These relatively unstable shelf ecosystems in turbulent waters support moderately diverse communities made up largely of consumers, like invertebrate detritivores and filter-feeders, including burrowing polychaetes, crustaceans, echinoderms, and molluscs. Filter feeders are most common in higher energy areas of currents and wave action. Primary producers are limited by substrate instability or light, with seagrass ecosystems (M1.1) occurring where these factors are not limiting to plant establishment and persistence. Low structural habitat complexity means a lack of shelter, and many organisms display predator avoidance traits like burrowing, shells or camouflage (e.g. sole).