Since May, thirty whales from three different species stranded near or on the beaches of Alaska. Although NOAA reported that the mortality rate of whales in the region is about three times higher than the historical average, biologists and whale experts do not know yet what is causing the deaths.
Researchers currently suspect that the large animals may have died poisoned by ingesting large amounts of toxic algae. On the other hand, this hypothesis cannot be confirmed for now since there are too few intact whales to study.
The stranded whales include eleven fin whales, fourteen humpback whales, a single gray whale and four other whales that researchers couldn’t identify due to their advanced stage of decomposition. Fin and humpback whales are tagged as endangered by the WWF.
Julie Speegle of the National Oceanic and Atmospheric Administration recently told reporters that the agency sees toxic algae as main culprits in the mysterious whale die-off. Yet NOAA admitted that there is no “conclusive evidence” to back that theory.
NOAA researchers also said that there may be more dead animals that were not found yet. Some of the carcasses were either found on the beach, while other were seen floating near the Alaskan coast.
The whales that ended up on the shore were either eaten by bears or reached a decomposition state that barred researchers from properly identifying them. So far, biologists were able to test blood and tissue sample from only one specimen.
British Columbia also faces a relatively high mortality of whales. While one fin whale was killed by a passing ship, in five other whales cause of death remains largely a mystery. To this point, Canadian biologists could perform laboratory tests only on two of the whales.
In May, Alaska authorities said that they were puzzled to find nine fin whales wash ashore around Kodiak Island over the course of one month. Their time of death and the fact that they belonged to the same species were particularly intriguing.
Both Humpbacks and fin whales use their huge mouth plates to filter sea water and catch large amounts of algae, small fish, and other tiny marine creatures. Researchers believe that the nine fin whales must have also ingested large amounts of toxic algae while feeding.
Harmful algae blooms reached unusually high levels during this season. This month, NOAAA reported that one of the largest toxic algal blooms stretches from the Mexican coast to the gulf of Alaska where most deaths were reported.
Image Source: Flickr