In the calm waters of Monterey Bay, a mother otter and her pup playing is deceiving. Scientists warn the species is struggling for survival.
"We do know, for instance, that it is not reduced reproduction that is limiting population growth; we know that it is indeed elevated mortality," USGS wildlife biologist Tim Tinker said. Tinker has been studying the otter population since the early 1990's.
The spring census found just over 2,600 otters along 375 miles of coast; a nearly 4 percent drop from the year before.
Betty and Jack Duffield noticed the decline immediately. Every year they visit Moss Landing State Beach in the shadow of the old power plant. It is a little known spot where an extraordinary number of otters hang out. Tuesday, Betty counted just 26.
"When wildlife decreases there's a problem; it's very disturbing," Betty Duffield said.
Researchers agree. They say the drop in the otter population is much more serious and much more significant than the problems seen this year with other marine mammals like sea lions.
Otters are often referred to as the cannery in the coal mine because they are an early indicator as to the overall health of the ocean.
Lab tests indicate the otters are dying primary from infectious disease, likely caused by manmade pollutants.
"The fact that a lot of that disease or a lot of those pathogens are coming from the shore tells us a lot about how we are managing things like the watershed, sewage agricultural runoff, things like that," Andy Peterson of the Monterey Bay Aquarium said.
Various groups are working together to better understand the threat and determine what can be done to better protect the ocean.
"We hope that the solutions that we can identify that will help sea otters will actually help a whole suite a species in the coastal ecosystem," Tinker said.
Otters were making a steady comeback until this year's count gave everyone reason for concern.