Population Assessment and Enhancement Initiative

Field researcher observing a monk seal.
Field researcher observing a monk seal.

The Hawaiian Monk Seal Population Assessment and Enhancement Initiative, provides annual high resolution information from each monk seal subpopulation to assess the species status and examine population trends. This information is used to evaluate survival, reproduction, growth, behavior and feeding habits. In addition, factors impeding the species recovery are identified and the field teams play a key role in implementing and evaluating the effectiveness of enhancement activities addressing those factors.

The Hawaiian Monk Seal Population Assessment and Enhancement Initiative is led by Thea Johanos-Kam.

Population assessment encompasses the small but growing monk seal subpopulation in the main Hawaiian Islands (MHI) as well as the Northwestern Hawaiian Islands (NWHI) where the majority of the population resides. Although seals from the NWHI and MHI are of the same stock, a group of potentially breeding individuals, the regions differ greatly in many aspects including habitat, population status and threats to species recovery; therefore, management, level of research and allocation of conservation resources also vary by region.

For more than 3 decades, field camps have been annually established during the breeding season at up to all six of the major monk seal reproductive sites in the NWHI (French Frigate Shoals, Laysan Island, Lisianski Island, Pearl and Hermes Reef, Midway Atoll and Kure Atoll) to gather information to assess the species status. Seals are also found at Nihoa, Mokumanamana (Necker) and Gardner Pinnacles, which are surveyed opportunistically.

Hind flipper tag.
Hind flipper tag.
An applied bleach mark.
An applied bleach mark.

The primary source of information for the small MHI subpopulation involves volunteers, agency partners, and the general public reporting observations through a sightings network, which is augmented by staff observations.

Permitted research activities include identifying individual seals by documenting scars and natural marks and applying uniquely numbered and color coded hind flipper tags and hair bleach marks. A photo ID database has been developed to assist with individual seal identification. These tools allow biologists to closely monitor reproduction, survival, injuries, entanglements, movements between islands, disappearances and deaths. In addition, scat (feces) and spew (regurgitate) samples are collected for food habits analysis. Also, necropsies on deceased seals are performed to help determine health status or cause of death. Samples collected from necropsies and tagging activities are added to a DNA tissue bank for genetic research.

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