Nutrient enrichment of the coastal zone is a worldwide consequence of human population growth. The population density of Northeast 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 region’s 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 waters. 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.
A protocol is being developed by the Network to monitor estuarine nutrient agents of change, or potential sources of nitrogen within the watersheds of each of the parks. These proxy indicators will include such things as: human population numbers, permitted water withdrawals for agriculture, fertilizer consumption, and land use.
Determine long-term trends in nitrogen loading estimations to NCBN park estuaries through nitrogen load modeling that incorporates human population density, atmospheric, fertilizer and wastewater nitrogen sources, non-point source discharge permits, permitted water withdrawals for domestic and agricultural consumption, fertilizer consumption and livestock population data.
The methodology for monitoring ENL is based on GIS modeling and analysis. This methodology has been developed and is currently under review. Principal Investigator: Scott Nixon, Ph.D.
Agents of Change variables are already gathered by local, state, and federal agencies. Regional testing involves determining the geographic scope of watershed data relevant for each network park, compiling current and historic (at 10-year intervals back to 1970) data from existing sources, and developing trajectories for each variable over time. This analysis will be used to identify the most useful indicators of nutrient load and to prepare guidance for updating the NPS database from other specific sources.
A monitoring protocol is being developed describing in detail how the historic data were compiled and reviewed as well as how to update this inventory, analyze and evaluate the new information for the network on a scheduled basis.