Fa. Parrish et Jj. Polovina, HABITAT THRESHOLDS AND BOTTLENECKS IN PRODUCTION OF THE SPINY LOBSTER(PANULIRUS-MARGINATUS) IN THE NORTHWESTERN HAWAIIAN-ISLANDS, Bulletin of marine science, 54(1), 1994, pp. 151-163
Variations in landings from the lobster fishery among banks of the nor
thwestern Hawaiian Archipelago were compared with bank topography and
benthic habitat characteristics. Summit depth, harvest area, amount of
shallow habitat, and latitude were considered in relation to pre-expl
oitation research catch rates and 6 years of commercial fishery landin
gs. A threshold between lobster production and the depth of bank summi
t was observed; banks with summits deeper than 30 m yielded few lobste
rs. The effect of benthic habitat relief was then examined for three s
elected, bathymetrically similar banks, two commercially productive an
d one unproductive. Percent cover of habitat variables with characteri
stic relief such as sand, algae, and coral outcrops were measured on e
ach of the banks during 70 scuba dives. Juvenile lobster stages were f
ound significantly associated with habitat scale. The nonlinear relati
onship indicated both high and low extremes in relief yield poor catch
per unit of effort (CPUE). Only the variable intermediate relief (5-3
0 cm) was associated with high sublegal lobster CPUE. The two producti
ve banks had much more benthic relief at this scale than did the unpro
ductive, suggesting that the abundance of intermediate relief habitat
represents a bottleneck to adult lobster production.