Santa Cruz, CA – Standing atop a ladder in the pool yard at the state Department of Fish and Game's Marine Wildlife Veterinary Care and Research Center in Santa Cruz, Ben Weitzman carefully stays behind a gauzy, black curtain that hangs on a fence. On the other side, an otter named Olive swims in a pool. "So we have the shade cloth set up just to reduce her interaction with humans. Primarily we don't want her to associate being fed with people," said Weitzman. He tosses over fresh shrimp and squid. Olive needs to eat the equivalent of about 30% her body weight a day. "What we're watching for is if she starts to be less interested in food. That could indicate something like a health issue," he added.
Weitzman is part of a team that has cared for Olive since late February when she was found oiled on Sunset Beach near Watsonville. She was unable to groom herself, which is essential to otter survival. Grooming traps air in an otter's hair coat and that insulates it from the cold sea water. Senior Wildlife Veterinarian Dr. David Jessup explains, "without air in their coat they're less buoyant, so it's harder for them to swim. It's harder for them to get food, so they get cold, they get hypoglycemic and their blood sugar level goes down because they can't forage. And those two can put them into shock and within a day or two they usually beach themselves or die."
Since the state built this center to care for oiled marine wildlife 12 years ago, Olive is the first oiled otter to make it here alive. Her arrival gave Dr. Jessup and his team the opportunity to put into practice three years of research on washing oiled otters. It's research that improves upon the response to the Exxon Valdez oil spill 20 years ago. "The efforts to wash oiled sea otters at Exxon Valdez were heroic by any measure, but they were frustrating too because they didn't turn out as well as people hoped," said Dr. Jessup.
Following the spill, about 360 otters were taken into care and around one-third died. Those that did survive took a long time to recover. Dr. Terrie Williams led that effort. Coincidentally she now works down the road from Olive at UC Santa Cruz. "There were so many questions. The first question was why weren't we more successful right from the start in cleaning the animals?" said Dr. Williams, "And what are the pieces that allow it to recover a lot faster? It was taking ten, twelve days if the animal didn't have animal internal damage. It was still taking about twelve days for the coat to start looking good. And the question was why was it taking so long?"
Those are the questions Dr. Jessup's team tackled, dissecting the washing process step by step. They switched a few things up: rinsing otters in soft water, instead of hard water, increasing the water temperature throughout the process and having the otters recover in warm soft water instead of cold sea water. It worked on their healthy, resident research otters after putting olive oil on their coats. But Olive was a very sick otter oiled and tarred by naturally occurring oil in the ocean. "She came back within 53 hours of contact with the soft, fresh water to where her coat was about 90%, 95% water proof," said Dr. Jessup, "if we can get animals to recover the water proof quality of their coat in half to a third of the time, it should result in fewer animals dying."
Now nearly six weeks after her rescue, Olive is ready to return to the wild, once the weather is just right. For Dr. Williams, Olive's recovery is an answer to decades old questions. "It's wonderful to see sort of the advance in our knowledge and to see an animal like Olive come in look as bad as anything we had during the Valdez spill and yet recover really quickly. So I'm hoping a lot of other otters will benefit from this," said Dr. Williams.
Staff from the Monterey Bay Aquarium implanted a tracking device in Olive, so researchers can continue to monitor her after her release.