Crabs are crustaceans, protected by a hard external shell and equipped with powerful claws. Common Sussex species, including the Shore Crab (Carcinus maenas), Edible Crab (Cancer pagurus) and Spider Crab (Maja squinado), are opportunistic feeders. They consume algae, dead marine life, shellfish and other invertebrates, breaking down organic material and recycling nutrients back into the marine environment. In doing so, they help prevent waste accumulating on the seabed and support healthier coastal habitats.
As crabs move, forage and shelter across the seabed, they disturb surface sediments and mix organic matter into the substrate. This small-scale disturbance oxygenates sediments and redistributes nutrients, creating favourable conditions for worms, shellfish and other invertebrates that underpin coastal food webs.
Crabs are also of considerable economic importance. Shellfish potting in Sussex dates back to the medieval period, and Edible Crab has long supported local fisheries in communities such as Selsey. However, Sussex IFCA’s catch data indicate a decline in crab landings in recent years, likely reflecting a combination of environmental change and fishing pressure.
Sussex IFCA’s Nearshore Trawling Byelaw protects seabed habitats from bottom-towed fishing gear in waters up to 4 km offshore between Selsey and Shoreham, and within the Selsey Bill and the Hounds Marine Conservation Zone. This allows marine habitats such as kelp, mussel beds and biogenic reef to regenerate, providing crucial shelter, feeding grounds, and nursery areas for crabs, offering protection from predators and increased survival rates. As these areas recover, crab populations strengthen, supporting food webs and contributing to more resilient inshore fisheries, while helping Sussex’s coastal ecosystems thrive for generations to come.
Written by guest author, Rebecca Belleni – Committee & Communications Manager Sussex IFCA