NOAA Expedition Wraps Up Summer of Research on Endangered Hawaiian Monk Seals in the Northwestern Hawaiian Islands

September 11, 2013

The NOAA Ship Oscar Elton Sette departed on a 20-day research expedition in the Northwestern Hawaiian Islands (NWHI) to study the endangered Hawaiian monk seal. The information gained will support NOAA's efforts to recover populations of this protected species. As part of the field operations, scientists plan to capture weaned monk seal pups at French Frigate Shoals and relocate them to Laysan Island.

Monk seal research is a primary focus of scientists at NOAA's Pacific Islands Fisheries Science Center. Biologists in the Protected Species Division's Hawaiian Monk Seal Research Program (HMSRP) annually monitor the status of monk seals at remote locations in the NWHI, study factors affecting abundance of the seals, and seek ways to enhance the seal population's recovery. Many HMSRP researchers work out of seasonal field camps at the six major NWHI monk seal breeding locations.

A monk seal research field camp at Pearl and Hermes Reef, NWHI.
A monk seal research field camp at Pearl and Hermes Reef, NWHI.

During its current voyage, from September 11 through 30, 2013, the Sette will retrieve researchers and their equipment from three sites — French Frigate Shoals, Laysan Island, and Pearl and Hermes Reef — where the scientists have been conducting seal studies for several months, working out of field camps established earlier this summer. The ship will also support seal censuses at four other sites, Midway Atoll, Kure Atoll, Nihoa Island and Necker Island (Mokumanamana), where no camps are established. The project will also deploy a temporary field camp at Lisianski Island to conduct monk seal research while the Sette is in the area.

Under the direction of the expedition's Chief Scientist Jessica Lopez, mission personnel will use small boats to move equipment and supplies from the field camps to the ship, where the material will be loaded for transport back to Honolulu. Included are tents, stoves, solar power arrays, computers, small boats, and more.

Monk seal moms and their pups at Nihoa Island.
Monk seal moms and their pups at Nihoa Island.
In an earlier expedition this weaned pup was transported to shore at Laysan Island.
In an earlier expedition this weaned pup was transported to shore at Laysan Island.

At Necker and Nihoa Islands, the scientists will spend a day at each place counting seals, applying identification tags to weaned seal pups, and documenting seals previously tagged. Identifying seals with tags at these two NWHI locations is an important aspect of the research because these islands are close to the main Hawaiian Islands (MHI). Subsequent sightings of the tagged seals will provide valuable information on the extent of seal movements between the NWHI and the MHI, something currently unknown. Scientists will also be deploying two remote digital cameras on Nihoa that will capture photos of seals on the beach throughout the year.

In addition to retrieving field researchers and their equipment, the Sette will transport weaned female seals from French Frigate Shoals, where survival of juvenile seals is low, to Laysan Island, where the juvenile survival rate is much higher. Scientists will safely capture the seals at French Frigate Shoals using stretcher nets and carry them to the ship in small boats. Once aboard the ship, the seals will be kept in cages on the deck. A veterinarian, scientists and shipboard personnel will monitor the health and behavior of the seals regularly during transport to ensure the animals arrive at their destination safely and in good health. Before releasing the seals, scientists will attach satellite tags to the animals so they can study where the seals move after they are released at their new island home. Scientists also plan to spend a few days on the island to monitor the seals' post-release behavior.

Periodically during the expedition, shipboard personnel will collect oceanographic data to measure and map subsurface ocean temperature and conductivity in the water column from the sea surface down to greater depths by taking CTD measurements. 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 Sette expedition will also provide logistical support for several partner agencies working in the NWHI. The expedition will deliver supplies and personnel to a field camp operated by the State of Hawaii Division of Forestry and Wildlife at Kure Atoll.

Operating area for the expedition in the Northwestern Hawaiian Islands.
Operating area for the expedition in the Northwestern Hawaiian Islands.