AGENCY:
National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce.
ACTION:
Notice; issuance of an incidental harassment authorization.
SUMMARY:
In accordance with regulations implementing the Marine Mammal Protection Act (MMPA), notification is hereby given that NMFS has issued an Incidental Harassment Authorization (IHA) to Deepwater Wind Block Island Transmission, LLC (DWBIT) to take marine mammals, by harassment, incidental to construction of the Block Island Transmission System.
DATES:
Effective November 1, 2014, through October 31, 2015.
ADDRESSES:
A copy of the IHA and application are available by writing to Jolie Harrison, Supervisor, Incidental Take Program, Permits and Conservation Division, Office of Protected Resources, National Marine Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910.
An electronic copy of the application and a list of references used in this document may be obtained by visiting the internet at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. NMFS prepared an Environmental Assessment (EA) and Finding of No Significant Impact (FONSI) in August 2014, which are available at the same internet address. Documents cited in this notice may be viewed, by appointment, during regular business hours, at the aforementioned address.
FOR FURTHER INFORMATION CONTACT:
John Fiorentino, Office of Protected Resources, NMFS, (301) 427-8477.
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 small numbers of marine mammals by U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region if certain findings are made and either regulations are issued or, if the taking is limited to harassment, a notice of a proposed authorization is provided to the public for review.
An authorization for incidental takings shall 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 (where relevant), and if the permissible methods of taking and requirements pertaining to the mitigation, 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.”
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].
Summary of Request
On March 11, 2013, NMFS received an application from DWBIT for the taking of marine mammals incidental to construction of the Block Island Transmission System (BITS). The application went through a series of revisions and the final version was submitted on November 26, 2013. NMFS determined that the application was adequate and complete on December 2, 2013.
DWBIT plans to develop the BITS, a bi-directional submarine transmission cable, over a 1-year period. The planned activity could begin in late 2014 and last through late 2015; however, portions of the project will only occur for short, sporadic periods of time over the 1-year period. The following specific aspects of the planned activities are likely to result in the take of marine mammals: Vibratory pile driving and the use of dynamically positioned (DP) vessel thrusters. Take, by Level B Harassment only, of individuals of nine species is anticipated to result from the specified activity.
Description of the Specified Activity
Overview
DWBIT plans to construct a bi-directional submarine transmission cable that will run from Block Island to the Rhode Island mainland. Construction of the marine portion of the BITS will involve three activities: Cable landfall construction on Block Island using a short-distance horizontal directional drill (HDD) from a temporary excavated trench box on Crescent Beach; cable landfall construction on Scarborough State Beach in Narragansett, Rhode Island using a long-distance HDD from a temporary offshore cofferdam; and installation of the submarine BITS cable. Cable landfall construction may require the installation and removal of a temporary offshore cofferdam, which will involve vibratory pile driving. The generation of underwater noise from vibratory pile driving and the DP vessel thruster may result in the incidental take of marine mammals.
The BITS will interconnect Block Island to the existing Narragansett Electric Company National Grid distribution system on the Rhode Island mainland. In connection with the BITS, Deepwater Wind Block Island, LLC (DWBI—a different applicant) proposes to develop the Block Island Wind Farm, a 30-megawatt offshore wind farm. Incidental take of marine mammals resulting from construction of the Block Island Wind Farm project will be assessed separately.
Dates and Duration
Construction activities could begin in late 2014 and are scheduled to be complete by late 2015. The anticipated project work windows are provided in Table 1.
Table 1—Anticipated Project Work Windows
Activity | Anticipated work window |
---|---|
Contracting, mobilization, and verification | January 2014-December 2014. |
Onshore short-distance HDD installation | December 2014-June 2015. |
Onshore/offshore long-distance HDD installation | January 2015-June 2015. |
Onshore cable installation | October 2014-May 2015. |
Substation construction | October 2014-May 2015. |
Offshore cable installation | April 2015-August 2015. |
Landfall demobilization and remediation | May 2015-June 2015. |
NMFS is issuing an IHA effective November 1, 2014, through October 31, 2015, based on the anticipated work windows for in-water construction that could result in the incidental take of marine mammals. While project activities may occur for 1 year, in-water vibratory pile driving is only expected to occur for up to 4 days (2 days each for construction of the cofferdam and 2 days each for removal of the cofferdam). Use of the DP vessel thruster during cable installation activities is expected to occur for 4 to 6 weeks (42 days maximum). Vibratory pile driving will occur during daylight hours only, starting approximately 30 minutes after dawn and ending 30 minutes prior to dusk. Cable installation (and subsequent use of the DP vessel thruster) will be conducted 24 hours per day.
Specified Geographic Region
The BITS cable will originate from a manhole on Block Island and traverse federal and state submerged lands in Rhode Island Sound from Block Island to Narragansett for a total distance of 19.8 miles with water depths reaching up to 39 meters (m). Figure 1.2-1 of DWBIT's application shows the project location in detail (see ADDRESSES). Vibratory pile driving for temporary offshore cofferdam will occur at a site located off of Scarborough State Beach. The temporary offshore cofferdam will be located between 685.8 m and 1,112.5 m from shore. Terrestrial cables and other terrestrial facilities associated with the BITS will be located in the towns of New Shoreham (Block Island) and Narragansett in Washington County, Rhode Island. Construction staging and laydown for offshore components of the project will occur at the Quonset Point port facility in North Kingstown, also in Washington County, Rhode Island.
Detailed Description of Activities
The following sections provide additional details associated with each portion of the BITS marine construction activities.
