12 



C(24MERCIAL FISHERIES 



Vol. 13, No. 4 



The types of fishing gear described above were chosen for their ability to give 

 an over-all picture of the bottan fauna of the region studied and were not limited 

 specificaUy to shrimp fishing. It was surmised that the otter trawl and dredge 

 would give results that would clearly indicate the potentialities of the grounds and 

 that the catches would be an index to the possible results to be obteined with a 

 standard ccmmercial-type beam trawl. 



FIGURE 3 - CRAB POTS (iN FOREGROUND) AND 

 SHRIMP TRAPS (iN BACKGROUND) ON THE 

 DECK OF THE JOHN N. COBB. 



OCEANOCTIAPHIC EQUimSNT : For collect- 

 ing water samples from subsurface levels in 

 each area, a Nans en-Knuds en-type reversing 

 bottle was used. Bottan-temperature deter- 

 minations were made ydth protected reversing 

 thermometers and bathythermographs. A 

 snapper-type sampler was used to collect bot- 

 tom samples at each fishing station. 



USE OF (SAR ; The shrimp traps were 

 usually set out on arrival at the fishing 

 grounds in rocky areas most likely to be in- 

 habited by the spot shrimp or prawn ( Pandalus 

 platyceros ) and not suitable for trawling. 

 ■Rie traps were fished fran 12 to 50 hours. 

 Bait used consisted of frozen squid and her- 

 ring. 



The dredge, used as a "try-net," was 

 towed frcm the starboard davit pf the John 

 N. Cobb with a scopel/ of 2 to 1, but the 

 scope was sometimes varied for experimental 

 purposes. Towing speed was usually l|-2 

 knots. If the gear produced good signs of 

 shrimp and a clear bottan was evident, the 

 otter trawl was used over the same grounds. 

 The otter trawl was set frcm the stern of 

 the vessel with a scope of 2^ to 1. The 

 towing speed for the otter trawl was slightly 

 faster (3 knots) than the dredge to insure 

 proper functioning of the doors. 



The net was hauled over the side and the catch released on deck. The shrimp 

 were separated from the debris, washed, and accurately weighed. Samples of each 

 catch were packed in 5-pound boxes, flooded with water, and quick-frozen. The 

 weight (in pounds) of each species was recorded for all catches. During the inves- 

 tigation, a total of 21 drags were made with the otter trawl; 51 were made with 

 the dredge; and 68 individual shrimp traps were set. Recording depth finder traces 

 were made of all grounds fished, and fishing was carried on in depths of 8 to 225 

 fathoms , 



DISCUSSION OF SHRIMP CATCHES ; Small quantities of shrimp were found through- 

 out most of the area explored, but possible commercial quantities of shrimp were 

 found in few of the waters explored. As a matter of convenience for discussion, 

 the area is divided into five districts, as follows: 



1. EAST COAST OF PRINCE OF WALES ISLAND 



2. WEST ARM OF BEHM CANAL. 

 3. UPPER BEHM CANAL. 



1/RATIO OF CABLE OUT TO DEPTH OF WATER. 



4. EAST ARM OF BEHM CANAL 



5. KETCHI KAN DISTRICT. 



