The U.S. Fish and Wildlife Service established the Biological Services Program to provide scientific information and methodologies on key environmental issues affecting fish and wildlife. The program's mission includes strengthening the Fish and Wildlife Service's role in environmental impact assessments, aiding decision-makers in addressing land and water use changes, and providing ecological information for Department of the Interior programs. The program's research and technical assistance are based on analyzing issues, decision-makers' needs, and the state-of-the-art to identify information gaps and determine priorities. The classification system for wetlands and deepwater habitats was developed by wetland ecologists with assistance from various organizations and agencies. It was published in 1977 and officially adopted by the Fish and Wildlife Service. The system is used in the National Wetlands Inventory and other programs. A one-year transition period allows for training and updating administrative manuals. During this period, the old classification system (Circular 39) may still be used where necessary. The classification system includes five major systems: Marine, Estuarine, Riverine, Lacustrine, and Palustrine. Each system has subsystems and classes based on substrate material, flooding regime, or vegetative life form. Classes are further divided into subclasses and dominance types. The system includes water regime, water chemistry, and soil modifiers to describe wetland and deepwater habitats. The classification system is hierarchical, with systems at the highest level, followed by subsystems and classes. It is designed to provide a uniform framework for wetland and deepwater habitat classification. The system includes definitions, limits, and descriptions of each system and subsystem. It also includes criteria for distinguishing organic soils from mineral soils and an artificial key to the systems. The classification system is intended to describe ecological taxa, arrange them in a system useful to resource managers, provide units for mapping, and ensure uniformity of concepts and terms. Wetlands are defined by plants, soils, and frequency of flooding. Deepwater habitats are ecologically related areas traditionally not considered wetlands. The system includes five major systems, each with specific characteristics and boundaries. The system is used for inventory, evaluation, and management of wetlands and deepwater habitats. It is compared with other classification systems and includes a glossary of terms, appendices with scientific and common names of plants and animals, and criteria for distinguishing organic soils from mineral soils. The system is designed to meet long-term objectives, including describing ecological units, arranging them in a system for resource management, providing units for inventory and mapping, and ensuring uniformity in concepts and terminology.The U.S. Fish and Wildlife Service established the Biological Services Program to provide scientific information and methodologies on key environmental issues affecting fish and wildlife. The program's mission includes strengthening the Fish and Wildlife Service's role in environmental impact assessments, aiding decision-makers in addressing land and water use changes, and providing ecological information for Department of the Interior programs. The program's research and technical assistance are based on analyzing issues, decision-makers' needs, and the state-of-the-art to identify information gaps and determine priorities. The classification system for wetlands and deepwater habitats was developed by wetland ecologists with assistance from various organizations and agencies. It was published in 1977 and officially adopted by the Fish and Wildlife Service. The system is used in the National Wetlands Inventory and other programs. A one-year transition period allows for training and updating administrative manuals. During this period, the old classification system (Circular 39) may still be used where necessary. The classification system includes five major systems: Marine, Estuarine, Riverine, Lacustrine, and Palustrine. Each system has subsystems and classes based on substrate material, flooding regime, or vegetative life form. Classes are further divided into subclasses and dominance types. The system includes water regime, water chemistry, and soil modifiers to describe wetland and deepwater habitats. The classification system is hierarchical, with systems at the highest level, followed by subsystems and classes. It is designed to provide a uniform framework for wetland and deepwater habitat classification. The system includes definitions, limits, and descriptions of each system and subsystem. It also includes criteria for distinguishing organic soils from mineral soils and an artificial key to the systems. The classification system is intended to describe ecological taxa, arrange them in a system useful to resource managers, provide units for mapping, and ensure uniformity of concepts and terms. Wetlands are defined by plants, soils, and frequency of flooding. Deepwater habitats are ecologically related areas traditionally not considered wetlands. The system includes five major systems, each with specific characteristics and boundaries. The system is used for inventory, evaluation, and management of wetlands and deepwater habitats. It is compared with other classification systems and includes a glossary of terms, appendices with scientific and common names of plants and animals, and criteria for distinguishing organic soils from mineral soils. The system is designed to meet long-term objectives, including describing ecological units, arranging them in a system for resource management, providing units for inventory and mapping, and ensuring uniformity in concepts and terminology.