The benthic zone starts at the shore and extends down along the bottom of the lake or ocean. This means that it could be as shallow as a few inches at its start, but may reach depths of 6,000 meters as it coincides with the abyssal plain at the bottom of the ocean. Because of the depths it can reach, the benthic zone is often characterized by low sunlight and low temperatures.
This usually attributes to little life and biodiversity, so one would be inclined to assume that it is a vast waste. However, the presence of sediment layers at the benthic zone provides many nutrients and adds greatly to species richness. Because the benthic zone has such a range of depths, many kinds of organisms may live there. Crustaceans, sponges, bivalves, snails, sea stars, fish, and many others can inhabit the zone.