698 



Fishery Bulletin 102(4) 



Rock crabs migrated into the estuary in November and 

 gradually left during April, May, and June. 



Hundreds of soft and postmolt male rock crabs were 

 caught each winter in the study area (Fig. 4). The high- 

 est numbers of molting rock crabs were collected each 

 December and January, and almost all of these crabs 

 had completed molting by February. Very few molting 

 or postmolt blue or lady crabs were caught. 



The relative abundances of the three species varied 

 by stratum (Fig. 5, A-C; Fig. 6). Blue crabs of both 



sexes were caught mainly in strata near river mouths 

 (strata 1. 2, and 6), in the Chapel Hill and Raritan 

 channels (strata 8 and 9) in summer, but mainly in 

 stratum 6 and in the channels in winter. Lady crabs 

 were widely distributed and were caught throughout 

 the study area, including the outer strata close to the 

 ocean. Male rock crabs were most frequently collected 

 in and near the channels and in strata 1 and 6, whereas 

 female rock crabs were sparsely scattered throughout 

 the study area. 



6 8 10 12 2 4 6 8 10 12 

 1991 1992 



4 6 8 

 1993 



10 1; 



4 6 8 10 12 

 1994 



6 8 10 12 2 4 6 8 10 12 2 4 6 8 10 12 2 4 6 8 10 1: 

 1991 1992 1993 1994 



10 12 2 4 6 8 10 12 

 1991 1992 



6 8 10 1 j 



1993 



4 6 8 10 12 

 1994 



O 



Figure 3 



Catch per unit of effort (number/towl of blue, lady, and rock crabs by month, 

 graphed with mean bottom temperatures. June 1991-December 1994. 



