National Oceanic and Atmospheric Administration researchers aboard the research vessel Oscar Elton Sette recently returned from a successful 21-day research mission to the Northwestern Hawaiian Islands. There, they picked up field camp staff deployed since June, translocated monk seals within the NWHI and disentangled five seals from marine debris.
The Hawaiian Monk Seal Research Program’s field teams had been monitoring the monk seal population and intervening to reduce monk seal mortality. High mortality of pups and yearlings is the main reason that the NWHI monk seal population has been declining for many years.
The 121 monk seal pups born this season is an increase in births compared to 2012 (111 pups) and 2013 (103 pups). Preliminary data also shows survival of young seals between 1 and 3 years of age improved at several sites this year, according to NOAA.
However, despite the apparent improved survival in the NWHI this year, pups born at some sites fare much better than at others. The first three years of a pup’s life is critical and when most losses occur. At some sites — French Frigate Shoals, Midway and Kure Atolls — just over 25 percent survive to age three while 60 to 70 percent survive at other sites — Laysan and Lisianski. Taking advantage of those differences, NOAA has been translocating healthy female seals born at sites where they aren’t likely to survive, to sites where their chances are far better. Several translocated seals from past years were observed thriving in their adopted homes this year. An additional 11 female monk seal pups were taken from French Frigate Shoals and Midway Atoll and moved to Lisianski and Laysan Islands. They did very well during transport and are currently being monitored with satellite tags.
Over the course of the season the NOAA researchers undertook other activities to increase seal survival including medical interventions, de-worming, mitigating shark predation and more. Five seals were disentangled and more than 2,000 pounds of marine debris removed from the ocean. In addition, 43 trapped Hawaiian green sea turtles were rescued and a dangerous entrapment hazard for turtles was removed
Every year, some pups are weaned prematurely and are too small to survive on their own even at the most favorable sites. NOAA has targeted these seals for captive rehabilitation at The Marine Mammal Center’s monk seal hospital, Ke Kai Ola, at the Natural Energy Laboratory of Hawaii Authority.
Earlier this summer, four monk seals including two premature pups and two juveniles were brought to Ke Kai Ola. These four seals were successfully released back in the NWHI and are doing well. Two more emaciated premature female pups were taken to Ke Kai Ola, where they will be wintering before being returned to the NWHI next year, NOAA stated.