Community structure of an estuarinemeiobenthic copepod assemblage

Abstract

The community organization of the meiobenthic copepods of two sub-tidallocations was compared with that of a low marsh, intertidal site in the same South Carolina estuary, over a 12 month period. Twenty-four collections of 4–8 replicate cores were gathered from the soft sediments between Spartina alterniflora plants. Total numbers of post-naupliar copepods ranged from 75 to 620·10 cm −2 . Of the 2 cyclopoid and 19 harpacticoid species, 8 comprised 97% of the fauna. The 4 most abundant species had summer or late fall peaks when copepods were most abundant, while 4 others had their minimal densities at this time. The monthly mean H′, J′ and number of species (1·50, 0·63 and 11·2, respectively) were not statistically different from the diversity values at the two subtidal locations. During the summer and fall months, horizontal, between replicate spatial correlations among the 3 most abundant low marsh species were very strong. Horizontally, Stenhelia (Delavalia) bifidia and Microarthridion littorale were negatively correlated, S. (D.) bifidia and Enhydrosoma propinquum positively correlated, while E. propinquum and M. littorale showed no interaction among the 24 collections. Based on a lack of readily identifiable microhabitat specializations, some combination of predation and physical disturbance seem the most likely regulators of the copepod assemblage at this low marsh site.