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Taking Marine Mammals Incidental to Specified Activities; Port of Miami Construction Project (Phase II)

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


Notice of issuance of an incidental harassment authorization.


In accordance with provisions of the Marine Mammal Protection Act (MMPA), notification is hereby given that an Incidental Harassment Authorization (IHA) has been issued to the U.S. Army Corps of Engineers-Jacksonville District (Corps) to take bottlenose dolphins (Tursiops truncatus), by harassment, incidental to deepening the Dodge-Lummus Island Turning Basin in Miami, FL (Turning Basin).


This authorization is effective from April 19, 2005, through April 18, 2006.


A copy of the application may be obtained by writing to Steve Leathery, Chief, Permits, Conservation and Education Division, Office of Protected Species, National Marine Fisheries Service, 1315 East-West Highway, Silver Spring, Md 20910, or by telephoning the contact listed here. Documents cited in this notice may be viewed, by appointment, during regular business hours, at this address.

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Kenneth R. Hollingshead, NMFS, (301) 713-2055, ext 128.

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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), will not have an 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. Except with respect to certain activities not pertinent here, the MMPA defines “harassment” as:

any act of pursuit, torment, or annoyance which (i) has the potential to injure a marine mammal or marine mammal stock in the wild [Level A harassment]; or (ii) has the potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioral patterns, including, but not limited to, migration, breathing, nursing, breeding, feeding, or sheltering [Level B harassment].

Section 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 IHA Request

On December 1, 2003, NMFS received a request from the Corps for a renewal of an IHA to take bottlenose dolphins incidental to using blasting while deepening the Turning Basin in the Port of Miami, south of Dodge-Lummus Island. An IHA for this activity was issued to the Corps previously on May 22, 2003 (68 FR 32016, May 29, 2003). This IHA expired on May 21, 2004. Since the work in the Turning Basin did not occur during that period, a new IHA is warranted.

The Port of Miami is one of the major terminal complexes in Florida. The majority of this tonnage is high-value general cargo transported in trailers and containers. The Port also accommodates a large cruise ship industry. Development has primarily centered on the Lummus Island terminal and container complex facilities. Expanding and deepening the Turning Basin would eliminate the need for vessels docked at Lummus Island to back to or from the Fisher Island Turning Basin.

Completion of the dredging project may employ a hopper dredge, clamshell dredge, cutterhead dredge and/or confined blasting. The dredging will remove 1.4 million cubic yards of material from an area 1,500 ft (457.2 m) in diameter. The Corps has contracted for dredging the Turning Basin to a maximum depth of 42 ft (12.8 m) plus a 2 ft (0.61 m) overdepth. Material removed from the dredging will be placed in the Miami Ocean Dredged Material Disposal Site.

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The Corps expects the contractor will employ underwater dredging and confined blasting to construct the project. Blasting has the potential to have adverse impacts on bottlenose dolphins and manatees (Trichechus manatus latirostris) inhabiting the area near the project. 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 has forwarded to NMFS a description of a completed project in San Juan Harbor, Puerto Rico to use 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 depth is sought. 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 and sea turtles from injury), prior to commencing work.

Comments and Responses

A notice of receipt of the application and proposed authorization was published on January 15, 2004 (69 FR 2333). That notice described the activity and anticipated effects on marine mammals. NMFS received comments from the Marine Mammal Commission (Commission) on the application and proposed authorization.

Comment 1: The Commission notes that, given that the formulae for determining the safety zones are based on theoretical considerations and modeling of the sound pressure levels to which animals would be exposed, the Commission believes that the applicant should collect empirical data during its operations that could assess the accuracy of the model.

Response: The caution and safety zones are based on theoretical models derived from empirical research conducted by Goertner (1981) and others. This research cannot be replicated in the United States because of ethical/humanitarian concerns using live animals, especially marine mammals. However, recent exposures of dolphin, porpoise and sea turtle cadavers to small-charge detonations should provide scientists with new information in the near future. Until the time that those results are available, NMFS has determined that the models provided by Young (1991), based on the research by Goertner (1981) are the best scientific information currently available. As explained in detail in the proposed notice and elsewhere in this document, due to the expense involved in calculating safety zones based on the NMFS dual criteria formula for explosives, the Corps adopted conservative formula, based on the Navy Diver Formula, to protect bottlenose dolphins and manatees from injury. Young's (1991) formula for open water explosions are provided here:

calf porpoise (3.3 ft) safe range = 578 W(lb).28

adult porpoise (8 ft) safe range = 434 W(lb).28

small whale 20-ft safe range = 327 W(lb).28

sea turtle safe range = 560 W(lb).33

Additional information can be found in the U.S. Navy's Final Environmental Impact Statement (Final EIS) on the Shock Trial of the Winston S. Churchill (see 66 FR 11288, February 23, 2001). What needs to be understood is that 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. Therefore, once measurements are conducted and the results analyzed, blast projects would be able to reduce their safety zones. NMFS, therefore, will require empirical measurements of blasts in those situations where it believes that non-conservative values for safety zones have been adopted and will only recommend these measurements be made in other cases. For Corps' blasting projects, the Corps is analyzing sound pressure measurements made during a blasting project in New York harbor and the Corps has agreed to measure attenuation levels at this site later in 2005. While the results from these measurements are not available to modify the safety zones here, the results from these measurements will provide information to make future assessments for safety zones at other blast locations.