1. Landfall Construction
On Block Island, DWBIT plans to bring the BITS cable ashore via a short-distance HDD. DWBIT will use the short-distance HDD to install either a steel or high density polyethylene conduit for the cable from the parking lot under Crescent Beach to a temporary excavated trench beginning at about mean high water. The excavated trench on Crescent Beach will be approximately 2 to 3 m wide, 4 m deep, and 11 m long. Spoils from the trench excavation will be stored on the respective beach and returned to the trench after cable installation. To support the short-distance HDD on Crescent Beach, DWBIT will install steel sheet piling to stabilize the excavated trench, possibly using a vibratory pile driver. The HDD will enter through the shore side of the excavated trench and the cable conduit will be installed between the trench and the manhole. The BITS cable will then be pulled from the excavated trench into the respective manhole through the newly installed conduit. Sheet piling installations will occur at low tide.
The coupling of land-based vibrations and nearshore sounds into the underwater acoustic field is not well understood and cannot be accurately predicted using current models. However, because the excavation for the cable trench and the HDD installation on the beach will occur onshore and because sand is generally a very poor conductor of vibrations, NMFS considers it unlikely that the underwater noise generated from either of these installations will result in harassment of marine mammals.
DWBIT is proposing to conduct the cable landfall on Scarborough State Beach using a long-distance HDD from the manhole located within the Rhode Island Department of Environmental Management parking lot to a temporary offshore cofferdam located between 685.8 m and 1,112.5 m from shore. From this location, a jet plow, supported by a DP cable installation barge, will be used to install the BITS cable below the seabed. Construction of the temporary cofferdam will consist of the installation of steel sheet piles to create an enclosed area approximately 15.2 by 6.1 m. The steel sheet piles will be installed and later removed using a vibratory hammer supported by a spud barge. DWBIT expects the cofferdam to be in place between January and the end of May.
Vibratory pile driving will be required to install the temporary cofferdam off of Scarborough State Beach. DWBIT assumes a 1,800 kilo Newton vibratory force for estimating source levels and frequency spectra. DWBIT modeled vibratory hammering at a source level of 194 decibels (dB) re 1 micro Pascal, using adjusted 1/3-octave band source levels from measurements of a similar offshore construction, and adjusted to account for the estimated force necessary for driving of the BITS cofferdam sheet piles. Detailed information on the acoustic modeling for this source is provided in Appendix A of DWBIT's application (see ADDRESSES).
2. Offshore Cable Installation
DWBIT will use a jet plow, supported by a DP cable installation barge, to install the BITS cable below the seabed. The jet plow will be positioned over the trench and pulled from shore by the cable installation vessel. The jet plow will likely be a rubber-tired or skid-mounted plow with a maximum width of about 4.6 m, and pulled along the seafloor behind the cable-laying barge with assistance of a non-DP material barge. High-pressure water from vessel-mounted pumps will be injected into the sediments through nozzles situated along the plow, causing the sediments to temporarily fluidize and create a liquefied trench. DWBIT anticipates a temporary trench width of up to 1.5 m. As the plow is pulled along the route behind the barge, the cable will be laid into the temporary, liquefied trench through the back of the plow. The trench will be backfilled by the water current and the natural settlement of the suspended material. Umbilical cords will connect the submerged jet plow to control equipment on the vessel to allow the operators to monitor and control the installation process and make adjustments to the speed and alignment as the installation proceeds across the water.
The BITS cable will be buried to a target depth of 1.8 m beneath the seafloor. The actual burial depth depends on substrate encountered along the route and could vary from 1.2 to 2.4 m. Where the BITS crosses two existing submarine cables on the outer continental shelf, the cable will be installed directly on the seafloor and protected from external aggression using a combination of sand bags and concrete mattresses. Anchored vessels will be used to install both the BITS and the associated cable armoring at these locations.
DP systems maintain their precise coordinates in waters through the use of automatic controls. These control systems use variable levels of power to counter forces from current and wind. During cable-lay activities, DWBIT expects that a reduced 50 percent power level will be used by DP vessels. DWBIT modeled scenarios using a source level of 180 dB re 1 micro Pascal for the DP vessel thruster, assuming water depths of 7, 10, 20, and 40 m, and thruster power of 50 percent. Detailed information on the acoustic modeling for this source is provided in Appendix A of DWBIT's application (see ADDRESSES).
Comments and Responses
A proposed IHA and request for public comments was published in the Federal Register on March 20, 2014 (78 FR 15573). During the 30-day public comment period, NMFS only received comments from the Marine Mammal Commission (Commission). The Commission's comments are summarized and addressed below. All comments have been compiled and posted at http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
Comment 1: The Commission recommended that NMFS require DWBIT to provide information regarding the data and assumptions used to derive cetacean density estimates.
Response: As stated in section 6 of their application (see ADDRESSES), DWBIT used sightings per unit effort (SPUE) reported in Kenney and Vigness-Raposa (2009) to derive density estimates for cetacean species in the project area. SPUE is derived by using a measure of survey effort and number of individual cetaceans sighted. SPUE allows for comparison between discrete units of time (i.e., seasons) and space within a project area. SPUE calculated by Kenney and Vigness-Raposa (2009) was derived from a number of sources, all of which are referenced in the application.
Comment 2: The Commission recommended that NMFS require DWBIT to address apparent inconsistencies in the density estimates for fin whales for this project with those for the BIWF (the wind farm) project.
Response: The proposed activity for installation of the BITS could begin in late 2014 and last through late 2015; however, portions of the project will only occur for short, sporadic periods of times over the 1-year period. Therefore the estimates of take of marine mammals were calculated based on density estimates during the predicted seasons within which the specific BITS activity was likely to occur. The estimates of take for the BIWF were also based on the density estimates during the predicted season of the proposed activity. In addition, the location of activities for the BIWF are further offshore and to the south of activities as described for the BITS. Density estimates, as reported by Kenney and Vigness-Raposa (2009), are temporally and spatially variable. Therefore, the maximum seasonal densities within the project areas differ given the specific location and time of year of the activity described.
Comment 3: The Commission recommended that NMFS include in each Federal Register notice for proposed incidental harassment authorizations a sufficiently detailed description of the status and distribution of the species of marine mammals likely to be affected by the proposed activities to allow the public to review and comment on the proposed authorization as a stand-alone document.
