Two California sea lions and an elephant seal were returned to the ocean Thursday as SeaWorld San Diego begins to wind down its 2016 rescue season.
So far this year, SeaWorld staffers have rescued 435 marine mammals, more than double the annual average of 150 to 200. Last year, more than 1,000 were rescued, an unusually high number that animal experts attributed to a reduction in food supplies caused by warming of ocean waters.
Most of the stranded sea lions have been both malnourished and dehydrated, because they receive their hydration from the fish they eat.
SeaWorld also has rescued 448 birds and six sea turtles so far this year. The total for sea turtles is a single-year high.
Scott Benson, of NOAA Fisheries — a division of the National Oceanic and Atmospheric Administration — told City News Service that the same warm waters could be encouraging the turtles to swim farther north than they should. The turtles aren't equipped to handle water that turns cold, he said.
Four of the turtles were stranded on beaches in Oregon, Washington and Vancouver Island, British Columbia last December and January, far north of their normal foraging areas.
Benson said sea turtle populations are increasing, which could also account for the larger number of strandings.