Comment 2: The Commission notes that it would be useful if NMFS or the applicant conducted pre- and post-blast surveys, and monitor and map the distribution of high intensity sound resulting from the shallow-water blasts.

Response: The Corps will have at least two trained biologists conducting a marine mammal/sea turtle watch from a small water craft and/or an elevated platform on the explosives barge, at least 30 minutes before through 30 minutes after each detonation to ensure that there are no dolphins or sea turtles in the area at the time of detonation. For this project, NMFS believes that level of monitoring is sufficient to ensure that no bottlenose dolphins will be injured or killed. Unlike other detonation projects that have the option to relocate its activity to ensure the lowest impact practicable, channel deepening projects do not have the ability to relocate. The Commission's concern regarding mapping areas of high intensity sound was answered in response to comment 1.

Comment 3: Because there are no reliable survey data for bottlenose dolphins in the project area, the Commission states NMFS may want to require the applicant conduct population surveys prior to initiating the proposed activities.

Response: NMFS does not believe that marine mammal surveys of this immediate area are warranted for this activity since the project is unlikely to result in more than a brief reaction to the activity that will not affect the reproduction or survival of the Western North Atlantic coastal or offshore bottlenose dolphin stocks (i.e., no animals will be injured or killed as a result of this activity). The Corps provided information regarding a survey conducted by the NMFS, Southeast Fisheries Science Center, Miami Laboratory. Studies have identified 159 individual animals residing in Biscayne Bay, 146 of which have been resighted at least one additional time. Many of these animals have been sighted within or transiting through the Port of Miami. Population studies conducted by the Southeast Fisheries Science Center have found that the size of the subpopulation of bottlenose dolphins in Biscayne Bay averages between 78 and 92 individuals (Joe Contillo, pers. com. May 5, 2003). These animals are part of significantly larger stocks of either the offshore or coastal stocks with a minimum population estimate of 24,897 and 2,482 animals, respectively. Therefore, even without marine mammal monitoring, it Start Printed Page 21176is likely that no more than a small number of dolphins will be temporarily disturbed by the Corps' blasting activity in Miami Harbor.

While such minor disturbance does not warrant implementation of a population abundance survey, the monitoring team will conduct observations from the boat prior to initiation of blasts. This will provide an indication whether dolphins can be expected to be in the area and, if so, how many animals might be present.

However, NMFS agrees that information on the marine mammal distribution and abundance along the east coast of the United States can be improved.

Comment 4: The Commission recommends that the proposed mitigation and monitoring measures be carried out as described, and that NMFS ensure that the proposed monitoring activities and observer effort are adequate to detect any marine mammals that may be within the danger or caution/safety zones calculated for a particular explosion.

Response: NMFS has reviewed the Corps proposed mitigation and monitoring program and has determined that it will be effective, to the maximum extent practicable, to prevent injury or mortality to any bottlenose dolphins. These mitigation/ monitoring measures are discussed later in this document. Recognizing that bottlenose dolphins are easy to spot because of schooling and short dive periods, and the relatively small zone for injury or mortality, it is unlikely that any dolphins would be able to travel through the potential zone of impact and not be seen by the observers. Protocols have been established to ensure that, once a dolphin (manatee, or sea turtle) is spotted within the watch zone, no detonation would occur.

Comment 5: An across-the-board definition of temporary threshold shift (TTS) as constituting no more than Level B harassment inappropriately dismisses possible injury and biologically significant behavioral effects (e.g., an increased risk of natural predation or ship strikes) that can result from repeated TTS harassment and from the cumulative effects of long-term exposure. The Commission therefore reiterated its recommendation that TTS be considered as having the potential to injure marine mammals (i.e., Level A harassment).

Response: NMFS has addressed the concern of the definition of TTS in previous small take authorizations (66 FR 22450, May 4, 2001; 67 FR 46712, July 16, 2002). These authorizations state that the best scientific information available supports NMFS' determination that TTS results in Level B harassment, rather than Level A harassment. Alternative suggestions that TTS should be considered Level A harassment are based on speculation due to hypothetical second level impacts. Without the introduction of new scientific information upon which NMFS can reevaluate its previous determination, additional discussion is not warranted at this time. NMFS encourages those interested in this subject to refer to the Navy Final EIS on the Churchill shock trial referenced previously.

