The fauna includes several species of zooplankton and benthic animals. Phytobenthos comprises the plants belonging to the benthos, mainly benthic diatoms and macroalgae (seaweed). They feed on pelagic and benthic fish. The scientific community divides bottom trawling into benthic trawling and demersal trawling. They are bottom feeders, mainly eating crustaceans and benthic invertebrates. They are opportunistic feeders and are mostly predators on benthic invertebrates. They are covered with sediment but largely devoid of benthic life (benthos). Bearded seal and walrus also feed on benthic invertebrates. Chemosynthetic bacteria are found in benthic marine ecosystems. These invertebrates play an important role in transporting substances for benthic nutrient cycling. They have long slender tails and live close to the seabed feeding on benthic invertebrates. The initial herbivorous mesozooplankton were probably larvae of benthic (seafloor) animals. Diatoms also grow attached to benthic substrates, floating debris, and on macrophytes. They are thought to feed on benthic invertebrates like adults. Reestablishment of benthic communities depend upon composition of adjacent communities for larval recruitment.