August 1966 



COMMERCIAL FISHERIES REVIEW 



17 



Table 2 - Average Catch of Spot Shnmp Per Trap Per Set and the Average Number of Whole Shrimp Per Pound by Trap Model | 



Trap Typei/ 



Total 



Units of Effort 



Average Catch/Trap/Set 



No . of Shrimp 



Average No. of Whole Shrimp/Pound 





Pounds 





In Pounds 







9 



355 



135 



2.63 



5,624 



15.9 



14 



210 



94 



2.23 



3,130 



14.9 



8 



477 



220 



2.17 



7,239 



15.2 



11 



470 



220 



2^14 



5,700 



12.1 



13 



468 



235 



1.99 



6,134 



13.1 



12 



178 



110 



1.62 



3,147 



17.7 



10 



349 



225 



1.55 



4,454 



12.8 



15 



125 



119 



1.05 



2.040 



16.4 



1/ 9, Metal frame, burlap covered, short tunnel. 





14. Metal frame, burlap covered, long tunnel. 





8. Wood lath trap, short tunnel. 





11. Plywood trap, sloping tunnel. 





13. Circular coUapsible trap. 





12. Plastic pipe frame trap, burlap covered. 





10. Plastic Igloo trap. 



15. Plastic pipe frame trap, |^ nylon web covered. 

 S 







Six stations in Moira Sound showed a good 

 abundance of spot shrimp. Catches ranged 

 from 38 to 238 pounds and averaged 134 pounds 

 per station (or 1.86 per trap per set). The 

 traps were set at depths from 25 to 85 fath- 

 oms. Good abundance of spot shrimp were 

 found from 40 to 73 fathoms, with the center 

 of abundance occurring between 50 and 65 

 fathoms. 



Results of the shrimp explorations indicated 

 commercial concentrations of spot shrimp are 

 available in HettaandKlak_as Inlets, and Chol- 

 mondeley and Moira Sound. Two commercial 

 vessels were fishing those areas at the time. 



Data used in the analysis of the gear effi- 

 ciency study were restricted to observations 

 made on the six strings of mixed gear. Anal- 

 ysis of the data collected at the 38 stations 

 showed that the metal frame trap equipped 

 with short and long tunnels were rated first 

 and second, respectively. The short tunnel, 

 metal frame, fished 135 times caught 354 

 pounds for an average catch of 2.63 pounds 

 per trap per set, while the long tunnel trap 

 was fished 94 times and caught 210 pounds or 

 an average catch of 2.23 pounds per trap per 

 set. The third most efficient trap was the 

 w_ood lath, which caught 477 pounds of shrimp 

 in 220 units of effort for an average catch of 

 2,17 pounds per trap per set. This trap was 

 followed closely by the plywood trap which 

 took 470 pounds of spot shrimp in 220 units 

 of effort for an average catch of 2.14 pounds 

 per trap per set. The circular collapsible 

 trap was the 5th most efficient and caught 468 

 pounds in 235 units of effort for an average 

 catch of 1.99 pounds per trap per set. The 

 6th and 7th most efficient traps were the plas- 

 tic pipe frame, burlap covered, and the plas- 

 tic igloo trap, respectively. The plastic pipe 



trap was fished 110 times and caught 178 

 pounds for an average catch of 1.62 pounds 

 per trap per set, while the igloo trap caught 

 349 pounds in 225 units of effort for an aver- 

 age catch of 1.55 pounds per trap per set. 

 The poorest trap was the plastic pipe frame 

 covered with |" woven mesh nylon web. This 

 trap took 125 pounds in 119 units of effort for 

 an average catch of 1.05 pounds per trap per 

 set. In this analysis the criterion used for 

 the most efficient trap was the highest aver- 

 age catch per unit of effort. 



The average size of shrimp caught varied 

 with trap type. The larger entry tunnels caught 

 larger shrimp. The 2 (inside diameter) en- 

 try rings which were used on most traps were 

 too small and the diameter should be enlarged. 

 The optimum tunnel size is not yet known. The 

 average size of the shrimp taken in the trap 

 with the two-inch tunnels ranged from 14.9 to 

 17.7 whole shrimp per pound. The igloo, ply- 

 wood, and circular collapsible traps which 

 had larger openings caught shrimp which av- 

 eraged from 12.1 to 13.1 whole shrimp per 

 pound. 



Note: See Commercial Fisheries Review , July 1966 p. 14, De- 

 cember 1965 p. 25. 



California 



VARIOUS SPECIES OF FISH COLLECTED 

 FOR BIOLOGICAL STUDIES: 



M/V "N. 5. 5cofieId " Cruise 66-S-l~T7ib- 



ruary 10-'2^,T566): The purpose of this cruise 

 by the California Department of Fish and 

 Game research vessel N. B. Scofield was to: 

 (1) collect eye lenses anS" Elood smears from 

 different fish species caught at widely sep- 



