Comment on NMFS’ Proposed Modification of LOA for Oil and Gas Seismic in Cook Inlet

Editor’s note:  The U.S. National Marine Fisheries Service published a Federal Register notice that reads in part as follows:

“The U.S. National Marine Fisheries Service is requesting comments on its proposal to modify a Letter of Authorization issued to Hilcorp Alaska LLC (Hilcorp) to take marine mammals incidental to oil and gas activities in Cook Inlet, Alaska.

NMFS must receive an comments and information by no later than September 16, 2019.

NMFS issued regulations governing the take of eleven species of marine mammals, by Level A and Level B harassment, incidental to Hilcorp’s oil and gas activities on July 31, 2019; 84 FR 37442). These regulations include mitigation, monitoring, and reporting requirements for the incidental take of marine mammals during the specified activities.

As detailed in the regulations (50 CFR 217.167), adaptive management measures allow NMFS to modify or renew Letters of Authorization as necessary if doing so creates a reasonable likelihood of more effectively accomplishing the goals of mitigation and monitoring set forth in those regulations.

NMFS proposes to modify a mitigation measure pertaining to 3D seismic surveying during Year 1 of Hilcorp’s activity. NMFS published a mitigation measure in error that stated before ramp up of seismic airguns during the 3D seismic survey, the entire exclusion zone (EZ) must be visually cleared by protected species observers

(PSOs). This measure is correct for operations beginning in daylight hours. However, visually clearing the entirety of the EZ to ramp up airgun activity at night was not NMFS’ intent. The intent was that PSOs should monitor the EZ to the greatest extent possible for 30 minutes prior to ramp-up of nighttime operations, but with the understanding that it is not possible to observe the entirety of the EZ at night and that Hilcorp would still be allowed to initiate ramp-up as long as no marine mammals were seen during this time. If any marine mammal is observed in the EZ, during daylight hours or at night, ramp up would not commence until either the animal has voluntarily left and been visually confirmed outside the EZ or the required amount of time (15 for porpoises and pinnipeds, 30 minutes for cetaceans) have passed without re-detection of the animal. The analysis and findings contained in the final rule were made under the premise that nighttime ramp up of airguns is allowable.”


“NMFS is requesting comment on amending the Year 1 Letter of Authorization to allow ramp up of airguns at night without requiring full clearance of the EZ by PSOs. Full clearance of the EZ by PSOs would still be required for all operations in daylight hours.”

Click here to read NMFS’ full Federal Register notice.



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