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Fishery Bulletin 98(2) 



able twine, we were not able to determine if gaps in 

 the webbing resulted from short-term degradation 

 of biodegradable twine, longer-term degradation of 

 nylon webbing, encounters with other fishing gear, 

 damage during grappling and recovery, or from some 

 other process. Generally, the proportion of pots with 

 damaged webbing increased as the condition of the 

 pot degraded (Table 21. Forty-five (34'7f ) of the com- 

 mercial pots had no biodegi-adable twine or gaps in 

 the webbing that would have allowed crabs to escape 

 and therefore were probably illegally set; 19 of these 

 were rated as good or excellent, and 26 as fair to 

 very poor. 



Organisms 



Organisms were found within 97 pots, including 

 40 (569;:) of the inside pots and 57 (767^) of the out- 

 side pots. Tanner crab was the most abundant spe- 

 cies (227 caught, mean 1.54 CPP), and second most 

 frequent occurring in 24 pots (16*^^) (Table 3). The 

 majority of Tanner crabs occurred in just two inside 

 pots that contained 125 and 22 crabs, respectively; 

 both pots were in good condition and were presumed 

 to have been lost less than a year, so they were prob- 

 ably set for subsistence purposes. Excluding these 

 two pots. Tanner crab CPP was only 0.55. Sunflower 

 stars (Pycnopodia helianthoides) occurred most fre- 

 quently (A29( ) and were the second most abundant 

 species (189 caught, mean 1.29 CPP). The next most 

 abundant species were hairy tritons (Fusitrito?} ore- 

 gonensis), 174 were caught (15"^ occurrence), and 

 white anemones (Metridiiun senile), 64 were caught 

 (3^^ occurrence), although some of the latter may 

 have been epibionts that were detached from the 

 webbing during pot retrieval. In addition, we found, 

 but did not count, many more individuals and species 

 attached to the exterior of the pot and attached lines, 



including barnacles, tubiculous polychaetes, anemo- 

 nes, bi'yozoans, brachiopods, mussels, clams, snails, 

 seastars, and basket stars iGorgonocephalus sp.) 



During the pilot study, 3 octopuses i Octopus dofle- 

 ini) were found in 4 pots with Tanner crabs, suggest- 

 ing that octopuses, which are known predators of 

 Tanner crabs (senior author, personal obs.), entered 

 the pot to prey on the crabs. Of 16 octopuses recov- 

 ered during the entire study, 6 occurred in pots with 

 Tanner crabs, and all 4 pots with 10 or more Tanner 

 crabs (accounting for 181 of 227 crabs) contained at 

 least one octopus, including the pot with 125 Tanner 

 crabs. Presence and absence of octopuses was signif- 

 icantly associated with Tanner crabs (in logarithmic 

 categories; ;^"=26.3). This association may have been 

 underestimated because octopuses were not always 

 located inside the pot. Using the ROV, we observed 

 one octopus sitting on top of a pyramidal pot; in such 

 a position, it probably would have been lost during 

 grappling and recovery. 



Crabs 



The recovered pots contained a total of 195 live 

 Tanner crabs, 2 dead crabs, and 30 empty carapaces. 

 From their size and condition, these empty cara- 

 paces were considered to be the result of death or 

 predation, rather than molting, and were not mea- 

 sured. Twenty-three of 32 empty carapaces or dead 

 crabs (72%) were found in pots with octopuses. Of 

 the live crabs, 191 were found in inside pots, and 4 

 in outside pots. Mean CW of all Tanner crabs was 

 129.8 ±1.8 mm for males (« = 160), and 85.1 ±3.0 mm 

 for females (/!=35l. 



Pot condition, an indicator of time elapsed since 

 it was lost, was examined for its effect on the size 

 of crabs caught. No excellent pots contained crabs, 

 but 152 crabs were recovered from 4 good pots. A 

 total of 166 Tanner crabs were found in 7 out of 42 

 best pots ( 17% frequency of occurrence), whereas 61 

 Tanner crabs were found in 17 of 105 worst pots 

 (16% ) (Table 4); mean CPP was 6.8 times greater in 

 best pots (3.951 than in worst pots (0.58). but this dif- 

 ference was not significant (MWU, Z=0.152, P>0.5). 

 Mean CW of 141 male Tanner crabs from best pots 

 (135.6 ±1.3 mm) was significantly larger than for 19 

 males from worst pots (87.1 ±6.0 mm: MWU, Z=6.29, 

 P<0.001; Table 4). This difference was significant 

 even after excluding pot no. 301, which contained 

 125 crabs; in this case, mean CW of 26 male crabs 

 in best pots was 130.6 ±5.7 mm (MWU, Z=4.194, 

 P<0.001). Seventy males larger than legal size (138 

 mm CW), with a mean CW of 144.9 mm were found 

 in best pots; no legal males were found in worst pots. 

 There was no significant difference in mean CW of 



