Hawaiian Monk Seal Assessment and Research Underway at Field Camps in the Northwestern Hawaiian Islands

With the help of the NOAA Ship Oscar Elton Sette, summer field camps for the annual assessment of Hawaiian monk seals in the Northwestern Hawaiian Islands (NWHI) were recently deployed by PIFSC at all major NWHI monk seal breeding locations.

Hawaiian Monk Seal
Hawaiian Monk Seal.

Field camp operations at most locations got a fresh start, but at Laysan Island, operations are simply continuing research that has been carried out there since last summer. Over the past winter, staff of the PIFSC Protected Species Division (PSD) operated a camp at Laysan Island for the first time to collect data on survival of juvenile seals during the winter and investigate whether de-worming of juvenile seals will increase their survival rate. The winter camp was set up in August 2009 and resupplied in December 2009 and March 2010. During their winter stay, scientists at the Laysan camp monitored the population and collected data on monk seal reproduction, reporting the birth of 21 pups.

At French Frigate Shoals (FFS), attention is being given to increasing survival of pups by monitoring shark activity and mitigating predation by sharks on pre-weaned monk seal pups. A remote camera system and standardized shark sighting/attack observation protocol are being used again this summer to systematically catalog shark activity and incidents in relation to monk seals (attacks, attempted attacks, and suspicious disappearances of pups). In preparation for the research at FFS, PSD staff met with stakeholders to get comments and advice on the Center's permit application to the Papahānaumokuākea Marine National Monument to allow removal of up to 20 Galapagos sharks within 400 m of several monk seal pupping islets at FFS.

Other studies to increase monk seal survival are continuing with the seal de-worming trial at Laysan Island. The objective is to rid juvenile monk seals of parasitic worms, with the expectation that this will lead to increased growth and survivorship of the seals. The de-worming study was initiated in August 2009 and additional treatments were carried out in December 2009 and March 2010. A fourth treatment was scheduled for May 2010. Analysis of the data from all four treatments will be carried out to determine whether differences in survival between treated and non-treated seals are significantly different. Preliminarily results with respect to survivorship of all 3 seal cohorts involved in the trial so far appear promising.

In addition to monitoring the monk seal population in the NWHI, program staff members continue to collect monk seal data and respond to related events in the main Hawaiian Islands.