Seattle, Washington (KINY) While there is good news with harbor seals, killer whales and sea lion populations rebounding in the Northeast Pacific Ocean, this means they are eating more salmon and thus threaten the endangered orca population, scientists say,
Researchers claim that between 1975 and 2015, marine mammals along the U.S. West coast ate 15,200 metric tons of chinook salmon, an increase form 6,100 metric tons.
The Journal Scientific Reports said the salmon caught by commercial and recreational fishermen from Northern California declined over that same period, from 16,400 metric tons to 9,600 metric tons each year.
Habitat damage, dams and pollution has also affected the salmon population. Salmon is also a key element of the diet for orcas.
Puget Sound orcas, have a narrower menu of fish stocks and fewer available fish than what they need. There were 140 of the endangered species in 2003, now they are just 76.
The study was paid for by the Pacific Salmon Commission, formed by the governments of the United States and Canada in 1985.