NOAA Expedition to the Northwestern Hawaiian Islands Providing Vital Support for Research on Hawaiian Monk Seals and Cetaceans

August 1, 2011
Hawaiian monk seal.
Hawaiian monk seal.

The NOAA Ship Oscar Elton Sette is at sea for 23 days on a scientific expedition to support Pacific Islands Fisheries Science Center (PIFSC) staff studying monk seals and cetaceans in the remote Northwestern Hawaiian Islands (NWHI).

Work on the highly endangered Hawaiian monk seal is being carried out by the PIFSC Monk Seal Research Program. Program scientists are responsible for monitoring the status of the seal population, conducting research to better understand 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, Laysan Island, Lisianski Island, Pearl and Hermes Reef, and Kure Atoll, where seasonal studies have been completed. The vessel's scientific crew will also conduct a census of seals at Nihoa Island and Necker 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.

Field camp supplies, equipment, and refuse will be prepared for removal from the field camps, then transported 
             in small boats and loaded onto the NOAA Ship Oscar Elton Sette. Field camp supplies, equipment, and refuse will be prepared for removal from the field camps, then transported 
             in small boats and loaded onto the NOAA Ship Oscar Elton Sette.
Field camp supplies, equipment, and refuse will be prepared for removal from the field camps, then transported in small boats and loaded onto the NOAA Ship Oscar Elton Sette.
A census of monk seals will be conducted on Necker and Nihoa Islands.
A census of monk seals will be conducted on Necker and Nihoa Islands.

At Necker and Nihoa Islands, scientists will spend a day at each place to count seals, apply identification tags to weaned seal pups, and document seals tagged on earlier expeditions. Identifying seals with tags at these two NWHI locations is important, as these islands are close to the main Hawaiian Islands (MHI). Subsequent sightings of the tagged seals will reveal the extent of seal movements between the NWHI and the MHI, something currently unknown. At Necker and Nihoa, researchers are also conducting a pilot study to try to increase juvenile seal survival. They will attempt to re-sight seals transported to Necker and Nihoa from French Frigate Shoals on previous years' expeditions. Results of this research will help determine the feasibility of using such relocations to increase juvenile female survival in the future.

The field party will also recover and deploy High-frequency Acoustic Recording Packages (HARPs) at Pearl and Hermes Atoll and the island of Kauai in the MHI. The HARP instruments are placed on the seafloor and left there for several months. They record acoustic data on marine biota in the area, including sounds produced by cetaceans. HARP data provide valuable information on cetacean distribution and ecology.

CTD casts will be conducted at intervals along the cruise track to collected oceanographic data.
CTD casts will be conducted at intervals along the cruise track to collected oceanographic data.

Besides the biological research on monk seals and cetaceans, shipboard personnel will collect oceanographic data on subsurface ocean temperature and conductivity periodically during the cruise by taking 'CTD' measurements. At selected locations, the CTD instrument will be lowered into the ocean from the ship. Measurements of temperature and conductivity will be taken to a depth of 500 meters. The data will be added to a comprehensive NOAA oceanographic database and used to better understand large-scale phenomena like climate change and the dynamics of local features like oceanic fronts.

The cruise will also provide support for several of NOAA's 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 cruise will transport personnel and supplies to a field camp operated by the State of Hawaii Division of Forestry and Wildlife at Kure Atoll.