[Federal Register Volume 80, Number 234 (Monday, December 7, 2015)]
[Notices]
[Pages 75978-75997]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-30745]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XE271


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to the Bravo Wharf Recapitalization 
Project

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 the U.S. Navy (Navy) for 
authorization to take marine mammals incidental to construction 
activities as part of a wharf recapitalization project. Pursuant to the 
Marine Mammal Protection Act (MMPA), NMFS is requesting public comment 
on its proposal to issue an incidental harassment authorization (IHA) 
to the Navy to incidentally take marine mammals, by Level B harassment 
only, during the specified activity.

DATES: Comments and information must be received no later than January 
6, 2016.

ADDRESSES: Comments on this proposal 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 to the Internet at 
www.nmfs.noaa.gov/pr/permits/incidental/construction.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: Laura McCue, Office of Protected 
Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Availability

    An electronic copy of the Navy's application and supporting 
documents, as well as a list of the references cited in this document, 
may be obtained by visiting the Internet at: www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. In case of problems accessing 
these documents, please call the contact listed above.

National Environmental Policy Act

    The Navy has prepared a draft Environmental Assessment (Wharf Bravo 
Recapitalization at Naval Station Mayport, Jacksonville, FL) in 
accordance with the National Environmental Policy Act (NEPA) and the 
regulations published by the Council on Environmental Quality. It is 
posted at the aforementioned site. NMFS will independently evaluate the 
EA and determine whether or not to adopt it. We may prepare a separate 
NEPA analysis and incorporate relevant portions of Navy's EA by 
reference. Information in the Navy's application, EA, and this notice 
collectively provide the environmental information related to proposed 
issuance of this IHA for public review and comment. We will review all 
comments submitted in response to this notice as we complete the NEPA 
process, including a decision of whether to sign a Finding of No 
Significant Impact (FONSI), prior to a final decision on the incidental 
take authorization request.

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 by U.S. 
citizens who engage in a specified activity (other than commercial 
fishing) within a specified area, the incidental, but not intentional, 
taking of small numbers of marine mammals, providing that certain 
findings are made and the necessary prescriptions are established.
    The incidental taking of small numbers of marine mammals may be 
allowed only if NMFS (through authority delegated by the Secretary) 
finds that the total taking by the specified activity during the 
specified time period will (i) have a negligible impact on the species 
or stock(s) and (ii) not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant). Further, the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such taking 
must be set forth, either in specific regulations or in an 
authorization.
    The allowance of such incidental taking under section 101(a)(5)(A), 
by harassment, serious injury, death, or a combination thereof, 
requires that regulations be established. Subsequently, a Letter of 
Authorization may be issued pursuant to the prescriptions established 
in such regulations, providing that the level of taking will be 
consistent with the findings made for the total taking allowable under 
the specific regulations. Under section 101(a)(5)(D), NMFS may 
authorize such incidental taking by harassment only, for periods of not 
more than one year, pursuant to requirements and conditions contained 
within an IHA. The establishment of prescriptions through either 
specific regulations or an authorization requires notice and 
opportunity for public comment.
    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.'' 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].''

Summary of Request

    On July 21, 2015, we received a request from the Navy for 
authorization of the taking, by Level B harassment only, of marine 
mammals, incidental to pile driving in association with the

[[Page 75979]]

Bravo Wharf recapitalization project at Naval Station Mayport, Florida 
(NSM). That request was modified on November 4 and November 10, and a 
final version, which we deemed adequate and complete, was submitted on 
November 17. In-water work associated with the project is expected to 
be completed within the one-year timeframe of the proposed IHA (October 
15, 2016 through September 30, 2017).
    The use of both vibratory and impact pile driving is expected to 
produce underwater sound at levels that have the potential to result in 
behavioral harassment of marine mammals. One species of marine mammal 
has the potential to be affected by the specified activities: 
bottlenose dolphin (Tursiops truncatus truncatus). This species may 
occur year-round in the action area.
    Similar wharf construction and pile driving activities in Naval 
Station Mayport have been authorized by NMFS in the past. The first 
authorization was effective between September 1, 2014 through August 
31, 2015, and the second authorization, which is currently ongoing, is 
effective from September 8, 2015 through September 7, 2016.

Description of the Specified Activity

Overview

    Bravo Wharf is a medium draft, general purpose berthing wharf that 
was constructed in 1970 and lies at the western edge of the NSM turning 
basin. Bravo Wharf is approximately 2,000 ft long, 125 ft wide, and has 
a berthing depth of 50 ft mean lower low water. The wharf is one of two 
primary deep draft berths at the basin and is capable of berthing ships 
up to and including large amphibious ships; it is one of three primary 
ordnance handling berths at the basin. The wharf is a diaphragm steel 
sheet pile cell structure with a concrete apron, partial concrete 
encasement of the piling and asphalt paved deck. The wharf is currently 
in poor condition due to advanced deterioration of the steel sheeting 
and lack of corrosion protection. This structural deterioration has 
resulted in the institution of load restrictions within 60 ft of the 
wharf face. The purpose of this project is to complete necessary 
repairs to Bravo Wharf. Please refer to the Navy's application for a 
schematic of the project plan.

Dates and Duration

    The total project is expected to require a maximum of 130 days of 
in-water pile driving. The project may require up to 24 months for 
completion; in-water activities are limited to a maximum of 130 days, 
separated into two phases. If in-water work will extend beyond the 
effective dates of the IHA, a second IHA application will be submitted 
by the Navy. There will be a maximum of 110 days for vibratory pile 
driving (seventy three days in phase I and thirty seven days in phase 
II), and a contingent 20 days of impact pile driving. The specified 
activities are expected to occur between October 1, 2016 and September 
30, 2017.

Specific Geographic Region

    NSM is located in northeastern Florida, at the mouth of the St. 
Johns River and adjacent to the Atlantic Ocean (see Figures 2-1 and 2-2 
of the Navy's application). The St. Johns River is the longest river in 
Florida, with the final 35 mi flowing through the city of Jacksonville. 
This portion of the river is significant for commercial shipping and 
military use. At the mouth of the river, near the action area, the 
Atlantic Ocean is the dominant influence and typical salinities are 
above 30 ppm. Outside the river mouth, in nearshore waters, moderate 
oceanic currents tend to flow southward parallel to the coast. Sea 
surface temperatures range from around 16 [deg]C in winter to 28 [deg]C 
in summer.
    The specific action area consists of the NSM turning basin, an area 
of approximately 2,000 by 3,000 ft containing ship berthing facilities 
at sixteen locations along wharves around the basin perimeter. The 
basin was constructed during the early 1940s by dredging the eastern 
part of Ribault Bay (at the mouth of the St. Johns River), with dredge 
material from the basin used to fill parts of the bay and other low-
lying areas in order to elevate the land surface. The basin is 
currently maintained through regular dredging at a depth of 50 ft, with 
depths at the berths ranging from 30-50 ft. The turning basin, 
connected to the St. Johns River by a 500-ft-wide entrance channel, 
will largely contain sound produced by project activities, with the 
exception of sound propagating east into nearshore Atlantic waters 
through the entrance channel (see Figure 2-2 of the Navy's 
application). Bravo Wharf is located in the western corner of the 
Mayport turning basin.

Detailed Description of Activities

    In order to rehabilitate Bravo Wharf, the Navy proposes to install 
a new steel sheet pile bulkhead at Bravo Wharf. The project consists of 
installing a total of approximately 880 single sheet piles (Phase I--
berths B-2 and B-3: 590; Phase II--berth B-1: 290). The wall will be 
anchored at the top and fill consisting of clean gravel and flowable 
concrete fill will be placed behind the wall. A concrete cap will be 
formed along the top and outside face of the wall to tie the entire 
structure together and provide a berthing surface for vessels. The new 
bulkhead will be designed for a fifty-year service life.
    All piles would be driven by vibratory hammer, although impact pile 
driving may be used as a contingency in cases when vibratory driving is 
not sufficient to reach the necessary depth. In the unlikely event that 
impact driving is required, either impact or vibratory driving could 
occur on a given day, but concurrent use of vibratory and impact 
drivers would not occur. The Navy estimates that a total of 130 in-
water work days may be required to complete pile driving activity, 
which includes twenty days for contingency impact driving, if 
necessary.

Description of Marine Mammals in the Area of the Specified Activity

    There are four marine mammal species which may inhabit or transit 
through the waters nearby NSM at the mouth of the St. Johns River and 
in nearby nearshore Atlantic waters. These include the bottlenose 
dolphin, Atlantic spotted dolphin (Stenella frontalis), North Atlantic 
right whale (Eubalaena glacialis), and humpback whale (Megaptera 
novaeangliae). Multiple additional cetacean species occur in South 
Atlantic waters but would not be expected to occur in shallow nearshore 
waters of the action area. Table 1 lists the marine mammal species with 
expected potential for occurrence in the vicinity of NSM during the 
project timeframe and summarizes key information regarding stock status 
and abundance. Taxonomically, we follow Committee on Taxonomy (2014). 
Please see NMFS' Stock Assessment Reports (SAR), available at 
www.nmfs.noaa.gov/pr/sars, for more detailed accounts of these stocks' 
status and abundance. Please also refer to NMFS' Web site 
(www.nmfs.noaa.gov/pr/species/mammals) for generalized species accounts 
and to the Navy's Marine Resource Assessment for the Charleston/
Jacksonville Operating Area, which documents and describes the marine 
resources that occur in Navy operating areas of the Southeast (DoN, 
2008). The document is publicly available at www.navfac.navy.mil/products_and_services/ev/products_and_services/marine_resources/marine_resource_assessments.html (accessed November 2, 2015).
    In the species accounts provided here, we offer a brief 
introduction to the species and relevant stock as well as available 
information regarding population trends and threats, and

[[Page 75980]]

describe any information regarding local occurrence. Multiple stocks of 
bottlenose dolphins may be present in the action area, either 
seasonally or year-round, and are described further below. We first 
address the three other species that may occur in the action area.

                                           Table 1--Marine Mammals Potentially Present in the Vicinity of NSM
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                                                                                     Stock abundance  (CV,
              Species                         Stock             ESA/MMPA status;       Nmin, most recent     PBR \3\   Annual M/   Relative occurrence;
                                                              strategic  (Y/N) \1\   abundance survey) \2\               SI \4\    season of occurrence
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                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
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                                                                    Family Balaenidae
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North Atlantic right whale.........  Western North Atlantic  E/D; Y                 476 (0; 476; 2013)....          1        4.3  Rare inshore, regular
                                      \5\.                                                                                         near/offshore; Nov-
                                                                                                                                   Apr.
Humpback whale.....................  Gulf of Maine.........  E/D; Y                 823 (0; 823; 2008)....        2.7        7.6  Rare; Fall-Spring.
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                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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                                                                   Family Delphinidae
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Atlantic spotted dolphin...........  Western North Atlantic  -; N                   44,715 (0.43; 31,610;         316          0  Rare; year-round.
                                                                                     2011).
Common bottlenose dolphin..........  Western North Atlantic  -; N                   77,532 (0.4; 56,053;          561       43.9  Rare; year-round.
                                      Offshore.                                      2011).
                                     Western North Atlantic  -/D; Y                 9,173 (0.46; 6,326;            63       0-12  Possibly common; \8\
                                      Coastal, Southern                              2010-11).                                     Jan-Mar.
                                      Migratory.
                                     Western North Atlantic  -/D; Y                 1,219 (0.67; 730; 2010-         7        0.4  Possibly common; \8\
                                      Coastal, Northern                              11).                                          year-round.
                                      Florida.
                                     Jacksonville Estuarine  -; Y                   412 \7\ (0.06; unk;        undet.        1.2  Possibly common; \8\
                                      System \6\.                                    1994-97).                                     year-round.
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\1\ 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 (see
  footnote 3) 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\ CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable. For certain stocks, abundance
  estimates are actual counts of animals and there is no associated CV. The most recent abundance survey that is reflected in the abundance estimate is
  presented; there may be more recent surveys that have not yet been incorporated into the estimate.
\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' SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
  fisheries, subsistence hunting, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value. All
  values presented here are from the draft 2015 SARs (www.nmfs.noaa.gov/pr/sars/draft.htm).
\5\ Abundance estimates (and resulting PBR values) for these stocks are new values presented in the draft 2015 SARs. This information was made available
  for public comment and is currently under review and therefore may be revised prior to finalizing the 2015 SARs. However, we consider this information
  to be the best available for use in this document.
\6\ Abundance estimates for these stocks are greater than eight years old and are therefore not considered current. PBR is considered undetermined for
  these stocks, as there is no current minimum abundance estimate for use in calculation. We nevertheless present the most recent abundance estimates
  and PBR values, as these represent the best available information for use in this document.
\7\ This abundance estimate is considered an overestimate because it includes non- and seasonally-resident animals.
\8\ Bottlenose dolphins in general are common in the project area, but it is not possible to readily identify them to stock. Therefore, these three
  stocks are listed as possibly common as we have no information about which stock commonly only occurs.

