WILDLIFE -- The oldest of the endangered Puget Sound orcas has been missing for months and is now considered dead in a year marked by seven deaths among killer whales that frequent the San Juan Islands.

The Center for Whale Research, which conducts orca surveys for the federal government, says J2, known as Granny, has not been seen since October and is likely dead.

Researcher Ken Balcomb wrote on the center’s website that she has been seen thousands of times over 40 years of surveys. She is typically seen at the head of the J pod, one of three family groups of whales.

Howard Garrett of the Orca Network says a 1987 published study estimated that J2 was born in 1911 putting her at 105, though there’s a 12-year margin of error.

Despite a baby boom in 2015, the closely tracked population of southern resident killer whales is now down to 78. Seven were declared missing or dead in 2016.

After a low in 2014 of just 78 individuals, the birth of eight new calves in 12 months looked buoyed hopes for the dwindling population. The last of the newborns, named J54, was first seen on Dec. 1, 2015, and brought the population up to 85.