Response: As required by regulation, section 4 of DWBIT's application included a detailed description of the status, distribution, and seasonal distribution of the affected species or stocks of marine animals likely to be affected by such activities (see ADDRESSES). As such, the DWBIT application was referenced accordingly in the FR notice for the proposed IHA and request for public comments (78 FR 15573, March 20, 2014). Further, the internet Web site for the NMFS Marine Mammal Stock Assessment Reports, which contain information on the biology and local distribution of species potentially affected by this project, was provided in the FR notice for the proposed IHA.
Comment 4: The Commission recommended that NMFS require DWBIT to provide estimated source levels associated with HDD and jet plowing activities, and to provide take estimates associated with those activities.
Response: Neither HDD nor jet plow noise were modelled for harassment because all the noise associated with these activities will be in-air. More specifically, the HDD rig will be located on land at Scarborough and Crescent Beaches. As discussed in the FR notice for the proposed IHA and request for public comments (78 FR 15573, March 20, 2014), the coupling of land-based vibrations and nearshore sounds into the underwater acoustic field is not well understood and cannot be accurately predicted using current models. However, because the HDD installation on the beach will occur onshore and because sand is generally a very poor conductor of vibrations, NMFS considers it unlikely that the underwater noise generated from the HDD installation will result in harassment of marine mammals. Regarding jet plow noise, all compressors will be located on the vessel itself and will not affect the surrounding underwater environment. Therefore, noise associated with jet plow activities was also discounted by NMFS as a potential source of harassment.
Comment 5: To reduce the potential for vessel strikes with endangered North Atlantic right whales, the Commission recommended that NMFS require DWBIT vessels to reduce speeds to 10 knots or less from November 1 to April 30 in all areas of operation.
Response: In 2008, NMFS promulgated a regulation implementing a mandatory 10-knot speed limit for vessels 65 feet or greater in length in designated seasonal management areas (SMAs) to reduce the threat of ship collisions with right whales (see 50 CFR 224.105). The SMAs were established to provide protection for right whales, and the timing, duration, and geographic extent of the speed restrictions were specifically designed to reflect right whale movement, distribution, and aggregation patterns. The vessel speed restriction is in effect in the mid-Atlantic SMA from November 1 through April 30 to reduce the threat of collisions between ships and right whales around their migratory route and calving grounds.
Right whales have been observed in or near Rhode Island during all four seasons; however, they are most common in the spring when they are migrating and in the fall during their southbound migration (Kenney and Vigness-Raposa 2009). The BITS project area is located outside of the Mid-Atlantic SMA; however, to minimize the potential for vessel collision with right whales and other marine mammal species all DWBIT vessels associated with the BITS construction, regardless of their length, will operate at speeds of 10 knots or less from the November 1 to April 30 time period, regardless of whether they are inside or outside of the designated SMA. In addition, all DWBIT vessels associated with the BITS construction will adhere to NMFS guidelines for marine mammal ship striking avoidance (available online at: http://www.nmfs.noaa.gov/pr/pdfs/education/viewing_northeast.pdf ), including maintaining a distance of at least 1,500 feet from right whales and having dedicated protected species observers who will communicate with the captain to ensure that all measures to avoid whales are taken. NMFS believes that the size of right whales, their slow movements, and the amount of time they spend at the surface will make them extremely likely to be spotted by protected species observers during construction activities within the BITS project area. NMFS does not anticipate any marine mammals to be impacted by vessel movement because only a limited number of vessels will be involved in construction activities and they will move at slow speeds throughout construction.
Comment 6: The Commission recommended that NMFS require DWBIT to include additional visual or acoustic monitoring measures as part of its monitoring plan to ensure that the entire Level B harassment zone for the DP vessel thruster is monitored and a significant portion of the Level B harassment zone for vibratory pile driving is also monitored.
Response: Exclusion zones (often defined as the Level A harassment zone of influence [ZOI] out to the 180 dB isopleth) and monitoring zones (often defined as the Level B harassment ZOI out to the 120 dB isopleth for continuous noise) are typically established to minimize impacts to marine mammals and monitor take of marine mammals (and sea turtles). However, noise analysis has indicated that both vibratory pile driving and DP vessel thruster use will not produce sound levels at 180 dB at any appreciable distance. In addition, NOAA has concluded that the modeled monitoring zones established out to the 120 dB isopleth will result in zones too large to effectively monitor (approximately 89.9 km for vibratory pile driving and up to 4.75 km for DP vessel thruster use). Therefore, NMFS has instead required that DWBIT monitor a zone equivalent to the size of the predicted 160 dB isopleth for DP vessel thruster use and vibratory pile driving activities, as follows: A preliminary monitoring zone of 200 m at the Scarborough State Beach cofferdam based on the modeled critical distance to the 160 dB isopleth will be established and monitored during all vibratory pile driving activities; and a preliminary monitoring zone of 5 m from the DP vessel based on the modeled distance to the 160 dB isopleth will be established and monitored during all cable installation activities. These monitoring zones will also serve as mitigation zones (see Mitigation below).
These preliminary monitoring zones will be field verified, adjusted as necessary, and monitored for individual take during installation and removal of the cofferdam and during the installation of the BITS cable. This monitoring zone represents the minimum area of coverage for Level B harassment. All marine mammal sightings which are visually feasible, including those beyond the 160 dB isopleth will be recorded and potential takes will be noted.
Description of Marine Mammals in the Area of the Specified Activity
There are 34 marine mammal species with possible or confirmed occurrence in the area of the specified activity (Table 2).
