UNIT 17 

 WESTERN PACIFIC BOTTOMFISH AND A R M O R H E A D FISHERIES 



mounts in international waters beyond the 

 Hancock Seamounts. The fishing grounds com- 

 prising the Hancock Seamounts represent less than 

 5% of the total fishing grounds, llie long-term 

 potential yield (Table 17-1) is 2,123 t, but recov- 

 ery to these former levels has not occurred. 



Standardized stock assessments were con- 

 ducted during 1985-93. Research cruises were fo- 

 cused on Southeast Hancock Seamount, and the 

 armorhead stock was sampled with bottom 

 longlines and calibrated against Japanese trawling 

 effort. Catch rates vary but have not shown the 

 increases expected after the fishing moratorium 

 was implemented (Figure 17-3). Furthermore, the 

 increase in the 1992 seamount-wide C^PL'E (Fig- 

 ure 17-1) caused by high recruitment was appar- 

 ently short-lived, as CPUE declined appreciably 

 in 1993 and thereafter. Closure ot only the small 

 U.S. EEZ portion of the pelagic armorhead's de- 

 mersal habitat may not be sufficient to allow popu- 

 lation recovery, because these seamounts remain 

 the only part of the fishery currently under man- 

 agement. 



ISSUES 



Scientific Advice and 

 Adequacy of Assessments 



Adequacy ot the biological and catch data col- 

 lected is a primary management concern for the 

 western Pacific bottomfish fishery. For example, 

 the reproductive biology of many of" the impor- 

 tant species in Guam, Mariana Islands, and Ameri- 

 can Samoa is unknown, and spawning stock bio- 

 mass cannot be computed. 



Transboundary Stocks 



and IVIanagement Jurisdictions 



The primary issue tor the armorhead seamount 

 fishery is how to implement some form of man- 

 agement on an international basis to provide con- 

 ditions more conducive for stock recovery. The re- 

 cruitment event of 1992 and subsequent stock de- 

 cline (probably trom overharvesting) reinforce the 

 need to implement some form ot management it 

 this fishery is to recover to early 1970's levels. 



Landings (t) 

 600 - 



Landings (tl 

 250 - 



Landings 



CPUE 

 (lbs/day) 



Landings 



Year 



Figure 17-2 



Bottomfish landings in metric tons (t) and 

 CPUE in pounds per day at the Main Hawaiian 

 Islands (above) and the Northwestern Hawai- 

 ian Islands (belowl. Note: This figure in Our 

 Living Oceans 7995 displayed the CPUE for the 

 Northwestern Hawaiian Islands prior to 1988 

 at double the correct value. 



CPUE 

 (Ibs./day) 



- 1,600 



- 1,400 



- 1,200 



- 1,000 



- 800 



- 600 



- 400 



- 200 



- 



I 



55 60 65 



70 75 



Year 



Management Concerns 



The spawning biomass of several important 

 MHI bottomfish species (ehu, hapu'upu'u, onaga, 

 opakapaka, and uku) appears to be at about 5- 

 3()"o of orii;inal levels. Thus, overtitihzation is a 

 concetn, and the Western Pacific Fishery Manage- 

 ment Council has recommended that Hawaii take 



1 91 



