Sea otter populations in Alaska's Prince William Sound have returned to what they were before the Exxon Valdez oil spill.
It took 25 years, but numbers for sea otters in the areas worst hit by the spill have officially recovered, according to a U.S. Geological Survey report, notes Reuters. About 20 animal species were adversely affected by the oil spill.
The spill in 1989 killed thousands of otters living in the area after 42 million liters of crude oil spilled into Prince William Sound.
"Although recovery timelines varied widely among species, our work shows that recovery of species vulnerable to long-term effects of oil spills can take decades," research biologist and lead author Brenda Ballachey said.
According to The Associated Press, about 1,000 sea otter bodies were found immediately following the spill and about the same number perished throughout the years as there was likely still oil around.
As a result of the spill, an unusual amount of middle-aged otters died, but the report notes that the pre-spill trend of either young or old otters dying has returned.
image courtesy of Wikimedia Commons
