Weinberg and Somerton; Variation in trawl geometry due to unequal warp length 



31 



5 10 15 



7 m offset 



long 



5 10 



9 m offset 



loiig 



15 



Distance from wing tip (m) 



Figure 12 



Mean off-bottom distances (in cm) at the five bottom contact sensor positions along the 

 footrope (circles) are shown for each warp offset. The positions are projected onto the wing 

 tip to wing tip plane to depict the footrope as it would appear if one were looking into the 

 net from the direction of travel. The vertical solid lines indicate the positions of the wing 

 tips on the long warp and short warp sides of the trawl. The dashed line indicates the 

 midpoint between wing tips. Note that the projection considers the reduction in effective 

 net width with increasing offset. 



cific cod and walleye pollock are found gilled in the 

 body of the net; therefore some mesh escapement may 

 occur, especially if any distortion of the net results in 

 altered water flow through the meshes. Video observa- 



tions of crabs (snow and Tanner crabs [Chionoecetes 

 sp.] and king crabs [Paralithodes sp.] show that they 

 also exhibit little or no herding response to the 83-112 

 Eastern trawl (Weinberg, unpubl. data). However, both 