    Northern Right whales occur in sub-polar to temperate waters in all 
major ocean basins in the world with a clear migratory pattern, 
occurring in high latitudes in summer (feeding) and lower latitudes in 
winter (breeding). North Atlantic right whales exhibit extensive 
migratory patterns, traveling along the eastern seaboard from calving 
grounds off Georgia and northern Florida to northern feeding areas off 
of the northeast U.S. and Canada in March/April and returning in 
November/December. Migrations are typically within 30 nmi of the 
coastline and in waters less than 50 m deep. Although this migratory 
pattern is well known, winter distribution for most of the population--
the non-calving portion--is poorly known, as many whales are not 
observed on the calving grounds. It is unknown where these animals 
spend the winter, although they may occur further offshore or may 
remain on foraging grounds during winter (Morano et al., 2012). During 
the winter calving period, right whales occur regularly in offshore 
waters of northeastern Florida. Critical habitat for right whales in 
the southeast (as identified under the ESA) is designated to protect 
calving grounds, and encompasses waters from the coast out to 15 nmi 
offshore from Mayport. More rarely, right whales have been observed 
entering the mouth of the St. Johns River for brief periods of time 
(Schweitzer and Zoodsma, 2011). Right whales are not present in the 
region outside of the winter calving season.
    Humpback whales are a cosmopolitan species that migrate seasonally 
between warm-water (tropical or sub-tropical) breeding and calving 
areas in winter months and cool-water (temperate to sub-Arctic/
Antarctic) feeding areas in summer months (Gendron and Urban, 1993). 
They tend to occupy shallow, coastal waters, although migrations are

[[Page 75981]]

undertaken through deep, pelagic waters. In the North Atlantic, 
humpback whales are known to aggregate in six summer feeding areas 
representing relatively discrete subpopulations (Clapham and Mayo, 
1987), which share common wintering grounds in the Caribbean (and to a 
lesser extent off of West Africa) (Winn et al., 1975; Mattila et al., 
1994; Palsb[oslash]ll et al., 1997; Smith et al., 1999; Stevick et al., 
2003; Cerchio et al., 2010). These populations or aggregations range 
from the Gulf of Maine in the west to Norway in the east, and the 
migratory range includes the east coast of the U.S. and Canada. The 
only managed stock in U.S. waters is the Gulf of Maine feeding 
aggregation, although other stocks occur in Canadian waters (e.g., Gulf 
of St. Lawrence feeding aggregation), and it is possible that whales 
from other stocks could occur in U.S. waters. Significant numbers of 
whales do remain in mid- to high-latitude waters during the winter 
months (Clapham et al., 1993; Swingle et al., 1993), and there have 
been a number of humpback sightings in coastal waters of the 
southeastern U.S. during the winter (Wiley et al., 1995; Laerm et al., 
1997; Waring et al., 2014). According to Waring et al. (2014), it is 
unclear whether the increased numbers of sightings represent a 
distributional change, or are simply due to an increase in sighting 
effort and/or whale abundance. These factors aside, the humpback whale 
remains relatively rare in U.S. coastal waters south of the mid-
Atlantic region, and is considered rare to extralimital in the action 
area. Any occurrences in the region would be expected in fall, winter, 
and spring during migration, as whales are unlikely to occur so far 
south during the summer feeding season.
    Neither the humpback whale nor the right whale would occur within 
the turning basin, and only the right whale has been observed to occur 
as far inshore as the mouth of the St. Johns River. Therefore, the 
potential for interaction with these species is unlikely. When 
considering frequency of occurrence, size of ensonified area (less than 
one square kilometer during both vibratory (approximately 0.61 km\2\) 
and impact driving (0.51 km\2\)), and duration (seventy three days in 
phase I, and thirty seven days in phase II), we consider the 
possibility for harassment of humpback and right whales to be 
discountable. Therefore, the humpback whale and right whale are 
excluded from further analysis and are not discussed further in this 
document.
    Atlantic spotted dolphins are distributed in tropical and warm 
temperate waters of the western North Atlantic predominantly over the 
continental shelf and upper slope, from southern New England through 
the Gulf of Mexico (Leatherwood et al., 1976). Spotted dolphins in the 
Atlantic Ocean and Gulf of Mexico are managed as separate stocks. The 
Atlantic spotted dolphin occurs in two forms which may be distinct sub-
species (Perrin et al., 1987; Rice, 1998); a larger, more heavily 
spotted form inhabits the continental shelf inside or near the 200-m 
isobath and is the only form that would be expected to occur in the 
action area. Although typically observed in deeper waters, spotted 
dolphins of the western North Atlantic stock do occur regularly in 
nearshore waters south of the Chesapeake Bay (Mullin and Fulling, 
2003). Specific data regarding seasonal occurrence in the region of 
activity is lacking, but higher numbers of individuals have been 
reported to occur in nearshore waters of the Gulf of Mexico from 
November to May, suggesting seasonal migration patterns (Griffin and 
Griffin, 2003).
    From recent observation reports from the Navy from previous 
construction activity at Naval Station Mayport, no spotted dolphins 
were observed. Similarly, dolphin research studies that have been 
conducted in the area also reported zero observed spotted dolphins in 
the project area (Gibson, pers. comm.). We consider the likelihood of 
Atlantic spotted dolphins being impacted by the construction activities 
to be discountable based on this information, combined with the zero 
estimated exposures (density: 0.005240/km\2\). Therefore, spotted 
dolphins are also excluded from further analysis and are not discussed 
further in this document.
    The following summarizes the population status and abundance of the 
remaining species.

Bottlenose Dolphin

    Bottlenose dolphins are found worldwide in tropical to temperate 
waters and can be found in all depths from estuarine inshore to deep 
offshore waters. Temperature appears to limit the range of the species, 
either directly, or indirectly, for example, through distribution of 
prey. Off North American coasts, common bottlenose dolphins are found 
where surface water temperatures range from about 10 [deg]C to 32 
[deg]C. In many regions, including the southeastern U.S., separate 
coastal and offshore populations are known. There is significant 
genetic, morphological, and hematological differentiation evident 
between the two ecotypes (e.g., Walker, 1981; Duffield et al., 1983; 
Duffield, 1987; Hoelzel et al., 1998), which correspond to shallow, 
warm water and deep, cold water. Both ecotypes have been shown to 
inhabit the western North Atlantic (Hersh and Duffield, 1990; Mead and 
Potter, 1995), where the deep-water ecotype tends to be larger and 
darker. In addition, several lines of evidence, including photo-
identification and genetic studies, support a distinction between 
dolphins inhabiting coastal waters near the shore and those present in 
the inshore waters of bays, sounds and estuaries. This complex 
differentiation of bottlenose dolphin populations is observed 
throughout the Atlantic and Gulf of Mexico coasts where bottlenose 
dolphins are found, although estuarine populations have not been fully 
defined.
    In the Mayport area, four stocks of bottlenose dolphins are 
currently managed, none of which are protected under the ESA. Of the 
four stocks--offshore, southern migratory coastal, northern Florida 
coastal, and Jacksonville estuarine system--only the latter three are 
likely to occur in the action area. Bottlenose dolphins typically occur 
in groups of 2-15 individuals (Shane et al., 1986; Kerr et al., 2005). 
Although significantly larger groups have also been reported, smaller 
groups are typical of shallow, confined waters. In addition, such 
waters typically support some degree of regional site fidelity and 
limited movement patterns (Shane et al., 1986; Wells et al., 1987). 
Observations made during marine mammal surveys conducted during 2012-
2013 in the Mayport turning basin show bottlenose dolphins typically 
occurring individually or in pairs, or less frequently in larger 
groups. The maximum observed group size during these surveys is six, 
while the mode is one. Navy observations indicate that bottlenose 
dolphins rarely linger in a particular area in the turning basin, but 
rather appear to move purposefully through the basin and then leave, 
which likely reflects a lack of biological importance for these 
dolphins in the basin. Based on currently available information, it is 
not possible to determine the stock to which the dolphins occurring in 
the action area may belong. These stocks are described in greater 
detail below.
    Western North Atlantic Offshore--This stock, consisting of the 
deep-water ecotype or offshore form of bottlenose dolphin in the 
western North Atlantic, is distributed primarily along the outer 
continental shelf and continental slope, but has been documented to 
occur relatively close to shore (Waring et al., 2014). The separation 
between offshore and coastal morphotypes varies

[[Page 75982]]

depending on location and season, with the ranges overlapping to some 
degree south of Cape Hatteras. Based on genetic analysis, Torres et al. 
(2003) found a distributional break at 34 km from shore, with the 
offshore form found exclusively seaward of 34 km and in waters deeper 
than 34 m. Within 7.5 km of shore, all animals were of the coastal 
morphotype. More recently, coastwide, systematic biopsy collection 
surveys were conducted during the summer and winter to evaluate the 
degree of spatial overlap between the two morphotypes. South of Cape 
Hatteras, spatial overlap was found although the probability of a 
sampled group being from the offshore morphotype increased with 
increasing depth, and the closest distance for offshore animals was 7.3 
km from shore, in water depths of 13 m just south of Cape Lookout 
(Garrison et al., 2003). The maximum radial distance for the largest 
ZOI is approximately 1.2 km (Table 3); therefore, it is unlikely that 
any individuals of the offshore morphotype would be affected by project 
activities. In terms of water depth, the affected area is generally in 
the range of the shallower depth reported for offshore dolphins by 
Garrison et al. (2003), but is far shallower than the depths reported 
by Torres et al. (2003). South of Cape Lookout, the zone of spatial 
overlap between offshore and coastal ecotypes is generally considered 
to occur in water depths between 20-100 m (Waring et al., 2014), which 
is generally deeper than waters in the action area. This stock is thus 
excluded from further analysis.
    Western North Atlantic Coastal, Southern Migratory--The coastal 
morphotype of bottlenose dolphin is continuously distributed from the 
Gulf of Mexico to the Atlantic and north approximately to Long Island 
(Waring et al., 2014). On the Atlantic coast, Scott et al. (1988) 
hypothesized a single coastal stock, citing stranding patterns during a 
high mortality event in 1987-88 and observed density patterns. More 
recent studies demonstrate that there is instead a complex mosaic of 
stocks (Zolman, 2002; McLellan et al., 2002; Rosel et al., 2009). The 
coastal morphotype was managed by NMFS as a single stock until 2009, 
when it was split into five separate stocks, including northern and 
southern migratory stocks. The original, single stock of coastal 
dolphins recognized from 1995-2001 was listed as depleted under the 
MMPA as a result of a 1987-88 mortality event. That designation was 
retained when the single stock was split into multiple coastal stocks. 
Therefore, all coastal stocks of bottlenose dolphins are listed as 
depleted under the MMPA, and are also considered strategic stocks.
    According to the Scott et al. (1988) hypothesis, a single stock was 
thought to migrate seasonally between New Jersey (summer) and central 
Florida (winter). Instead, it was more recently determined that a mix 
of resident and migratory stocks exists, with the migratory movements 
and spatial distribution of the southern migratory stock the most 
poorly understood of these. Stable isotope analysis and telemetry 
studies provide evidence for seasonal movements of dolphins between 
North Carolina and northern Florida (Knoff, 2004; Waring et al., 2014), 
and genetic analyses and tagging studies support differentiation of 
northern and southern migratory stocks (Rosel et al., 2009; Waring et 
al., 2014). Although there is significant uncertainty regarding the 
southern migratory stock's spatial movements, telemetry data indicates 
that the stock occupies waters of southern North Carolina (south of 
Cape Lookout) during the fall (October-December). In winter months 
(January-March), the stock moves as far south as northern Florida where 
it overlaps spatially with the northern Florida coastal and 
Jacksonville estuarine system stocks. In spring (April-June), the stock 
returns north to waters of North Carolina, and is presumed to remain 
north of Cape Lookout during the summer months. Therefore, the 
potential exists for harassment of southern migratory dolphins, most 
likely during the winter only.
    Bottlenose dolphins are ubiquitous in coastal waters from the mid-
Atlantic through the Gulf of Mexico, and therefore interact with 
multiple coastal fisheries, including gillnet, trawl, and trap/pot 
fisheries. Stock-specific total fishery-related mortality and serious 
injury cannot be directly estimated because of the spatial overlap 
among stocks of bottlenose dolphins, as well as because of unobserved 
fisheries. The primary known source of fishery mortality for the 
southern migratory stock is the mid-Atlantic gillnet fishery (Waring et 
al., 2014). Between 2004 and 2008, 588 bottlenose dolphins stranded 
along the Atlantic coast between Florida and Maryland that could 
potentially be assigned to the southern migratory stock, although the 
assignment of animals to a particular stock is impossible in some 
seasons and regions due to spatial overlap amongst stocks (Waring et 
al., 2014). Many of these animals exhibited some evidence of human 
interaction, such as line/net marks, gunshot wounds, or vessel strike. 
In addition, nearshore and estuarine habitats occupied by the coastal 
morphotype are adjacent to areas of high human population and some are 
highly industrialized. It should also be noted that stranding data 
underestimate the extent of fishery-related mortality and serious 
injury because not all of the marine mammals that die or are seriously 
injured in fishery interactions are discovered, reported or 
investigated, nor will all of those that are found necessarily show 
signs of entanglement or other fishery interaction. The level of 
technical expertise among stranding network personnel varies widely as 
does the ability to recognize signs of fishery interactions. Finally, 
multiple resident populations of bottlenose dolphins have been shown to 
have high concentrations of organic pollutants (e.g., Kuehl et al., 
1991) and, despite little study of contaminant loads in migrating 
coastal dolphins, exposure to environmental pollutants and subsequent 
effects on population health is an area of concern and active research.
    Western North Atlantic Coastal, Northern Florida--Please see above 
for description of the differences between coastal and offshore 
ecotypes and the delineation of coastal dolphins into management 
stocks. The northern Florida coastal stock is one of five stocks of 
coastal dolphins and one of three known resident stocks (other resident 
stocks include South Carolina/Georgia and central Florida dolphins). 
The spatial extent of these stocks, their potential seasonal movements, 
and their relationships with estuarine stocks are poorly understood. 
During summer months, when the migratory stocks are known to be in 
North Carolina waters and further north, bottlenose dolphins are still 
seen in coastal waters of South Carolina, Georgia and Florida, 
indicating the presence of additional stocks of coastal animals. 
Speakman et al. (2006) documented dolphins in coastal waters off 
Charleston, South Carolina, that are not known resident members of the 
estuarine stock, and genetic analyses indicate significant differences 
between coastal dolphins from northern Florida, Georgia and central 
South Carolina (NMFS, 2001; Rosel et al., 2009). The northern Florida 
stock is thought to be present from approximately the Georgia-Florida 
border south to 29.4[deg] N. (Waring et al., 2014).
    The northern Florida coastal stock ventures into the St. Johns 
River in large numbers, but rarely moves past Naval Station Mayport. 
The mouth of the St. Johns River may serve as a foraging area for this 
stock and the Jacksonville estuarine stock (Gibson, pers. comm).

