Centuries ago, sea otters were plentiful along the Oregon coast, but the fur trade came along and wiped them out. Wildlife authorities tried to restart the population in the 1970s by transplanting otters from Alaska to southern Oregon, but the population again fizzled out for reasons that have puzzled scientists, reports Oregon Public Broadcasting. Now, a new study may help explain why that repopulation effort failed and point the way toward making the next one work. It turns out, the otters from Alaska were northerners, genetically speaking, and perhaps couldn't hack the shift to the warmer waters, per a post at the University of Oregon. That would explain why the same repopulation effort worked in Washington state to the north. The Alaskan otters were more at home there.
Scientists got a handle on the what type of sea otters lived along the Oregon coast centuries ago by scraping DNA off the teeth of specimens at archaeological sites as well at the Smithsonian. As the New York Times explains, the otters are divided into northern and southern subspecies—think Alaska vs. California. Oregon apparently served as kind of a dividing line between the subspecies before the days of the fur trade, with southern otters in southern Oregon and their distinct northern cousins in northern Oregon. One possible takeaway from the study in Proceedings of the Royal Society B is that when the next repopulation effort is attempted in Oregon—planning already is underway—otters from California should be used in the southern part of the state and otters from Alaska or nearby locales should be used in the northern part of the state. (Read more sea otter stories.)