Table 2—Marine Mammal Species With Possible or Confirmed Occurrence in Project Area
Common name | Scientific name | Status | Occurrence | Seasonality | Range | Abundance | |
---|---|---|---|---|---|---|---|
Toothed whales (Odontocetes) | |||||||
Atlantic white-sided dolphin | Lagenorhynchus acutus | Confirmed | Year-round | North Carolina to Canada | 23,390 | ||
Atlantic spotted dolphin | Stenella frontalis | 50,978 | |||||
Bottlenose dolphin | Tursiops truncatus | Strategic (northern coastal stock) | 9,604 | ||||
Short-beaked common dolphin | Delphinus delphis | Common | Year-round | North Carolina to Canada | 120,743 | ||
Harbor porpoise | Phocoena phocoena | Strategic | Common | Year-round | North Carolina to Greenland | 89,054 | |
Killer whale | Orcinus orca | (1) | |||||
False killer whale | Pseudorca crassidens | (1) | |||||
Long-finned pilot whale | Globicephala malaena | 12,619 | |||||
Short-finned pilot whale | Globicephala macrohynchus | 24,674 | |||||
Risso's dolphin | Grampus griseus | 20,479 | |||||
Striped dolphin | Stenella coeruleoalba | 94,462 | |||||
White-beaked dolphin | Lagenorhynchus albirostris | 2,003 | |||||
Sperm whale | Physeter macrocephalus | Endangered | 4,804 | ||||
Pygmy sperm whale | Kogia breviceps | Strategic | 395 | ||||
Dwarf sperm whale | Kogia sima | 395 | |||||
Cuvier's beaked whale | Ziphius cavirostris | Strategic | 3,513 | ||||
Blainville's beaked whale | Mesoplodon densirostris | 3,513 | |||||
Gervais' beaked whale | Mesoplodon europaeus | Strategic | 3,513 | ||||
True's beaked whale | Mesoplodon mirus | Strategic | 3,513 | ||||
Bryde's whale | Balaenoptera edeni | ||||||
Northern bottlenose whale | Hyperoodon ampullatus | ||||||
Baleen whales (Mysticetes) Minke whale | Balaenoptera acutorostrata | Common (spring and summer) | Spring, summer, fall | Caribbean to Greenland | 8,987 | ||
Blue whale | Balaenoptera musculus | Endangered | (1) | ||||
Fin whale | Balaenoptera physalus | Endangered | Common | Year-round | Caribbean to Greenland | 3,985 | |
Humpback whale | Megaptera novaeangliae | Endangered | Confirmed | Year-round | Caribbean to Greenland | 11,570 | |
North Atlantic right whale | Eubalaena glacialis | Endangered | Confirmed | Year-round | Southeastern U.S. to Canada | 444 | |
Sei whale | Balaenoptera borealis | Endangered | (1) | ||||
Pinnipeds Gray seals | Halichoerus grypus | Confirmed | Year-round | New England to Canada | 348,900 | ||
Harbor seals | Phoca vitulina | Common | Spring, summer, winter | Florida to Canada | 99,340 | ||
Hooded seals | Cystophora cristata | (1) | |||||
Harp seal | Phoca groenlandica | (1) | |||||
West Indian manatee | Trichechus manatus | Endangered | 3,802 | ||||
(1) Unknown. |
The highlighted species in Table 2 are pelagic and/or northern species, or are so rarely sighted that their presence in the project area, and therefore take, is unlikely. These species are not considered further in this IHA notice. The West Indian manatee is managed by the U.S. Fish and Wildlife Service and is also not considered further in this IHA notice. Further information on the biology and local distribution of these species can be found in section 4 of DWBIT's application (see ADDRESSES), and the NMFS Marine Mammal Stock Assessment Reports, which are available online at: http://www.nmfs.noaa.gov/pr/species/.
Potential Effects of the Specified Activity on Marine Mammals
The proposed IHA (78 FR 15573, March 20, 2014) included a summary and discussion of the ways that the types of stressors associated with the specified activity (i.e., vibratory pile driving and use of the DP vessel thrusters) have been observed to impact marine mammals. 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 the analysis of how this specific activity will impact marine mammals and will consider the content of this “Potential Effects of the Specified Activity on Marine Mammals” section, the “Estimated Take by Incidental Harassment” section, the “Mitigation” section, and the “Anticipated Effects on Marine Mammal Habitat” 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.
Potential effects of the specified activities on marine mammals involve acoustic effects related to sound produced by in-water vibratory pile driving and use of DP vessel thrusters. Detailed information on these effects was provided in the proposed IHA (78 FR 15573, March 20, 2014) and that information has not changed.
Anticipated Effects on Marine Mammal Habitat
There are no feeding areas, rookeries, or mating grounds known to be biologically important to marine mammals within the proposed project area. There is also no designated critical habitat for any ESA-listed marine mammals. Harbor seals haul out on Block Island and points along Narragansett Bay, the most important haul-out being on the edge of New Harbor, about 2.4 km from the proposed BITS landfall on Block Island. The only consistent haul-out locations for gray seals within the vicinity of Rhode Island are around Monomoy National Wildlife Refuge and Nantucket Sound in Massachusetts (more than 80 nautical miles from the proposed project area). NMFS' regulations at 50 CFR 224.105 designated the nearshore waters of the Mid-Atlantic Bight as the Mid-Atlantic SMA for right whales. Mandatory vessel speed restrictions are in place in that SMA from November 1 through April 30 to reduce the threat of collisions between ships and right whales around their migratory route and calving grounds.
The BITS involves activities that will disturb the seafloor and potentially affect benthic and finfish communities. Installation of the BITS cable and the temporary offshore cofferdam will result in the temporary disturbance of no more than 45.3 acres of seafloor. These installation activities will also result in temporary and localized increases in turbidity around the proposed project area. DWBIT is required to install additional protective armoring over the BITS where it will cross two existing marine cables in federal waters. At the cable crossing locations, the installation of additional protective armoring will result in the permanent conversion of about 1.7 acre of soft substrate to hard substrate. The BITS cable may also require additional protective armoring in areas where the burial depth achieved is less than 1.2 m. DWBIT expects that additional protection will be required at a maximum of 1 percent of the entire BITS cable, resulting in a conversion of up to 1 acre of soft substrate to hard substrate along the cable route. During the installation of additional protective armoring at the cable crossings and as necessary along the cable route, anchors and anchor chains will temporarily impact about 1.8 acres of bottom substrate during each anchoring event.
