46 
Fishery Bulletin 106(1) 
Norwegian fishery do not at present contain a degrad- 
able escapement panel. Such panels are mandatory in 
some regions, such as Alaska. 
Catch rates, sex ratio, and size distribution were 
clearly different for square and conical pots. CPUE 
data from the square pots will provide much higher 
estimates of the exploitable part of the population (i.e., 
large male crabs) than data from conical pots. Large 
differences were also observed in the catch dynamics; 
the square pot reached equilibrium at much shorter 
soak times than did the conical pot. Gear saturation 
may lead to underestimation of population abundance 
at high densities of crabs. In an area with high crab 
density, no effects of increasing soak time beyond two 
days were found (Zhou and Kruse, 2000), and smaller 
pots underestimated population density to a higher 
extent than did the larger pots (Nizyaev and Bukin, 
2002). The relationship between pot design, catch dy- 
namics, and selectivity observed in the present study 
demonstrates the importance of adjusting for and stan- 
dardizing the duration of soak time when CPUE data 
from pots are used in population assessments. Most 
importantly, when using effective pots like the square 
pot tested in this study, soak time needs to be short in 
order to prevent underestimation of population size and 
biased sex and size distributions. 
Acknowledgments 
The authors are grateful for the invaluable comments 
and advice from the referees and the editorial staff. We 
also thank B. K. H. Ulvestad and A.-B. S. Tysseland for 
preparing the figures. 
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