KODIAK, Alaska (AP) — National Oceanic and Atmospheric Administration researchers say 44 whales that died two years ago in the Gulf of Alaska could have been killed by algal toxins but are not ruling out other possibilities.

Research has shown that toxic algal blooms could be linked to warming surface water temperatures, and a mass of warm water known as "the blob" was present in the northern Pacific Ocean at that time, The Daily Kodiak reported (http://bit.ly/2plzTZG) Thursday.

Around the same time as the Alaska whale die-off, a similar event happened in waters near the Canadian province of British Columbia.

Whale carcasses in the Canadian die-off contained algal toxins. Some species of algae produce algal toxins that can kill animals.

Researchers could not perform the testing they wanted to on the whales that died in Alaska waters because many carcasses were decomposed or not easily retrievable.

Fisheries veterinarian Kate Savage of the administration said it is possible that the whales that died in Alaska could have been killed by algal toxins but could not rule out other factors — including predation, vessel strikes and infectious diseases.

The death of the whales in the summer of 2015 coincided with the unusual deaths of other animals in Alaska's Prince William Sound and Kodiak Archipelago.

Thousands of common murre seabirds died in those areas over the course of a year starting in the spring of 2015.

That fall, hundreds of tufted puffin carcasses washed ashore at the isolated St. Paul Island in the Bering Sea.

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Information from: Kodiak (Alaska) Daily Mirror, http://www.kodiakdailymirror.com