Jet plowing and cofferdam installation will cause either the displacement or loss of benthic and finfish resources in the immediate areas of disturbance. This may result in a temporary loss of forage items and a temporary reduction in the amount of benthic habitat available for foraging marine mammals in the immediate proposed project area. However, the amount of habitat affected represents a very small percentage of the available foraging habitat in the proposed project area. Increased underwater sound levels from cofferdam installation and use of the DP vessel thruster may temporarily result in marine mammals avoiding or abandoning the area.
Because of the temporary nature of the disturbance, the availability of similar habitat and resources in the surrounding area, and the lack of important or unique marine mammal habitat, the impacts to marine mammals and the food sources that they utilize are not expected to cause significant or long-term consequences for individual marine mammals or their populations.
Mitigation
In order to issue an incidental take authorization (ITA) 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 (where relevant).
Mitigation Measures
DWBIT will implement the following mitigation measures during vibratory pile driving and use of the DP vessel thruster:
1. Marine Mammal Exclusion Zone
Protected species observers will visually monitor a 200-m radius exclusion zone during all in-water vibratory pile driving. This distance is estimated to be the 160 dB isopleth based on DWBIT's sound exposure model. A minimum of two observers will be stationed aboard each noise-producing construction support vessel. Each observer will visually monitor a 360-degree field of vision from the vessel. Observers will begin monitoring at least 30 minutes prior to vibratory pile driving, continue monitoring during vibratory pile driving, and stop monitoring 30 minutes after vibratory pile driving has ended. If a marine mammal is seen approaching or entering the 200-m exclusion zone during vibratory pile driving, DWBIT will stop vibratory pile driving as a precautionary measure to minimize noise impacts on the animal.
2. Soft-Start Procedures
DWBIT will use a soft-start (or ramp-up) procedure at the beginning of vibratory pile driving. This procedure will require an initial set of three strikes from the vibratory hammer at 40 percent energy with a 1-minute waiting period between subsequent 3-strike sets. DWBIT will repeat the procedure two additional times. DWBIT will initiate a soft-start at the beginning of each day of pile driving and if pile driving stops for more than 30 minutes. DWBIT will not initiate a soft-start if the monitoring zone is obscured by fog, inclement weather, poor lighting conditions, etc.
3. Delay and Shut-Down Procedures
DWBIT will delay vibratory pile driving and reduce DP vessel thruster use if a marine mammal is observed within the 160-dB isopleth marine mammal exclusion zone and until the exclusion zone is clear of marine mammals. DWBIT will stop vibratory pile driving if a marine mammal is seen within the estimated 160-dB isopleth, 200-m radius exclusion zone at the Scarborough State Beach cofferdam and will not be reinitiated until the 200-m radius is clear of marine mammals for at least 30 minutes.
4. DP Thruster Power Reduction
A constant tension must be maintained during cable installation and any significant stoppage in vessel maneuverability during jet plow activities will result in damage to the cable. Therefore, during DP vessel operations, DWBIT will reduce DP thruster power to the maximum extent possible if a marine mammal approaches or enters a 5-m radius from the vessel (estimated to be the 160-dB isopleth from the vessel). This reduction would not be implemented at the risk of compromising safety and/or the integrity of the BITS. DWBIT will not increase power until the 5-m zone is clear of marine mammals for 30 minutes.
5. Time of Day and Weather Restrictions
DWBIT will conduct vibratory pile driving off of Scarborough State Beach during daylight hours only, starting approximately 30 minutes after dawn and ending 30 minutes before dusk. DWBIT will not initiate vibratory pile driving until the entire marine mammal exclusion zone is visible. If a soft-start is initiated before the onset of inclement weather, DWBIT will complete that segment of vibratory pile driving.
6. Vessel Speed Restrictions
All DWBIT vessels, regardless of length, will operate at speeds of 10 knots or less from November 1 through April 30.
7. Ship Strike Avoidance
DWBIT will adhere to NMFS guidelines for marine mammal ship strike avoidance ( http://www.nmfs.noaa.gov/pr/pdfs/education/viewing_northeast.pdf ).
Mitigation Conclusions
NMFS has carefully evaluated the applicant's mitigation measures and considered a range of other measures in the context of ensuring that NMFS prescribes the means of effecting 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:
- The manner in which, and the degree to which, the successful implementation of the measure is expected to minimize adverse impacts to marine mammals;
- The proven or likely efficacy of the specific measure to minimize adverse impacts as planned; and
- The practicability of the measure for applicant implementation.
Based on our evaluation of the applicant's proposed measures, as well as other measures considered by NMFS or recommended by the public, NMFS has determined that the mitigation measures provide the means of effecting the least practicable impact on marine mammals species or stocks and their habitat, paying particular attention to rookeries, mating grounds, and areas of similar significance.
