AP Photo/National Park Service
This file photo released by the National Park Service shows humpback whales near Point Carolus at the mouth of Glacier Bay, Alaska, in this May 15, 2006 file photo.

ANCHORAGE, Alaska — A scientist says researchers may never solve the recent deaths of 18 endangered whales whose carcasses were found floating near Alaska's Kodiak Island.

Kate Wynne, a marine mammal specialist for the University of Alaska Sea Grant Program, says samples taken from one of the 10 fin whales were at least a week old, which could throw test results off. The carcasses of most of the eight humpback whales were too decomposed for sampling.

The whale carcasses were found between Memorial Day weekend and early July.

Both species of whales feed close together and scientists speculate the animals might have eaten something toxic in significantly warmer than average water temperatures.

Wynne says one test came back negative for one toxin that would be present in harmful algal blooms and another test is still pending.

Other test results also are pending.