Known as the Northeast U.S. Continental Shelf Large Marine Ecosystem ( NES LME ), the ecosystem spans approximately 100,000 square miles and supports some of the highest revenue-generating fisheries in the nation. During the past 40 years, the ecosystem has experienced extensive fishing by domestic and foreign fleets, changes in ocean water temperatures due to climate change, and pressures from increasing human populations along the coast .
Michael Fogarty, who heads the Ecosystem Assessment Program at the Northeast Fisheries Science Center ( NEFSC ) of NOAA ‘s Fisheries Service in Woods Hole, Mass., says his team ‘s report card highlights the motivation to understand natural and human-related changes in this region and to develop effective management and extenuation strategies.
“ There are many pressures on the ecosystem including fishing, befoulment, habitat passing from coastal development, and impacts on nautical animation from shipping and other uses of the ocean, ” Fogarty said. “ In addition, changing climate conditions are warming ocean waters, changing ocean chemistry and circulation patterns, and altering atmospheric systems. These changes have, in turn, been linked to changes in the distribution and abundance of fish species in the region and their major sources of food. ”
The report is the first in a plan series of ecosystem status reports by Fogarty and his colleagues in the NEFSC ‘s Ecosystem Assessment Program to document changes in the NES LME, one of 64 regions in the worldly concern ‘s ocean designated as a big marine ecosystem. LMEs are large coastal ocean waters adjacent to continents and characterized by distinct bathymetry, hydrology, productiveness and inter-related nautical populations. LMEs produce 80 percentage of the worldly concern ‘s annual fishery yields, and most of the impacts of homo activities in the ocean occur within their waters.
Some of the highlights of the program ‘s first report :
- Warming of coastal and shelf waters has led to northward shifts in distribution of some fish species and changes to a warmer-water fish community.
- The community structure of zooplankton, a major food source for whales and many other marine species including fish, has changed, due in part to climate and physical processes acting over the North Atlantic Basin, indicating the importance of winds and atmospheric circulation patterns to the function and structure of this ecosystem.
- Species-selective harvesting patterns have also contributed to shifts in the composition of the ecosystem, which is now dominated by small pelagic fishes such as herring and mackerel, shellfish species, and elasmobranchs (skates and small sharks) of relatively low economic value.
- The trajectory of regional human population size suggests that human-induced pressure on the ecosystem will continue to increase.
- The Northeast U.S. Continental Shelf is classified as experiencing ecosystem overfishing, although marked improvement has occurred in the condition of a number of harvested species. Exploitation rates, or the rate at which fish are removed from the ocean, have been significantly reduced in many fish stocks during the last decade, indicating that management measures put in place to reduce overfishing are beginning to show dividends.
Fogarty says sustained long-run monitoring by many agencies and institutions in the Northeast region has enabled scientists and others to trace changes in the ecosystem .
“ In the future, we need to continue to monitor the oceanographic, ecological, and human indicators analyzed in this report card to detect any extra changes in the organization. These indicators besides provide significant inputs to models that can be used to help guide management decisions and to forecast future changes. ”