Sea Shepherd is known for chasing down illegal whaling and fishing boats—sometimes in epic, record-breaking fashion—and now the environmental group has turned its attention to protecting one of the world’s most endangered seals.

 

Found only in Lake Saimaa in Finland, the Saimaa ringed seal is one of only a handful of seal subspecies that live in freshwater. It’s thought that they were separated from the saltwater-dwelling ringed seal species when the land rose after the ice age.

 

But today, they’re critically endangered; only 310 seals survive in the wild. Before the species was granted protection in the 1950s, fishers were paid bounties for every seal skull they collected. Saimaa ringed seals were seen as a nuisance, competing with the fishers for their catch. But by the 1960s, a new threat emerged: nylon nets. The old cotton nets didn’t harm the seals, as they would decompose. But the nylon nets cut into and kill the species.

 

Even new regulations establishing no-fishing zones around the lake have failed to stem the seal’s decline. That’s where Sea Shepherd comes in.

 

It will be forming its own team to keep an eye on the species. From April through June—the animal’s mating season—Sea Shepherd volunteers will patrol the newly established reserves and check for illegal fishing nets and traps. Once they spot illegal activity, they’ll alert local law enforcement, who can document and confiscate illegal gear.