Monitoring and Reporting
In order to issue an ITA 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 ITAs 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. Monitoring measures prescribed by NMFS should accomplish one or more of the following general goals:
1. An increase in the probability of detecting marine mammals, both within the mitigation zone (thus allowing for more effective implementation of the mitigation) and in general to generate more data to contribute to the analyses mentioned below;
2. An increase in the understanding of how many marine mammals are likely to be exposed to levels of continuous noise from vibratory pile driving and use of a DP vessel thruster that we associate with specific adverse effects, such as behavioral harassment, TTS, or PTS;
3. An increase in our understanding of how marine mammals respond to stimuli expected to result in take and how anticipated adverse effects on individuals (in different ways and to varying degrees) may impact the population, species, or stock (specifically through effects on annual rates of recruitment or survival) through any of the following methods:
- Behavioral observations in the presence of stimuli compared to observations in the absence of stimuli (need to be able to accurately predict received level, distance from source, and other pertinent information);
- Physiological measurements in the presence of stimuli compared to observations in the absence of stimuli (need to be able to accurately predict received level, distance from source, and other pertinent information);
- Distribution and/or abundance comparisons in times or areas with concentrated stimuli versus times or areas without stimuli;
4. An increased knowledge of the affected species; and
5. An increase in our understanding of the effectiveness of certain mitigation and monitoring measures.
Monitoring Measures
DWBIT submitted a marine mammal monitoring plan as part of the IHA application. It can be found in section 12 of their application (see ADDRESSES). NMFS did not require any modification or supplementation to that proposed monitoring plan.
1. Visual Monitoring
DWBIT will use protected species observers to visually monitor the surrounding area during all in-water vibratory pile driving and use of DP vessel thrusters. These observers will monitor beyond the estimated 160-dB isopleths, in addition to conducting mitigation monitoring within these zones. Observers will estimate distances to marine mammals visually, using laser range finders, or by using reticle binoculars during daylight hours. During night operations (DP vessel thruster use only), observers will use night-vision binoculars. Observers will record their position using hand-held or vessel global positioning system units for each sighting, vessel position change, and any environmental change. Each observer will scan the surrounding area for visual indication of marine mammal presence. Observers will be located from the highest available vantage point on the associated operational platform (e.g., support vessel, barge or tug), estimated to be at least 6 m above the waterline.
Prior to initiation of construction work, all crew members on barges, tugs, and support vessels will undergo environmental training, a component of which will focus on the procedures for sighting and protection of marine mammals. DWBIT will also conduct a briefing with the construction supervisors and crews and observers to define chains of command, discuss communication procedures, provide an overview of the monitoring purposes, and review operational procedures. The DWBIT Construction Compliance Manager (or other authorized individual) will have the authority to stop or delay vibratory pile driving activities if deemed necessary.
2. Acoustic Field Verification
DWBIT will conduct field verification of the estimated 160-dB isopleths during vibratory pile driving and use of the DP vessel thruster to determine whether the proposed distances are adequate to minimize impacts to marine mammals.
DWBIT will conduct field verification of the 200-m radius marine mammal exclusion zone at the Scarborough State Beach cofferdam. DWBIT will take acoustic measurements during vibratory pile driving of the last half (deepest sheet pile segment) for any given open-water pile and will also measure from two reference locations at two water depths (a depth at mid-water and at about 1 m above the seafloor). If the field measurements determine that the 160-dB isopleth is less than or beyond the proposed 200-m distance, a new zone may be established accordingly. DWBIT will notify NMFS and the USACE within 24 hours if a new marine mammal exclusion zone is established that extends beyond 200 m. Implementation of a smaller zone will be contingent on NMFS' review and will not be used until NMFS approves the change.
DWBIT will also perform field verification of the 160-dB isopleth associated with DP vessel thruster use during cable installation. DWBIT will take acoustic measurements from two reference locations at two water depths (a depth at mid-water and at about 1 m above the seafloor). Similar to field verification during vibratory pile driving, the DP thruster power reduction zone may be modified as necessary.
Reporting Measures
Observers will record dates and locations of construction operations; times of observations; location and weather; details of marine mammal sightings (e.g., species, age, numbers, behavior); and details of any observed take.
DWBIT will provide the following notifications and reports during construction activities:
- Notification to NMFS and the U.S. Army Corps of Engineers (USACE) within 24-hours of beginning construction activities and again within 24-hours of completion;
- Detailed report of field-verification measurements within 7 days of completion (including: sound levels, durations, spectral characteristics, DP thruster use, etc.) and notification to NMFS and the USACE within 24-hours if a new zone is established;
- Notification to NMFS and USACE within 24-hours if field verification measurements suggest a larger marine mammal exclusion zone;
- Final technical report to NMFS and the USACE within 120 days of completion of the specified activity documenting methods and monitoring protocols, mitigation implementation, marine mammal observations, other results, and discussion of mitigation effectiveness.
In the unanticipated event that the specified activity clearly causes the take of a marine mammal in a manner not permitted by the authorization (if issued), such as an injury, serious injury, or mortality (e.g., ship-strike, gear interaction, and/or entanglement), DWBIT will immediately cease the specified activities and immediately report the incident to the Incidental Take Program Supervisor, Permits and Conservation Division, Office of Protected Resources, NMFS, at 301-427-8401 and/or by email to Jolie.Harrison@noaa.gov and John.Fiorentino@noaa.gov and the Northeast Regional Stranding Coordinator at 978-281-9300 (Mendy.Garron@noaa.gov). The report must include the following information:
- Time, date, and location (latitude/longitude) of the incident;
- Name and type of vessel involved;
- Vessel's speed during and leading up to the incident;
- Description of the incident;
- Status of all sound source use in the 24 hours preceding the incident;
- Water depth;
- Environmental conditions (e.g., wind speed and direction, Beaufort sea state, cloud cover, and visibility);
- Description of all marine mammal observations in the 24 hours preceding the incident;
- Species identification or description of the animal(s) involved;
- Fate of the animal(s); and
- Photographs or video footage of the animal(s) (if equipment is available).
DWBIT will not resume its activities until NMFS is able to review the circumstances of the prohibited take. NMFS will work with DWBIT to determine what is necessary to minimize the likelihood of further prohibited take and ensure MMPA compliance. DWBIT may not resume their activities until notified by us via letter, email, or telephone.
