MARINE MAMMAL COMMISSION - Annual Report for 1995 



Figure 1. The Hawaiian Archipelago 



Natural factors impeding population growth have 

 been the species' limited range and habitat, predation 

 by sharks, die-offs caused by disease or natural 

 biotoxins, attacks on female and juvenile seals by 

 aggressive groups of adult male seals (referred to as 

 "mobbing" behavior), and possibly ecosystem chang- 

 es, such as climate fluctuation, that may have affected 

 prey abundance and carrying capacity. 



Lead responsibility for the recovery of Hawaiian 

 monk seals rests with the National Marine Fisheries 

 Service under authority of the Endangered Species Act 

 and the Marine Mammal Protection Act. Other 

 agencies and organizations, however, share important 

 duties and roles. Because most monk seal pupping 

 and haul-out habitat (i.e., all major breeding sites 

 except Kure) lies within the Hawaiian Islands National 

 Wildlife Refuge, the Fish and Wildlife Service is a 

 particularly important partner. Other key partners 

 include the Navy, the Coast Guard, the Army Corps 

 of Engineers, the Western Pacific Regional Fishery 

 Management Council, the State of Hawaii, and Sea 

 Life Park, Hawaii. As discussed in past annual 

 reports, the Marine Mammal Commission was instru- 



mental in initiating the monk seal recovery program 

 late in the 1970s. Since then, it has provided advice 

 and assistance at key points in the program's develop- 

 ment. 



Recent Developments 



As noted above, Hawaiian monk seal numbers are 

 declining. After a modest increase early in the 1980s, 

 overall beach counts of seals began decreasing late in 

 the 1980s. This trend has continued through 1995 

 when combined mean beach counts for all islands 

 dropped 26 percent below 1989 levels and 33 percent 

 below 1986 levels. Most of this decline is due to a 

 decrease at French Frigate Shoals, the largest monk 

 seal colony. However, counts also fell during this 

 period at Laysan and Lisianski Islands. Reasons for 

 these trends differ by location. 



Based on increasing numbers of underweight and 

 starving animals (mostly pups and juveniles), the 

 decline at French Frigate Shoals is thought to be 

 related to a reduction in the availability of prey 

 resources. At Laysan and Lisianski Islands evidence 



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