[Federal Register Volume 69, Number 101 (Tuesday, May 25, 2004)]
[Notices]
[Pages 29693-29696]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-11800]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 031604B]


Taking Marine Mammals Incidental to Specified Activities; Alafia 
River Navigation Channel, Tampa, FL

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

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

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

DATES: Comments and information must be received no later than June 24, 
2004.

ADDRESSES: Comments on the application should be addressed to Michael 
Payne, Chief, Marine Mammal Conservation Division, Office of Protected 
Resources, NMFS, 1315 East-West Highway, Silver Spring, MD 20910-3225. 
The mailbox address for providing e-mail comments on this action is 
[email protected] Include in the subject line of the e-mail comment 
the following document identifier: ID[numsign]031604B. Comments sent 
via email, including all attachments, must not exceed a 10-megabyte 
file size. A copy of the application containing a list of references 
used in this document may be obtained by writing to the address 
provided or by telephoning the contact listed under the heading FOR 
FURTHER INFORMATION CONTACT. Publications referenced in this document 
are available for viewing, by appointment during regular business 
hours, at the address provided here during this comment period.

FOR FURTHER INFORMATION CONTACT: Kenneth R. Hollingshead, NMFS, (301) 
713-2322, ext 128.

SUPPLEMENTARY INFORMATION:

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce to allow, upon request, the 
incidental, but not intentional, taking of marine mammals by U.S. 
citizens who engage in a specified activity (other than commercial 
fishing) within a specified geographical region if certain findings are 
made and either regulations are issued or, if the taking is limited to 
harassment, a notice of a proposed authorization is provided to the 
public for review.
    Permission may be granted if NMFS finds that the taking will have a 
negligible impact on the species or stock(s) and will not have an

[[Page 29694]]

unmitigable adverse impact on the availability of the species or 
stock(s) for subsistence uses and that the permissible methods of 
taking and requirements pertaining to the monitoring and reporting of 
such takings are set forth. NMFS has defined ``negligible impact'' in 
50 CFR 216.103 as ``an impact resulting from the specified activity 
that cannot be reasonably expected to, and is not reasonably likely to, 
adversely affect the species or stock through effects on annual rates 
of recruitment or survival.''
    Subsection 101(a)(5)(D) of the MMPA established an expedited 
process by which citizens of the United States can apply for an 
authorization to incidentally take small numbers of marine mammals by 
harassment. 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].
    Subsection 101(a)(5)(D) establishes a 45-day time limit for NMFS 
review of an application followed by a 30-day public notice and comment 
period on any proposed authorizations for the incidental harassment of 
small numbers of marine mammals. Within 45 days of the close of the 
comment period, NMFS must either issue or deny issuance of the 
authorization.

Summary of Request

    On February 26, 2004, NMFS received a request from the Corps for an 
authorization to take bottlenose dolphins incidental to using blasting 
during expansion of the Alafia River Navigation Channel by widening the 
channel to 250 ft (76.2 m) and deepening the channel to 42 ft (12.8 m) 
at mean low low water (mllw). The existing turning basin would be 
enlarged to a diameter of 1200 ft (365.8 m) with a depth of 42 ft (12.8 
m) at mllw. The specific geographic area of the construction will be 
within the boundaries of the Alafia River Navigation Channel, part of 
the Tampa harbor navigation project. The Alafia River is located in 
northern Tampa Bay, Hillsborough County, Florida.
    Completion of the dredging project may employ a clamshell dredge, 
cutterhead dredge and/or blasting. The dredging will remove 5.5 million 
cubic yards of material from the existing navigation channel and 
turning basin. Material removed from the dredging will be placed in the 
Tampa Ocean Dredged Material Disposal Site and at two ``beneficial use 
of dredged material'' sites located near the project area. The project 
is proposed to start in February 2005 and is estimated to last for 24 
months.
    The Corps expects the contractor to employ underwater confined 
blasting and dredging to construct the project. Blasting may have 
adverse impacts on bottlenose dolphins and manatees (Trichechus manatus 
latirostris) inhabiting near or utilizing the Alafia River channel in 
the northern portion of Tampa Bay. Dolphins and other marine mammals 
have not been documented as being directly affected by dredging 
activities other than blasting.
    While the Corps does not presently have a blasting plan from the 
contractor, which will specifically identify the number of holes that 
will be drilled, the amount of explosives that will be used for each 
hole, the number of blasts per day (usually no more than 3/day), or the 
number of days the construction is anticipated to take to complete, the 
Corps submitted a description of a completed project in San Juan 
Harbor, Puerto Rico as an example. For that project, the maximum weight 
of the explosives used for each event was 375 lbs (170 kg) and the 
contractors detonated explosives once or twice daily from July 16 to 
September 9, for a total of 38 individual detonations. Normal practice 
is for each charge to be placed approximately 5 - 10 ft (1.5 - 3 m) 
deep within the rock substrate, depending on how much rock needs to be 
broken and how deep a channel depth is authorized. The charges are 
placed in the holes and tamped with rock. Therefore, if the total 
explosive weight needed is 375 lbs (170 kg) and they have 10 holes, 
they would average 37.5 lbs (17.0 kgs)/hole. However, a more likely 
weight for this project may be only 90 lbs (41 kgs) and, therefore, 9 
lbs (4.1 kg)/hole. Charge weight and other determinations are expected 
to be made by the Corps and the contractor approximately 30-60 days 
prior to commencement of the construction project. Because the charge 
weight and other information is not presently available, NMFS will 
require the Corps to provide this information to NMFS, including 
calculations for impact/mitigation zones (for the protection of marine 
mammals from injury), prior to commencing work. However, as described 
later in this document, mitigation measures will require the Corps to 
limit detonations to the minimum level necessary to accomplish the task 
and the larger the charge weight, the greater the safety zone that will 
be required to protect marine mammals.

