NMFS’ Marine Mammal Seismic IHA for Shell in the Chukchi Says No Long-Term Impacts and Explains How NMFS Addresses Cumulative Effects

The U.S. National Marine Fisheries Service has issued an Incidental Harassment Authorization under the Marine Mammal Protection Act to Shell Gulf of Mexico Inc. (Shell) to take marine mammals, by harassment, incidental to offshore exploration drilling on Outer Continental Shelf leases in the Chukchi Sea, Alaska. This IHA is effective July 1, 2015, through October 31, 2015.

The Federal Register notice of this action includes NMFS’ response to several critical comments on the proposed IHA. For example, NGOs commented that there

“are large gaps in basic scientific information about both the Chukchi Sea ecosystem and marine mammal responses to noise, and that these gaps prevent adequate analysis of the potential impacts of Shell’s proposed activities on wildlife.”

NMFS responded to this comment by stating that

“Industrial activities have been occurring (at varying levels) in the U.S. Arctic Ocean for decades, and the available measurable indicators do not suggest that these activities are having long-term impacts on marine mammal species/stocks in the area. For example, bowhead whales continued to increase in abundance during periods of intense seismic activity in the Chukchi Sea in the 1980s (Raftery et al., 1995; Angliss and Outlaw, 2007), even without implementation of current mitigation requirements. This increase has been observed to continue to date (Givens et al. 2013). Additionally, industry has been collecting data and conducting monitoring in the region for many years and will continue to do so under this IHA. Therefore, NMFS’ negligible impact finding is supported by the available facts and science.”

NGOs also commented that

“NMFS must address cumulative, long-term effects of increased noise and other impacts from oil and gas activity properly before further activity is authorized.”

NMFS responded to this comment in part as follows:

“Neither the MMPA nor NMFS’ implementing regulations specify how to consider other activities and their impacts on the same populations when conducting a negligible impact analysis. However, consistent with the 1989 preamble for NMFS’ implementing regulations (54 FR 40338, September 29, 1989), the impacts from other past and ongoing anthropogenic activities are incorporated into the negligible impact analysis via their impacts on the environmental baseline (e.g., as reflected in the density/distribution and status of the species, population size and growth rate, and ambient noise). Additionally, NMFS analyzed cumulative effects in NMFS’ EA for the ‘Issuance of an Incidental Harassment Authorization for the Take of Marine Mammals by Harassment Incidental to Conducting an Exploration Drilling Program in the U.S. Chukchi Sea’ and other relevant data to inform its MMPA determination here. Pursuant to the National Environmental Policy Act (NEPA), those documents contained a cumulative impacts assessment, as well as an assessment of the impacts of the proposed exploratory drilling program on marine mammals and other protected resources.

NMFS considered the impacts analyses (i.e., direct, indirect, and cumulative) contained in the EA and other relevant NEPA documents cited in our response to comment in reaching its conclusion that any marine mammals exposed to the sounds produced by the drillship, ice management/icebreaking vessels, support vessels and aircraft, and airguns would be disturbed for only a short period of time with no likely consequences for annual rates of recruitment or survival and would not be harmed or killed. Furthermore, the required mitigation and monitoring measures are expected to reduce the likelihood or severity of any impacts to marine mammal species or stocks or their habitats.

Moreover, NMFS gave careful consideration to a number of other issues and sources of information. In particular, NMFS relied upon a number of scientific reports, including the 2014 U.S. Alaska Marine Mammal Stock Assessment Reports (SARs), to support its findings. The SARs contain a description of each marine mammal stock, its geographic range, a minimum population estimate, current population trends, current and maximum net productivity rates, optimum sustainable population levels and allowable removal levels, and estimates of annual human-caused mortality and serious injury through interactions with commercial fisheries and subsistence harvest data.

After careful consideration of the proposed activities, the context in which Shell’s proposed activities would occur, the best available scientific information, and all effects analyses (including cumulative effects), NMFS has determined that the specified activities: (1) Would not result in more than the behavioral harassment (i.e., Level B harassment) of small numbers of marine mammal species or stocks; (2) the taking by harassment would have a negligible impact on affected species or stocks; and (3) the taking by harassment would not have an unmitigable adverse impact on the availability of such species or stocks for taking for subsistence uses.”

Click here to read NMFS’ Federal Register notice of Shell’s IHA.

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