Expanded Seal Survey Effort at Rarely Visited Locations

November 5, 2014

In 2014, through cooperative support from other agencies, the Hawaiian Monk Seal Research Program was able to increase survey effort at Niʻihau and Nihoa Islands which are rarely visited, primarily because of restricted access or limited number of research cruise days available. This is significant, as Niʻihau has the largest subpopulation of seals in the main Hawaiian Islands, and indications from limited data suggest that Nihoa is a growing Northwestern Hawaiian Island subpopulation which may be larger than either the Midway Atoll or Kure Atoll subpopulations.

Niʻihau Seal Surveys

R1KU (at center) recovers post surgery on Niʻihau.
R1KU (at center) recovers post surgery on Niʻihau.

On September 16, the 2nd ever on-the-ground NMFS monk seal survey of the privately owned Niʻihau Island was conducted; the first count was in September 2013. This survey was conducted with funding from the U.S. Navy and in cooperation with Niʻihau Ranch, with the Niʻihau residents serving as island guides for the seal researchers. Four teams covered nearly the entire island perimeter in a single day. A total of 61 seals were counted, including 20 weaned or nursing pups. The number of pups is significant, as it is more than the combined total of 15 pups born amongst the rest of the main Hawaiian Islands this year. Another highlight was the sighting of R1KU, a juvenile female that received medical treatment for an injured eye and was released back on Niʻihau mid-March. Her surgical wound was completely healed and she had gained a significant amount of weight resulting in a robust body condition, which is good news!

Nihoa Seal Surveys

A field researcher prepares to survey seals on a beach at Nihoa.
A field researcher prepares to survey seals on a beach at Nihoa.

U.S. Fish and Wildlife Service invited a 2-person Hawaiian Monk Seal Research Program field team to participate in their research trip to Nihoa from September 23 to October 3. This allowed us to more than quadruple our typical annual research effort at Nihoa, which is usually only 1 or 2 days. The seal team worked off the transport vessel the M/V Searcher. There were 10 total pups, 8 were weaned and tagged, a young nursing pup was necropsied and the other was still nursing. Additionally 2 adult males were tagged. The two remote cameras which were installed a year ago to monitor the beach year-round were serviced and the accumulated images from the 2 months were downloaded.