Number of otters killed off the coast of California in 2011, reached a record high, in addition, scientists have noted a sharp increase in deaths of animals from the Red shark attacks, according to the U.S. Geological Survey (USGS).
Sea otters and sea otters (Enhydra lutris) were virtually exterminated the entire habitat along the northern coast of the Pacific Ocean in the XX century. Their number fell from several hundred thousand to two thousand individuals, then fishing animals was banned.
"In 2011, researchers found 335 dead sea otters on the coast of California, which is a record. Addition, experts are at a loss as significant increase in the number of sea otters killed by the bites of white sharks. According to statistics, in the 80's and early 90 — s only 8% of otters died from shark attacks, and in 2010-2011, the figure was 30%, "- said in a statement.
Confirm the conclusions of the scientists found "evidence": the fragments of teeth and characteristic white sharks shark bites left on the corpses of otters.
"Surprisingly, no evidence that white sharks feed on sea otters, no. Maybe sharks mistake otters for their favorite prey — seals and sea lions," — said one of the study's authors, Michael Harris (Michael Harris), as quoted by in the message.
According to the scientist, the sharks are trying otters "taste", but do not eat, as they prefer the larger and more fatty marine mammals.
"However, even the" test "for the sea otter shark bites are fatal," — said Harris.
Concern of researchers is the fact that over a third of the dead sea otters were females.
It clarifies the USGS, to date, the number of California sea otters is 2.7 thousand. The American scientists seek to increase this figure to 3.1 thousand individuals, which will bring the California sea otters from the threat of extinction.
USGS biologists and veterinarians since 1968 have been working on the analysis of mortality in sea otters, establish the cause of death of the animals, as well as developing strategies to restore the population of sea otters.