The maximum number of specimens found at 

 any one station was 3,521, of which 3,470 were 

 the gastropod, Crepidula fornicata (station 2, 

 October 1966). The mean number of specimens 

 before dredging for stations 2-24 (minus the inter- 

 tidal stations) was 120.14 (1201.4/m2), ^^lile the 

 after-dredging mean was 25.63 (256.3/m2). This 

 constitutes a 79% reduction in the number of 

 specimens found at the post-dredging stations.^ 



Comparison With Other Areas 



Direct comparisons between the standing 

 crop estimates at Goose Creek and other areas 

 is complicated by the diverse methods of obtaining 

 these estimates used by workers in the field. 

 As previously indicated, Holme (1953) and 

 Sanders (1956, 1958) used HCl to remove the 

 carbonates from the carapaces of crustaceans 

 and both removed all specimens greater than 0.2 g 

 dry weight from their samples. For reasons pre- 

 viously mentioned, it is important in this investi- 

 gation to obtain data on the populations of the 

 larger forms which dominate the communities of 

 the shallow, estuarine study area being investi- 

 gated. Variation in sieve mesh size between 

 studies is also an important factor accounting for 

 differences in infaunal biomass estimates, but 

 Sanders (1956) attempted to compare numerical 

 results of several investigations by plotting mesh 

 size against the log of the number of animals 

 per square meter. The lowest estimates were those 

 obtained by Holme (1953) from the English 

 Channel (160/m2) and Miyadi (1940, 1941a, 

 1941b) from Japanese bays (266-1, 290/m2). 

 Sanders' mean number of animals for Long Island 

 Sound was 16,443/m2, although 63% of his sta- 

 tions had fewer than 8,500 animals/m^. The mean 

 number of animals at Goose Creek (l,201.4/m2) 

 is considerably lower than that obtained by 

 Sanders, but it is unlikely that this parameter 

 is the most useful in comparing areas since his 

 Ampelisca and Nepthys incisa-Yoldia limatula 

 communities contained relatively dense popula- 

 tions of small organisms, while at Goose Creek 

 amphipods and protobranch pelecypods made 

 up a very small proportion of the biomass. 



«The data for the means of the stations (per 0.1 m^ samples) 

 were provided as a more accurate estimate of such quantities 

 as species number, because extrapolations from 0.1 m^ to 1.0 m^ 

 in the case of small numbers like 5.47 specimens/0.1 m^ seem 

 to introduce an inordinate amount of potential error. 



In a comparison of the dry weights of Long 

 Island Sound with other areas, Sanders gives a 

 figure for the mean total dry weight (including 

 "large animals") of 54.627 g/m^. This corresponds 

 to a dry weight of only "small animals" of 15.88 

 g/m^, a figure which is roughly twice as great 

 as the highest mean value for the other areas 

 discussed. Pfitzenmeyer (1970) performed a study 

 closer in purpose to the present investigation than 

 those described by Sanders. His pre-dredging 

 mean dry weight (including large forms) was 0.90 

 g/m^, while the immediate post-dredging mean 

 was 0.67 g/m2. 



Holme's (1953) mean dry weight was 11.2 g/m^, 

 including "large" animals. 



The figure obtained by Sanders for total dry 

 weight are in good agreement with those com- 

 puted for the present study, since the pre-dredging 

 dry weight for Goose Creek was 36.83 g/m^, 

 while the Long Island Sound figure was 54.627 

 g/m^. The substantial variance of these data from 

 those of Holme (11.2 g/m^) and Pfitzenmeyer 

 (0.90 g/m2) has been accounted for, in principle, 

 by Sanders in his 1956 paper. 



464 



