Date of Award

Fall 1994

Document Type


Degree Name

Master of Science (MS)


Biological Sciences



Committee Director

Daniel M. Dauer

Committee Member

Mark J. Butler, IV

Committee Member

Raymond W. Alden, III

Call Number for Print

Special Collections LD4331.B46 M334


The effects of organic enrichment on benthic community structure were evaluated in a field study conducted in Pocomoke Sound in the vicinity of a seafood processing plant. The empirically derived Species Abundance and Biomass (SAB) curves of Pearson and Rosenberg (1978) were used to model patterns of organic enrichment at the study site, called Pig Point, as well as two reference sites located within Pocomoke Sound. The Split Moving Windows (SMW) method was used to detect the ecotone point as defined in the Pearson and Rosenberg (1978) model and the Two Term Local Quadrat Variance (TTLQV) method was used to evaluate the spatial distribution of key species, indicative of organic enrichment. The null hypothesis of the study was that macrobenthic community structure in the vicinity of the seafood processing plant was not altered by organic enrichment. Areas of agreement with the SAB curves included: (1) lower species richness and abundance of individuals for the first 30 mat the Pig Point Site and values comparable to the two reference sites for the remainder of the transects (30-200 m) and (2) an azoic zone due to extreme organic enrichment at one of the three transects at the Pig Point Study Site. Severe reductions in the macrobenthic community appeared to be restricted to a distance less than 30 m from the source of organic enrichment. Departures from the Pearson and Rosenberg model include: (1) an absence of an ecotone at the Pig Point Site using the SMW method, and (2) no Peak of Opportunists as determined using either a peak in abundance in the SAB plots or the TTLQV method. Biomass estimates for the three 2 O O m transects varied greatly among the three sites and showed only partial support for the model. For example biomass values for the first 30 m, at the Pig Point Site varied from the highest to the lowest values recorded at the three sites. Widespread high biomass values for the clam Macoma balthica indicated a pattern of organic enrichment that may extent for several kilometers.


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