COCUMGNTAriON CENTER ICLARM 



CONTENTS 



Page 



Introduction 1 



History of the problem 1 



Magnitude of pot loss 2 



Experimental design 3 



Materials and methods 3 



Description of pots 3 



Selecting, handling, and tagging crab 3 



Unbaited pot experiments 5 



Box shaped pots 5 



Fiberglass pyramid pots 5 



Radical pyramid pots 5 



Conical snow crab pots 5 



Crowding experiment 5 



Baited pot experiment 5 



Confined crab viability experiment 5 



Incidental catch observations 6 



Results 7 



Escape from standard pots 7 



Effect of bait or dead crab 8 



Mortality in pots 8 



Tag returns 9 



Viability of escaped crab 9 



Incidental catches 9 



Summary and conclusions 10 



Acknowledgments 11 



Literature cited 11 



Figures 



1. This abandoned Japanese-type snow crab pot, recovered 3 mo after close of the commercial fishing 

 season, contained 12 king crab and 14 snow crab 2 



2. Dimensions and weights for crab pots used in the experiments 4 



3. Average escapement retransformed to percent for small and large king crab from standard pots 8 



4. King crab escapement from baited and unbaited pots after various soak intervals 8 



5. Entry of new king crab into pots containing herring, dead crab, or no bait 9 



Tables 



1. Eicap)ement and soak time of undersize and legal-size king crab for various pot types 6 



2. Escapement of legal-size king crab from standard pots 7 



3. Escapement of undersize king crab from standard pots 7 



4. Observed mortality in pots at retrieval for tagged king crab confined in pots of various designs or 

 configurations 10 



5. Combined return of tags from undersize and legal-size king crab that escaped from each 1974 experi- 

 ment during various soak intervals 11 



6. Combined return of tags from undersize and legal-size king crab that escaped from each 1975 experi- 

 ment during various soak intervals 11 



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