Sussex IFCA has historically undertaken fish surveys throughout the district in order to monitor juveniles of commercially important species and to further understanding of the ecosystem health, particularly within Marine Protected Areas. Seine net surveys have been undertaken since 2010 over Chichester Harbour, Cuckmere, Medmerry, Pagham Harbour, Rye Bay, and Tide Mills. Between 2011 and 2018, the Authority also undertook beam trawl surveys across Chichester Harbour and Rye Bay. Where possible, fish are identified to species level, although in some cases species are recorded at genus level. In each sample, 50 individuals of each species are are measured in total length, with any additional being counted. Once recorded, fish are returned alive to the sea.