Ocean & Shoreline Management 14 (1990) 35-50 Evaluation of the Benthic Resource Value of Impounded and Non-Impounded Tidal Creeks in Virginia, USA* Mark W. Luckenbach, Robert J. Diaz, Erik C. Zobrist:~ & Cindy H. Hutton Division of Geological and Benthic Oceanography, Virginia Institute of Marine Science, School of Marine Science, College of William and Mary, Gloucester Point, Virginia 23062, USA (Received 19 September 1988; revised version accepted 15 July 1989) ABSTRACT Potential effects of impounding tidal creeks include alterations in the resource value of downstream wetland habitats. Benthic invertebrates serve as food for higher trophic levels (e.g. crabs and fishes) and, because of their sedentary life style, are constrained to cope with local environmental conditions. Comparisons of macrobenthic invertebrate biomass available to higher levels were made between two impounded and non-impounded creek pairs in coastal Virginia. The results indicate that neither the total amount nor the distribution of this resource varied between impounded and non-impounded creeks. The implication is that impounding the headwater regions of a tidal creek does not severely reduce the resource value of downstream habitats to higher trophic levels. INTRODUCTION Impounded tidal creeks are common features along the United States Atlantic coast from Virginia to Georgia. Constructed in the past primarily as irrigation ponds in Virginia and for rice cultivation to the south, impoundments now serve a variety of purposes. In Virginia their use as irrigation ponds continues and additionally they are known to trap sediments, nutrients and non-point source agricultural pollutants. 1 * Contribution No. 1564 from the Virginia Institute of Marine Science. Present address: Department of Biology, University of South Carolina, Columbia, South Carolina 29205, USA 35 Ocean & Shoreline Management 0951-8312/90/$03-50 © 1990 Elsevier Science Publishers Ltd, England. Printed in Northern Ireland