An assessment of ecological conditions in a constructed tidal marsh and two natural reference tidal marshes in coastal Virginia

Abstract

A comparison of a constructed tidal marsh with two adjacent natural tidal marshes was conducted. The marshes were sampled for fish, shellfish, benthic infauna, marsh surface utilization, vegetation community type, stem density and cover, salinity, temperature, dissolved oxygen, organic carbon, bird utilization, and zooplankton. The proximity of study sites permitted simultaneous sampling to test for marsh preference by fish and shellfish. Subsurface organic carbon, Spartina alterniflora stem density, low marsh zone surface utilization, zooplankton abundance and bird nesting sites were all greater in the natural marshes. Other attributes such as stem density of the high marsh, high marsh zone surface utilization, surface organic carbon, and benthic infauna community structure and abundance were similar between the constructed and natural marshes. Seasonal differences were observed for fish and shellfish abundance between the constructed and natural marshes. The study is among the first to use simultaneous sampling techniques to investigate fish and shellfish use between constructed and adjacent natural reference wetlands.