Draft Report - Candidate Variables for Monitoring Estuarine Nutrient Enrichment Within the NPS Coastal Barrier Network
Kopp BS, Neckles HA, Roman CT, Nixon SW. 2002. Draft Report - Candidate Variables for Monitoring Estuarine Nutrient Enrichment Within the NPS Coastal Barrier Network. NPS Coastal and Barrier Network
Nutrient enrichment of the coastal zone is a worldwide consequence of human population growth. Land clearing, fertilizer production and application discharge of sewage and septic systems and fossil fuel combustion have accelerated nitrogen and phosphorus loading to coastal ecosystems since the 1950s (, Nixon 1995. Cloern 2001). Estuaries in the northeastern U.S are particularly threatened by human disturbances within the densely populated coastal zone (Roman et-al. 2000). The Northeast (froth Maine to Maryland) currently accounts for about one-third of the coastal-population of the entire United States (NOAA 1998). The population density of this narrow coastal fringe is more than double that of any other region of the country and it continues to grow. The consequent residential agricultural and urban expansion will result in a continued increase in anthropogenic nutrient loading to the regions coastal zone. Estuaries can generally assimilate some degree of enrichment without major ecological ramifications but excessive nutrient inputs typically lead to dense blooms of phytoplankton and fast-growing macroalgae loss of seagrasses and decreased oxygen availability in sediments and bottom layers (Valiela et al. 1992-. Nixon 19)5. Bonirn 1996...Bricker et al 1999), Cascading effects may include changes in the species composition and abundance of invertebrates. decline in fish and wildlife habitat value, and the collapse of commercially harvestable fin- and shellfish stocks.