[[Page 75983]]

    The northern Florida coastal stock is susceptible to interactions 
with similar fisheries as those described above for the southern 
migratory stock, including gillnet, trawl, and trap/pot fisheries. From 
2004-08, 78 stranded dolphins were recovered in northern Florida 
waters, although it was not possible to determine whether there was 
evidence of human interaction for the majority of these (Waring et al., 
2014). The same concerns discussed above regarding underestimation of 
mortality hold for this stock and, as for southern migratory dolphins, 
pollutant loading is a concern.
    Jacksonville Estuarine System--Please see above for description of 
the differences between coastal and offshore ecotypes and the 
delineation of coastal dolphins into management stocks primarily 
inhabiting nearshore waters. The coastal morphotype of bottlenose 
dolphin is also resident to certain inshore estuarine waters (Caldwell, 
2001; Gubbins, 2002; Zolman, 2002; Gubbins et al., 2003). Multiple 
lines of evidence support demographic separation between coastal 
dolphins found in nearshore waters and those in estuarine waters, as 
well as between dolphins residing within estuaries along the Atlantic 
and Gulf coasts (e.g., Wells et al., 1987; Scott et al., 1990; Wells et 
al., 1996; Cortese, 2000; Zolman, 2002; Speakman, et al. 2006; Stolen 
et al., 2007; Balmer et al., 2008; Mazzoil et al., 2008). In 
particular, a study conducted near Jacksonville demonstrated 
significant genetic differences between coastal and estuarine dolphins 
(Caldwell, 2001; Rosel et al., 2009). Despite evidence for genetic 
differentiation between estuarine and nearshore populations, the degree 
of spatial overlap between these populations remains unclear. Photo-
identification studies within estuaries demonstrate seasonal 
immigration and emigration and the presence of transient animals (e.g., 
Speakman et al., 2006). In addition, the degree of movement of resident 
estuarine animals into coastal waters on seasonal or shorter time 
scales is poorly understood (Waring et al., 2014).
    The Jacksonville estuarine system (JES) stock has been defined as 
separate primarily by the results of photo-identification and genetic 
studies. The stock range is considered to be bounded in the north by 
the Georgia-Florida border at Cumberland Sound, extending south to 
approximately Jacksonville Beach, Florida. This encompasses an area 
defined during a photo-identification study of bottlenose dolphin 
residency patterns in the area (Caldwell, 2001), and the borders are 
subject to change upon further study of dolphin residency patterns in 
estuarine waters of southern Georgia and northern/central Florida. The 
habitat is comprised of several large brackish rivers, including the 
St. Johns River, as well as tidal marshes and shallow riverine systems. 
Three behaviorally different communities were identified during 
Caldwell's (2001) study: The estuarine waters north (Northern) and 
south (Southern) of the St. Johns River and the coastal area, all of 
which differed in density, habitat fidelity and social affiliation 
patterns. The coastal dolphins are believed to be members of a coastal 
stock, however (Waring et al., 2014). Although Northern and Southern 
members of the JES stock show strong site fidelity, members of both 
groups have been observed outside their preferred areas. Dolphins 
residing within estuaries south of Jacksonville Beach down to the 
northern boundary of the Indian River Lagoon Estuarine System (IRLES) 
stock are currently not included in any stock, as there are 
insufficient data to determine whether animals in this area exhibit 
affiliation to the JES stock, the IRLES stock, or are simply transient 
animals associated with coastal stocks. Further research is needed to 
establish affinities of dolphins in the area between the ranges, as 
currently understood, of the JES and IRLES stocks.
    The JES stock is susceptible to similar fisheries interactions as 
those described above for coastal stocks, although only trap/pot 
fisheries are likely to occur in estuarine waters frequented by the 
stock. Only one dolphin carcass bearing evidence of fisheries 
interaction was recovered during 2003-07 in the JES area, and an 
additional sixteen stranded dolphins were recovered during this time, 
but no determinations regarding human interactions could be made for 
the majority (Waring et al., 2014). Nineteen bottlenose dolphins died 
in the St. Johns River (SJR), Florida between May 24 and November 7, 
2010, all of which came from the JES stock. The cause of these deaths 
was undetermined. The same concerns discussed above regarding 
underestimation of mortality hold for this stock and, as for stocks 
discussed above, pollutant loading is a concern. Although no 
contaminant analyses have yet been conducted in this area, the JES 
stock inhabits areas with significant drainage from industrial and 
urban sources, and as such is exposed to contaminants in runoff from 
these. In other estuarine areas where such analyses have been 
conducted, exposure to anthropogenic contaminants has been found to 
likely have an effect (Hansen et al. 2004; Schwacke et al., 2004; Reif 
et al., 2008).
    The original, single stock of coastal dolphins recognized from 
1995-2001 was listed as depleted under the MMPA as a result of a 1987-
88 mortality event. That designation was retained when the single stock 
was split into multiple coastal stocks. However, Scott et al. (1988) 
suggested that dolphins residing in the bays, sounds and estuaries 
adjacent to these coastal waters were not affected by the mortality 
event and these animals were explicitly excluded from the depleted 
listing (Waring et al., 2014). Gubbins et al. (2003), using data from 
Caldwell (2001), estimated the stock size to be 412 (CV = 0.06). 
However, NMFS considers abundance unknown because this estimate likely 
includes an unknown number of non-resident and seasonally-resident 
dolphins. It nevertheless represents the best available information 
regarding stock size. Because the stock size is likely small, and 
relatively few mortalities and serious injuries would exceed PBR, the 
stock is considered to be a strategic stock (Waring et al., 2014).
    An unusual mortality event (UME) occurred between 2013 and 2015 
spanning the Atlantic coast, which impacted all stocks of bottlenose 
dolphins in the area. Over 1,800 dolphins stranded in this time period. 
The preliminary conclusion of the cause of this UME was morbillivirus. 
The bottlenose dolphin stocks in this area (SJR and coastal areas) may 
be considered vulnerable to impacts from future activities due to this 
recent event.

Potential Effects of the Specified Activity on Marine Mammals and Their 
Habitat

    This section includes a summary and discussion of the ways that 
components of the specified activity (e.g., sound produced by pile 
driving) 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 
section will include an analysis of how this specific activity will 
impact marine mammals and 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 
this activity on the reproductive success or survivorship of 
individuals and from that on the affected marine mammal populations or 
stocks. In the following discussion, we provide general background 
information on

[[Page 75984]]

sound and marine mammal hearing before considering potential effects to 
marine mammals from sound produced by vibratory and impact pile 
driving.

Description of Sound Sources

    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 hertz (Hz) or cycles per second. Wavelength is the 
distance between two peaks of a sound wave; lower frequency sounds have 
longer wavelengths than higher frequency sounds and attenuate 
(decrease) more rapidly in shallower water. Amplitude is the height of 
the sound pressure wave or the `loudness' of a sound and is typically 
measured using the decibel (dB) scale. A dB is the ratio between a 
measured pressure (with sound) and a reference pressure (sound at a 
constant pressure, established by scientific standards). It is a 
logarithmic unit that accounts for large variations in amplitude; 
therefore, relatively small changes in dB ratings correspond to large 
changes in sound pressure. When referring to sound pressure levels 
(SPLs; the sound force per unit area), sound is referenced in the 
context of underwater sound pressure to 1 microPascal ([mu]Pa). One 
pascal is the pressure resulting from a force of one newton exerted 
over an area of one square meter. The source level (SL) represents the 
sound level at a distance of 1 m from the source (referenced to 1 
[mu]Pa). The received level is the sound level at the listener's 
position. Note that all underwater sound levels in this document are 
referenced to a pressure of 1 [micro]Pa and all airborne sound levels 
in this document are referenced to a pressure of 20 [mu]Pa.
    Root mean square (rms) is the quadratic mean sound pressure over 
the duration of an impulse. Rms is calculated by squaring all of the 
sound amplitudes, averaging the squares, and then taking the square 
root of the average (Urick, 1983). Rms 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.
    When underwater objects vibrate or activity occurs, sound-pressure 
waves are created. These waves alternately compress and decompress the 
water as the sound wave travels. Underwater sound waves radiate in all 
directions away from the source (similar to ripples on the surface of a 
pond), except in cases where the source is directional. The 
compressions and decompressions associated with sound waves are 
detected as changes in pressure by aquatic life and man-made sound 
receptors such as hydrophones.
    Even in the absence of sound from the specified activity, the 
underwater environment is typically loud due to ambient sound. Ambient 
sound is defined as environmental background sound levels lacking a 
single source or point (Richardson et al., 1995), and the sound level 
of a region is defined by the total acoustical energy being generated 
by known and unknown sources. These sources may include physical (e.g., 
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds 
produced by marine mammals, fish, and invertebrates), and anthropogenic 
sound (e.g., vessels, dredging, aircraft, construction). A number of 
sources contribute to ambient sound, including the following 
(Richardson et al., 1995):
     Wind and waves: The complex interactions between wind and 
water surface, including processes such as breaking waves and wave-
induced bubble oscillations and cavitation, are a main source of 
naturally occurring ambient noise for frequencies between 200 Hz and 50 
kHz (Mitson, 1995). In general, ambient sound levels tend to increase 
with increasing wind speed and wave height. Surf noise becomes 
important near shore, with measurements collected at a distance of 8.5 
km from shore showing an increase of 10 dB in the 100 to 700 Hz band 
during heavy surf conditions.
     Precipitation: Sound from rain and hail impacting the 
water surface can become an important component of total noise at 
frequencies above 500 Hz, and possibly down to 100 Hz during quiet 
times.
     Biological: Marine mammals can contribute significantly to 
ambient noise levels, as can some fish and shrimp. The frequency band 
for biological contributions is from approximately 12 Hz to over 100 
kHz.
     Anthropogenic: Sources of ambient noise related to human 
activity include transportation (surface vessels and aircraft), 
dredging and construction, oil and gas drilling and production, seismic 
surveys, sonar, explosions, and ocean acoustic studies. Shipping noise 
typically dominates the total ambient noise for frequencies between 20 
and 300 Hz. In general, the frequencies of anthropogenic sounds are 
below 1 kHz and, if higher frequency sound levels are created, they 
attenuate rapidly (Richardson et al., 1995). Sound from identifiable 
anthropogenic sources other than the activity of interest (e.g., a 
passing vessel) is sometimes termed background sound, as opposed to 
ambient sound.
    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 
shipping 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 the 
specified activity may be a negligible addition to the local 
environment or could form a distinctive signal that may affect marine 
mammals.
    The underwater acoustic environment in the Mayport turning basin is 
likely to be dominated by noise from day-to-day port and vessel 
activities. The basin is sheltered from most wave noise, but is a high-
use area for naval ships, tugboats, and security vessels. When 
underway, these sources can create noise between 20 Hz and 16 kHz 
(Lesage et al., 1999), with broadband noise levels up to 180 dB. While 
there are no current measurements of ambient noise levels in the 
turning basin, it is likely that levels within the basin periodically 
exceed the 120 dB threshold and, therefore, that the high levels of 
anthropogenic activity in the basin create an environment far different 
from quieter habitats where behavioral reactions to sounds around the 
120 dB threshold have been observed (e.g., Malme et al., 1984, 1988).
    In-water construction activities associated with the project would 
include impact pile driving and vibratory pile driving. The sounds 
produced by these activities fall into one of two general sound types: 
Pulsed and non-pulsed (defined in the following). The distinction 
between 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

