28 



COMMERCIAL FISHERIES REVIEW 



Vol. 28, No. 9 



cruise in Puget Sound and northern Oregon 

 coastal waters. 



The primary objectives of the cruise 

 were to: (1) develop a method of fishing a 

 dandyline -rigged small-mesh 94-foot fish 

 trawl with a single towing warp; (2) assess 

 the intra-station variability in composition 

 of fish and shellfish catches associated with 

 a series of replicate tows made at the 300 

 and 375 fathom stations on the trackline 

 southwest of the Columbia River mouth; and 

 (3) collect additional data on the composition, 

 distribution and abundance of demersal fish 

 species at stations deeper than 450 fathoms 

 on the Columbia River trackline using the 

 small-mesh 94-foot fish trawl and 70-foot 

 shrimp trawl. 



GEAR: The following trawls were fished 

 using V-type otterboards and either a single 

 or double warp trawling arrangement: (1) 

 standard 400-mesh (94-foot) commercial 

 Eastern otter trawl with no liner in the codend, 

 (2) 70-foot semi-balloonGulf of Mexico shrimp 

 trawl and (3) 94-foot small mesh fish trawl. 

 The latter trawl had essentially the same 

 physical dimensions as the 400-mesh com- 

 mercial Eastern otter trawl. The major dif- 

 ference was in the smaller mesh sizes which 

 were 2|- inches in the wings and square 

 and IS inches in the belly, intermediate, 

 and codend. Because of the great depths to 

 be fished, 4 - and 8 -inch glass floats were used 

 on headropes of all trawls. The 10-fathom 

 danleanos which consisted of 7 -fathom cables 

 from the doors to the butterfly with 3-fathom 

 legs from the butterfly to the net were used 

 in conjunction with the above trawls. 



METHODS OF OPERATION: The double 

 warp trawling operation was conducted in the 

 standard manner. The single warp operation 

 was modified to permit the use of the dan- 

 leanos. Both doors were hung from the star- 

 board stanchion and the 50-fathom bridles 

 from the doors to the single towing warp were 

 wound on the main win'ch. The 10-fathom 

 danleanos and trawl were wound on a reel on 

 ttie stern of the vessel. After the trawl and 

 danleanos were payed out from the reel, they 

 were connected to the doors by extensions 

 from the back of the doors. Both towing 

 warps were connected end to end to permit 

 trawling at depths greater than 500 fathoms. 



RESULTS: A total of 24 drags--8 with the 

 94-foot small-mesh fish trawl, 10 with the 

 400-mesh Eastern fish trawl, and 6 with the 



70-foot shrimp trawl--were made during the 

 cruise. 



GEAR EVALUATION: SCUBA-equipped 

 divers observed the 94-foot small-mesh ver- 

 sion of the 400-mesh Eastern fish trawl rig- 

 ged with 10-fathom danleanos, V-type doors, 

 and 90-foot "tickler" chain attached to the 

 footrope, to evaluate its fishing configuration 

 in 10 fathoms of water. In general, the fish- 

 ing configuration of the net was good with a 

 horizontal measured spread of 29 feet be- 

 tween wing-tips, and an estimated height of 

 10 feet at the center of the net and 6 feet at 

 the wing tips. The "tickler" chain was 4 to 

 10 inches off bottom at the center part of the 

 net and on bottom along the wings. Along 

 the wings the "tickler" remained under or 

 slightly behind the footrope, but at the cen- 

 ter the "tickler" was in front of and at about 

 a 45° angle to the footrope. The butterfly part 

 of the danleano remained upright at all times. 

 A tension of 3,500 pounds as measured by a 

 dynamometer was exerted on the main tow- 

 ing cable during the experiments. 



REPLICATE SERIES EXPERIMENT: Two 

 series of replicate tows (6- and 4 -one -hour 

 tow series) were made with the 400-mesh 

 commercial Eastern otter trawl southwest 

 of the Columbia River mouth at 268-310 and 

 358-394 fathoms, respectively. The results 

 indicate that at the depths sampled, species 

 dominance in the catches remains the same 

 and the size of catches of the dominant spe- 

 cies do not vary excessively. For instance, 

 at 268-310 fathoms, catches per hour of 

 sablefish ( Anoplopoma fimbria ) ranged from 

 400 to 1,600 pounds, Dover sole (Microsto- 

 mus pacificus) from 35 to 300 pounds, chan- 

 nel rockfish ( Sebastolobus alascanus ) from 

 20 to 50 pounds, and Tanner crabs ( Chion- 

 oecetes tanneri ) from 30 to 65 pounds^ St 

 358-394 fathoms the catches per hour were 

 less variable, with sablefish (725 to 1,000 

 pounds), Dover sole (70 to 100 pounds), 

 channel rockfish (105 to 180 pounds), and 

 Tanner crabs (115 to 182 pounds). 



DEEP-WATER EXPLORATIONS: A to- 

 tal of 5 drags at depths greater than 500 

 fathoms was made southwest of the Colum- 

 bia River mouth. Three of the drags were 

 made with the 94 -foot small-mesh fish trawl 

 at depths of 500, 600-710, and 820-840 fath- 

 oms yielding catches of 84, 614, and 1,024 

 pounds, respectively. The towing time of the 

 3 drags were ^, 2, and 3 hours, respec- 

 tively. The 2 drags made at 500 and 



