2000-2002 University Marine Biological Station Millport (UMBSM) Clyde Sea Area Hydraulic Dredging Assessment Survey

As hydraulic dredging is emerging as a preferred technique in Scottish waters for the fishing of razor clams (Enis spp.), an investigation evaluating the environmental impacts of hydraulic dredging as a fishing technique was carried out. The study investigated the impact of dredging on co-existing fauna and predators as well as the effects on sediment composition and characteristics. Populations of Enis arcuatus and Enis siliqua were studied in the Clyde Sea area and the Hebrides and Orkney Islands. These study sites are commercially sensitive and therefore their exact geographic locations have not been included in the report. Additional sites were also identified within the Clyde Sea area. Hydraulic dredging was found to have a high diversity of by-catch within the Clyde Sea area. Production estimates and recruitment levels of razor clams are discussed within the study.