[[Page 75985]]

Southall et al., (2007) for an in-depth discussion of these concepts.
    Pulsed sound sources (e.g., 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; Harris, 1998; NIOSH, 1998; ISO, 2003; ANSI, 2005) 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.
    Impact hammers operate by repeatedly dropping a heavy piston onto a 
pile to drive the pile into the substrate. Sound generated by impact 
hammers is characterized by rapid rise times and high peak levels, a 
potentially injurious combination (Hastings and Popper, 2005). 
Vibratory hammers install piles by vibrating them and allowing the 
weight of the hammer to push them into the sediment. Vibratory hammers 
produce significantly less sound than impact hammers. Peak SPLs may be 
180 dB or greater, but are generally 10 to 20 dB lower than SPLs 
generated during impact pile driving of the same-sized pile (Oestman et 
al., 2009). Rise time is slower, reducing the probability and severity 
of injury, and sound energy is distributed over a greater amount of 
time (Nedwell and Edwards, 2002; Carlson et al., 2005).

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals, 
and exposure to sound can have deleterious effects. To appropriately 
assess these potential effects, 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 
measured or estimated hearing ranges on the basis of available 
behavioral data, audiograms derived using auditory evoked potential 
techniques, anatomical modeling, and other data. The lower and/or upper 
frequencies for some of these functional hearing groups have been 
modified from those designated by Southall et al. (2007). The 
functional groups and the associated frequencies are indicated below 
(note that these frequency ranges do not necessarily correspond to the 
range of best hearing, which varies by species):
     Low-frequency cetaceans (mysticetes): Functional hearing 
is estimated to occur between approximately 7 Hz and 25 kHz (extended 
from 22 kHz; Watkins, 1986; Au et al., 2006; Lucifredi and Stein, 2007; 
Ketten and Mountain, 2009; Tubelli et al., 2012);
     Mid-frequency cetaceans (larger toothed whales, beaked 
whales, and most delphinids): Functional hearing is estimated to occur 
between approximately 150 Hz and 160 kHz;
     High-frequency cetaceans (porpoises, river dolphins, and 
members of the genera Kogia and Cephalorhynchus; now considered to 
include two members of the genus Lagenorhynchus on the basis of recent 
echolocation data and genetic data [May-Collado and Agnarsson, 2006; 
Kyhn et al. 2009, 2010; Tougaard et al. 2010]): Functional hearing is 
estimated to occur between approximately 200 Hz and 180 kHz; and
     Pinnipeds in water: Functional hearing is estimated to 
occur between approximately 75 Hz to 100 kHz for Phocidae (true seals) 
and between 100 Hz and 40 kHz for Otariidae (eared seals), with the 
greatest sensitivity between approximately 700 Hz and 20 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 et al., 
2013).
    One cetacean species is expected to potentially be affected by the 
specified activity. Bottlenose dolphins are classified as mid-frequency 
cetaceans.

Acoustic Effects, Underwater

    Potential Effects of Pile Driving Sound--The effects of sounds from 
pile driving might result in one or more of the following: Temporary or 
permanent hearing impairment, non-auditory physical or physiological 
effects, behavioral disturbance, and masking (Richardson et al., 1995; 
Gordon et al., 2003; Nowacek et al., 2007; Southall et al., 2007). The 
effects of pile driving on marine mammals are dependent on several 
factors, including the size, type, and depth of the animal; the depth, 
intensity, and duration of the pile driving sound; the depth of the 
water column; the substrate of the habitat; the standoff distance 
between the pile and the animal; and the sound propagation properties 
of the environment. Impacts to marine mammals from pile driving 
activities are expected to result primarily from acoustic pathways. As 
such, the degree of effect is intrinsically related to the received 
level and duration of the sound exposure, which are in turn influenced 
by the distance between the animal and the source. The further away 
from the source, the less intense the exposure should be. The substrate 
and depth of the habitat affect the sound propagation properties of the 
environment. Shallow environments are typically more structurally 
complex, which leads to rapid sound attenuation. In addition, 
substrates that are soft (e.g., sand) would absorb or attenuate the 
sound more readily than hard substrates (e.g., rock) which may reflect 
the acoustic wave. Soft porous substrates would also likely require 
less time to drive the pile, and possibly less forceful equipment, 
which would ultimately decrease the intensity of the acoustic source.
    In the absence of mitigation, impacts to marine species would be 
expected to 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 
impulsive 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).
    Hearing Impairment and Other Physical Effects--Marine mammals 
exposed to high intensity sound repeatedly or for prolonged periods can 
experience hearing threshold shift (TS), which is the loss of hearing 
sensitivity

[[Page 75986]]

at certain frequency ranges (Kastak et al., 1999; Schlundt et al., 
2000; Finneran et al., 2002, 2005). TS can be permanent (PTS), in which 
case the loss of hearing sensitivity is not recoverable, or temporary 
(TTS), in which case the animal's hearing threshold would recover over 
time (Southall et al., 2007). Marine mammals depend on acoustic cues 
for vital biological functions, (e.g., orientation, communication, 
finding prey, avoiding predators); thus, TTS may result in reduced 
fitness in survival and reproduction. However, this depends on the 
frequency and duration of TTS, as well as the biological context in 
which it occurs. TTS of limited duration, occurring in a frequency 
range that does not coincide with that used for recognition of 
important acoustic cues, would have little to no effect on an animal's 
fitness. Repeated sound exposure that leads to TTS could cause PTS. PTS 
constitutes injury (direct auditory tissue effects), but TTS does not 
(Southall et al., 2007). The following subsections discuss in somewhat 
more detail the possibilities of TTS, PTS, and non-auditory physical 
effects.
    Temporary Threshold Shift--TTS is the mildest form of hearing 
impairment that can occur during exposure to a strong sound (Kryter, 
1985). While experiencing TTS, the hearing threshold rises, and a sound 
must be stronger in order to be heard. In terrestrial mammals, TTS can 
last from minutes or hours to days (in cases of strong TTS). For sound 
exposures at or somewhat above the TTS threshold, hearing sensitivity 
in both terrestrial and marine mammals recovers rapidly after exposure 
to the sound ends. Few data on sound levels and durations necessary to 
elicit mild TTS have been obtained for marine mammals, and none of the 
published data concern TTS elicited by exposure to multiple pulses of 
sound. Available data on TTS in marine mammals are summarized in 
Southall et al. (2007).
    Given the available data, the received level of a single pulse 
(with no frequency weighting) might need to be approximately 186 dB re 
1 [mu]Pa\2\-s (i.e., 186 dB sound exposure level [SEL] or approximately 
221-226 dB p-p [peak]) in order to produce brief, mild TTS. Exposure to 
several strong pulses that each have received levels near 190 dB rms 
(175-180 dB SEL) might result in cumulative exposure of approximately 
186 dB SEL and thus slight TTS in a small odontocete, assuming the TTS 
threshold is (to a first approximation) a function of the total 
received pulse energy.
    The above TTS information for odontocetes is derived from studies 
on the bottlenose dolphin and beluga whale (Delphinapterus leucas). 
There is no published TTS information for other species of cetaceans. 
However, preliminary evidence from a harbor porpoise exposed to pulsed 
sound suggests that its TTS threshold may have been lower (Lucke et 
al., 2009). As summarized above, data that are now available imply that 
TTS is unlikely to occur unless odontocetes are exposed to pile driving 
pulses stronger than 180 dB re 1 [mu]Pa rms.
    Permanent Threshold Shift--When PTS occurs, there is physical 
damage to the sound receptors in the ear. In severe cases, there can be 
total or partial deafness, while in other cases the animal has an 
impaired ability to hear sounds in specific frequency ranges (Kryter, 
1985). There is no specific evidence that exposure to pulses of sound 
can cause PTS in any marine mammal. However, given the possibility that 
mammals close to a sound source might incur TTS, there has been further 
speculation about the possibility that some individuals might incur 
PTS. Single or occasional occurrences of mild TTS are not indicative of 
permanent auditory damage, but repeated or (in some cases) single 
exposures to a level well above that causing TTS onset might elicit 
PTS.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals but are assumed to be similar to those in humans and 
other terrestrial mammals. PTS might occur at a received sound level at 
least several decibels above that inducing mild TTS if the animal were 
exposed to strong sound pulses with rapid rise time. Based on data from 
terrestrial mammals, a precautionary assumption is that the PTS 
threshold for impulse sounds (such as pile driving pulses as received 
close to the source) is at least 6 dB higher than the TTS threshold on 
a peak-pressure basis and probably greater than 6 dB (Southall et al., 
2007). On an SEL basis, Southall et al. (2007) estimated that received 
levels would need to exceed the TTS threshold by at least 15 dB for 
there to be risk of PTS. Thus, for cetaceans, Southall et al. (2007) 
estimate that the PTS threshold might be an M-weighted SEL (for the 
sequence of received pulses) of approximately 198 dB re 1 [mu]Pa\2\-s 
(15 dB higher than the TTS threshold for an impulse). Given the higher 
level of sound necessary to cause PTS as compared with TTS, it is 
considerably less likely that PTS could occur.
    Measured source levels from impact pile driving can be as high as 
214 dB rms. Although no marine mammals have been shown to experience 
TTS or PTS as a result of being exposed to pile driving activities, 
captive bottlenose dolphins and beluga whales exhibited changes in 
behavior when exposed to strong pulsed sounds (Finneran et al., 2000, 
2002, 2005). The animals tolerated high received levels of sound before 
exhibiting aversive behaviors. Experiments on a beluga whale showed 
that exposure to a single watergun impulse at a received level of 207 
kPa (30 psi) p-p, which is equivalent to 228 dB p-p, resulted in a 7 
and 6 dB TTS in the beluga whale at 0.4 and 30 kHz, respectively. 
Thresholds returned to within 2 dB of the pre-exposure level within 
four minutes of the exposure (Finneran et al., 2002). Although the 
source level of pile driving from one hammer strike is expected to be 
much lower than the single watergun impulse cited here, animals being 
exposed for a prolonged period to repeated hammer strikes could receive 
more sound exposure in terms of SEL than from the single watergun 
impulse (estimated at 188 dB re 1 [mu]Pa\2\-s) in the aforementioned 
experiment (Finneran et al., 2002). However, in order for marine 
mammals to experience TTS or PTS, the animals have to be close enough 
to be exposed to high intensity sound levels for a prolonged period of 
time. Based on the best scientific information available, these SPLs 
are far below the thresholds that could cause TTS or the onset of PTS.
    Non-auditory Physiological Effects--Non-auditory physiological 
effects or injuries that theoretically might occur in marine mammals 
exposed to strong underwater sound include stress, neurological 
effects, bubble formation, resonance effects, and other types of organ 
or tissue damage (Cox et al., 2006; Southall et al., 2007). Studies 
examining such effects are limited. In general, little is known about 
the potential for pile driving to cause auditory impairment or other 
physical effects in marine mammals. Available data suggest that such 
effects, if they occur at all, would presumably be limited to short 
distances from the sound source and to activities that extend over a 
prolonged period. The available data do not allow identification of a 
specific exposure level above which non-auditory effects can be 
expected (Southall et al., 2007) or any meaningful quantitative 
predictions of the numbers (if any) of marine mammals that might be 
affected in those ways. Marine mammals that show behavioral avoidance 
of pile driving, including some odontocetes and some pinnipeds, are 
especially unlikely to incur auditory impairment or non-auditory 
physical effects.