Summary of Request for Regulations

    While the Corps was coordinating with NMFS on the application and 
issuance of an IHA for the Miami Turning Basin in early 2003 (see 68 FR 
32016, May 29, 2003 and 69 FR 2899, January 21, 2004), the Corps 
identified at least 6 additional Federal navigation projects that might 
need similar MMPA authorizations within the next few years, if confined 
blasting is used as a construction technique. To ensure consistency 
across MMPA authorizations for these dredging projects, and efficiency 
for both agencies, NMFS recommended that the Corps apply for these 
authorizations under section 101(a)(5)(A) of the MMPA, instead of 
individually under section 101(a)(5)(D) of the MMPA. This request was 
received on December 1, 2003. At this time only the Miami Turning Basin 
and this Alafia River project are proposed to be covered by the section 
101(a)(5)(A) rulemaking. This rule, if implemented, and Letters of 
Authorization (LOA) issued under that rule, would replace the IHA 
process for these activities in the Jacksonville District. Each 
application for an LOA for additional projects within the Jacksonville 
District for confined blasting within the District would require 
separate public review and comment, prior to issuance of an LOA. NMFS 
expects to start this rulemaking shortly.

Description of the Marine Mammals Affected by the Activity

    General information on marine mammal species found off the
    east coast of the United States can be found in Waring et al. 
(2001, 2002). These reports are available on the Internet at the 
following location: http://www.nmfs.noaa.gov/prot_res/PR2/Stock_Assessment_Program/sars.html
    Bottlenose dolphins and West Indian manatees are the only marine 
mammal species expected in the activity area. However, take 
authorizations for manatees are issued by the U.S. Fish and Wildlife 
Service (USFWS) and are not covered by this proposed IHA or any future 
rulemaking for LOAs issued by NMFS. Wang et al. (2002) provides the 
following minimum population estimates for the Gulf of Mexico 
bottlenose dolphin stocks: outer shelf, 43,233; shelf and slope, 4,530; 
western Gulf, 2,938; northern Gulf, 3,518; eastern Gulf, 8,953; and 
Bay, Sound & Estuarine waters, 3,933.
    The best estimate is that the Tampa Bay bottlenose dolphin 
population

[[Page 29695]]

(which includes any dolphins within the Alafia River) consists of 559 
individuals (Wang et al., 2002). Previous population estimates for 
Tampa Bay include Wells et al. (1996), Weigle (1990), Scott et al. 
(1989) Wells (1986), Thompson (1981), and O'Dell and Reynolds (1980). A 
monitoring study of bottlenose dolphins in Tampa Bay was conducted from 
1988-1993. The results of that study were published in Wells et al. 
(1996). It is the most recent study of those animals currently 
available (R. Wells, pers. comm. to T. Jordan, Corps, 2004). The study 
identified a population size ranging between 437 and 728 individuals 
utilizing three different survey and population estimation techniques. 
Some of these animals have been shown to be in the vicinity of the 
Alafia River channel. In a subsequent examination of the data, Urian 
(2002) identified five populations of bottlenose dolphins in Tampa Bay. 
Two of these populations utilize the area adjacent to the Alafia River 
channel. Specific population levels for these two groups were not 
provided in the study.

