POINT REYES NATIONAL SEASHORE, Calif. — Two juvenile California sea lions paused at the edge of the sea, raising their whiskered faces toward the silvery water before sliding in to freedom.
For the Marine Mammal Center crew standing nearby Thursday, it was a significant day: Rescued sea lions No. 10,000, nicknamed Milestone, and 10,001, Zodiac Girl, had been nursed back to health and returned to the wild where they belong.
“There’s always some attachment. There’s always some animal that captures your heart,” said Shelbi Stoudt, the center staffer who organizes releases. “It’s a bittersweet feeling because you’re sending them back home, but you also don’t get to see them anymore.”
Since it opened its doors 36 years ago, the nonprofit marine mammal hospital has become famous for nursing sick marine critters back to health — but its biggest contribution perhaps has been its role in collecting and storing thousands of tissue and other samples from animals it rescued along 600 miles of California coast.
A mix of laboratory science, marine zoo and educational outreach has led to dozens of scientific papers and helped push understanding of the effects of toxic algae, disease and climate change on these coastal denizens.
While rescues are a chief focus of the center, only about half of the animals the center takes in survive to be released. Still, many of the more than 17,000 rescued marine mammals — including entangled whales, otters and elephant seals — have contributed samples that will help further research that can aid threatened and endangered species around the world.
Many of the animals nursed back to health are not facing imminent extinction — there are about 200,000 California sea lions in the wild — but their maladies and genetic makeup are similar to species in peril.
And the center is studying the exposure of sea lions to carcinogens. About 17 percent of the adult sea lions taken in by the center have a specific cancer first found in 1979.
Researchers are studying the levels of carcinogens, such as DDT and PCBs, which are banned in the U.S. but still are found in sea lion blubber.
“It’s shocking how many animals we’ve treated, but the information we’ve received from them, that’s one of the most important aspects of the center’s work,” Stoudt said.