[[Page 75987]]

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 showed 
pronounced behavioral reactions, including avoidance of loud 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, but also 
including pile driving) 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., 2003; 
Wartzok et al., 2003; Nowacek et al., 2007). Responses to continuous 
sound, such as vibratory pile installation, have not been documented as 
well as responses to pulsed sounds.
    With both types of pile driving, it is likely that the onset of 
pile driving could result in temporary, short term changes in an 
animal's typical behavior and/or avoidance of the affected area. These 
behavioral changes may include (Richardson et al., 1995): Changing 
durations of surfacing and dives, number of blows per surfacing, or 
moving direction and/or speed; reduced/increased vocal activities; 
changing/cessation of certain behavioral activities (such as 
socializing or feeding); visible startle response or aggressive 
behavior (such as tail/fluke slapping or jaw clapping); avoidance of 
areas where sound sources are located; and/or flight responses (e.g., 
pinnipeds flushing into water from haul-outs or rookeries). Pinnipeds 
may increase their haul-out time, possibly to avoid in-water 
disturbance (Thorson and Reyff, 2006).
    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 be expected to be biologically significant if the 
change affects growth, survival, or reproduction. Significant 
behavioral modifications that could potentially lead to effects on 
growth, survival, or reproduction include:
     Drastic changes in diving/surfacing patterns (such as 
those thought to cause beaked whale stranding due to exposure to 
military mid-frequency tactical sonar);
     Habitat abandonment due to loss of desirable acoustic 
environment; and
     Cessation of feeding or social interaction.
    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).

Auditory Masking

    Natural and artificial sounds can disrupt behavior by masking, or 
interfering with, a marine mammal's ability to hear other sounds. 
Masking occurs when the receipt of a sound is interfered with by 
another coincident sound at similar frequencies and at similar or 
higher levels. Chronic exposure to excessive, though not high-
intensity, sound could cause masking at particular frequencies for 
marine mammals, which utilize sound for vital biological functions. 
Masking can interfere with detection of acoustic signals such as 
communication calls, echolocation sounds, and environmental sounds 
important to marine mammals. Therefore, under certain circumstances, 
marine mammals whose acoustical sensors or environment are being 
severely masked could also be impaired from maximizing their 
performance fitness in survival and reproduction. If the coincident 
(masking) sound were man-made, it could be potentially harassing if it 
disrupted hearing-related behavior. It is important to distinguish TTS 
and PTS, which persist after the sound exposure, from masking, which 
occurs during the sound exposure. Because masking (without resulting in 
TS) is not associated with abnormal physiological function, it is not 
considered a physiological effect, but rather a potential behavioral 
effect.
    The frequency range of the potentially masking sound is important 
in determining any potential behavioral impacts. Because sound 
generated from in-water pile driving is mostly concentrated at low 
frequency ranges, it may have less effect on high frequency 
echolocation sounds made by porpoises. However, lower frequency man-
made sounds are more likely to affect detection of communication calls 
and other potentially important natural sounds such as surf and prey 
sound. It may also affect communication signals when they occur near 
the sound band and thus reduce the communication space of animals 
(e.g., Clark et al., 2009) and cause increased stress levels (e.g., 
Foote et al., 2004; Holt et al., 2009).
    Masking has the potential to impact species at the population or 
community levels as well as at individual levels. Masking affects both 
senders and receivers of the signals and can potentially have long-term 
chronic effects on marine mammal species and populations. Recent 
research suggests that low frequency ambient sound levels have 
increased by as much as 20 dB (more than three times in terms of SPL) 
in the world's ocean from pre-industrial periods, and that most of 
these increases are from distant shipping (Hildebrand, 2009). All 
anthropogenic sound sources, such as those from vessel traffic, pile 
driving, and dredging activities, contribute to the elevated ambient 
sound levels, thus intensifying masking.
    The most intense underwater sounds in the proposed action are those 
produced by impact pile driving. Given that the energy distribution of 
pile driving covers a broad frequency spectrum, sound from these 
sources would likely be within the audible range of marine mammals 
present in the project area. Impact pile driving activity is relatively 
short-term, with rapid pulses occurring for approximately fifteen 
minutes per pile. The probability for impact pile driving resulting 
from this proposed action masking acoustic signals important to the 
behavior and survival of marine mammal species is likely to be 
negligible. Vibratory pile driving is also relatively short-term, with 
rapid oscillations occurring for approximately one and a half hours per 
pile. It is possible that vibratory pile driving resulting from this 
proposed action may mask acoustic signals important to the behavior and 
survival of marine mammal species, but the

[[Page 75988]]

short-term duration and limited affected area would result in 
insignificant impacts from masking. Any masking event that could 
possibly rise to Level B harassment under the MMPA would occur 
concurrently within the zones of behavioral harassment already 
estimated for vibratory and impact pile driving, and which have already 
been taken into account in the exposure analysis.

Anticipated Effects on Habitat

    The proposed activities at NSM would not result in permanent 
impacts to habitats used directly by marine mammals, but may have 
potential short-term impacts to food sources such as forage fish and 
may affect acoustic habitat (see masking discussion above). There are 
no known foraging hotspots or other ocean bottom structure of 
significant biological importance to marine mammals present in the 
marine waters of the project area; however the surrounding areas may be 
foraging habitat for the dolphins. Therefore, the main impact issue 
associated with the proposed activity would be temporarily elevated 
sound levels and the associated direct effects on marine mammals, as 
discussed previously in this document. The most likely impact to marine 
mammal habitat occurs from pile driving effects on likely marine mammal 
prey (i.e., fish) within NSM and minor impacts to the immediate 
substrate during installation and removal of piles during the wharf 
construction project.

Pile Driving Effects on Potential Prey (Fish)

    Construction activities may produce both pulsed (i.e., impact pile 
driving) and continuous (i.e., vibratory pile driving) sounds. Fish 
react to sounds which are especially strong and/or intermittent low-
frequency sounds. Short duration, sharp sounds can cause overt or 
subtle changes in fish behavior and local distribution. Hastings and 
Popper (2005) identified several studies that suggest fish may relocate 
to avoid certain areas of sound energy. Additional studies have 
documented effects of pile driving (or other types of sounds) on fish, 
although several are based on studies in support of large, multiyear 
bridge construction projects (e.g., Scholik and Yan, 2001, 2002; Popper 
and Hastings, 2009). Sound pulses at received levels of 160 dB re 1 
[mu]Pa may cause subtle changes in fish behavior. SPLs of 180 dB may 
cause noticeable changes in behavior (Pearson et al., 1992; Skalski et 
al., 1992). SPLs of sufficient strength have been known to cause injury 
to fish and fish mortality. The most likely impact to fish from pile 
driving activities at the project area would be temporary behavioral 
avoidance of the area. The duration of fish avoidance of this area 
after pile driving stops is unknown, but a rapid return to normal 
recruitment, distribution and behavior is anticipated. In general, 
impacts to marine mammal prey species are expected to be minor and 
temporary due to the short timeframe for the project.

Pile Driving Effects on Potential Foraging Habitat

    The area likely impacted by the project is relatively small 
compared to the available habitat in nearshore and estuarine waters in 
the region. Avoidance by potential prey (i.e., fish) of the immediate 
area due to the temporary loss of this foraging habitat is also 
possible. The duration of fish avoidance of this area after pile 
driving stops is unknown, but a rapid return to normal recruitment, 
distribution and behavior is anticipated. Any behavioral avoidance by 
fish of the disturbed area would still leave significantly large areas 
of fish and marine mammal foraging habitat in the nearby vicinity.
    In summary, given the short daily duration of sound associated with 
individual pile driving events and the relatively small areas being 
affected, pile driving activities associated with the proposed action 
are not likely to have a permanent, adverse effect on any fish habitat, 
or populations of fish species. Therefore, pile driving is not likely 
to have a permanent, adverse effect on marine mammal foraging habitat 
at the project area. The Mayport turning basin itself is a man-made 
basin with significant levels of industrial activity and regular 
dredging, and is unlikely to harbor significant amounts of forage fish. 
Thus, any impacts to marine mammal habitat are not expected to cause 
significant or long-term consequences for individual marine mammals or 
their populations.

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.
    Measurements from similar pile driving events were coupled with 
practical spreading loss to estimate zones of influence (ZOI; see 
Estimated Take by Incidental Harassment); these values were used to 
develop mitigation measures for pile driving activities at NSM. The 
ZOIs effectively represent the mitigation zone that would be 
established around each pile to prevent Level A harassment to marine 
mammals, while providing estimates of the areas within which Level B 
harassment might occur. In addition to the specific measures described 
later in this section, the Navy would conduct briefings between 
construction supervisors and crews, marine mammal monitoring team, and 
Navy staff prior to the start of all pile driving activity, and when 
new personnel join the work, in order to explain responsibilities, 
communication procedures, marine mammal monitoring protocol, and 
operational procedures.

Monitoring and Shutdown for Pile Driving

    The following measures would apply to the Navy's mitigation through 
shutdown and disturbance zones:
    Shutdown Zone--For all pile driving activities, the Navy will 
establish a shutdown zone intended to contain the area in which SPLs 
equal or exceed the 190 dB rms acoustic injury criteria. The purpose of 
a shutdown zone is to define an area within which shutdown of activity 
would occur upon sighting of a marine mammal (or in anticipation of an 
animal entering the defined area), thus preventing injury of marine 
mammals (as described previously under Potential Effects of the 
Specified Activity on Marine Mammals, serious injury or death are 
unlikely outcomes even in the absence of mitigation measures). Modeled 
radial distances for shutdown zones are shown in Table 3. However, a 
minimum shutdown zone of 15 m (which is larger than the maximum 
predicted injury zone) will be established during all pile driving 
activities, regardless of the estimated zone. Vibratory pile driving 
activities are not predicted to produce sound exceeding the 190-dB 
Level A harassment threshold, but these precautionary measures are 
intended to prevent the already unlikely possibility of physical 
interaction with construction equipment and to further reduce any 
possibility of acoustic injury. For impact driving of steel piles, if 
necessary, the radial distance of the shutdown would be established at 
40 m.
    Disturbance Zone--Disturbance zones are the areas in which SPLs 
equal or exceed 160 and 120 dB rms (for impulse and continuous sound, 
respectively). Disturbance zones provide utility for monitoring 
conducted for mitigation purposes (i.e., shutdown zone monitoring) by 
establishing monitoring

[[Page 75989]]

protocols for areas adjacent to the shutdown zones. Monitoring of 
disturbance zones enables observers to be aware of and communicate the 
presence of marine mammals in the project area but outside the shutdown 
zone and thus prepare for potential shutdowns of activity. However, the 
primary purpose of disturbance zone monitoring is for documenting 
incidents of Level B harassment; disturbance zone monitoring is 
discussed in greater detail later (see Proposed Monitoring and 
Reporting). Nominal radial distances for disturbance zones are shown in 
Table 3. Given the size of the disturbance zone for vibratory pile 
driving, it is impossible to guarantee that all animals would be 
observed or to make comprehensive observations of fine-scale behavioral 
reactions to sound, and only a portion of the zone (e.g., what may be 
reasonably observed by visual observers stationed within the turning 
basin) would be observed.
    In order to document observed incidents of harassment, monitors 
record all marine mammal observations, regardless of location. The 
observer's location, as well as the location of the pile being driven, 
is known from a GPS. The location of the animal is estimated as a 
distance from the observer, which is then compared to the location from 
the pile. It may then be estimated whether the animal was exposed to 
sound levels constituting incidental harassment on the basis of 
predicted distances to relevant thresholds in post-processing of 
observational and acoustic data, and a precise accounting of observed 
incidences of harassment created. This information may then be used to 
extrapolate observed takes to reach an approximate understanding of 
actual total takes.
    Monitoring Protocols--Monitoring would be conducted before, during, 
and after pile driving activities. In addition, observers shall record 
all incidents of marine mammal occurrence, regardless of distance from 
activity, and shall document any behavioral reactions in concert with 
distance from piles being driven. Observations made outside the 
shutdown zone will not result in shutdown; that pile segment would be 
completed without cessation, unless the animal approaches or enters the 
shutdown zone, at which point all pile driving activities would be 
halted. Monitoring will take place from fifteen minutes prior to 
initiation through thirty minutes post-completion of pile driving 
activities. Pile driving activities include the time to install or 
remove a single pile or series of piles, as long as the time elapsed 
between uses of the pile driving equipment is no more than thirty 
minutes. Please see the Monitoring Plan (www.nmfs.noaa.gov/pr/permits/incidental/construction.htm), developed by the Navy in agreement with 
NMFS, for full details of the monitoring protocols.
    The following additional measures apply to visual monitoring:
    (1) Monitoring will be conducted by qualified observers, who will 
be placed at the best vantage point(s) practicable to monitor for 
marine mammals and implement shutdown/delay procedures when applicable 
by calling for the shutdown to the hammer operator. Qualified observers 
are typically trained biologists, with the following minimum 
qualifications:
     Visual acuity in both eyes (correction is permissible) 
sufficient for discernment of moving targets at the water's surface 
with ability to estimate target size and distance; use of binoculars 
may be necessary to correctly identify the target;
     Experience and ability to conduct field observations and 
collect data according to assigned protocols (this may include academic 
experience);
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates and times when in-water construction 
activities were suspended to avoid potential incidental injury from 
construction sound of marine mammals observed within a defined shutdown 
zone; and marine mammal behavior; and
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    (2) Prior to the start of pile driving activity, the shutdown zone 
will be monitored for fifteen minutes to ensure that it is clear of 
marine mammals. Pile driving will only commence once observers have 
declared the shutdown zone clear of marine mammals; animals will be 
allowed to remain in the shutdown zone (i.e., must leave of their own 
volition) and their behavior will be monitored and documented. The 
shutdown zone may only be declared clear, and pile driving started, 
when the entire shutdown zone is visible (i.e., when not obscured by 
dark, rain, fog, etc.). In addition, if such conditions should arise 
during impact pile driving that is already underway, the activity would 
be halted.
    (3) If a marine mammal approaches or enters the shutdown zone 
during the course of pile driving operations, activity will be halted 
and delayed until either the animal has voluntarily left and been 
visually confirmed beyond the shutdown zone or fifteen minutes have 
passed without re-detection of the animal. Monitoring will be conducted 
throughout the time required to drive a pile.