In the event that DWBIT discovers an injured or dead marine mammal, and the lead visual observer determines that the cause of the injury or death is unknown and the death is relatively recent (i.e., in less than a moderate state of decomposition), DWBIT will immediately report the incident to the Incidental Take Program Supervisor, Permits and Conservation Division, Office of Protected Resources, at 301-427-8401 and/or by email to Jolie.Harrison@noaa.gov and John.Fiorentino@noaa.gov and the Northeast Regional Stranding Coordinator at 978-281-9300 (Mendy.Garron@noaa.gov). The report must include the same information identified in the paragraph above this section. Activities may continue while NMFS reviews the circumstances of the incident. NMFS will work with DWBIT to determine whether modifications in the activities are appropriate.
In the event that DWBIT discovers an injured or dead marine mammal, and the lead visual observer determines that the injury or death is not associated with or related to the authorized activities (e.g., previously wounded animal, carcass with moderate to advanced decomposition, or scavenger damage), DWBIT will report the incident to the Incidental Take Program Supervisor, Permits and Conservation Division, Office of Protected Resources, at 301-427-8401 and/or by email to Jolie.Harrison@noaa.gov and John.Fiorentino@noaa.gov and the Northeast Regional Stranding Coordinator at 978-281-9300 (Mendy.Garron@noaa.gov), within 24 hours of the discovery. DWBIT will provide photographs or video footage (if available) or other documentation of the stranded animal sighting to us.
Estimated Take by Incidental 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].
Project activities that have the potential to harass marine mammals, as defined by the MMPA, include noise associated with vibratory pile driving of the temporary cofferdam, and noise associated with the use of DP vessel thrusters during cable installation. Harassment could take the form of masking, temporary threshold shift, avoidance, or other changes in marine mammal behavior. NMFS anticipates that impacts to marine mammals will be in the form of behavioral harassment and no take by injury, serious injury, or mortality is authorized. NMFS does not anticipate take resulting from the movement of vessels associated with construction because there will be a limited number of vessels moving at slow speeds over a relatively shallow, nearshore area.
NMFS' current acoustic exposure criteria are shown in Table 3 below. Sound levels from vibratory pile driving or use of the DP vessel thruster will not reach the Level A harassment threshold of 180/190 dB (cetaceans/pinnipeds) during the proposed BITS project. DWBIT modeled distances to these acoustic exposure criteria are shown in Table 4. Details on the model characteristics and results are provided in the Underwater Acoustic Report at the end of DWBIT's application (see ADDRESSES). DWBIT and NMFS believe that this estimate represents the worst-case scenario and that the actual distance to the Level B harassment threshold may be shorter.
Table 3—NMFS' Current Acoustic Exposure Criteria
Criterion | Criterion definition | Threshold |
---|---|---|
Non-Explosive Sound | ||
Level A Harassment (Injury) | Permanent Threshold Shift (PTS) (Any level above that which is known to cause TTS) | 180 dB re 1 microPa-m (cetaceans)/190 dB re 1 microPa-m (pinnipeds) root mean square (rms). |
Level B Harassment | Behavioral Disruption (for impulse noises) | 160 dB re 1 microPa-m (rms). |
Level B Harassment | Behavioral Disruption (for continuous, noise) | 120 dB re 1 microPa-m (rms). |
Table 4—DWBIT's Modeled Distances to Acoustic Exposure Criteria
Activity | Distance to level B harassment (120 dB) | Distance to level A harassment (180/190 dB) |
---|---|---|
Vibratory pile driving (for long-distance HDD) | >40 km | N/A. |
DP vessel thruster use | 4,750 m | N/A. |
DWBIT estimated species densities within the proposed project area in order to estimate the number of marine mammal exposures to sound levels above 120 dB. DWBIT used sightings per unit effort (SPUE) from Kenney and Vigness-Raposa (2009) for relative cetacean abundance and the Northeast Navy OPAREA Density Estimates (DoN 2007) for seal abundance. Based on multiple reports, harbor seal abundance off the coast of Rhode Island is thought to be about 20 percent of the total abundance for southern New England. Because the seasonality and habitat use of gray seals off the coast of Rhode Island roughly overlaps with harbor seals, DWBIT applied this 20 percent estimate to both pinniped species. While the density estimates relied upon for this IHA are from 2007 and 2009, they are the best scientific data available. NMFS is not aware of any efforts to collect more recent density estimates than those relied upon here.
Estimated takes were calculated by multiplying the average highest species density (per 100 km2) by the zone of influence (maximum ensonified area of 120 dB), multiplied by a correction factor of 1.5 to account for marine mammals underwater, multiplied by the number of days of the specified activity. A detailed description of the DWBIT's model used to calculate zones of influence is provided in the Underwater Acoustic Report at the end of their application (see ADDRESSES).
DWBIT used a zone of influence of 4,352 km2 and a total construction period of 4 days to estimate take from vibratory pile driving. In contrast to their application, DWBIT clarified that the vibratory pile driving will likely occur over a 2-day period during the winter and a 2-day period during the spring. Their take calculations were revised after the application was submitted. For each species, DWBIT used the estimated seasonal density (winter and spring) to calculate take for a total of 4 days (2 days each season). DWBIT's requested take numbers are provided in Table 5 and this is also the number of takes NMFS is authorizing (Table 6). DWBIT's calculations do not take into account whether a single animal is harassed multiple times or whether each exposure is a different animal. Therefore, the numbers in Table 5 are the maximum number of animals that may be harassed during vibratory pile driving (i.e., DWBIT assumes that each exposure event is a different animal). These estimates do not account for mitigation measures that DWBIT will implement during vibratory pile driving.
DWBIT used a zone of influence of 23.0 km2 and a maximum installation period of 42 days to estimate take from use of the DP vessel thruster during cable installation. The zone of influence represents the average ensonified area across the three representative water depths along the cable route (7m, 10 m, 20 m, and 40 m). DWBIT expects cable installation to occur between April and August; to be conservative, DWBIT used the highest seasonal species density to calculate take. Again, DWBIT's calculations do not take into account whether a single animal is harassed multiple times or whether each exposure is a different animal. Therefore, the numbers in Table 5 are the maximum number of animals that may be harassed during cable installation. These estimates do not account for mitigation measures that DWBIT will implement during the cable installation.
