Sublittoral

Sublittoral 

a life zone of the sea floor limited to the continental shelf and characterized by certain flora and fauna. The sublittoral is bounded by the littoral on the landward side and by the deep-sea zone on the seaward side. The seaward boundary may shift. Between the sublittoral and deep-sea zones is a transitional horizon situated at depths varying from 200 to 500–1,000 m in different parts of the ocean; characterized by a mixture of fauna, this zone is called the pseudoabyssal, profundal, and archi-benthic by different authors. The sublittoral is often bounded only by the zone of distribution of benthic plants at depths of 40–150 m. The width of the sublittoral depends on the width of the continental shelf and ranges from a few kilometers to hundreds of kilometers.

The sublittoral, biologically the most productive zone of the sea, has an extraordinarily abundant and diverse population capable of generating hundreds and thousands of grams of living matter per square meter. Significant numbers of aquatic plants, especially flowering plants, as well as corals (in the tropics), are usually limited to the upper horizon of the sublittoral. Animals predominate at greater depths; echinoderms, mollusks, worms, and crustaceans are especially numerous. The major commercial supplies of marine benthic fish, invertebrates, and plants are concentrated in the sublittoral.

N. G. VINOGRADOVA