Soft Start

    The use of a soft start procedure is believed to provide additional 
protection to marine mammals by warning or providing a chance to leave 
the area prior to the hammer operating at full capacity, and typically 
involves a requirement to initiate sound from the hammer at reduced 
energy followed by a waiting period. This procedure is repeated two 
additional times. It is difficult to specify the reduction in energy 
for any given hammer because of variation across drivers and, for 
impact hammers, the actual number of strikes at reduced energy will 
vary because operating the hammer at less than full power results in 
``bouncing'' of the hammer as it strikes the pile, resulting in 
multiple ``strikes.'' For impact driving, we require an initial set of 
three strikes from the impact hammer at reduced energy, followed by a 
thirty-second waiting period, then two subsequent three strike sets. 
Soft start will be required at the beginning of each day's impact pile 
driving work and at any time following a cessation of impact pile 
driving of thirty minutes or longer.
    We have carefully evaluated the Navy's proposed mitigation measures 
and considered their effectiveness in past implementation to 
preliminarily determine whether they are likely to effect the least 
practicable impact on the affected marine mammal species and stocks and 
their habitat. Our evaluation of potential measures included 
consideration of the following factors in relation to one another: (1) 
The manner in which, and the degree to which, the successful 
implementation of the measure is expected to minimize adverse impacts 
to marine mammals, (2) the proven or likely efficacy of the specific 
measure to minimize adverse impacts as planned; and (3) the 
practicability of the measure for applicant implementation.
    Any mitigation measure(s) we prescribe should be able to 
accomplish, have a reasonable likelihood of

[[Page 75990]]

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 number (total number or number at 
biologically important time or location) of individual marine mammals 
exposed to stimuli expected to result in incidental take (this goal may 
contribute to 1, above, or to reducing takes by behavioral harassment 
only).
    (3) A reduction in the number (total number or number at 
biologically important time or location) of times any individual marine 
mammal would be exposed to stimuli expected to result in incidental 
take (this goal may contribute to 1, above, or to reducing takes by 
behavioral harassment only).
    (4) A reduction in the intensity of exposure to stimuli expected to 
result in incidental take (this goal may contribute to 1, above, or to 
reducing the severity of behavioral harassment only).
    (5) Avoidance or minimization of adverse effects to marine mammal 
habitat, paying particular attention to the prey base, blockage or 
limitation of passage to or from biologically important areas, 
permanent destruction of habitat, or temporary 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.
    Based on our evaluation of the Navy's proposed measures, as well as 
any other potential measures that may be relevant to the specified 
activity, we have preliminarily determined that the proposed mitigation 
measures provide the means of effecting the least practicable impact on 
marine mammal 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 
incidental take 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.
    Any monitoring requirement we prescribe should improve our 
understanding of one or more of the following:
     Occurrence of marine mammal species in action area (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 responses to acute stressors, or impacts of 
chronic exposures (behavioral or physiological).
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of an individual; or (2) Population, 
species, or stock.
     Effects on marine mammal habitat and resultant impacts to 
marine mammals.
     Mitigation and monitoring effectiveness.
    The Navy's proposed monitoring and reporting is also described in 
their Marine Mammal Monitoring Plan, on the Internet at 
www.nmfs.noaa.gov/pr/permits/incidental/construction.htm.

Visual Marine Mammal Observations

    The Navy will collect sighting data and behavioral responses to 
construction for marine mammal species observed in the region of 
activity during the period of activity. All observers (MMOs) will be 
trained in marine mammal identification and behaviors and are required 
to have no other construction-related tasks while conducting 
monitoring. The Navy will monitor the shutdown zone and disturbance 
zone before, during, and after pile driving, with observers located at 
the best practicable vantage points. Based on our requirements, the 
Navy would implement the following procedures for pile driving:
     MMOs would be located at the best vantage point(s) in 
order to properly see the entire shutdown zone and as much of the 
disturbance zone as possible.
     During all observation periods, observers will use 
binoculars and the naked eye to search continuously for marine mammals.
     If the shutdown zones are obscured by fog or poor lighting 
conditions, pile driving at that location will not be initiated until 
that zone is visible. Should such conditions arise while impact driving 
is underway, the activity would be halted.
     The shutdown and disturbance zones around the pile will be 
monitored for the presence of marine mammals before, during, and after 
any pile driving or removal activity.
    Individuals implementing the monitoring protocol will assess its 
effectiveness using an adaptive approach. The monitoring biologists 
will use their best professional judgment throughout implementation and 
seek improvements to these methods when deemed appropriate. Any 
modifications to protocol will be coordinated between NMFS and the 
Navy.

Data Collection

    We require that observers use approved data forms. Among other 
pieces of information, the Navy will record detailed information about 
any implementation of shutdowns, including the distance of animals to 
the pile and description of specific actions that ensued and resulting 
behavior of the animal, if any. In addition, the Navy will attempt to 
distinguish between the number of individual animals taken and the 
number of incidences of take. We require that, at a minimum, the 
following information be collected on the sighting forms:
     Date and time that monitored activity begins or ends;
     Construction activities occurring during each observation 
period;
     Weather parameters (e.g., percent cover, visibility);
     Water conditions (e.g., sea state, tide state);
     Species, numbers, and, if possible, sex and age class of 
marine mammals;
     Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel, and if possible, 
the correlation to SPLs;
     Distance from pile driving activities to marine mammals 
and distance from the marine mammals to the observation point;
     Description of implementation of mitigation measures 
(e.g., shutdown or delay);
     Locations of all marine mammal observations; and
     Other human activity in the area.

Reporting

    A draft report would be submitted to NMFS within 90 days of the 
completion

[[Page 75991]]

of marine mammal monitoring, or sixty days prior to the requested date 
of issuance of any future IHA for projects at the same location, 
whichever comes first. The report will include marine mammal 
observations pre-activity, during-activity, and post-activity during 
pile driving days, and will also provide descriptions of any behavioral 
responses to construction activities by marine mammals and a complete 
description of all mitigation shutdowns and the results of those 
actions and an extrapolated total take estimate based on the number of 
marine mammals observed during the course of construction. A final 
report must be submitted within thirty days following resolution of 
comments on the draft report.

Estimated Take by Incidental Harassment

    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 anticipated takes would be by Level B harassment resulting from 
vibratory and impact pile driving and involving temporary changes in 
behavior. The proposed mitigation and monitoring measures are expected 
to minimize the possibility of injurious or lethal takes such that take 
by Level A harassment, serious injury, or mortality is considered 
discountable. However, it is unlikely that injurious or lethal takes 
would occur even in the absence of the planned mitigation and 
monitoring measures.
    If a marine mammal responds to a stimulus by changing its behavior 
(e.g., through relatively minor changes in locomotion direction/speed 
or vocalization behavior), 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). 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. In particular, for 
stationary activities, it is more likely that some smaller number of 
individuals may accrue a number of incidences of harassment per 
individual than for each incidence to accrue to a new individual, 
especially if those individuals display some degree of residency or 
site fidelity and the impetus to use the site (e.g., because of 
foraging opportunities) is stronger than the deterrence presented by 
the harassing activity.
    The turning basin is not considered important habitat for marine 
mammals, as it is a man-made, semi-enclosed basin with frequent 
industrial activity and regular maintenance dredging. The surrounding 
waters may be an important foraging habitat for the dolphins; however 
the small area of ensonification does not extend outside of the turning 
basin and into this foraging habitat (see Figure 6-1 in the Navy's 
application). Therefore, behavioral disturbances that could result from 
anthropogenic sound associated with these activities are expected to 
affect only a relatively small number of individual marine mammals that 
may venture near the turning basin, although those effects could be 
recurring over the life of the project if the same individuals remain 
in the project vicinity. The Navy has requested authorization for the 
incidental taking of small numbers of bottlenose dolphins in the 
Mayport turning basin that may result from pile driving during 
construction activities associated with the project described 
previously in this document.
    In order to estimate the potential incidents of take that may occur 
incidental to the specified activity, we must first estimate the extent 
of the sound field that may be produced by the activity and then 
consider in combination with information about marine mammal density or 
abundance in the project area. We first provide information on 
applicable sound thresholds for determining effects to marine mammals 
before describing the information used in estimating the sound fields, 
the available marine mammal density or abundance information, and the 
method of estimating potential incidents of take.

Sound Thresholds

    We use generic sound exposure thresholds to determine when an 
activity that produces sound might result in impacts to a marine mammal 
such that a take by harassment might occur. To date, no studies have 
been conducted that explicitly examine impacts to marine mammals from 
pile driving sounds or from which empirical sound thresholds have been 
established. These thresholds (Table 2) are used to estimate when 
harassment may occur (i.e., when an animal is exposed to levels equal 
to or exceeding the relevant criterion) in specific contexts; however, 
useful contextual information that may inform our assessment of effects 
is typically lacking and we consider these thresholds as step 
functions. NMFS is working to revise these acoustic guidelines; for 
more information on that process, please visit www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.

               Table 2--Current Acoustic Exposure Criteria
------------------------------------------------------------------------
           Criterion                Definition           Threshold
------------------------------------------------------------------------
Level A harassment              Injury (PTS--any   180 dB (cetaceans)/
 (underwater).                   level above that   190 dB (pinnipeds)
                                 which is known     (rms).
                                 to cause TTS).
Level B harassment              Behavioral         160 dB (impulsive
 (underwater).                   disruption.        source)/120 dB
                                                    (continuous source)
                                                    (rms).
Level B harassment (airborne).  Behavioral         90 dB (harbor seals)/
                                 disruption.        100 dB (other
                                                    pinnipeds)
                                                    (unweighted).
------------------------------------------------------------------------


[[Page 75992]]

Distance to Sound Thresholds

    Underwater Sound Propagation Formula--Pile driving generates 
underwater noise that can potentially result in disturbance to marine 
mammals in the project area. Transmission loss (TL) is the decrease in 
acoustic intensity as an acoustic pressure wave propagates out from a 
source. TL parameters vary with frequency, temperature, sea conditions, 
current, source and receiver depth, water depth, water chemistry, and 
bottom composition and topography. The general formula for underwater 
TL is:

TL = B * log10(R1/R2),

Where:
R1 = the distance of the modeled SPL from the driven 
pile, and
R2 = the distance from the driven pile of the initial 
measurement.

