action.
    We believe this proposed critical habitat designation will provide 
Federal agencies, private entities, and the public with clear 
notification of critical habitat for elkhorn and staghorn corals and 
the boundaries of the habitat. This designation will allow Federal 
agencies and others to evaluate the potential effects of their 
activities on critical habitat to determine if ESA section 7 
consultation with NMFS is needed given the specific definition of the 
PCE above. Consistent with recent agency guidance on conducting adverse 
modification analyses (NMFS, 2005), we will apply the statutory 
provisions of the ESA, including those in section 3 that define 
``critical habitat'' and ``conservation,'' to determine whether a 
proposed future action might result in the destruction or adverse 
modification of critical habitat.

Application of ESA Section 4(a)(3)(B)(I)

    Section 4(a)(3)(B) prohibits designating as critical habitat any 
lands or other geographical areas owned or controlled by the Department 
of Defense (DOD), or designated for its use, that are subject to an 
integrated natural resources management plan (INRMP), if we determine 
that such a plan provides a benefit to the coral species (16 U.S.C. 
1533(a)(3)(B)). The legislative history to this provision explains:

     ``The conferees would expect the [Secretary] to assess 
an INRMP's potential contribution to species conservation, giving 
due regard to those habitat protection, maintenance, and improvement 
projects and other related activities specified in the plan that 
address the particular conservation and protection needs of the 
species for which critical habitat would otherwise be proposed. 
Consistent with current practice, the Secretary would establish 
criteria that would be used to determine if an INRMP benefits the 
listed species for which critical habitat would be proposed'' 
(Conference Committee report, 149 Cong. Rec. H. 10563; November 6, 
2003).

    No areas within the specific areas being proposed for designation 
are covered by relevant INRMPs. Although Naval Air Station Key West 
(NASKW) is within the specific areas being proposed for designation, 
the current INRMP was adopted in 2001 and does not address listed 
corals, nor corals in general. NASKW is in the process of updating the 
2001 INRMP and has issued a draft of the document to NMFS for review. 
If the draft INRMP were to become final and provide a benefit to the 
two corals as described above, then we would not designate critical 
habitat within the boundaries covered by the INRMP. NASKW is, however, 
being proposed for exclusion pursuant to section 4(b)(2), as explained 
below.

Application of ESA Section 4(b)(2)

    The foregoing discussion described the specific areas within U.S. 
jurisdiction that fall within the ESA section 3(5) definition of 
critical habitat in that they contain the physical feature

[[Page 6903]]

essential to the corals' conservation that may require special 
management considerations or protection. Before including areas in a 
designation, section 4(b)(2) of the ESA requires the Secretary to take 
into consideration the economic impact, impact on national security, 
and any other relevant impacts of designation of any particular area. 
Additionally, the Secretary has the discretion to exclude any area from 
designation if he determines the benefits of exclusion (that is, 
avoiding some or all of the impacts that would result from designation) 
outweigh the benefits of designation based upon the best scientific and 
commercial data available. The Secretary may not exclude an area from 
designation if exclusion will result in the extinction of the species. 
Because the authority to exclude is discretionary, exclusion is not 
required for any particular area under any circumstances.
    The analysis of impacts below summarizes the comprehensive analysis 
contained in our Draft Section 4(b)(2) Report, first by considering 
economic, national security, and other relevant impacts that we 
projected would result from including each of the four specific areas 
in the proposed critical habitat designation. This consideration 
informed our decision on whether to exercise our discretion to propose 
excluding particular areas from the designation. Both positive and 
negative impacts were identified and considered (these terms are used 
interchangeably with benefits and costs, respectively). Impacts were 
evaluated in quantitative terms where feasible, but qualitative 
appraisals were used where that is more appropriate to particular 
impacts.
    The ESA does not define what ``particular areas'' means in the 
context of section 4(b)(2), or the relationship of particular areas to 
``specific areas'' that meet the statute's definition of critical 
habitat. As there was no biological basis to subdivide the four 
specific critical habitat areas into smaller units, we treated these 
areas as the ``particular areas'' for our initial consideration of 
impacts of designation.

