Marine Ecology: Continental Shelf to Deep Sea

Abstract

Continental shelves are areas of shallow water (depth <200 m) that fringe continents. Their width varies considerably (averaging 80 km); some areas (e.g., the coast of Chile) have virtually no shelf, while shelves in other areas cover several hundred kilometers (e.g., the Arctic Ocean). Continental shelves can have high primary production due to the availability of adequate sunlight (owing to these areas being in the euphotic zone), allowing abundant and diverse higher trophic level organisms to inhabit these areas. The deep sea consists of the water column below a depth of 200 m and the seafloor. It accounts for 95% of the total volume of the ocean, which is the largest habitat for life on the Earth, and is mostly unexplored. Its physicochemical environments are quite different from those in shallow-water environments, such as relatively low temperature, high hydrostatic pressure, and darkness. These environmental parameters, together with limited food availability, influence the morphology, behavior, and ecology of deep-sea creatures. Methods used for understanding deep-sea life are shown here.