The Comparison of Large Nekton Between a Pristine and Urbanized Estuary and Between Two National Estuarine Research Reserve Systems in South Carolina
Date of Award
Master of Science in Coastal Marine and Wetland Studies
Coastal and Marine Systems Science
College of Science
Robert F. Young
Eric T. Koepfler
Large nekton were compared between two geographically and morphologically similar salt marsh estuaries, Murrells Inlet and North Inlet, that differ substantially in their degree of urbanization, and between two geographically separate but pristine salt marsh estuaries, North Inlet and the ACE Basin. Nekton were collected monthly from 12 sites per estuary using a trammel net. Monthly values for catch per unit effort (CPUE), species richness, Shannon diversity, evenness and Fulton condition index were calculated for each location. It was hypothesized that all values in North Inlet would be significantly higher than in the more urbanized site, Murrells Inlet, but would not differ from the other pristine site, Ace Basin. Muscle tissue was collected in North and Murrells Inlets from Lagodon rhomboides for carbon and nitrogen stable isotope analysis, in order to identify possible food web differences between the systems. An independent samples t-test or Mann-Whitney U test was used to test the hypotheses. Mean CPUE and species richness values were significantly higher in North Inlet than in Murrells Inlet, while there was no significant difference between Shannon diversity and evenness values. There was no significant difference in the mean CPUE, Shannon diversity and Shannon evenness values between North Inlet and the ACE Basin. Mean species richness was significantly higher in the ACE Basin. No definitive cause for the differences between North and Murrells Inlets were found, but urbanization, and upland development is the most likely cause. The difference in species richness between North Inlet and the ACE Basin is most likely due to the larger size of the ACE Basin and latitudinal differences between the two systems. Differences in large nekton were greater in the smaller estuaries that differed in the amount of urbanization than in the two pristine estuaries that differ in size and latitude. While the delta 15N values showed no difference in L. rhomboides trophic level between North and Murrells Inlets, the carbon values showed a slight difference in the base of the food web in North and Murrells Inlets. The difference in carbon values maybe due to the fish feeding from multiple foodwebs or multiple trophic levels. Fulton condition factors also were not significantly different for pinfish between North and Murrells Inlets.
Smith, Christopher Anthony, "The Comparison of Large Nekton Between a Pristine and Urbanized Estuary and Between Two National Estuarine Research Reserve Systems in South Carolina" (2012). Electronic Theses and Dissertations. 58.