1999 

 OUR LIVING OCEANS 



Figure 16-3 



The Main Hawaiian Islands 

 (MHI) and Northwestern Ha- 

 waiian Islands (NWHI). 



Total discard rate 

 07 - 



00-1- 



83 84 85 



Figure 16-4 



Lobster discard rate (ratio of 

 lobsters discarded to total 

 lobsters caught), 1983-97. 

 The season was closed in 

 1993. The effect of new regu- 

 lations took place in 1996. 



Lobster Discards 



III the 1 ')8U's, problems were identified related 

 to high catch rates ot then sublegal-sized lobsters 

 and associated discard niortalirv caused bv top- 

 level predators (sharks and jacks) and on-deck han- 

 dling. Escape vents were mandated in 1987 to re- 

 lease small lobsters on the bottom or during trap 

 hauling. Nonetheless, from 1983 through 1995 



the lobster (spiny lobster and slipper lobster com- 

 bined) discard rate (the reported ratio ol lobsters 

 discarded to total lobsters caught) generally in- 

 creased, rising from 0.28 in 198.? to 0.62 in 1995 

 (Figure 16-4). Although the escape vents reduce 

 the number of small lobsters in each trap (based 

 on research results), the average size ol lobsters in 

 the population declined during this period. 



Alter 1995, the discard rate decreased signitl- 

 cantly due to a relaxation of the minimum legal 

 size requirement in favor of an optional retain-all 

 policy. Implementation ot the retain-all policv was 

 based on research conducted by the National 

 Marine Fisheries Services Honolulu Laboratory 

 to determine the effects ot on-deck exposure on 

 the mortality of sublegal and egg-bearing lobster. 

 Handling mortalities tor two on-deck handling 

 methods (dr\' and wet) and a variety of exposure 

 times were estimated to be as high as 77'?'(i for spiny 

 lobsters and 44% for slipper lobsters, depending 

 on the duration of exposure after being brt)ught 

 on deck. 



Scientific Information and 

 Adequacy of Assessments 



Despite the multispecies nature of the NWHI 

 lobster fishery and regulatory measures, mo.st of 

 the biological research has been directed at spiny 



1 86 



