Classification of Marine Sublittoral Habitats, with Application to the Northeastern North America Region
Page C. Valentine, Brian J. Todd, and Vladimir E. Kostylev
Abstract. Habitats are defined as spatially recognizable areas where the physical, chemical, and biological environment is distinctly different from surrounding environments. A habitat can be delimited as narrowly or as broadly as the data and purpose permit, and this flexibility of scale influences the development of habitat classification schemes. Recent habitat classifications focus on a wide range of habitats that occur in European, American, and worldwide seafloor environments. The proposed classification of marine sublittoral habitats is based on recent studies in the American and Canadian parts of northeastern North America using multibeam and side-scan sonar surveys, video and photographic transects, and sediment and biological sampling. A guiding principle in this approach to habitat classification is that it will be useful to scientists and managers of fisheries and the environment. The goal is to develop a practical method to characterize the marine sublittoral (chiefly the subtidal continental shelf and shelf basin) habitats in terms of (1) their topographical, geological, biological, and oceanographical attributes and (2) the natural and anthropogenic processes that affect the habitats. The classification recognizes eight seabed themes (informal units) as the major subject elements of the classification. They are seabed topography, dynamics, texture, grain size, roughness, fauna and flora, habitat association and usage, and habitat recovery from disturbance. Themes include one or many classes of habitat characteristics related to seabed features, fauna and flora, and processes that we view as fundamental for recognizing and analyzing habitats. Within the classes, a sequence of subclasses, categories, and attributes addresses habitat characteristics with increasing detail. Much of the classification is broadly applicable worldwide (excluding some lowlatitude environments), but faunal and floral examples are representative of the northeastern North America region. In naming habitats, the classification emphasizes seabed substrate dynamics, substrate type, and seabed physical and biological complexity. The classification can accommodate new classes, subclasses, categories, and attributes, and it can easily be modified or expanded to address habitats of other regions. It serves as a template for a database that will provide a basis for organizing and comparing habitat information and for recognizing regional habitat types.