8-4 



The fifteen-minute tows utilized through December 1973 repre- 

 sent a considerably larger area sampled in comparison to the 10-minute 

 tows utilized during the remainder of the program. For this reason data 

 prior to 1974 cannot be used to make quantitative comparisons with the 

 1974 through 1977 data base. It can, however, be used qualitatively in 

 comparing spatial and temporal trends in species relative abundance. 

 Data collected as part of the 5-minute duplicate tows utilized during 

 May and June 1975 must also be viewed with caution; however, in this 

 case, data from the duplicate tows were combined, thus approximating a 

 single 10-minute tow. Data collected from the duplicate 10-minute 

 trawls utilized July 1975 through October 1977 can be used to make 

 quantitative comparisons with data obtained from single 10-minute trawls 

 used January 1974 through April 1975 since only the first tow was used 

 for data analyses . 



Organisms collected in the trawls were identified and counted 

 in the field. In addition, beginning in July 1976, length and weight 

 (wet) data were collected for several of the more important species. 

 Crustaceans were weighed and sexed, and gravid females noted. Size 

 measurements were taken as follows: crabs were measured for greatest 

 carapace width; sand shrimp for total length; and lobsters for both 

 total length and carapace length. Starfish were weighed and greatest 

 diameter measured. 



When large numbers (several hundred individuals) of a species 

 were collected, counts were based on a subsample of the total. The size 

 of the subsample varied with the individual species; in general, 25 

 individuals were used for a subsample and total count was estimated on 

 the basis of the weight of the subsample compared to the total weight of 

 the individuals. In the case of small, highly abundant species such as 

 the sand shrimp, ten 100-ml subsamples were counted to arrive at the 

 total estimated count. From July 1975 through October 1977, when dupli- 

 cate 10-minute trawls were used, the contents of both tows were identi- 

 fied and counted. At each station and sample period, length and weight 

 data were collected for organisms in the first tow; organisms in the 



