A study of the distribution and ecology of the macrobenthic communities in Eckerts Bayou on Galveston Island, Texas.

Biological, hydrological, and geological samples were collected monthly for twelve months, from August 1976 through July 1977, at twenty stations in Eckerts Bayou, Galveston, Texas. A total of 130 species, including 53 polychaetous annelids, 35 crustaceans, 14 bivalves, and 10 gastropods, were collected during the study. The most abundant organism was the polychaete Streblopio benedicti, while the most ubiquitous species were the polychaetes Streblopio benedicti and Mediomastus californiensis, and the amphipods Ampelisca abdita and Corophium louisianum. Two-dimensional analyses were utilized to delineate site and species groups. Two site and five species groups were constructed from the two-dimensional data. An assemblage of 48 species was grouped which exhibited no apparent site restrictions. The Shannon-Wiener diversity index was indicative of a within-habitat situation where species composition did not fluctuate widely, but where H'(= sum of Pi log2 pi) was affected by the seasonal variation of the number of individuals of a few species.