Habitat degradation and loss have contributed to the global loss of biodiversity. Knowledge of habitat requirements, and protection of key habitat functions and values, are therefore necessary components of conservation plans for species of concern. For many species of coastal fish and invertebrate, estuary habitats are essential. They are also Essential, in that the function of these habitats is now federally-recognized and regulated. These topics will be illustrated with selected coastal species of the Northeastern US, with special attention to the Essential Fish Habitat provisions of the Magnuson - Stevens Sustainable Fisheries Act, and its implications for development in the coastal zone.

I. Habitat and its conservation value
A. Definition of habitat
B. Assessment of habitat as a general factor in extinction
II. Estuary as habitat for fishes
A. Categories
1. estuary-resident
2. marine-estuarine
3. diadromous
B. Ecological functions of estuaries
C. Important estuarine habitat variables
1. Water quality
2. Submerged aquatic vegetation
3. Hydrodynamics
D. Estuary in the landscape view
1. Quality of estuary is function of how parts work together, sensitive to spatial structure (size, placement) of parts and their association
2. example?
III. Essential Fish Habitat
A. The Magnuson - Stevens Act and NMFS
1. Historical focus on regulating catch rates
2. Incorporating an ecosystem perspective
3. Definition of essential fish habitat
4. Refinement: 4 levels
5. The consultation process
B. Other organizations: ASMFC, The Nature Conservancy, Conservation Law Foundation (this is the group that has successfully sued NMFS arguing it has not pursued the objectives of the MSA as required by that Act.
1. ASMFC: what role in development?
2. TNC: the elements perspective on stewardship
3. CLF: Speaking for "environmental groups and the "resources."
IV. Prospects for EFH and the property rights issue
A. "the Tragedy of the commons"
B. The Surf clam success story
C. Recovery of some stocks in the western, North Atlantic