Judge throws roadblock into Hilcorp oil exploration in Cook Inlet, citing potential impacts to beluga whales

A federal judge on Tuesday sided with conservation groups and rejected a federal rule that allows Hilcorp to carry out oil and gas activity in Cook Inlet that could disrupt or potentially harm the Inlet’s endangered beluga whale population.

The oil company in 2018 applied for incidental take authorization from the National Marine Fisheries Service, so it could carry out exploratory drilling and related work between 2019 and 2024 that could potentially disrupt the beluga whales and other marine mammals with its loud noise.

The agency issued the approval in 2019, prompting a lawsuit from Homer-based Cook Inletkeeper and the Center for Biological Diversity, a national group.

U.S. District Court Judge Sharon Gleason on Tuesday determined that the agency had not properly considered the impact from tug boat noise associated with the activities, though the Fisheries Service’s recovery plan for the whales had identified noise from tugs as a major threat to the animals, according to the 52-page ruling.

The court “finds that the agency determination that noise from Hilcorp’s tugs towing the drill rig would not cause any take by harassment of Cook Inlet beluga whales is arbitrary and capricious for the reasons set forth herein, and the agency relied on this erroneous determination in its issuance of the Incidental Take Regulations” and other reviews, Gleason wrote.

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The number of beluga whales that remain in Cook Inlet year-round, one of five beluga stocks in Alaska, has fallen from about 1,300 in 1979 to an estimated 279 in 2018. The National Oceanic and Atmospheric Administration has said it does not know why the population is not recovering. It lists diminishing food supply, habitat loss, pollution and human-caused noise as some of the whales’ key threats.


The whales emit rapid clicking sounds to use echolocation, rather than sight, to communicate and hunt. The noise from tugs or other activities can disrupt them.

Hilcorp did not immediately respond to requests for comment Tuesday.

The court ordered the parties to propose an “appropriate remedy” within 14 days.

The decision could potentially impact Hilcorp’s plans for oil and gas exploration in federal and state waters, but it would not affect existing production, like the natural gas production used for power and heat in Anchorage and elsewhere, said Bob Shavelson, head of Cook Inletkeeper.

Hilcorp conducted seismic work in Cook Inlet in 2019 under the rule, Shavelson said.

Alex DeMarban

Alex DeMarban is a longtime Alaska journalist who covers business, the oil and gas industries and general assignments. Reach him at 907-257-4317 or