It was sad enough hearing about the tens of thousands of endangered antelopes that mysteriously died in May this year, now scientists have another depressing quandary on their hands: Whales are dying at an alarmingly high rate around Alaska, and they don’t know why.
Since May, 30 large whales have died in the western Gulf of Alaska, according to the National Oceanic and Atmospheric Administration (NOAA). The first carcasses to be discovered belonged to fin whales and were found in the waters near Kodiak, with one that washed up now serving as dinner for hungry bears, Alaska Dispatch News (ADN) reports. Now, those affected include humpbacks and a gray whale, along with others that have yet to be identified.
While large whale strandings are not unheard of in this area, the numbers are substantially higher than those recorded over the past five years and six times higher than the previous year. This is why the event has now officially been declared an Unusual Mortality Event – basically an unexpected, significant die-off. Since the early ‘90s, 61 of these have been formally recognized around the U.S., affecting a range of mammalian species.
Unfortunately, scientists are a bit stumped here. Most of the animals were discovered floating, severely decomposed and not retrievable for examination. Only one has so far been sampled, but frustratingly that gave up no clues as to the possible cause of death. However, a few ideas floated around during a teleconference on Thursday, according to ADN.
A lingering warm mass, for example, is driving surface temperatures up in the Pacific, and they’re not predicted to dip any time soon as El Niño swings around.
“That always concerns us because that means there’s probably a change in overall pathogen exposure, possibly harmful algal blooms and other factors,” Teri Rowles, the lead marine mammal scientist for NOAA Fisheries, said during the teleconference.
Algal blooms may actually be a leading suspect given that an extensive bloom that began earlier this year has slowly spread along the West Coast, stretching all the way from central California to Washington and maybe higher. And these marine organisms aren’t harmless: They produce a toxin called domoic acid that could pose a hazard to animals.
Without a known cause, there isn’t a lot that scientists can do to reduce further losses, but an independent team is currently being assembled to work with those in the Marine Mammal Unusual Mortality Events group. By reviewing data collected so far and examining any other carcasses where possible, hopefully a plan of action can be put in place. In the meantime, you can help the NOAA out by reporting here any stranded animals you happen upon.