A record low 105 Hawaiian monk seal pups were born in the Northwestern Hawaiian Islands this year, a worrying sign for a critically endangered species declining at an annual rate of 4 percent, federal scientists said.
This year’s births were the lowest since record-keeping began three decades ago (the previous low of 119 was marked in 2009) and compares with nearly 200 pups born in the islands in 2002.
But in a positive sign, juvenile seals in the area are surviving at higher rates, raising hopes more seals will enter adulthood and start producing pups of their own, said Charles Littnan, the lead scientist for the Hawaiian Monk Seal Research Program.
"There are hopeful signs for the long term for the population in the northwest, as long as we’re still able to continue to do our efforts to help boost it by making sure as many females survive as possible," Littnan said Tuesday at the Pacific Islands Fisheries Science Center, which is part of the National Oceanic and Atmospheric Administration.
A team of researchers spent seven weeks on a summer trip to the remote archipelago to study and help the seals. Normally their annual field camp lasts four to six months but budget cuts forced them to shorten the trip this year.
The remote islands northwest of Hawaii’s main islands are where the vast majority of Hawaiian monk seals — about 900 to 950 out of a total population of under 1,100 animals — live. The seals are struggling as fewer than one in five pups born there reaches adulthood. In contrast, more than 80 percent of the seals born around Kauai, Oahu and other populated islands live to be adults.
Seven out of the 31 pups born at French Frigate Shoals this year were killed or injured by sharks. A small group of Galapagos sharks began attacking baby seals at this atoll in the 1990s, and this behavior still wipes out a large number of seals there each year. The sharks swim into shallow waters to take bites out of recently weaned pups resting along the beach.
To help the pups, Littnan’s team has been moving a few away from French Frigate Shoals each year. This year, they plucked two female pups off the beach, put them on boats, and took them to Laysan Island. Littnan estimates this has more than tripled the chance they will survive.
The team was hoping to move six pups from French Frigate Shoals, but this year’s truncated schedule prevented that. Littnan said he hopes budgets will allow the program to once more spend four to six months in the Northwestern Hawaiian Islands next year.
Pups are doing better at Kure Atoll than last year, when an abusive adult male named KE18 killed two young seals and injured 11 others.
Scientists removed KE18 from the wild in January to prevent him from attacking more seals for years to come. He is now at a University of California-Santa Cruz research laboratory.
Seals at Kure displayed virtually no sign of male aggression this year, Littnan said.