Comment 6: The Commission recommends that prior to the Corp (contractor) initiating blasting, NMFS review and approve the specific blasting plan, including the maximum weight of the explosives that will be used for each explosive event, the number of holes that will be drilled, the amount of explosives that will be used for each hole, the number of blasts each day, and the number of days the construction is anticipated to take to complete to ensure that it is within the range of the project provided by the applicant to NMFS as an example.

Response: NMFS will require the Corps provide this information to NMFS, including calculations for impact/mitigation ranges (for the protection of marine mammals and sea turtles from injury), 30 days prior to commencing work. However, the Puerto Rico project was provided by the Corps as an example of an earlier project and has no relationship to the current Miami project. Because NMFS believes that it does not have the expertise to determine the adequacy of the dredging/blasting plan, it will leave those determinations up to the Corps and its contractors, but will ensure, during its review of the blasting plan, that the caution and safety zones are adequate to protect marine mammals from injury or mortality.

Comment 7: NMFS should advise the Corps that manatees have been observed in this area. If there is the potential that manatees will also be taken incidental to the proposed activities, authorization for such taking would be needed from the U.S. Fish and Wildlife Service (USFWS).

Response: Under section 7 of the ESA, the Corps completed consultation with the USFWS on June 19, 2002 for this project. The USFWS concurred with the Corps that activities associated with the Corps' dredging and blasting project in the Dodge-Lummus Island Turning Basin were not likely to adversely affect listed species.

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 at the following location:​prot_​res/​PR2/​Stock_​Assessment_​Program/​sars.html

The only marine mammal species likely to be found in the Turning Basin are the bottlenose dolphin and West Indian manatee. Manatees are under the jurisdiction of the USFWS. There is no stock assessment available concerning the status of bottlenose dolphins in the inshore and nearshore waters off south Florida. Additionally, while neither a status review nor peer-reviewed reports on the status of the Biscayne Bay bottlenose dolphins have been published, the Southeast Fisheries Science Center, NMFS, is currently working on this report. Preliminary information indicates a documented population of 159 bottlenose dolphins residing within the boundaries of the Biscayne Bay area. A total of 146 bottlenose dolphins have been resighted in the Port of Miami area at least one additional time. These animals were often sighted within or transiting through the Port of Miami. It is not known whether bottlenose dolphins inhabit the Turning Basin or whether they simply use the area as a transit to North Biscayne Bay or offshore via the main port channel. The defined stocks of bottlenose dolphins that reside closest to the project area, therefore, are the western North Atlantic coastal (central Florida management unit) and offshore stocks of bottlenose dolphins with a minimum population estimated to be 24,897 for the offshore stock. Abundance of the coastal stock in central Florida is 10,652 in winter, but unknown in summer. Additional assessment information for these two stocks is available at the previously mentioned URL.

Potential Effects on Habitat

The Corps expects the effects on marine mammal habitat to be minimal. The bottom of the basin is rock and sand, and the walls of the Turning Basin are vertical rock. The Corps also believes that the area of the Turning Basin may not be suitable habitat for dolphins in Biscayne Bay. It is more likely that the animals use the area to traverse to North Biscayne Bay or offshore via the main port channel. In addition, as a large number of fish are not expected to perish during the detonations (Corps, 2004), there will not Start Printed Page 21177be a significant effect on dolphins' food supply.

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. NMFS concurs.

In general, potential impacts to marine mammals from explosive detonations could include both lethal and non-lethal injury, as well as Level B harassment. In the absence of mitigation, 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.”

A second possible cause of mortality 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 estimated range for the onset of extensive lung hemorrhage to marine mammals varies depending upon the animal's weight, with the smallest mammals having the greatest potential hazard range.

NMFS' criteria for determining non-lethal injury (Level A harassment) from explosives are 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.

NMFS has also established dual criteria for what constitutes Level B acoustic harassment: (1) An energy-based temporary threshold shift (TTS) from received sound levels 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). The Level B Harassment zone, therefore, is the distance from the mortality/serious injury zone to the radius where neither of these criterion is exceeded.

Mitigation and Monitoring

In the absence of acoustic measurements (due to the high cost and complex instrumentation needed), in order to protect endangered, threatened and protected species (manatees, dolphins, sea turtles), the following equations have been adopted 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 believed to be conservative because they are based on humans, who are more sensitive than dolphins, and on unconfined charges, while the proposed blasts in the Turning Basin will be confined (stemmed) charges. The equations, based on the Navy Diver Formula, are:

Caution Zone radius = 260 (lbs/delay)1/3

Safety Zone radius = 520 (lbs/delay)1/3

The Caution Zone represents the radius in feet from the detonation beyond which mortality is not expected from an open-water blast. The Safety Zone is the approximate distance in feet beyond which injury (Level A harassment) is unlikely from an open-water explosion. These zones will be used for implementing mitigation measures.

