The longest sighted humpback whale recorded in Southeast Alaska was found dead Sunday morning.

“Festus” — or whale #441 in fluke identification photos — was floating in Glacier Bay National Park water off Point Carolus, according to a Glacier Bay National Park & Preserve news release. Charter vessel operator Paul Johnson on the M/V Yakobi reported the whale to park staff around 10:20 a.m. Sunday.

After notifying the National Marine Fisheries Service, park staff towed the whale to shore on Sunday afternoon and it will go through a necropsy examination on Tuesday.

A preliminary examination of the carcass by park biologists indicates that it is an adult male, about 40 feet in length. More information on the cause of death and the condition of the whale is expected to be available after the necropsy.

Researcher Charles Jurasz first documented Festus in Lynn Canal in 1972. Listed in the Juneau Flukes Catalog, fisheries biologist John Moran saw Festus in the Juneau area in 2007. He was last sighted in June 2015 in Glacier Bay, according to the news release. With a 44-year sighting history, Festus was the longest-sighted humpback whale recorded in Southeast Alaska. Glacier Bay National Park is encouraging anyone with pertinent information, or who may have seen a sick or injured whale in the area recently to call (907) 697-2230.

“We would like to hear from anyone who was in the area in the past several days and may have observed anything unusual so that we can better understand causes of humpback whale mortality,” Superintendent Philip Hooge said in the release.

Contact reporter Lisa Phu at 523-2246 or lisa.phu@juneauempire.com.