Biogeographic Characterization of Fishes from Intertidal Sandflats in Pamlico River, North Carolina

Abstract

The spatial and temporal changes in fish community structure in Pamlico River, North Carolina were analyzed. Salinity and temperature are important water quality parameters influencing fish community structure in estuaries. Fish were collected with an 18 m long bag seine from sandy habitats in Pamlico River, North Carolina. Each station was sampled bi-monthly (August to November) in 2009-2010. The North Carolina Division of Marine Fisheries (NCDMF) Program 123 has been collecting fish from two stations in Pamlico River since 1987. There are two main differences between this study and Program 123. First, Program 123 has a much narrower geographic sampling area than this study. I sampled 18 fixed locations from Washington, North Carolina to the mouth of Pamlico Sound; whereas, NCDMF sampled only two stations near Bath, North Carolina. Second, sampling frequency was higher in this study than in Program 123. I sampled bi-weekly in October and November, 2009 and August to November, 2010; whereas, Program 123 sampled monthly from September to November, 2009 and 2010. Analysis of similarity (ANOSIM), non-metric multidimensional scaling (MDS), and canonical correspondence analysis (CCA) were used to test for differences in fish community structure both spatially and temporally, in Pamlico River, and to test for the correlation of water quality to fish community structure. Analysis of variance (ANOVA) was used to test for significance in water quality among the various sections. Five species (Anchoa mitchilli, Menidia beryllina, Brevoortia tyrannus, Leiostomus xanthurus, and Lagodon rhomboides) accounted for 97.4% of the total abundance in Pamlico River. Temporal and spatial changes in fish community structure were important in Pamlico River. Temperature was the most important environmental factor correlating with temporal fish community structure in Pamlico River. Salinity was the most important factor in spatial fish community structure. Program 123 captured greater catch per unit effort (CPUE) than this study because Program 123 only sampled the Central section, where greatest fish abundance occurred. However, greater species diversity was captured in this study than in Program 123.