Whales are dying at an alarming rate in the western Gulf of
Alaska, and federal investigators say they're determined to find out why.
At least 30
large whales have died in Alaska since May, the National Oceanic and
Atmospheric Administration said this week in declaring the first "unusual
mortality event" for large whales ever declared in the state.
Authorities in
the Canadian province of British Columbia have also reported unusual whale
deaths, and officials in Alaska have also noted widespread deaths of common
murres, a species of bird, along the Alaska Peninsula, NOAA said.
Fewer than 15 large whale strandings have been reported in the
area each year since 2010, according to NOAA.
What's causing
the deaths is unknown, the agency said.
Samples are
being collected to test for bacteria, viruses and biotoxins like algae that
might be responsible, the agency said.
"Biotoxins
will be one of the top priorities, but not the only priority that we'll be
looking at to rule in or rule out whether it's playing a role in this death
investigation and these mortalities, both in Canada and the U.S.," said
NOAA Fisheries scientist Teri Rowles to theAlaska Daily News.
So far, the corpse of only one Alaska whale has been tested and
most of the carcasses have been floating and couldn't be retrieved, the agency
said.
Results of the
investigation could take months or even years, they said..
The die-off
comes amid a major algae
bloom that stretches
from central California north to Washington, according to NOAA. Waters off
Alaska could also be impacted, the agency said.
Unusual mortality events involve an increase in the number or
tempo of marine mammal deaths or deaths involving vulnerable species or other
conditions suggesting something unusual is causing the deaths.
Since 1991, NOAA
has recorded 61 such events. Nearly half have ultimately been traced to
infections, biotoxins, human interactions or malnutrition. Biotoxins from algae
blooms are responsible for the majority of recent declarations, according to
NOAA.
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