When conducting the activities identified in §217.160(c), the mitigation measures contained in any LOAs issued under §§216.106 of this chapter and 217.166 must be implemented. These mitigation measures must include but are not limited to:

(a) Hilcorp must conduct a sound source verification (SSV) for 3D seismic and sub-bottom profiler use. Results of this SSV must be sent to NMFS and mitigation and monitoring zones may be adjusted based on the results of the SSV.

(b) If any marine mammal species for which take is not authorized are sighted within or entering the relevant zones within which they are be exposed to sound above the 120 dB re 1 µPa (rms) threshold for continuous (e.g., vibratory pile-driving, drilling) sources or the 160 dB re 1 µPa (rms) threshold for non-explosive impulsive (e.g., seismic airguns) or intermittent (e.g., scientific sonar) sources, Hilcorp must take appropriate action to avoid such exposure (e.g., by altering speed or course or by shutdown of the sound source).

(c) If the allowable number of takes in an LOA listed for any marine mammal species is met or exceeded, Hilcorp must immediately cease survey operations involving the use of active sound source(s), record the observation, and notify NMFS Office of Protected Resources.

(d) Hilcorp must notify NMFS Office of Protected Resources at least 48 hours prior to the start of oil and gas activities each year.

(e) Hilcorp must conduct briefings as necessary between vessel crews, marine mammal monitoring team, and other relevant personnel prior to the start of all survey activity, and when new personnel join the work, in order to explain responsibilities, communication procedures, marine mammal monitoring protocol, and operational procedures.

(f) Hilcorp must establish monitoring and exclusion zones.

(1) For all relevant in-water activity, Hilcorp must implement shutdown zones/exclusion zones (EZs) with radial distances as identified in any LOA issued under §§216.106 of this chapter and 217.166. If a marine mammal is sighted within or entering the EZ, such operations must cease.

(2) For all relevant in-water activity, Hilcorp must designate safety zones for monitoring (SZ) with radial distances as identified in any LOA issued under §§216.106 of this chapter and 217.166 and record and report occurrence of marine mammals within these zones.

(3) For all relevant in-water activity, Hilcorp must implement a minimum EZ of a 10 m radius around the source.

(g) Hilcorp must implement shutdown measures.

(1) Hilcorp must deploy protected species observers (PSO) and PSOs must be posted to monitor marine mammals within the monitoring zones during use of active acoustic sources and pile driving in water.

(2) Monitoring must begin 15 minutes prior to initiation of stationary source activity and 30 minutes prior to initiation of mobile source activity, occur throughout the time required to complete the activity, and continue through 30 minutes post-completion of the activity. Pre-activity monitoring must be conducted to ensure that the EZ is clear of marine mammals, and activities may only commence once observers have declared the EZ clear of marine mammals. In the event of a delay or shutdown of activity resulting from marine mammals in the EZ, the marine mammals' behavior must be monitored and documented.

(3) A determination that the EZ is clear must be made during a period of good visibility (i.e., the entire EZ must be visible to the naked eye).

(4) If a marine mammal is observed within or entering the EZ, Hilcorp must halt all noise producing activities for which take is authorized at that location. If activity is delayed due to the presence of a marine mammal, the activity may not commence or resume 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.

(5) Monitoring must be conducted by trained observers, who must have no other assigned tasks during monitoring periods. Trained observers must be placed at the best vantage point(s) practicable to monitor for marine mammals and implement shutdown or delay procedures when applicable through communication with the equipment operator. Hilcorp must adhere to the following additional observer qualifications:

(i) Hilcorp must use independent, dedicated, trained visual PSOs, meaning that the PSOs must be employed by a third-party observer provider, must not have tasks other than to conduct observational effort, collect data, and communicate with and instruct relevant vessel crew with regard to the presence of protected species and mitigation requirements (including brief alerts regarding maritime hazards), and must have successfully completed an approved PSO training course appropriate for their designated task.

(ii) Hilcorp must submit PSO resumes for NMFS review and approval. Resumes must be accompanied by a relevant training course information packet that includes the name and qualifications (i.e., experience, training completed, or educational background) of the instructor(s), the course outline or syllabus, and course reference material as well as a document stating successful completion of the course. NMFS will approve or disapprove PSOs within one week from the time that the necessary information is received by NMFS, after which PSOs meeting the minimum requirements will automatically be considered approved.

(iii) To the maximum extent practicable, the lead PSO must devise the duty schedule such that experienced PSOs are on duty with those PSOs with appropriate training but who have not yet gained relevant experience.

(6) Operations must shut down completely if a beluga whale is sighted within the relevant Level B harassment isopleth.

(h) Hilcorp must implement soft start techniques for impact pile driving.

(1) Hilcorp must conduct an initial set of three strikes from the impact hammer 30 seconds apart, at 40 percent energy, followed by a 1-minute waiting period, then two subsequent three strike sets.

(2) Soft start is required for any impact driving, including at the beginning of the day, after 30 minutes of pre-activity monitoring, and at any time following a cessation of impact pile driving of 30 minutes or longer.

(i) Hilcorp must implement ramp ups for seismic airgun use.

(1) Ramp up must be used at the start of airgun operations, including after a shutdown, and after any period greater than 30 minutes in duration without airgun operations.

(2) The rate of ramp up must be no more than 6 dB per 5-minute period.

(3) Ramp up must begin with the smallest gun in the array that is being used for all airgun array configurations.

(4) During the ramp up, the EZ for the full airgun array must be implemented.

(5) If the complete EZ has not been visible for at least 30 minutes prior to the start of operations, ramp up must not commence.

(6) Ramp up of the airguns must not be initiated if a marine mammal is sighted within or entering the EZ at any time.

(j) Hilcorp must use aircraft for mitigation.

(1) Hilcorp must use aircraft daily to survey the planned seismic survey area prior to the start of seismic surveying. Surveying must not begin unless the aerial flights confirm the planned survey area for that day is clear of beluga whales. If weather conditions make flying before the start of seismic in daylight unsafe, Hilcorp may delay the aerial survey until weather conditions improve and it is safe to fly.

(2) If beluga whales are sighted during flights, start of seismic surveying must be delayed until it is confirmed the area is free of beluga whales.

(k) Hilcorp must implement exclusion zones for beluga whales.

(1) Hilcorp must not operate with noise producing activity within 10 miles (16 km) of the mean higher high water (MHHW) line of the Susitna Delta (Beluga River to the Little Susitna River) between April 15 and October 15. Hilcorp must not conduct seismic activity within the Level B isopleth distance of the mouth of the Kasilof River between January 1 and May 31.

(m) Hilcorp must abide by all mitigation measures described in the Biological Opinion for Hilcorp Alaska and Harvest Alaska Oil and Gas Activities, Cook Inlet, Alaska.