Potential Effects on Marine Mammals

    According to the Corps, bottlenose dolphins and other marine 
mammals have not been documented as being directly affected by dredging 
activities and therefore the Corps does not anticipate any incidental 
harassment of bottlenose dolphins by dredging.
    Potential impacts to marine mammals from explosive detonations 
include both lethal and non-lethal injury, as well as Level B 
harassment. Marine mammals may be killed or injured as a result of an 
explosive detonation due to the response of air cavities in the body, 
such as the lungs and bubbles in the intestines. Effects are likely to 
be most severe in near-surface waters where the reflected shock wave 
creates a region of negative pressure called ``cavitation.'' This is a 
region of near total physical trauma within which no animals would be 
expected to survive. A second possible cause of mortality or lethal 
injury is the onset of extensive lung hemorrhage. Extensive lung 
hemorrhage is considered debilitating and potentially fatal. 
Suffocation caused by lung hemorrhage is likely to be the major cause 
of marine mammal death from underwater shock waves. The onset of 
extensive lung hemorrhage for marine mammals will vary depending upon 
the animal's weight, with the smallest mammals having the greatest 
potential hazard range.
    NMFS has also established criteria for determining non-lethal 
injury (Level A harassment) and non-injurious (Level B harassment) 
harassment from underwater explosions (see 66 FR 22450, May 4, 2001). 
For non-lethal injury from explosives the criteria are established as 
the peak pressure that will result in: (1) the onset of slight lung 
hemorrhage, or (2) a 50-percent probability level for a rupture of the 
tympanic membrane. These are injuries from which animals would be 
expected to recover on their own.
    Although each of the tamped charges are fairly small (probably less 
than the 37 lbs (16.8 kg) per drilled hole used in Puerto Rico) and 
detonation staggered to reduce total pressure, the maximum horizontal 
extent for mortality/lethal injury and non-lethal injury (Level A 
harassment), estimated based on the total charge weight (375 lbs in the 
case of Puerto Rico) would be less than 1875 ft (571 m) and 3750 ft 
(1143 m) respectively. As these distances are based on an open-water 
charge calculation, and as stemmed/confined blasts result in a 
significant decrease in the strength of the pressure wave released as 
compared to an open water blast, the zones for mortality and non-
serious injury would be significantly less than these distances. As a 
result of these small impact zones, the relatively shallow waters for 
blasting, and the nature of bottlenose dolphins to remain in surface 
waters, the biological monitoring (aerial- and vessel-based) is 
expected to be effective in locating all marine mammals prior to them 
entering an area where injury or mortality might result and thereby 
preventing any takes by injury or mortality.
    NMFS has also established dual criteria for what constitutes Level 
B acoustic harassment for all marine mammals: (1) an energy-based 
temporary threshold shift (TTS) from received sound levels of 182 dB re 
1 microPa2-sec cumulative energy flux in any 1/3 octave band above 100 
Hz for odontocetes (derived from experiments with bottlenose dolphins 
(Ridgway et al., 1997; Schlundt et al., 2000); and (2) 12 psi peak 
pressure (cited by Ketten (1995) as associated with a safe outer limit 
for minimal, recoverable auditory trauma (i.e., TTS)).

Mitigation

    The Corps proposes to implement mitigation measures that will 
establish both caution- and safety-zone radii to ensure that bottlenose 
dolphins will not be injured or killed during blasting and that impacts 
will be at the lowest level practicable. In the absence of acoustic 
measurements of the shock and pressure waves emanating from the 
detonations (due to the high cost and complex instrumentation needed), 
the following equations have been proposed by the Corps for blasting 
projects to determine zones for injury or mortality from an open water 
explosion and to assist the Corps in establishing mitigation to reduce 
impacts to the lowest level practicable. These equations are 
conservative because they are based on humans, which are more sensitive 
to the effects from the pressure wave of the detonation than are 
dolphins and because they are based on unconfined charges while the 
proposed blasts in the Alafia River will be confined or stemmed charges 
(i.e., placed in a hole drilled in rock and tamped with rock). Studies 
(e.g., Nedwell and Thandavamoorthy 1992) have shown that stemmed/
confined blasts have a greater than 90 percent decrease in the strength 
of the pressure wave released as compared to an open water blast.
    The equations, based on Young (1991), are:
Caution Zone radius = 260 (lbs/delay)\1/3\
Safety Zone radius = 520 (lbs/delay)\1/3\
    with R = 260 times or 520 times the cube root of the weight of the 
explosive charge in pounds where R = radius of the safety zone in ft 
and W = weight of the explosive charge in lbs. The Caution Zone 
represents the radius from the point of detonation beyond which 
mortality would not be expected from an open-water blast. The Safety 
Zone is the approximate distance beyond which non-serious injury (Level 
A harassment) would be unlikely from an open-water explosion. These 
zones will be used for implementing mitigation measures to protect both 
marine mammals and sea turtles, although the activity area is 
apparently not good habitat for sea turtles.
    In the area where explosives are required to obtain channel design 
depth for each explosive charge, the Corps proposes that detonation 
will not occur if a marine mammal is sighted within the Safety Zone by 
a member of the marine mammal observer program.
    Although the Caution Zone is considered to be an area for potential 
mortality, the Corps and NMFS believe that because all explosive 
charges will be stemmed, the true areas for potential mortality and 
injury will be significantly smaller than this area and, therefore, for 
reasons mentioned previously, it is unlikely that even non-serious 
injury will occur. This is particularly true in this case, since 
bottlenose dolphins are commonly found on the surface of the water and 
implementation of a mitigation/ monitoring program is unlikely to miss 
bottlenose dolphins in such a small area.

