KODIAK, Alaska (AP) – Two dead gray whales have been found in Alaska, raising the death toll so far this year to seven whales.

The Kodiak Daily Mirror reported Tuesday that the National Oceanic and Atmospheric Administration confirmed the two whale deaths near Kodiak.

NOAA has declared an “unusual mortality event” and launched an investigation into the cause of the large number of deaths.

Officials say a dead gray whale was spotted floating and later beached in Kodiak Island’s Portage Bay southwest of Anchorage last week.

During an aerial survey Friday, another dead gray whale was seen floating on the northern side of Aiaktalik Island near Kodiak Island.

Officials say the eastern North Pacific gray whale population that migrates from Mexico to the Arctic each summer was last estimated at about 27,000 animals.

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