Marine mammal experts are testing tissue samples for a potential common cause of the surge in carcasses found on the state's beaches this year.

Waters off the coast of Maine are warming faster than 99 percent of the world's oceans. That's forcing whales northward in pursuit of prey, threatening some of their already dwindling populations.

NOAA and NASA satellites measured an average sea-surface temperature of 68.93 degrees Fahrenheit in the Gulf of Maine on Aug. 8, only 0.05 degrees below the all-time record high of 68.98 set in 2012. It is the epicenter of the U.S. lobster fishing industry, an important feeding ground for rare North Atlantic right whales .

The rate of dead seal strandings in Maine is about three times the normal rate for the summer and is close to 60. Most of the seals that have been stranded this summer have been found dead, NOAA said. The dead seals have included gray seals and harbor seals.

Porpoise spotted heading up the Pastolik River