NOAA Ship Provides Critical Support for Research on Endangered Hawaiian Monk Seal
The NOAA Ship Oscar Elton Sette is at sea for 19 days on a scientific expedition to support Pacific Islands Fisheries Science Center (PIFSC) staff studying monk seals in the remote Northwestern Hawaiian Islands (NWHI). Work on the highly endangered Hawaiian monk seal is being carried out by the Monk Seal Research Program, the PIFSC group responsible for monitoring the status of the seal population, identifying factors affecting abundance of the seals, and finding ways to enhance the population's recovery. To this end, the program operates seasonal field camps at the six major monk seal breeding locations in the NWHI.
During its current expedition, the Sette will pick up scientists and their equipment from field camps at French Frigate Shoals, Lisianski Island, Pearl and Hermes Reef, and Kure Atoll, where seasonal studies have been completed. The vessel's crew will also exchange personnel and resupply an existing camp at Laysan Island and conduct surveys of seals at Nihoa Island.
Under the direction of Chief Scientist Chad Yoshinaga, field staff and Sette personnel will load all equipment and supplies from the dismantled island camps onto the ship, materials which have supported teams of 3-4 scientists for 4 months of arduous field work. Included are tents, stoves, solar power arrays, computers, leftover food, small boats, and more. Everything brought ashore is removed and must be transported by hand and shuttled via small boats from the islands to the ship anchored offshore.
On the outbound leg of the cruise, scientists will use a small boat launched from the Sette to conduct a survey of waters around Nihoa Island. On the inbound leg, they will land on Nihoa to count seals on the beach, document tagged seals, and apply identification tags to weaned seal pups. Identifying seals with tags at Nihoa will allow researchers to assess the juvenile survival of native born seals and seals that were relocated to Nihoa in 2008. Nihoa is the NWHI island closest to the main Hawaiian Islands (MHI), so subsequent sightings of seals tagged at Nihoa are likely to reveal the extent of seal movements between the NWHI and the MHI, something currently unknown. On the inbound leg of the cruise, the Sette field team will also transport 6 weaned seals collected from French Frigate Shoals, an area of low pup survival, and release the seals at Nihoa Island, where their survival is expected to be higher. This is the second year of a pilot study to try to increase juvenile seal survival. The experiment will help determine the feasibility of using such relocations to increase juvenile female survival in the future.
In addition to the population assessment research at Nihoa Island, field staff will conduct a monk seal foraging ecology study there. Scientists will return to Nihoa Island via charter vessel in late August to deploy satellite tags on seals. The tags will record data on the movement and dive patterns of the seals and later transmit the data via satellite to PIFSC computers. The data will provide scientists with key information on the seals' foraging behavior. During this study, scientists will describe the health and disease status of the Nihoa Island seal population for the first time. The work is being done in collaboration with researchers at two California institutions, the Moss Landing Marine Laboratory and The Marine Mammal Center.
A new aspect of the monk seal research this year is a deworming trial. In this study, several juvenile seals at Laysan Island will be given medication to eliminate parasitic worms from their bodies. Deworming animals is a common low-risk veterinary practice that often has beneficial effects. The body condition and survivorship of treated seals will be compared to that of non-treated (control) juveniles to determine if reducing worm burden boosts overall health. Deworming medication will be given to seals four times during the next year. The first treatment cycle in August will be conducted by a 5-person team lead by a veterinarian from the Marine Mammal Center (Sausalito, California).
Besides the biological research on monk seals, shipboard personnel will periodically collect oceanographic data during the cruise to measure subsurface ocean temperature and conductivity. At selected stations along the route, a CTD instrument will be deployed from the ship. Data collected by the sensors on the CTD will be added to a comprehensive NOAA oceanographic database and used to better understand large-scale phenomena, such as climate change, and the dynamics of local features like oceanic fronts.
During the multi-faceted research expedition, the Sette will also provide logistic support for several partner agencies working in the NWHI. Supplies and equipment will be transported for the U.S. Fish and Wildlife Service, which maintains field stations at French Frigate Shoals and Midway Island and a permanent field camp at Laysan Island. The ship will transport personnel and supplies to a field camp operated by the State of Hawaii Division of Forestry and Wildlife at Kure Atoll. It will also pick up researchers from the Hawaii Institute of Marine Biology who have been conducting shark research at French Frigate Shoals over the summer.