    This formula neglects loss due to scattering and absorption, which 
is assumed to be zero here. The degree to which underwater sound 
propagates away from a sound source is dependent on a variety of 
factors, most notably the water bathymetry and presence or absence of 
reflective or absorptive conditions including in-water structures and 
sediments. Spherical spreading occurs in a perfectly unobstructed 
(free-field) environment not limited by depth or water surface, 
resulting in a 6 dB reduction in sound level for each doubling of 
distance from the source (20*log[range]). Cylindrical spreading occurs 
in an environment in which sound propagation is bounded by the water 
surface and sea bottom, resulting in a reduction of 3 dB in sound level 
for each doubling of distance from the source (10*log[range]). A 
practical spreading value of fifteen is often used under conditions, 
such as at the NSM turning basin, where water increases with depth as 
the receiver moves away from the shoreline, resulting in an expected 
propagation environment that would lie between spherical and 
cylindrical spreading loss conditions. Practical spreading loss (4.5 dB 
reduction in sound level for each doubling of distance) is assumed 
here.
    Underwater Sound--The intensity of pile driving sounds is greatly 
influenced by factors such as the type of piles, hammers, and the 
physical environment in which the activity takes place. A number of 
studies, primarily on the west coast, have measured sound produced 
during underwater pile driving projects. However, these data are 
largely for impact driving of steel pipe piles and concrete piles as 
well as vibratory driving of steel pipe piles. Vibratory driving of 
steel sheet piles was monitored during the first year of construction 
at the nearby Wharf C-2 at Naval Station Mayport during 2015. 
Measurements were conducted from a small boat in the turning basin and 
from the construction barge itself. Details are available in DoN 
(2015). Source levels averaged 151 dB re 1 [mu]Pa rms (DoN, 2015). No 
impact driving was measured at this location; therefore, proxy levels 
for impact driving have been calculated from other available source 
levels.
    In order to determine reasonable SPLs and their associated effects 
on marine mammals that are likely to result from impact pile driving at 
NSM, we considered existing measurements from similar physical 
environments (sandy sediments and water depths greater than 15 ft) for 
impact and vibratory driving of 24-in steel pipe piles and for steel 
sheet piles. These studies, largely conducted by the Washington State 
Department of Transportation and the California Department of 
Transportation, show typical values around 160 dB for vibratory driving 
of 24-in pipe piles and sheet piles, and around 185-195 dB for impact 
driving of similar pipe piles (all measured at 10 m; e.g., Laughlin, 
2005a, 2005b; Illingworth and Rodkin, 2010, 2012, 2013; CalTrans, 
2012). For impact driving of sheet piles a proxy source value of 189 dB 
(CalTrans, 2012) was selected for use in acoustic modeling based on 
similarity to the physical environment at NSM and because of the 
measurement location in mid-water column. All calculated distances to 
and the total area encompassed by the marine mammal sound thresholds 
are provided in Table 3.

             Table 3--Distances to Relevant Underwater Sound Thresholds and Areas of Ensonification
----------------------------------------------------------------------------------------------------------------
                                                                                          Distance     Area (sq
             Pile type                       Method                  Threshold            (m) \1\       km\2\)
----------------------------------------------------------------------------------------------------------------
Steel sheet piles..................  Vibratory............  Level A harassment (180               0            0
                                                             dB).                             1,166     0.614439
                                                            Level B harassment (120
                                                             dB).
                                     Impact...............  Level A harassment (180              40        0.002
                                                             dB).                               858         0.51
                                                            Level B harassment (160
                                                             dB).
----------------------------------------------------------------------------------------------------------------
\1\ Areas presented take into account attenuation and/or shadowing by land. Calculated distances to relevant
  thresholds cannot be reached in most directions form source piles. Please see Figures 6-1 and 6-2 in the
  Navy's application.

    The Mayport turning basin does not represent open water, or free 
field, conditions. Therefore, sounds would attenuate as per the 
confines of the basin, and may only reach the full estimated distances 
to the harassment thresholds via the narrow, east-facing entrance 
channel. Distances shown in Table 3 are estimated for free-field 
conditions, but areas are calculated per the actual conditions of the 
action area. See Figures 6-1 and 6-2 of the Navy's application for a 
depiction of areas in which each underwater sound threshold is 
predicted to occur at the project area due to pile driving.

Marine Mammal Densities

    For all species, the best scientific information available was 
considered for use in the marine mammal take assessment calculations. 
Density for bottlenose dolphins is derived from site-specific surveys 
conducted by the Navy (see Appendix C of the Navy's application for 
more information); it is not currently possible to identify observed 
individuals to stock. This survey effort consists of 24 half-day 
observation periods covering mornings and afternoons during four 
seasons (December 10-13, 2012, March 4-7, 2013, June 3-6, 2013, and 
September 9-12, 2013). During each observation period, two observers (a 
primary observer at an elevated observation point and a secondary 
observer at ground level) monitored for the presence of marine mammals 
in the turning basin (0.712 km\2\) and an additional grid east of the 
basin entrance. Observers tracked marine mammal movements and behavior 
within the observation area, with observations recorded for five-minute 
intervals every half-hour. Morning sessions typically ran from 7:00-
11:30 and afternoon sessions from 1:00 to 5:30.
    Most observations of bottlenose dolphins were of individuals or 
pairs, although larger groups were

[[Page 75993]]

occasionally observed (median number of dolphins observed ranged from 
1-3.5 across seasons). Densities were calculated using observational 
data from the primary observer supplemented with data from the 
secondary observer for grids not visible by the primary observer. 
Season-specific density was then adjusted by applying a correction 
factor for observer error (i.e., perception bias). The seasonal 
densities range from 1.98603 (winter) to 4.15366 (summer) dolphins/
km\2\. We conservatively use the largest density value to assess take, 
as the Navy does not have specific information about when in-water work 
may occur during the proposed period of validity.

Description of Take Calculation

    The following assumptions are made when estimating potential 
incidents of take:
     All marine mammal individuals potentially available are 
assumed to be present within the relevant area, and thus incidentally 
taken;
     An individual can only be taken once during a 24-h period; 
and,
     There will be 110 total days of vibratory driving (seventy 
three days in phase I and thirty seven days in phase II) and twenty 
days of impact pile driving.
     Exposures to sound levels at or above the relevant 
thresholds equate to take, as defined by the MMPA.
    The estimation of marine mammal takes typically uses the following 
calculation:

Exposure estimate = (n * ZOI) * days of total activity
Where:

n = density estimate used for each species/season
ZOI = sound threshold ZOI area; the area encompassed by all 
locations where the SPLs equal or exceed the threshold being 
evaluated
n * ZOI produces an estimate of the abundance of animals that could 
be present in the area for exposure, and is rounded to the nearest 
whole number before multiplying by days of total activity.

    The ZOI impact area is estimated using the relevant distances in 
Table 3, taking into consideration the possible affected area with 
attenuation due to the constraints of the basin. Because the basin 
restricts sound from propagating outward, with the exception of the 
east-facing entrance channel, the radial distances to thresholds are 
not generally reached.
    There are a number of reasons why estimates of potential incidents 
of take may be conservative, assuming that available density or 
abundance estimates and estimated ZOI areas are accurate. We assume, in 
the absence of information supporting a more refined conclusion, that 
the output of the calculation represents the number of individuals that 
may be taken by the specified activity. In fact, in the context of 
stationary activities such as pile driving and in areas where resident 
animals may be present, this number more realistically represents the 
number of incidents of take that may accrue to a smaller number of 
individuals. While pile driving can occur any day throughout the in-
water work window, and the analysis is conducted on a per day basis, 
only a fraction of that time (typically a matter of hours on any given 
day) is actually spent pile driving. The potential effectiveness of 
mitigation measures in reducing the number of takes is typically not 
quantified in the take estimation process. For these reasons, these 
take estimates may be conservative.
    The quantitative exercise described above indicates that no 
incidents of Level A harassment would be expected, independent of the 
implementation of required mitigation measures. See Table 4 for total 
estimated incidents of take.

                              Table 4--Calculations for Incidental Take Estimation
----------------------------------------------------------------------------------------------------------------
                                      n (animals/                                           Proposed authorized
             Species                    km\2\)             Activity          n * ZOI \1\         takes \2\
----------------------------------------------------------------------------------------------------------------
                                                Phase I (73 days)
----------------------------------------------------------------------------------------------------------------
Bottlenose dolphin \3\...........          4.15366   Vibratory driving...              3                    219
----------------------------------------------------------------------------------------------------------------
                                               Phase II (37 days)
----------------------------------------------------------------------------------------------------------------
Bottlenose dolphin \3\...........          4.15366   Vibratory driving...              3                    111
----------------------------------------------------------------------------------------------------------------
                                      Contingency impact driving (20 days)
----------------------------------------------------------------------------------------------------------------
Bottlenose dolphin \3\...........          4.15366   Impact driving......              1                     40
                                                                                          ----------------------
    Total exposures..............  ................  ....................  ..............                   370
----------------------------------------------------------------------------------------------------------------
\1\ See Table 3 for relevant ZOIs. The product of this calculation is rounded to the nearest whole number.
\2\ The product of n * ZOI is multiplied by the total number of activity-specific days to estimate the number of
  takes.
\3\ It is impossible to estimate from available information which stock these takes may accrue to.

Analyses and Preliminary Determinations

Negligible Impact Analysis

    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.'' 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 
Level B harassment 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 behavioral 
harassment, we consider 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 
the number and nature of estimated Level A harassment takes, the number 
of estimated mortalities, and effects on habitat.
    Pile driving activities associated with the wharf construction 
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 underwater sounds generated

[[Page 75994]]

from pile driving. Potential takes could occur if individuals of these 
species are present in the ensonified zone when pile driving is 
happening.
    No injury, serious injury, or mortality is anticipated given the 
nature of the activities and measures designed to minimize the 
possibility of injury to marine mammals. The potential for these 
outcomes is minimized through the construction method and the 
implementation of the planned mitigation measures. Specifically, 
vibratory hammers will be the primary method of installation (impact 
driving is included only as a contingency and is not expected to be 
required), and this activity does not have the potential to cause 
injury to marine mammals due to the relatively low source levels 
produced (less than 180 dB) and the lack of potentially injurious 
source characteristics. Impact pile driving produces short, sharp 
pulses with higher peak levels and much sharper rise time to reach 
those peaks. If impact driving is necessary, implementation of soft 
start and shutdown zones significantly reduces any possibility of 
injury. Given sufficient ``notice'' through use of soft start (for 
impact driving), marine mammals are expected to move away from a sound 
source that is annoying prior to it becoming potentially injurious. 
Environmental conditions in the confined and protected Mayport turning 
basin mean that marine mammal detection ability by trained observers is 
high, enabling a high rate of success in implementation of shutdowns to 
avoid injury.
    Effects on individuals that are taken by Level B harassment, on the 
basis of reports in the literature as well as monitoring from other 
similar activities, will likely be limited to reactions such as 
increased swimming speeds, increased surfacing time, or decreased 
foraging (if such activity were occurring) (e.g., Thorson and Reyff, 
2006; HDR, Inc., 2012). Most likely, individuals will simply move away 
from the sound source and be temporarily displaced from the areas of 
pile driving, although even this reaction has been observed primarily 
only in association with impact pile driving. The pile driving 
activities analyzed here are similar to, or less impactful than, 
numerous other construction activities conducted in San Francisco Bay 
and in the Puget Sound region, which have taken place with no reported 
injuries or mortality to marine mammals, and no known long-term adverse 
consequences from behavioral harassment. These activities are also 
nearly identical to the pile driving activities that took place at 
Wharf C-2 at NSM, which also reported zero injuries or mortality to 
marine mammals and no known long-term adverse consequences from 
behavioral harassment. 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 the overall 
stock is unlikely to result in any significant realized decrease in 
viability for the affected individuals, and thus would not result in 
any adverse impact to the stock as a whole. Level B harassment will be 
reduced to the level of least practicable impact through use of 
mitigation measures described herein and, if sound produced by project 
activities is sufficiently disturbing, animals are likely to simply 
avoid the turning basin while the activity is occurring.
    In summary, this negligible impact analysis is founded on the 
following factors: (1) The possibility of injury, serious injury, or 
mortality may reasonably be considered discountable; (2) the 
anticipated incidents of Level B harassment consist of, at worst, 
temporary modifications in behavior; (3) the absence of any significant 
habitat within the project area, including known areas or features of 
special significance for foraging or reproduction; (4) the presumed 
efficacy of the proposed mitigation measures in reducing the effects of 
the specified activity to the level of least practicable impact. In 
addition, these stocks are not listed under the ESA, although coastal 
bottlenose dolphins are designated as depleted under the MMPA. 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 have only short-term 
effects on individuals. 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, we preliminarily find that the total marine mammal 
take from the Navy's wharf construction activities will have a 
negligible impact on the affected marine mammal species or stocks.

