474 



Fishery Bulletin 89(3). 1991 



1 1 r~ 



PENOBSCOT BAY 

 BOOTHBAY HBR, 



CHESAPEAKE 



/CAPE HATTERAS 

 76° 74° 



68° 



66" 



Locations of stations occupied 

 in the study are plotted by sea- 

 son and gear, cumulatively for 

 all years, in Figures 2a-e. Fall 

 trawl stations were similar in 

 location and number to spring 

 and were not plotted. 



The trawlnets used were the 

 #36 and #41 commercial-type 

 otter trawls. The #41 Yankee 

 trawl was used only in spring 

 1978-81. The #36 Yankee trawl 

 has an opening width of 10.4 

 m, while the #41 Yankee has 

 an opening width of 11.8 m. In 

 both nets, the mesh size is 

 12.7cm stretched with a cod- 

 end liner of 1.25 cm stretched 

 mesh. Rollers at the front edge 

 of the nets reduce snagging on 

 the bottom. The nets are towed 

 at 6.3 km/hour for 30 minutes 

 per station on a 24-hour basis. 

 Additional details on gear, 

 methods, and sampling area 

 for trawl surveys are described 

 by Grosslein (1969), Grosslein 

 and Azarovitz (1982), Sissen- 

 wine et al. (1983), and Survey 

 Working Group, NEFSC (1988). 



Crab catches in clam dredge 

 surveys in 1978-86 were used 

 to supplement the trawl data. 

 Dredges used in 1978 were 

 1.22 m wide; since 1979, they 

 have been 1.52 m wide. Both 

 have 5 cm mesh bags (Muraw- 

 ski and Serchuk 1989). The 

 dredges employ jets of water 

 at their openings to loosen 

 sediments, and are towed at 

 2.7 km/hour for 4 minutes (1.22 

 m dredge) or 5 minutes (1.52 m 

 dredge) per station, on a 24- 

 hour basis. 



Catchability factors were 

 used to standardize the catches 

 for the two trawlnets and the 



Figure 1 



Northwest Atlantic coast and continen- 

 tal shelf with subarea locations mentioned 

 in text. 



