Many marine mammal predators, particularly California sea lions and Pacific harbor seals, have increased in abundance in recent decades. This has created an imbalance in our predator-prey ecosystem.
Harbor seals and sea lions have been protected under the Marine Mammal Protection Act (MMPA) since 1972, meaning they cannot be harassed, captured, hunted, or killed.
Between 1970 and 2015, the annual biomass of Chinook salmon consumed by pinnipeds increased from 68 to 624 metric tons. Take that number and convert it into adult equivalents, and by 2015, pinnipeds consumed double that of resident orca whales and six times greater than the combined commercial and recreational catches.
Removal of haul-out spots and dredge-spoil islands in places like the Columbia river could make it more difficult for pinnipeds to forage for salmon. De-listing these mammals from the MMPA would allow the removal or relocation of these predators.
However, killing or removing seals is no magic fix.
One common-sense solution is to give the seals more fish to eat, by increasing wild populations over time from the improvements that are necessary.
Certainly, finding a balance between predator and prey is a key component of the management plan. But the scientists’ claims are true: we can’t just eliminate predators. We have to take an “all-in” approach to save wild salmon by implementing the solutions listed in our book.