Small Numbers Analysis

    As described previously, of the 370 incidents of behavioral 
harassment predicted to occur for bottlenose dolphin, we have no 
information allowing us to parse those predicted incidents amongst the 
three stocks of bottlenose dolphin that may occur in the project area. 
Therefore, we assessed the total number of predicted incidents of take 
against the best abundance estimate for each stock, as though the total 
would occur for the stock in question. For one of the bottlenose 
dolphin stocks, the total predicted number of incidents of take 
authorized would be considered small--approximately four percent for 
the southern migratory stock- even if each estimated taking occurred to 
a new individual. This is an extremely unlikely scenario as, for 
bottlenose dolphins in estuarine and nearshore waters, there is likely 
to be some overlap in individuals present day-to-day.
    The total number of authorized takes proposed for bottlenose 
dolphins, if assumed to accrue solely to new individuals of the JES or 
northern Florida coastal stocks, is higher relative to the total stock 
abundance, which is currently considered unknown for the JES stock and 
is 1,219 for the northern Florida coastal stock. However, these numbers 
represent the estimated incidents of take, not the number of 
individuals taken. That is, it is highly likely that a relatively small 
subset of these bottlenose dolphins would be harassed by project 
activities.
    JES bottlenose dolphins range from Cumberland Sound at the Georgia-
Florida border south to approximately Palm Coast, Florida, an area 
spanning over 120 linear km of coastline and including habitat 
consisting of complex inshore and estuarine waterways. JES dolphins, 
divided by Caldwell (2001) into Northern and Southern groups, show 
strong site fidelity and, although members of both groups have been 
observed outside their preferred areas, it is likely that the majority 
of JES dolphins would not occur within waters ensonified by project 
activities.
    In the western North Atlantic, the Northern Florida Coastal Stock 
is present in coastal Atlantic waters from the Georgia/Florida border 
south to 29.4[deg] N. (Waring et al., 2014), a span of more than 90 
miles. There is no obvious boundary defining the offshore extent of 
this stock. They occur in waters less than 20 m deep; however, they may 
also occur in lower densities over the continental shelf (waters 
between 20 m and 100 m depth) and overlap spatially with the offshore 
morphotype (Waring et al., 2014).
    In summary, JES dolphins are known to form two groups and exhibit 
strong site fidelity (i.e., individuals do not

[[Page 75995]]

generally range throughout the recognized overall JES stock range); and 
neither stock is expected to occur at all in a significant portion of 
the larger ZOI, which is almost entirely confined within NSM. Given 
that the specified activity will be stationary within an enclosed basin 
not recognized as an area of any special significance that would serve 
to attract or aggregate dolphins, we therefore believe that the 
estimated numbers of takes, were they to occur, likely represent 
repeated exposures of a much smaller number of bottlenose dolphins and 
that these estimated incidents of take represent small numbers of 
bottlenose dolphins.
    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 mitigation and monitoring 
measures, we preliminarily find that small numbers of marine mammals 
will be taken relative to the populations of the affected species or 
stocks.

Impact on Availability of Affected Species for Taking for Subsistence 
Uses

    There are no relevant subsistence uses of marine mammals implicated 
by this action. Therefore, we have 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)

    No marine mammal species listed under the ESA are expected to be 
affected by these activities. Therefore, we have determined that 
section 7 consultation under the ESA is not required.

National Environmental Policy Act (NEPA)

    The Navy has prepared a Draft Environmental Assessment (EA; 
Environmental Assessment for the Wharf Bravo Recapitalization at Naval 
Station Mayport, Jacksonville, FL) in accordance with NEPA and the 
regulations published by the Council on Environmental Quality. We have 
posted it on the NMFS Web site (see SUPPLEMENTARY INFORMATION) 
concurrently with the publication of this proposed IHA. NMFS will 
independently evaluate the EA and determine whether or not to adopt it. 
We may prepare a separate NEPA analysis and incorporate relevant 
portions of the Navy's EA by reference. Information in the Navy's 
application, EA, and this notice collectively provide the environmental 
information related to proposed issuance of the IHA for public review 
and comment. We will review all comments submitted in response to this 
notice as we complete the NEPA process, including a decision of whether 
to sign a Finding of No Significant Impact (FONSI), prior to a final 
decision on the IHA request. The 2015 NEPA documents are available for 
review at www.nmfs.noaa.gov/pr/permits/incidental/construction.htm.

Proposed Authorization

    As a result of these preliminary determinations, we propose to 
authorize the take of marine mammals incidental to the Navy's Bravo 
wharf recapitalization project, provided the previously mentioned 
mitigation, monitoring, and reporting requirements are incorporated. 
Specific language from the proposed IHA is provided next.
    This section contains a draft of the IHA. The wording contained in 
this section is proposed for inclusion in the IHA (if issued).
    1. This Incidental Harassment Authorization (IHA) is valid for one 
year from the date of issuance.
    2. This IHA is valid only for pile driving activities associated 
with the Bravo Wharf Recapitalization Project at Naval Station Mayport, 
Florida.
    3. General Conditions
    (a) A copy of this IHA must be in the possession of the Navy, its 
designees, and work crew personnel operating under the authority of 
this IHA.
    (b) The species authorized for taking is the bottlenose dolphin 
(Tursiops truncatus).
    (c) The taking, by Level B harassment only, is limited to the 
species listed in condition 3(b). See Table 1 for numbers of take 
authorized.

                                        Table 1--Authorized Take Numbers
----------------------------------------------------------------------------------------------------------------
                                                                               Authorized take
                                                            ----------------------------------------------------
                          Species                                                                 Contingency
                                                                 Phase I          Phase II       impact driving
----------------------------------------------------------------------------------------------------------------
Bottlenose dolphin.........................................             219              111                 40
----------------------------------------------------------------------------------------------------------------

    (d) The taking by injury (Level A harassment), serious injury, or 
death of the species listed in condition 3(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.
    (e) The Navy shall conduct briefings between construction 
supervisors and crews, marine mammal monitoring team, and Navy staff 
prior to the start of all pile driving activity, and when new personnel 
join the work, in order to explain responsibilities, communication 
procedures, marine mammal monitoring protocol, and operational 
procedures.
    4. Mitigation Measures
    The holder of this Authorization is required to implement the 
following mitigation measures:
    (a) For all pile driving, the Navy shall implement a minimum 
shutdown zone of 15 m radius around the pile. If a marine mammal comes 
within or approaches the shutdown zone, such operations shall cease. 
For impact driving of steel piles, the minimum shutdown zone shall be 
of 40 m radius.
    (b) The Navy shall establish monitoring locations as described 
below. Please also refer to the Marine Mammal Monitoring Plan (see 
www.nmfs.noaa.gov/pr/permits/incidental/construction.htm).
    i. For all pile driving activities, a minimum of two observers 
shall be deployed, with one positioned to achieve optimal monitoring of 
the shutdown zone and the second positioned to achieve optimal 
monitoring of surrounding waters of the turning basin, the entrance to 
that basin, and portions of the Atlantic Ocean. If practicable, the 
second observer should be deployed to an elevated position, preferably 
opposite Bravo Wharf and with clear sight lines to the wharf and out 
the entrance channel.
    ii. These observers shall record all observations of marine 
mammals, regardless of distance from the pile being driven, as well as 
behavior and potential behavioral reactions of the animals. 
Observations within the turning basin shall be distinguished from those 
in the entrance channel and nearshore waters of the Atlantic Ocean.

[[Page 75996]]

    iii. All observers shall be equipped for communication of marine 
mammal observations amongst themselves and to other relevant personnel 
(e.g., those necessary to effect activity delay or shutdown).
    (c) Monitoring shall take place from fifteen minutes prior to 
initiation of pile driving activity through thirty minutes post-
completion of pile driving activity. Pre-activity monitoring shall be 
conducted for fifteen minutes to ensure that the shutdown zone is clear 
of marine mammals, and pile driving may commence when observers have 
declared the shutdown zone clear of marine mammals. In the event of a 
delay or shutdown of activity resulting from marine mammals in the 
shutdown zone, animals shall be allowed to remain in the shutdown zone 
(i.e., must leave of their own volition) and their behavior shall be 
monitored and documented. Monitoring shall occur throughout the time 
required to drive a pile. The shutdown zone must be determined to be 
clear during periods of good visibility (i.e., the entire shutdown zone 
and surrounding waters must be visible to the naked eye).
    (d) If a marine mammal approaches or enters the shutdown zone, all 
pile driving activities at that location shall be halted. If pile 
driving is halted or delayed due to the presence of a marine mammal, 
the activity may not commence or resume until either the animal has 
voluntarily left and been visually confirmed beyond the shutdown zone 
or fifteen minutes have passed without re-detection of the animal.
    (e) Monitoring shall be conducted by qualified observers, as 
described in the Monitoring Plan. Trained observers shall be placed 
from the best vantage point(s) practicable to monitor for marine 
mammals and implement shutdown or delay procedures when applicable 
through communication with the equipment operator. Observer training 
must be provided prior to project start and in accordance with the 
monitoring plan, and shall include instruction on species 
identification (sufficient to distinguish the species listed in 3(b)), 
description and categorization of observed behaviors and interpretation 
of behaviors that may be construed as being reactions to the specified 
activity, proper completion of data forms, and other basic components 
of biological monitoring, including tracking of observed animals or 
groups of animals such that repeat sound exposures may be attributed to 
individuals (to the extent possible).
    (f) The Navy shall use soft start techniques recommended by NMFS 
for impact pile driving. Soft start requires contractors to provide an 
initial set of strikes at reduced energy, followed by a thirty-second 
waiting period, then two subsequent reduced energy strike sets. Soft 
start shall be implemented at the start of each day's impact pile 
driving and at any time following cessation of impact pile driving for 
a period of thirty minutes or longer.
    (g) Pile driving shall only be conducted during daylight hours.
    5. Monitoring
    The holder of this Authorization is required to conduct marine 
mammal monitoring during pile driving activity. Marine mammal 
monitoring and reporting shall be conducted in accordance with the 
Monitoring Plan.
    (a) The Navy shall collect sighting data and behavioral responses 
to pile driving for marine mammal species observed in the region of 
activity during the period of activity. All observers shall be trained 
in marine mammal identification and behaviors, and shall have no other 
construction-related tasks while conducting monitoring.
    (b) For all marine mammal monitoring, the information shall be 
recorded as described in the Monitoring Plan.
    6. Reporting
    The holder of this Authorization is required to:
    (a) Submit a draft report on all monitoring conducted under the IHA 
within ninety days of the completion of marine mammal monitoring, or 
sixty days prior to the issuance of any subsequent IHA for projects at 
NSM, whichever comes first. A final report shall be prepared and 
submitted within thirty days following resolution of comments on the 
draft report from NMFS. This report must contain the informational 
elements described in the Monitoring Plan, at minimum (see 
www.nmfs.noaa.gov/pr/permits/incidental/construction.htm), and shall 
also include:
    i. Detailed information about any implementation of shutdowns, 
including the distance of animals to the pile and description of 
specific actions that ensued and resulting behavior of the animal, if 
any.
    ii. Description of attempts to distinguish between the number of 
individual animals taken and the number of incidents of take, such as 
ability to track groups or individuals.
    iii. An estimated total take estimate extrapolated from the number 
of marine mammals observed during the course of construction 
activities, if necessary.
    (b) Reporting injured or dead marine mammals:
    i. In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by this IHA, 
such as an injury (Level A harassment), serious injury, or mortality, 
Navy shall immediately cease the specified activities and report the 
incident to the Office of Protected Resources, NMFS, and the Southeast 
Regional Stranding Coordinator, NMFS. The report must include the 
following information:
    A. Time and date of the incident;
    B. Description of the incident;
    C. Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
    D. Description of all marine mammal observations in the 24 hours 
preceding the incident;
    E. Species identification or description of the animal(s) involved;
    F. Fate of the animal(s); and
    G. Photographs or video footage of the animal(s).
    Activities shall not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS will work with Navy to 
determine what measures are necessary to minimize the likelihood of 
further prohibited take and ensure MMPA compliance. Navy may not resume 
their activities until notified by NMFS.
    ii. In the event that Navy 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), Navy shall immediately report 
the incident to the Office of Protected Resources, NMFS, and the 
Southeast Regional Stranding Coordinator, NMFS.
    The report must include the same information identified in 6(b)(i) 
of this IHA. Activities may continue while NMFS reviews the 
circumstances of the incident. NMFS will work with Navy to determine 
whether additional mitigation measures or modifications to the 
activities are appropriate.
    iii. In the event that Navy 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), Navy shall report the incident to the 
Office of Protected Resources, NMFS, and the Southeast Regional 
Stranding Coordinator, NMFS, within 24 hours of the discovery. Navy 
shall provide photographs or video footage or other documentation of 
the stranded animal sighting to NMFS.

[[Page 75997]]

    7. This Authorization may be modified, suspended or withdrawn if 
the holder fails to abide by the conditions prescribed herein, or if 
NMFS determines 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 analyses, the draft authorization, and 
any other aspect of this Notice of Proposed IHAs for Navy's wharf 
construction activities. Please include with your comments any 
supporting data or literature citations to help inform our final 
decision on Navy's request for an MMPA authorization.

     Dated: December 2, 2015.
Perry F. Gayaldo,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2015-30745 Filed 12-4-15; 8:45 am]
 BILLING CODE 3510-22-P