DWBIT did not request, and NMFS is not authorizing, take from vessel strike. NMFS does not anticipate marine mammals to be impacted by vessel movement because a limited number of vessels will be involved in construction activities and they will move at slow speeds (10 knots or less) throughout construction.
Table 5—DWBIT's Estimated Take for the BITS Project
Table 6—Species Information and Take Authorized by NMFS
Common species name | Authorized take | Abundance of stock | Percentage of stock potentially affected (percent) | Population trend |
---|---|---|---|---|
Atlantic white-sided dolphin | 456 | 23,390 | 1.95 | N/A. |
Short-beaked common dolphin | 644 | 120,743 | 0.53 | N/A. |
Harbor porpoise | 108 | 89,054 | 0.12 | N/A. |
Minke whale | 43 | 8,987 | 0.48 | N/A. |
Fin whale | 153 | 3,985 | 3.84 | N/A. |
Humpback whale | 17 | 11,570 | 0.15 | Increasing. |
North Atlantic right whale | 8 | 444 | 1.80 | Increasing. |
Gray seal | 780 | 348,900 | 0.22 | Increasing. |
Harbor seal | 538 | 99,340 | 0.54 | N/A. |
Analysis and Determinations
Negligible Impact
Negligible impact is “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” (50 CFR 216.103). 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, NMFS must consider other factors, such as the likely nature of any responses (their intensity, duration, etc.), the context of any responses (critical reproductive time or location, migration, etc.), as well as the number and nature of estimated Level A harassment takes, the number of estimated mortalities, and effects on habitat.
DWBIT did not request, and NMFS is not authorizing, take of marine mammals by injury, serious injury, or mortality. NMFS expects that take will be in the form of behavioral harassment. Exposure to sound levels above 120 dB during vibratory pile driving will not last for more than 12 hours per day for 4 non-consecutive days. Exposure to sound levels above 120 dB during use of the DP vessel thruster may last for 24 hours per day for 42 days. While use of the DP thruster may last for consecutive days, the vessel will be moving and therefore not focused on one specific area for the entire duration. Given the duration and intensity of the activity, and the fact that shipping contributes to the ambient sound levels around Rhode Island, NMFS does not anticipate the take estimates to impact annual rates of recruitment or survival. Animals may temporarily avoid the immediate area, but are not expected to permanently abandon the area. Marine mammal habitat may be impacted by elevated sound levels and sediment disturbance, but these impacts will be temporary. Furthermore, there are no feeding areas, rookeries, or mating grounds known to be biologically important to marine mammals within the proposed project area. There is also no designated critical habitat for any ESA-listed marine mammals. The mitigation measures are expected to reduce the number and/or severity of takes by (1) giving animals the opportunity to move away from the sound source before the pile driver reaches full energy; (2) reducing the intensity of exposure within a certain distance by reducing the DP vessel thruster power; and (3) preventing animals from being exposed to increased sound levels within 200 m of vibratory pile driving.
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 monitoring and mitigation measures, NMFS finds that the total marine mammal take from DWBIT's BITS project will have a negligible impact on the affected marine mammal species or stocks.
Small Numbers
The number of individual animals that may be exposed to sound levels above 120 dB is small relative to the species or stock size (Table 6). The authorized take numbers are the maximum numbers of animals that are expected to be harassed during the BITS project; it is possible that some of these exposures may occur to the same individual. NMFS finds 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, NMFS has determined that the total taking of affected species or stocks will not have an unmitigable adverse impact on the availability of such species or stocks for taking for subsistence purposes.
Endangered Species Act (ESA)
There are three marine mammal species that are listed as endangered under the ESA: Fin whale, humpback whale, and North Atlantic right whale. Under section 7 of the ESA, the USACE (the federal permitting agency for the actual BITS construction) consulted with NMFS on the proposed BITS project. NMFS also consulted internally on the issuance of an IHA under section 101(a)(5)(D) of the MMPA for this activity. NMFS Northeast Region (now known as the Greater Atlantic Region) issued a Biological Opinion on January 30, 2014, concluding that the Block Island Wind Farm project (which includes the BITS) may adversely affect but is not likely to jeopardize the continued existence of fin whale, humpback whale, or North Atlantic right whale. The effects of the IHA on listed marine mammal species fall within the scope of effects analyzed in the Biological Opinion for the Block Island Wind Farm project. Therefore, a new consultation is not required for issuance of this IHA. Following the issuance of the IHA, an incidental take statement (ITS), with associated reasonable and prudent measures and terms and conditions, will be issued to exempt any take of listed marine mammal species from the take prohibition in section 9 of the ESA. Under the terms of section 7(b)(4) and section 7(o)(2) of the ESA, taking that results from, but is not the purpose of the agency action is not considered to be prohibited under the ESA provided that such taking is in compliance with the terms and conditions of the authorized Incidental Take Statement. The ITS will be appended to the January 30, 2014 Biological Opinion.
National Environmental Policy Act (NEPA)
In compliance with the National Environmental Policy Act of 1969 (42 U.S.C. 4321 et seq.), as implemented by the regulations published by the Council on Environmental Quality (40 CFR parts 1500-1508), and NOAA Administrative Order 216-6, NMFS prepared an Environmental Assessment (EA) analyzing the potential impacts of the issuance of an IHA for the proposed activities. The final EA was prepared in August 2014 and NMFS made a Finding of No Significant Impact for this action. These documents are available on our Web site at http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. Accordingly, an Environmental Impact Statement is not required and none was prepared.
Dated: August 22, 2014.
Perry F. Gayaldo,
Deputy Director, Office of Protected Resources, National Marine Fisheries Service.
[FR Doc. 2014-20473 Filed 8-27-14; 8:45 am]
BILLING CODE 3510-22-P