The bodies of two sea lions were found along the Washington coast with gunshot wounds to the head, bringing the total of animals killed in recent weeks to 18.

Officials this week confirmed that two more animals were found dead in the Puget Sound. As My NorthWest reported, the bodies of the animals showed severe decomposition, leading officials to think that they had been killed several weeks ago.

“We found these sea lions both washed up in the West Seattle area on December 4 and December 5. One we believe was reported across the waterway previously, so that animal just washed to the West Seattle area after about a day,” said Casey Mclean, who works with a local marine wildlife nonprofit group called SR.

Because the animals were decomposed, officials believe they may have been killed around the same time as a series of others found dead along the shore. There have been a total of 18 dead sea lions found in the past few weeks, several with gunshot wounds, and others that appeared to have been killed by humans. At least one had been decapitated.

As NBC News reported last month, the killings have created concern among wildlife officials who said the animals are at greater risk during fishing season, when there is greater contact between humans and the sea lions.

The total sea lion population has increased greatly due to conservation efforts over the last 40 years, but that has led to greater risk for the marine mammals. In the last 20 years, close to 700 sea lions have been found dead with gunshot and stab wounds, National Geographic reported.

“We are concerned about a number of recent reports of marine mammal deaths caused by gunshots in the greater Seattle area. All marine mammals are protected by the Marine Mammal Protection Act and OLE investigates all reported unlawful takes of sea lions,” Greg Busch, assistant director of the NOAA Fisheries’ Office of Law Enforcement, said in a statement.

The male sea lion was often spotted in the waters around Point Reyes National Seashore. https://t.co/tVweuGeswC — HuffPost Green (@HuffPostGreen) December 9, 2018

There is some worry among wildlife experts that the killings could increase in the coming weeks, as November and December are the busiest commercial fishing times along the coast.

Those killing sea lions could face some serious consequences. As NBC News noted, sea lions are protected by the U.S. by the Marine Mammal Protection Act, so anyone who kills one could face a fine of up to $28,520 and up to a year in prison for each animal killed.