During the study period three different sized trawls were used to collect 

 the samples. Table 2 identifies the vessel and trawl size used during eacn 

 cruise. A #36 Yankee otter trawl was used on spring and fall offshore surveys 

 througn 1972, and all subsequent fall surveys. Initially, the #36 trawl was 

 adequate to provide spring abundance indices needed for most commercially 

 important species. However, in the late-1960's and early-1970's the abundance 

 of fish dropped, so a larger trawl was needed for adequate sampling. A 

 modified, two seam, high opening #41 Yankee otter trawl was used on spring 

 surveys from 1973 through 1981. During inshore surveys conducted from the 

 fal-1 of 1972 through the spring of 1975, a 3/4 size #36 trawl rigged with a 

 chain sweep and ground cables was used. The smaller, 3/4 size #36 Yankee 

 otter trawl was used during these early inshore surveys because the vessel 

 used (R/V ATLANTIC TWIN) could not handle the larger, heavier trawls. Basic 

 performance characteristics and trawl specifications for these three trawls 

 are presented in Table 3. All the trawls were lined with 1.25 cm stretched 

 mesh knotless webbing in the cod end and upper belly to retain small fish that 

 would otherwise escape through the large mesh. 



All trawls and otter doors used during the study period had been tested 

 and measured during special gear mensuration cruises. During these cruises 

 each trawl was towed in several directions relative to the surface current, at 

 several different speeds, and at different ratios of wire out relative to 

 depth (scope). During these tows the opening of each trawl was monitored 

 acoustically with trawl -mounted transducers. Each trawl and set of doors had 

 to perform within certain specifications before it was used on a survey. 



Most of the surveys conducted since 1963 used the b7 m research vessel 

 ALBATROSS IV, but recently the survey work has been shared by the 47 m R/V 

 DELAWARE II; both are stern trawlers. The chartered R/V ATLANTIC TWIN was 



