epibenthos

Epibenthos refers to organisms that inhabit the surface of the seabed or attach to objects on the seabed, living on the outer boundary of the benthic zone. Epibenthic organisms differ from infauna, which dwell within sediments, and from pelagic organisms that live in the water column. The epibenthos includes a wide range of taxa, from sessile sponges and bryozoans to mobile crustaceans, echinoderms, molluscs and polychaete worms.

They occupy both hard substrata (rocks, coral, shells) and soft sediments, where individuals live on the surface or attached to biogenic structures. Some organisms are permanently attached, others are mobile and actively forage on the seabed. Distribution is influenced by depth, substrate type, hydrodynamic regime, and disturbance.

Ecologically, epibenthos contributes to habitat complexity, provides food for predators, and participates in nutrient cycling and energy flow at the seabed. In shallow ecosystems, epibenthic communities are often diverse and sensitive indicators of environmental change; in deeper regions they reflect depth, substrate, and food supply.

Sampling methods include dredges and grabs for soft sediments, shell-hash and rock surfaces, as well as suction samplers and camera-based surveys. Remote-operated vehicles and towed cameras enable study in deep water. Anthropogenic impacts such as bottom trawling, pollution, and deoxygenation threaten epibenthic habitats, with management strategies including protected areas and gear restrictions.