It was struck and killed by a big rig on Moday.
Jim Oswald is with the Marine Mammal Center in Sausalito. He says the sea lion might have become sick and disoriented as it swam from the San Francisco Bay to an inlet in the Delta.
“I don’t know that we’ll ever know exactly why but in the case of California sea lions one of the diseases that affect them out here is a toxic algae poisoning that affects the area of the brain that causes disorientation.”
The California Highway Patrol said a truck driver thought he had struck a cow, then stopped and saw it was a sea lion.
Sea lions often venture far in search of food. A year ago one showed up at the Tracy Animal Shelter.