Nutrient Enhanced Coastal Ocean Productivity in the Northern Gulf of Mexico:211 Understanding the Effects of Nutrients on a Coastal Ecosystem

摘要

The continental shelf adjacent to the Mississippi River is a highly productive211u001esystem, often referred to as the fertile fisheries crescent. This productivity is 211u001eattributed to the effects of the river, especially nutrient delivery. In the 211u001elater decades of the 20th century, though, changes in the system were becoming 211u001eevident. Nutrient loads were seen to be increasing and reports of hypoxia were 211u001ebecoming more frequent. During the most recent summers, a broad area (up to 211u001e20,000 km(2)) of near bottom, inner shelf waters immediately west of the 211u001eMississippi River delta became hypoxic (dissolved oxygen concentrations less than 211u001e2mg/l). In 1990, the Coastal Ocean program of the National Oceanic and 211u001eAtmospheric Administration initiated the Nutrient Enhanced Coastal Ocean 211u001eProductivity (NECOP) study of this area to test the hypothesis that anthropogenic 211u001enutrient addition to the coastal ocean has contributed to coastal eutrophication 211u001ewith a significant impact on water quality. Three major goals of the study were 211u001eto determine the fate the degree to which coastal productivity in the region is 211u001eenhanced by terrestrial input, to determine the impact of enhanced productivity 211u001eon water quality, and to determine the fate of fixed carbon and its impact on 211u001eliving marine resources. NECOP involved 49 federal and academic scientists from 211u001e14 institutions from 1990 through 1996.