It's true that seals and sea lions do eat salmon, but it's a very small portion of their diet, as they eat many other species. Marine mammals like these are important predators in the marine ecosystem, as they help to control disease in populations of their prey, and ensure that the healthiest survive to reproduce. These predators, in turn, are controlled by the Bigg’s killer whale—also known as transients—that have seals and sea lions on their menu.

Decades of removing top predators from the oceans through hunting and overfishing have shown us that the rest of the ecosystem is at risk when we do so. Removing these predators now will not improve the salmon catch for human fishers, or killer whales. In fact, it may even decrease the catch.