An Assessment of Southeast United States Headwater Tidal Creek Sediment Contamination and the Macrobenthic Community over a Twenty-Year Period in Relation to Coastal Development

Parker, Catharine Evelyn

An Assessment of Southeast United States Headwater Tidal Creek Sediment Contamination and the Macrobenthic Community over a Twenty-Year Period in Relation to Coastal Development

Authors

Parker, Catharine Evelyn

Abstract

Salt marshes and the tidal creeks that drain them are essential ecosystems along the southeastern coastline as they provide nursery, feeding, and protective habitat for many coastal organisms. Headwater tidal creeks are sentinel habitats which provide early warning of potential harm, thus making them ideal systems to evaluate the effects of increasing coastal suburban and urban development on estuarine environmental quality. Out of 43 tidal creeks sampled between 1994 and 2006, 18 were sampled again in 2014/2015 for sediment contamination and macrobenthic community composition. Macrobenthic organisms link primary prey resources to predators and obtain contaminants through fine-grained sediments during feeding. Creek watersheds were classified as forested, forested to suburban, suburban, or urban land use based on their percent impervious cover (IC) levels during several time points. Forested to suburban creeks are those that changed classifications over the last 20 years. Analyses of historical and current data resulted in significant relationships between IC and a number of sediment contaminants (e.g., polycyclic aromatic hydrocarbons) and benthic community metrics (e.g., pollution indicative species). In addition, 11 of the creeks sampled in 2014/2015 have paired data from 1994/1995 and a number of metrics (e.g., macrobenthic density) changed over the 20-year span. Results indicate increased chemical contamination and alterations to macrobenthic communities in headwater tidal creeks is occurring with increasing levels of development. These results expand our knowledge of how these systems respond to coastal development and provide managers with information about how predicted human population growth along the coast may alter tidal creek health.