The Magnuson Fishery Conservation and Management Act of 1976, was enacted initially to protect U.S. waters between 3 and 200 miles offshore from foreign fishing pressure, to manage marine fisheries within the 200 mile exclusive economic zone [EEZ], and to build up the domestic fleet. Renamed the Magnuson-Stevens Fishery Conservation and Management Act to include the Sustainable Fisheries Act amendments in 1996, it is the major law that governs how commercial fish species are managed in the United States.
Among the 1996 amendments is a requirement that federal fisheries managers take steps to delineate and protect essential fish habit (EFH), which are those habitats deemed essential for breeding, feeding, migration, etc. at all life stages. The New England Fisheries Management Council appointed an EFH Technical Team to determine which habitats are essential for the 19 commercial fish and shellfish species that it manages in federal waters off New England. Under the provisions of the SFA (Sustainable Fisheries Act), the team was also charged to identify threats to essential habitat from fishing and nonfishing activities and to propose habitat conservation measures. The law requires other federal agencies to consult with the National Marine Fisheries Service (NMFS) on any project that might impact EFH, thus providing a legal tool to protect fish habitat.
Determining which habitats are essential to marine fish is a daunting task because far less is known about habitat requirements for marine species than for terrestrial species. The EFH Technical Team worked closely with scientists from the National Marine Fisheries Service (NMFS) to produce scientifically-defensible habitat delineations. The major data source available to the team was trawl surveys carried out by NMFS. These were designed to assess populations of managed species throughout New England waters and were based on depth strata; however, the surveys were not originally designed to provide specific habitat data. For EFH delineations, the NMFS surveys were averaged over ten minute squares of latitude and longitude, a scale much too coarse to relate the presence of different fish species to specific habitat types. For most species, the technical team defined EFH operationally as those ten minute squares that represent the top 90th percentile of abundance. The intention of the Magnuson-Stevens Act is that the delineation of EFH will be an iterative process; as more information is gathered, the delineations will be refined.
Given the large number of species under consideration, the wide variety of range and habitat requirements of these species, the need to account for all life stages, and the coarse scale of the available data, it is not surprising that most of the waters between 3 and 200 miles off the New England coast have been designated as essential fish habitat for at least one commercial fish or shellfish species. Also, several inshore bays and estuaries were designated as EFH based on data from the National Oceanic and Atmospheric Administration’s Estuarine Living Marine Resources program. Fishing and other activities are not excluded from these areas, but EFH designation gives the management council a tool to encourage mitigation of activities that may be harmful to fish habitats.
A
higher level of recognition known as habitat areas of particular concern (HAPC), has been assigned to two areas within New England waters. One HAPC is a gravel area on Georges Bank that is considered a nursery area for juvenile cod; the second HAPC is comprised of several rivers that are migration and spawning habitats for the Atlantic salmon. At the time of this writing, the Council is considering another HAPC to protect juvenile cod in the coastal waters inshore of the nine or ten meter depth contour where eelgrass, kelp, rock reef, cobble, and gravel habitats provide nursery areas. This proposal is based on extensive inshore trawl surveys carried out by the Massachusetts Division of Marine Fisheries plus a number of targeted studies on the habitat requirements of juvenile cod.
The legal implications of HAPC designations are not clear because the law is new. Presumably, fisheries managers will be alerted to the value of these habitats so that they protect HAPCs from harmful impacts. One of the major concerns in recent years has been the effects of bottom trawls and scallop dredges on fish habitat. Many juvenile fish and other marine organisms depend on the fine-scale physical and biogenic structure of the benthic community for protection from predators, a structure that is disrupted by dragging. Since most New England commercial fish and scallops are caught by dragging the benthos, the issue of protecting the seafloor is a particularly sensitive one. 
While the New England Fisheries Management Council has not taken any comprehensive management measures to address the impacts of fishing gear on the benthic community, it has attempted to minimize potential habitat impacts to specific sensitive areas in its periodic adjustments to existing fisheries management plans. The Council has proposed setting aside a designated research area for the study of the impacts of fishing gear on different habitat types and other habitat-related issues.
The habitat provision of the Magnuson-Stevens Act is an innovative, ecosystems approach to fisheries management. It assumes that increasing knowledge about fish-habitat relationships will enable us to refine our EFH and HAPC delineations as well as help us to understand and mitigate threats to groundfish and shellfish habitat. Hopefully, the funding will be available for scientists to provide the answers.