macrofoulers

Macrofoulers, or macrofouling organisms, are large, sessile or slow-moving organisms that attach to submerged surfaces, forming fouling communities. They differ from microfouling, which is caused by microorganisms on the same surfaces.

Common macrofoulers include barnacles (Cirripedia), mussels and other bivalves, oysters, bryozoans, tunicates (sea squirts), sponges, hydroids, certain seaweeds (macroalgae), and soft corals. They can colonize hulls of ships, offshore platforms, piers, pipes, and aquaculture equipment.

Ecology and succession: colonization often begins with rapid, short-lived organisms, followed by more stable assemblages; there is competition for space, preference for flow and light conditions; complex communities provide habitat for other invertebrates and small fishes in some environments.

Impacts: Macrofouling increases hydrodynamic drag on vessels, fuel consumption, and greenhouse gas emissions; on stationary structures, it adds weight and can accelerate corrosion or biofouling-related damage; can clog cooling or water-intake systems; dissemination of invasive species via hull fouling.

Management: Anti-fouling coatings (from historic tributyltin to contemporary copper-based and non-biocidal surface technologies) aim to reduce settlement; mechanical cleaning; hull cleaning; use of antifouling regimes in aquaculture; non-toxic, fouling-release coatings; ultrasonic and electrochemical methods; maintenance schedules; monitoring of fouling communities.

Research and regulation: antifouling substances are subject to environmental guidelines; policies encourage non-toxic alternatives and robust performance evaluation.