New rules banning fishermen from throwing away unwanted fish they have caught could harm wildlife and fail to improve fish stocks, a University of Strathclyde report has found.
The study, published in the journal Nature Communications, suggests new reforms to the European Union's Common Fisheries Policy (CFP) ending the practice of throwing away unwanted fish caught at sea may have unintended consequences. The new CFP took effect on 1 January 2014 and will phase out the discarding of fish between 2015 and 2019.
The aim is to improve fish stocks but Professor Mike Heath, who led the research team from Strathclyde's Department of Mathematics and Statistics, said this outcome was uncertain.
Professor Heath said: "Wildlife everywhere capitalises on waste from human activity, and discarded fish are food for a wide range of seabirds, marine mammals, seabed animals and other fish. Therefore, banning discards of fish could have unintended effects on the ecosystem."
The team developed a computer simulation model of the North Sea marine ecosystem and used it to investigate the effects of changes in the fishing pressure and the proportion of fishery catch which is discarded at sea. Forcing vessels to land fish which are currently discarded leads to adverse effects on seabirds and marine mammals and on seabed animals but without any improvements in fish stocks, the study found.
In contrast, changing fishing practices so that unwanted fish are no longer captured had dramatic effects in the model which affected the entire food web, with major benefits for birds, mammals, and fish stocks. This could be achieved by "improved selectivity", through the use of fishing gear designed to avoid unwanted catches and judicious timing and location of fishing.
Although both approaches to eliminating discarding satisfy the societal demand for reductions in waste of natural resources, the conservation benefits are quite d
|Contact: Lachlan Mackinnon|
University of Strathclyde