The review of existing knowledge on the production of unwanted catches and discarding practices showed that catches of unwanted fractions of target fisheries species can be large in demersal fisheries, particularly those using bottom trawl, but the magnitude varies according to season of the year, depth and specific fishery practiced. In periods of high abundance of recruits, bottom trawling on fish nursery areas can generate large amounts of unwanted catches, that are usually discarded for legal reasons (undersize specimens or catches over quota). The project carried out field tests of fishing technologies aiming at the reduction of unwanted by-catch, jointly developed with fishers, and trialled them in real commercial conditions. The results showed that it is possible to decrease the production of unwanted by-catch through implementing changes in fishing procedures. For example in purse seine fishing simple modifications to the procedure of handling the catch while still in the water led to an important reduction in the mortality of sardine. More selective nets, fitted with selective devices in bottom trawl were also trialled. For example, new types of sorting grids specifically designed for Mediterranean trawls proved effective in decreasing the by-catch of hake or rose shrimp juveniles. Also substituting part of the trawl with a new type of mesh, called T90, helped increase the selectivity of hake. In small scale fisheries, it was demonstrated that a guarding net fitted to the footrope of the trammel net can reduce unwanted by-catch, as well as operational costs. In surface longline fisheries targeting swordfish, an important reduction in the catch rates of undersize swordfish was demonstrated by adopting circle hooks instead of the traditional “J” hooks. In addition to technological solutions, the project has progressed in the field of IT to avoid unwanted catches: the project developed a GIS tool by combining maps of potential high discards with ‘fisheries footprint’ spatial information that can assist in marine spatial planning to exclude fishing from certain areas with high potential of production of unwanted catches. Early detection of undersize fish by using the remotely operated DeepVision system fitted to a trawl is a technology that has been trialed successfully in the project, after modifying the original design, and that could have potential application in pre-catch detection when the difficulties in automatic species recognition are solved.
The post-release survival of unwanted catches has been researched in different commercial species and types of fishing, by way of experiments following standard methodologies. Demonstrated high survival of discards can be used to justify an exemption to the Landings Obligation for specific regulated species and therefore this type of research is of high interest for the policy implementation aspects.
Several project results can be exploited directly by the fishing industry to increase fisheries selectivity to facilitate compliance with the regulation, such as the juvenile sorting grids, the T90 mesh panel or the guarding net. Other project results can be exploited by scientists to continue research on topics related to the discard ban. For instance, the project designed a prototype to assess automatically the vitality of very small fishes. The project also produced a system to control the properties of artificial light that can be used in selectivity devices using artificial light stimuli.
All project results were communicated to the industry, policy makers, fisheries managers and other relevant stakeholders by means of key communication actions. Communication activities included the organization of joint meetings with fisheries Regional Advisory Committee MEDAC (representing the fishing industry in the Mediterranean sea), the General Fisheries Commission for the Mediterranean, organizing fishermen’s exchanges to promote the horizontal communication of results between peers and producing 22 short video films highlighting the project’s result to wider audiences. A dedicated web-site
http://minouw-project.eu(se abrirá en una nueva ventana) serves as repository for all the written and video material produced for the project.
