ANCHORAGE— Conservation groups filed a lawsuit today challenging the Trump administration’s approval of rules allowing Hilcorp Alaska LLC to harm Cook Inlet beluga whales and other marine mammals as it expands its offshore oil and gas operations in Cook Inlet.

Cook Inletkeeper and the Center for Biological Diversity sued the National Marine Fisheries Service in federal district court in Alaska to block the “take authorization” rule it issued in July. The authorization would allow harm to marine mammals from Hilcorp’s seismic blasting, pile driving and other offshore-oil development activities over the next five years.

“Hilcorp routinely violates Alaska’s worker safety and environmental rules,” said Bob Shavelson, advocacy director for Cook Inletkeeper. “We certainly cannot trust them or the Trump administration to protect the endangered Beluga whale and our valuable Cook Inlet fisheries from the unrelenting blasts of seismic airguns.”

Hilcorp bought 14 new federal leases in Cook Inlet in 2017, shortly after failing to control an underwater gas leak from its pipeline there for nearly four months. The Texas-based company has repeatedly been fined for safety violations by Alaska regulators, who wrote that “disregard for regulatory compliance is endemic to Hilcorp’s approach to its Alaska operations.”

“We can’t allow Hilcorp’s acoustic attack on endangered Cook Inlet beluga whales,” said Julie Teel Simmonds, a senior attorney at the Center for Biological Diversity. “The Trump administration doesn’t care about protecting marine mammals, so we’re turning to the courts. Only about 320 belugas remain in Cook Inlet. They need protection from Hilcorp as it expands its dirty and dangerous offshore-drilling operations.”

Hilcorp has been aggressively expanding its oil operations in Alaska, reportedly buying all of BP’s fossil fuel interests in Alaska for $5.6 billion. Hilcorp Alaska is also working on the Liberty project, an offshore drilling island in the Beaufort Sea, but the Center and other groups filed a lawsuit in December 2018 challenging approval of that project.

The Marine Mammal Protection Act generally prohibits killing, harming or harassing a marine mammal. While the federal government can authorize certain industrial activities to harm and harass marine mammals, such activities must harm only a “small number” of animals and have no more than a “negligible impact” on the population.

Today’s lawsuit notes that the authorization fails to meet these statutory standards because it underestimates the number of marine mammals harmed, lacks a reasonable basis for concluding the activities will have a negligible impact, does not sufficiently avoid or mitigate the harm Hilcorp’s oil and gas activities will have and impermissibly dismissed the recommendations it received from the federal Marine Mammal Commission.

The suit also notes that the agency ignored its obligations to carefully study Hilcorp’s impact on critically endangered Cook Inlet beluga whales and their prey under both the Endangered Species Act and National Environmental Policy Act.

Seismic blasting used in oil exploration can reach 250 decibels and be heard for miles. It can cause hearing loss in marine mammals, disturb essential behaviors such as feeding and breeding, mask communications between individual whales and reduce catch rates of commercial fish.