Wetlands and Water Quality. A Regional Review of Recent Research in the United States on the Role of Freshwater and Saltwater Wetlands as Sources, Sinks, and Transformers of Nitrogen, Phosphorus, and Various Heavy Metals

摘要

The coterminous United States and Alaska were divided into seven geographic regions representing groups of Corps of Engineers Districts. Within each geographic region, the quality and quantity of literature were examined by wetland type and function within wetland type. The specific water quality functions examined included wetlands as sources, sinks, and transformers of nutrients and heavy metals. A review of literature on mass balance studies of nutrients and heavy metals was also provided for each region. Recommendations are provided to address data gaps identified during the literature review. Study results indicated considerable diversity in the quantity and quality of wetlands water quality literature between and within each geographic region of the coterminous United States and Alaska. In general, wetlands water quality has been studied most intensely in the estuarine marshes of the Gulf and North Atlantic coasts. Water quality in freshwater wetlands has not received attention commensurate with the wide distribution of these wetland types. Most previous wetlands water quality research has been fragmented into site-specific or function-specific studies. Very few mass balance studies have been conducted. Two complementary approaches to addressing wetlands water quality research data gaps are recommended.