In the Turning Basin or any area where explosives are required to obtain channel design depth, marine mammal/sea turtle protection measures will be employed by the Corps. For each explosive charge, the Corps will ensure that detonation will not occur if a marine mammal is sighted by a dedicated marine mammal/sea turtle observer within the safety zone, a circular area around the detonation site with the following radius: R = 520(W)1/3 (520 times the cube root of the weight of the explosive charge in pounds) where: R = radius of the safety zone in ft; W = weight of the explosive charge in lbs).

Although the area inside the Caution Zone is considered to be an area for potential mortality and the area inside the safety zone to be an area for potential injury, the Corps and NMFS believe that because all explosive charges will be stemmed (placed in a drilled hole and tamped with rock), the areas for potential mortality and injury will be significantly smaller than these areas and, therefore, it is unlikely that even non-serious injury would occur if, as is believed to be the case, monitoring this zone will be effective. For example, since bottlenose dolphins are commonly found on the surface of the water, implementation of a mitigation/monitoring program is expected by NMFS to be 100 percent effective.

The Corps will implement mitigation measures and a monitoring program that will establish both caution- and safety-zone radii to ensure that bottlenose dolphins will not be injured during blasting and that impacts will be at the lowest level practicable. Additional mitigation measures 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 hr before sunset to ensure adequate observation of marine mammals and sea turtles 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, manatee, or sea turtle; (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/sea turtle watch with no less than two qualified observers from a small water craft and/or an elevated platform on the explosives barge, beginning at least 30 minutes before and continuing for at least 30 minutes after each detonation to ensure that there are no dolphins or sea turtles in the area at the time of detonation.

The observer monitoring program will take place in a circular area at least three times the radius of the above described Caution Zone (called the watch zone). Any marine mammal(s) in the caution, safety, or watch zones will not be forced to move out of those zones by human intervention. Detonation shall not occur until the animal(s) move(s) out of the safety zone on its own volition.


NMFS will require the Corps to submit a report of activities 120 days before the expiration of the 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 or sea turtles being within the safety zone.

In the unlikely event a marine mammal or marine turtle is injured or killed during blasting, the Contractor Start Printed Page 21178shall immediately notify the NMFS Regional Office.

Endangered Species Act

Under section 7 of the ESA, the Corps completed consultation with NOAA Fisheries on September 23, 2002 and with the USFWS on June 19, 2002 for this project. Both agencies concurred with the Corps that activities associated with the Corps' dredging project in the Dodge-Lummus Island Turning Basin were not likely to adversely affect listed species.

Issuance of an IHA to the Corps constitutes an agency action that is subject to section 7 of the ESA. Although the IHA does not authorize takes of listed species, it is related to activities that may result in effects to listed marine species. As the effects of the activities on listed marine species were analyzed during consultation under section 7 of the ESA between the Corps, USFWS and NMFS, and as the action has not changed from that considered in the consultations, the discussion of effects that are contained in the Biological Opinion issued by NMFS to the Corps on September 23, 2002 and by the USFWS' informal consultation pertain also to this action. In conclusion, NMFS has determined that issuance of an IHA does not lead to any effects to listed species apart from those that were considered in the consultation on the Corp's action.

National Environmental Policy Act

The Corps prepared a Final EIS in 1989 for the Navigation Study for the Miami Harbor Channel. A copy of this document is available upon request (see ADDRESSES). In addition, NMFS completed an Environmental Assessment (EA) and made a Finding of No Significant Impact (FONSI) on the impacts of blasting activities in Florida waters on marine life, particularly bottlenose dolphins. Therefore, preparation of an EIS on this action is not required by section 102(2) of the NEPA or its implementing regulations. A copy of the EA and FONSI are available upon request (see ADDRESSES).


NMFS has determined that the Corps' proposed action, including mitigation measures to protect marine mammals, should result, at worst, in the temporary modification in behavior by small numbers of bottlenose dolphins, including temporarily vacating the area to avoid the blasting activities and the potential for minor visual and acoustic disturbance from the detonations. This action is expected to have a negligible impact on the affected species or stocks of marine mammals. 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.


NMFS has reissued an IHA to the Corps for the potential harassment of small numbers of bottlenose dolphins incidental to deepening the Dodge-Lummus Island Turning Basin in Miami, FL (Turning Basin), provided the previously mentioned mitigation, monitoring, and reporting requirements are incorporated. NMFS has 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.

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Dated: April 19, 2005.

Laurie K. Allen,

Director, Office of Protected Resources, National Marine Fisheries Service.

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[FR Doc. 05-8226 Filed 4-22-05; 8:45 am]