Impacts of Designation

    The primary impacts of a critical habitat designation result from 
the ESA section 7(a)(2) requirement that Federal agencies ensure their 
actions are not likely to result in the destruction or adverse 
modification of critical habitat. Determining these impacts is 
complicated by the fact that section 7(a)(2) also requires that Federal 
agencies ensure their actions are not likely to jeopardize the species' 
continued existence. One incremental impact of designation is the 
extent to which Federal agencies modify their proposed actions to 
ensure they are not likely to destroy or adversely modify the critical 
habitat beyond any modifications they would make because of listing and 
the jeopardy requirement. When a modification would be required due to 
impacts to both the species and critical habitat, the impact of the 
designation may be co-extensive with the ESA listing of the species. 
Additional impacts of designation include state and local protections 
that may be triggered as a result of designation, and positive impacts 
that may arise from conservation of the species and their habitat, and 
education of the public to the importance of an area for species 
conservation.
    A Draft ESA 4(b)(2) Report describes the impacts analysis in detail 
(NMFS, 2007). The report describes the projected future Federal 
activities that would trigger section 7 consultation requirements 
because they may affect the PCE. Additionally, the report describes the 
project modifications we identified that may reduce impacts to the PCE, 
and states whether the modifications are more likely to be solely a 
result of the critical habitat designation or co-extensive with another 
regulation, including the ESA listing of the species. The report also 
identifies the potential national security and other relevant impacts 
that may arise due to the proposed critical habitat designation. This 
report is available on NMFS' Southeast Region Web site at https://
sero.nmfs.noaa.gov/pr/esa/acropora.htm.

Economic Impacts

    As discussed above, economic impacts of the critical habitat 
designation result through implementation of section 7 of the ESA in 
consultations with Federal agencies to ensure their proposed actions 
are not likely to destroy or adversely modify critical habitat. These 
economic impacts may include both administrative and project 
modification costs; economic impacts that may be associated with the 
conservation benefits of the designation are described later.
    Because elkhorn and staghorn corals are newly listed and we lack a 
lengthy consultation history for these species, we needed to make 
assumptions about the types of future Federal activities that might 
require section 7 consultation under the ESA. We examined the 
consultation record over the last 10 years, as compiled in our Public 
Consultation Tracking System (PCTS) database, to identify types of 
Federal activities that have the potential to adversely affect elkhorn 
or staghorn coral critical habitat. We request Federal action agencies 
to provide us with information on future consultations if our 
assumptions omitted any future actions likely to affect the proposed 
critical habitat. We identified 13 categories of activities conducted 
by 7 Federal action agencies: Airport repair and construction; 
anchorages; construction of new aids to navigation; beach nourishment 
and bank stabilization; coastal construction; discharges to navigable 
waters; dredging and disposal; fishery management; maintenance 
construction; maintenance dredging and disposal; military installation 
management; resource management; and development or modification of 
water quality standards. Notably, all categories of projected future 
actions that may trigger consultation because they have the potential 
to adversely affect the PCE also have the potential to adversely affect 
the corals themselves. There are no categories of activities that would 
trigger consultation on the basis of the proposed critical habitat 
designation alone. However, it is feasible that a specific future 
project within a category of activity would have impacts on critical 
habitat but not on the species. Because the total surface area covered 
by the proposed PCE (although unquantified) is far larger than the 
total surface area on which the corals (again unquantified) currently 
occur, it is likely there will be more consultations with impacts on 
critical habitat than on the species. Nonetheless, it was impossible to 
determine how many of those projects there may be over the 10-year 
horizon of our impacts analysis.
    To avoid underestimating impacts, we assumed that all of the 
projected future actions in these categories will require formal 
consultations for estimation of both administrative and project 
modification costs. This assumption likely results in an overestimation 
of the number of future formal consultations.
    We next considered the range of modifications we might seek for 
these activities to avoid adverse modification of elkhorn and staghorn 
coral critical habitat. We identified 13 potential project 
modifications that we may require to reduce impacts to the PCE through 
section 7 consultation under the ESA. To be conservative in estimating 
impacts, we assumed that project modifications would be required to 
address adverse effects from all projected future agency actions 
requiring consultation. Although we made the assumption that all 
potential project modifications would be required by NMFS, not all of 
the modifications

[[Page 6904]]

identified for a specific category of activity would be necessary for 
an individual project, so we were unable to identify the exact 
modification or combinations of modifications that would be required 
for all future actions.
    We also identified whether a project modification would be required 
due to the listing of the species or another existing regulatory 
authority to determine if the cost of the project modification was 
likely to be co-extensive or incremental. Several project modifications 
(i.e., conditions monitoring, diver education, horizontal directional 
drilling (HDD), tunneling or anchoring cables and pipelines, sediment 
control measures, fishing gear maintenance, and water quality standard 
modification) were characterized as fully co-extensive with the listing 
of the species or other existing statutory or regulatory authority, 
because the nature of the actions that would require these 
modifications typically involve a large action area likely to include 
both the PCE and either the listed corals or other coral reef 
resources. Other project modifications (i.e., project reloc