Marine mammals outdueling fisherman for salmon, and it's a problem for orcas

Marine mammal populations have been rebounding along the West Coast in recent decades, and apparently they're eating a lot to celebrate.

According to a new study, marine mammals, such as orcas, sea lions and harbor seals, up and down the West Coast may now be eating more Chinook salmon than those being caught by commercial and recreational fisheries combined.

Which, as one might expect, is a big pressure on the salmon population. Typically, when discussing challenges salmon face in their ecosystem, fishing is high on the list. But according to the study conducted by federal, state, and tribal researchers, there's more to the picture than a single factor (at least, in recent years).

And those challenges can cut both ways: southern resident killer whales (the Puget Sound orcas) have a narrower menu of fish stocks and fewer available fish compared to their northern counterparts.

Historically, the southern resident killer whales have struggled with lack of food, pollution and impacts from boats, and have been listed as an endangered species in the U.S. since 2005. There are now just 76 left.

"Every other one of those predators has a chance to eat that salmon before. They're the last ones to sit at the table and get a chance to eat," Brandon Chasco, lead author of the study and an Oregon State University postdoctoral student told the Associated Press.

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