(a) Marine mammal monitoring protocols. Hilcorp must conduct briefings between construction supervisors and crews and the observer team prior to the start of all pile driving and removal activities, and when new personnel join the work. Trained observers must receive a general environmental awareness briefing conducted by Hilcorp staff. At minimum, training must include identification of marine mammals that may occur in the project vicinity and relevant mitigation and monitoring requirements. All observers must have no other construction-related tasks while conducting monitoring.

(b) Visibility. Activities must only commence when the entire exclusion zone (EZ) is visible to the naked eye and can be adequately monitored. If conditions (e.g., fog) prevent the visual detection of marine mammals, activities must not be initiated. For activities other than seismic surveying, activity must be halted in low visibility but vibratory pile driving or removal will be allowed to continue if started in good visibility.

(c) Monitoring periods. 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 animals' behavior must be monitored and documented.

(d) Placement of PSOs.

(1) At least one on-duty PSO must be placed on the source vessel (for seismic and geohazard surveys) or drill rig (for pipe driving and VSP).

(2) During seismic surveys a mitigation vessel must be used with at least one on-duty PSO aboard the vessel monitoring for marine mammal occurrence.

(e) Reporting measures—(1) Take limits. Hilcorp must contact NMFS when they have reached the limit of authorized takes of beluga whale within a year.

(2) Monthly reports. Monthly reports must be submitted to NMFS for all months during which in-water seismic activities take place. The monthly report must contain and summarize the following information: Dates, times, locations, heading, speed, weather, sea conditions (including Beaufort sea state and wind force), and associated activities during all seismic operations and marine mammal sightings; Species, number, location, distance from the vessel, and behavior of any sighted marine mammals, as well as associated seismic activity (number of power-downs and shutdowns), observed throughout all monitoring activities; An estimate of the number (by species) exposed to the seismic activity (based on visual observation) at received levels greater than or equal to the NMFS thresholds discussed above with a discussion of any specific behaviors those individuals exhibited; A description of the implementation and effectiveness of the terms and conditions of the Biological Opinion's Incidental Take Statement (ITS) and mitigation measures of the LOA.

(3) Annual reports. (i) Hilcorp must submit an annual report within 90 days after each activity year, starting from the date when the LOA is issued (for the first annual report) or from the date when the previous annual report ended.

(ii) Annual reports will detail the monitoring protocol, summarize the data recorded during monitoring, and estimate the number of marine mammals that may have been harassed during the period of the report.

(iii) NMFS will provide comments within 30 days after receiving annual reports, and Hilcorp must address the comments and submit revisions within 30 days after receiving NMFS comments. If no comment is received from the NMFS within 30 days, the annual report will be considered completed.

(4) Final report.

(i) Hilcorp must submit a comprehensive summary report to NMFS not later than 90 days following the conclusion of marine mammal monitoring efforts described in this subpart.

(ii) The final report must synthesize all data recorded during marine mammal monitoring, and estimate the number of marine mammals that may have been harassed through the entire project.

(iii) NMFS will provide comments within 30 days after receiving this report, and Hilcorp must address the comments and submit revisions within 30 days after receiving NMFS comments. If no comment is received from the NMFS within 30 days, the final report will be considered as final.

(5) Reporting of injured or dead marine mammals.

(i) In the event that personnel involved in the survey activities discover an injured or dead marine mammal, Hilcorp must report the incident to the Office of Protected Resources (OPR), NMFS (301-427-8401) and to regional stranding network (877- 925-7773) as soon as feasible. The report must include the following information:

(A) Time, date, and location (latitude/longitude) of the first discovery (and updated location information if known and applicable);

(B) Species identification (if known) or description of the animal(s) involved;

(C) Condition of the animal(s) (including carcass condition if the animal is dead);

(D) Observed behaviors of the animal(s), if alive;

(E) If available, photographs or video footage of the animal(s); and

(F) General circumstances under which the animal was discovered.

(ii) In the event of a ship strike of a marine mammal by any vessel involved in the survey activities, Hilcorp must report the incident to OPR, NMFS and to regional stranding networks as soon as feasible. The report must include the following information:

(A) Time, date, and location (latitude/longitude) of the incident;

(B) Species identification (if known) or description of the animal(s) involved;

(C) Vessel's speed during and leading up to the incident;

(D) Vessel's course/heading and what operations were being conducted (if applicable);

(E) Status of all sound sources in use;

(F) Description of avoidance measures/requirements that were in place at the time of the strike and what additional measures were taken, if any, to avoid strike;

(G) Environmental conditions (e.g., wind speed and direction, Beaufort sea state, cloud cover, visibility) immediately preceding the strike;

(H) Estimated size and length of animal that was struck;

(I) Description of the behavior of the marine mammal immediately preceding and following the strike;

(J) If available, description of the presence and behavior of any other marine mammals immediately preceding the strike;

(K) Estimated fate of the animal (e.g., dead, injured but alive, injured and moving, blood or tissue observed in the water, status unknown, disappeared); and

(L) To the extent practicable, photographs or video footage of the animal(s).

(iii) In the event of a live stranding (or near-shore atypical milling) event within 50 km of the survey operations, where the NMFS stranding network is engaged in herding or other interventions to return animals to the water, the Director of OPR, NMFS (or designee) will advise Hilcorp of the need to implement shutdown procedures for all active acoustic sources operating within 50 km of the stranding. Shutdown procedures for live stranding or milling marine mammals include the following:

(A) If at any time, the marine mammal(s) die or are euthanized, or if herding/intervention efforts are stopped, the Director of OPR, NMFS (or designee) will advise Hilcorp that the shutdown around the animals' location is no longer needed.

(B) Otherwise, shutdown procedures must remain in effect until the Director of OPR, NMFS (or designee) determines and advises Hilcorp that all live animals involved have left the area (either of their own volition or following an intervention).

(C) If further observations of the marine mammals indicate the potential for re-stranding, additional coordination with Hilcorp must occur to determine what measures are necessary to minimize that likelihood (e.g., extending the shutdown or moving operations farther away) and Hilcorp must implement those measures as appropriate.

(iv) If NMFS determines that the circumstances of any marine mammal stranding found in the vicinity of the activity suggest investigation of the association with survey activities is warranted, and an investigation into the stranding is being pursued, NMFS will submit a written request to Hilcorp indicating that the following initial available information must be provided as soon as possible, but no later than 7 business days after the request for information.

(A) Status of all sound source use in the 48 hours preceding the estimated time of stranding and within 50 km of the discovery/notification of the stranding by NMFS; and

(B) If available, description of the behavior of any marine mammal(s) observed preceding (i.e., within 48 hours and 50 km) and immediately after the discovery of the stranding.

(C) In the event that the investigation is still inconclusive, the investigation of the association of the survey activities is still warranted, and the investigation is still being pursued, NMFS may provide additional information requests, in writing, regarding the nature and location of survey operations prior to the time period above.