[[Page 29696]]

    Additional mitigation measures that will significantly lower 
potential impacts to marine mammals (and sea turtles) include: (1) 
confining the explosives in a hole with drill patterns restricted to a 
minimum of 8 ft (2.44 m) separation from any other loaded hole; (2) 
restricting the hours of detonation from 2 hours after sunrise to 1 
hour before sunset to ensure adequate observation of marine mammals in 
the safety zone; (3) staggering the detonation for each explosive hole 
in order to spread the explosive's total overpressure over time, which 
in turn will reduce the radius of the caution zone; (4) capping the 
hole containing explosives with rock in order to reduce the outward 
potential of the blast, thereby reducing the chance of injuring a 
dolphin or manatee; (5) matching, to the extent possible, the energy 
needed in the ``work effort'' of the borehole to the rock mass to 
minimize excess energy vented into the water column; and (6) conducting 
a marine mammal watch with no less than two qualified observers from a 
small water craft and/or an elevated platform on the explosives barge, 
at least 30 minutes before and continue for 30 minutes after each 
detonation to ensure that there are no dolphins, manatees or sea 
turtles in the area at the time of detonation.

Monitoring Program

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

Reporting

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

Endangered Species Act

    Under section 7 of the ESA, the Corps completed consultation with 
the USFWS on December 14, 1998 for this project. The USFWS concluded 
that the work would not likely jeopardize the continued existence of 
the manatee, if standard manatee protection conditions were 
implemented. The Corps reinitiated consultation with the USFWS by 
letter dated July 5, 2000, because blasting was identified as a 
component of the project. On July 24, 2000 and September 5, 2000, the 
USFWS provided the Corps with recommendations for protecting manatees 
while conducting blasting operations. These recommendations have been 
incorporated into the project. Because the proposed issuance of this 
IHA to the Corps is a federal action under section 7 of the ESA that 
might affect sea turtles (a listed species under NMFS' jurisdiction), 
NMFS has begun consultation on the proposed issuance of an IHA under 
section 101(a)(5)(D) of the MMPA for this activity. Consultation will 
be concluded prior to a determination on whether or not to issue an 
IHA.

National Environmental Policy Act

    The Corps prepared an Environmental Assessment (EA) on the 
Navigation Study for Tampa Harbor-Alafia River, Florida in September 
2000 and made a finding of no significant impact on October 11, 2000. A 
copy of this document is available for viewing (see ADDRESSES). NMFS is 
reviewing this EA in relation to the Corps' application and will 
determine the appropriate action to take under NEPA prior to making a 
determination on the issuance of an IHA.

Preliminary Conclusions

    NMFS has preliminarily determined that the Corps' proposed action, 
including mitigation measures to protect marine mammals, should result, 
at worst, in the temporary modification in behavior by bottlenose 
dolphins resulting from temporary hearing impairment (TTS), but may 
also include temporarily vacating the Alafia River area to avoid the 
blasting activity and the potential for minor visual and acoustic 
disturbance from dredging and detonations. Because this project will 
affect at most a few dolphins due to its local impact, short time 
duration, and implementation of effective vessel-based and aerial 
monitoring programs, NMFS believes that only a small number of dolphins 
may be taken by Level B harassment and this is expected to have only a 
negligible impact on the affected species or stocks of bottlenose 
dolphins. In addition, no take by injury and/or death is anticipated, 
and harassment takes will be at the lowest level practicable due to 
incorporation of the mitigation measures described in this document.

Proposed Authorization

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

Information Solicited

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

    Dated: May 18, 2004.
Laurie K. Allen,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 04-11800 Filed 5-24-04; 8:45 am]
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