Seeking Oregon’s Lost Sea Otters

When archeologists sifted through the remains of an American Indian village at the mouth of the Coquille River in what is now the city of Bandon, they found the bones of wildlife the village’s residents depended on for food, clothing and more.

Sea lion bones were the most common among marine mammals, a cultural staple for Oregon’s coastal tribes. But the next most common were the bones of sea otters, outnumbering the remains of the seals and whales more prominent in the ocean today.

“It was pretty surprising,” said Roberta Hall, an Oregon State University anthropologist who led the excavations. “The otter was a valuable item. It was a wealth item and was traded for great distances.”

It was especially surprising because the wild sea otter--”elakha” to Indians--no longer lives along the Oregon coast.

Now, in the first stage of an effort to return the sea otter to Oregon, Portland State University researchers are focusing a genetic magnifier on otter bones from prehistoric settlements. They want to learn more about the otters that once plied Oregon’s shores by the thousands, their valuable pelts fueling early exploration of the region.

The researchers hope to weave information from ancient otter DNA into a detailed picture of the native Oregon otter, once a keystone of the coastal community. In particular, they want to know whether the native otter was more closely related to the northern sea otter, which populates the Aleutian Islands of Alaska, or the southern sea otter, which lives on the California coast--or whether it was some blend of the two.

Scouring the Beach for Genetic Footprint

The aging bones of the native otters hint at their species, but the Portland State team is searching for the genetic blueprint locked within the otters’ DNA. The researchers hope to recover the first DNA from prehistoric sea otter remains. From it, they would try to reconstruct the now-hidden family tree of Oregon’s long-missing otter, along with a vision of how that tree grew and changed through time.

“DNA adds that much more clarity,” said Kim Valentine, a Portland State grad student who will conduct most of the laboratory work for the project, which is to be financed through donations and grants. “It adds light to the picture that you couldn’t get any other way.”

The blend of archeological, paleontological, biological and even molecular detective work should tell the researchers which modern species of otter would be best suited for the Oregon coast. They also hope such genetic groundwork will help avoid a repeat of a 1970s reintroduction of almost 100 Alaskan otters to Oregon, which failed when the animals all disappeared.

Some scientists suspect those animals might have been a different species, with teeth of a different size and shape, from the original Oregon otter and not as well adapted to life on the Oregon coast.

“It’s possible that those just came from the wrong population,” said Virginia Butler, a professor of anthropology at Portland State and a leader of the otter project. “There may be characteristics that distinguish the Oregon sea otter, and we’d like to know as specifically as we can what those are.”

The sea otter is deeply rooted in Oregon history. Its rich and luxurious pelts were a currency of early coastal commerce.

Such value and prestige carried throughout the world, fueling European exploration and domination of the West Coast. Fur hunters from Russia, Spain, France, England and the fledgling United States had killed more than a million sea otters along the Pacific Coast by the time wagon trains began bringing settlers to Oregon.

When the Atomic Energy Commission planned nuclear tests in Alaska’s Aleutian Islands in the 1970s, biologists shipped Aleutian otters to the Northwest, releasing 59 on the west side of Washington’s Olympic Peninsula in 1969 and 1970 and 93 otters on the Southern Oregon coast in 1970 and 1971.

Otters eat mainly shellfish such as sea urchins, crabs, clams, mussels and snails, and biologists figured the rocky reefs on Oregon’s south coast, like the Olympic Peninsula, represented prime otter range.

Now protected from hunting under the Marine Mammal Protection Act, the reintroduced otters held on in Washington and have multiplied into a population of more than 500. In Oregon, though, the otters disappeared by about 1980.

That puzzled biologists such as Ron Jameson, who tracked the transplanted animals and now works for the U.S. Geological Survey’s Biological Resources Division in Corvallis. “My feeling is that most of them were trying to get home, and where they ended up, no one knows,” Jameson said. “Maybe they ended up in Washington and joined the population there.”

A later examination of otter bones from prehistoric sites along the Oregon coast showed that the original Oregon otter might have been a kind of intermediate species, with teeth and a jaw different from those of otters to the north in Alaska and to the south in California. Those differences might have put the Alaskan otters brought to Oregon in the 1970s at a disadvantage, in the same way a plant adapted to the wet Northwest would have a hard time living in the desert.

If that’s the case, said anthropologist R. Lee Lyman of the University of Missouri, who examined the otter bones, “perhaps those transplanted sea otters were doomed from the moment they were captured.”

He suggested in a 1996 paper that genetic analysis of the otter remains might unearth an answer, especially because most biologists now agree that any reintroduced wildlife should be as closely related to a region’s original species as possible.

Lyman’s suggestion made sense to David Hatch, an engineer with the city of Portland who researched the history of the sea otter in Oregon while serving on a committee that last year named a new Oregon State University research boat Elakha, for the otter. When he later organized the Elakha Alliance, a group hoping to return sea otters to Oregon’s waters, one of its first orders of business was to recruit the Portland State researchers to carry out the genetic analysis.

“When the time comes, we want any otter that comes back to Oregon to have the best possible chance,” Hatch said. “We know a lot more now than we did in the 1970s, and we have the tools to learn even more.”

Hatch has come to see the otter as a missing link in Oregon’s coastal ecosystem. Without the otter to control sea urchin numbers, urchin hordes mowed down the kelp forests that grew along rocky sections of coast and served as nurseries for fish.