Approximately 35 hectares of Spartina alterniflora marsh has, over a 14-year period, developed naturally on unconfined dredged material placed within the intertidal zone of Winyah Bay, South Carolina. The above-and below-ground vegetative structure, benthic macrofauna, and resident fish and shellfish assemblages of two varying-aged zones (4 and 8 years) of this marsh were evaluated and compared in September 1988. Vegetative structure (stem height, density, percent cover, and biomass) in both zones was within the range reported for natural sites, with a trend toward greater below-ground development with age. The macrofaunal assemblages of both zones were similar in both species comtx)sition and numbers of species (17-21 species), with oligochaetes and polychaetes dominating both assemblages. Overall density of macrofauna in the 8-year-old zone (19,943 individuals per m 2) was significantly greater than that in the 4-year-old zone (4,628 individuals per m~). Differences between zones (particularly the presence of large-bodied molluscs in the older site) seemed to reflect age. The fish and shellfish assemblage collected from the younger site was dominated by Fundulus heteroclitus and Palaemonetes pugio. Gut contents of F. heteroctitus included a variety of marsh-surface prey, similar to that reported elsewhere.Overall, both zones seemed to represent well established, viable, low intertidal marsh habitat.

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Windmill Point (WP) is an 8-ha dredged material island site in the intertidal reach of the James River. This fine-textured, freshwater site was one of the first habital development projects built by the U. S. Army Corps of Engineers (CE). Long-term physical, chemical, and biological monitoring has been conducted since 1974. Three nearby natural wetlands have been used for comparison purposes in order to document site success or failure and the speed of wetland development. With the exception of some herbaceous plmV~ings on the WP containment dikes, vegetation has colonized naturally. Over time, predominant species have been Peltandra virginica, Pontederia cordata, and Sagittaria tat~)tia. Wildlife and fish populations and species diversity have been consistently greater al WP than at the 3 reference wetlands. Benthos regained pro-disposal levels within 6 months. Five heavy metals and 14 PCBs were examined in soil and plant samples. Only DDE was found to translocate to wetland plant shoots, and kepone was found to be relatively _~table. WP was broken into 2 smaller islands by flooding in 1983 and now consists of as much shallow aquatic habitat as emergent wetlands. The CE recognizes that active site management o f such rivcrine wetlands through placement of additional dredged material and dike repair is needed to ensure long-term site integrity.

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