Only 54,000 Sei whales are alive today, which is one-fifth of its original population from before 1950, according to the Canisius College Ambassadors for Conservation. But the population’s decline was still not enough to stop one Santa Monica sushi bar from placing the endangered species on its menu.

Brian Vidor, the former owner of the now-defunct California food establishment, “The Hump,” and the restaurant’s parent company, Typhoon Restaurant Inc., pleaded guilty Monday, each for the sale of a marine mammal after the restaurant was caught selling Sei whale meat to customers, according to the Los Angeles Times.

Vidor also admitted to having prior knowledge of and granting permission to chefs to cook the meat. The chefs, Kiyoshiro Yamamoto and Susumu Ueda pleaded guilty earlier on in the year to misdemeanors for conspiracy and the sale of marine mammals, an action that violates the Marine Mammal Protection Act, enacted in 1972. The two have not yet been sentenced. Ginichi Ohira, who sold the whale meat to the restaurant, has also pleaded guilty.

“The Hump,” located in Santa Monica Municipal Airport, was known for its unique and exotic blend of seafood medley. Then in 2009, producers for “The Cove,” a documentary about Japan’s dolphin hunting, secretly taped the restaurant serving whale meat to customers.

The restaurant was then shut down in 2010 when undercover agencies, investigating the restaurant based on the recording, infiltrated the sushi bar disguised as a group of customers. Chef Yamamoto served them pieces of meat from a package, whispering that it was whale meat.

The agents involved were sent by the U.S. Fish and Wildlife Service, U.S. Customs and Border Protection, and the National Oceanic and Atmospheric Administration. The meat was later tested and found to be at least three years old, according to LAist.

If Judge Dale S. Fischer agrees to the plea bargain, Vidor and Typhoon will face a joint $27,500 fine together. Typhoon will receive an 18-month probation period and Vidor 12 months. Sentencing for both is due to take place on Feb. 23.