NOAA authorizes Juneau fuel dock rebuild to harass harbor seals, sea lions and whales

NOAA Fisheries issued PetroMarine Services an incidental harassment authorization Oct. 26 for rebuilding its Juneau Rock Dump fuel dock in Gastineau Channel. The permit allows the company to incidentally harass marine mammals during pile work, including up to 846 Level A takes of harbor seals.

Level A is the harassment category with the potential to injure an animal. Level B is behavioral disturbance. The company's application projects 846 Level A and 612 Level B harbor seal takes, so 58% of the seal takes fall at the higher level.

It projects 3 Level A and 159 Level B takes for Steller sea lions and 3 Level A and 8 Level B takes for harbor porpoises. It projects eight Level B takes of humpback whales and 21 of killer whales, with none at Level A.

NOAA's proposed authorization, published in September, cites a 2020 monitoring report suggesting a resident group of about 10 to 12 harbor seals in Gastineau Channel in winter. It estimates 18 harbor seals a day in the Level B zone, using monitoring data from earlier construction near downtown Juneau. Alaska News covered that proposal in "Pile driving at a Juneau fuel dock could damage seals' hearing".

NOAA and PetroMarine say neither expects serious injury or mortality. The application calls the effects on seals and sea lions short-term and temporary.

Under the monitoring plan, protected species observers must watch the water before, during and after pile work. Impact hammers start at reduced power, and work stops if an animal enters a shutdown zone. The largest Level A zone, 1,545 meters, covers harbor porpoises during impact driving of the 30-inch mooring and breasting dolphin piles, the project's largest.

The harbor seal shutdown zone is only 25 meters. NOAA's record says that is smaller than the Level A zone because harbor seals are difficult to detect. Once PetroMarine uses up the 846 Level A harbor seal takes, it must use a shutdown zone of up to 890 meters during impact driving of the dolphin piles.

The project replaces a T-dock and fuel float built in 1971 and improves existing fuel lines, according to PetroMarine's application. It calls for 81 days of in-water work between January and December 2027, once PetroMarine obtains required permits and selects a contractor. The company must send NOAA a draft monitoring report within 90 days of finishing monitoring.

Public comment closed Oct. 13. NOAA received no substantive comments and kept the numbers and safeguards it had proposed. The authorization runs through Oct. 25, 2027.