By-catch reduction devices in the European Crangon fisheries
van Marlen, B.; de Haan, D.; Revill, A.S.; Dahm, K.E.; Wienbeck, H.; Purps, M.; Coenjaerts, J.; Polet, H. (2002). By-catch reduction devices in the European Crangon fisheries, in: Paschen, M. (Ed.) Proceedings of the Fifth International Workshop on Methods for the Development and Evaluation of Maritime Technologies, Rostock 7-10 November 2001. Contributions on the Theory of Fishing Gears and Related Marine Systems, 2: pp. 207-220 In: Paschen, M. (Ed.) (2002). Proceedings of the Fifth International Workshop on Methods for the Development and Evaluation of Maritime Technologies, Rostock 7-10 November 2001. Contributions on the Theory of Fishing Gears and Related Marine Systems, 2. Neuer Hochschulschriftenverlag: Rostock. ISBN 3-935319-88-6. 204 pp., more In: Contributions on the Theory of Fishing Gears and Related Marine Systems. Neuer Hochschulschriftenverlag: Rostock, more |
| Authors | | Top | - van Marlen, B., more
- de Haan, D., more
- Revill, A.S.
- Dahm, K.E.
| - Wienbeck, H.
- Purps, M.
- Coenjaerts, J.
- Polet, H., more
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| Abstract | EU-Study 98/012 “Reduction of discards in Crangon trawls (DISCRAN)” aimed at collecting catch and by-catch data, compare various designs and further develop effective and acceptable selective devices (veil nets and sorting grids) in the European Crangon fisheries. The project started with a literature review and model tests. Over the years 1999 and 2000 a total of 547 valid hauls were carried out in German, Dutch, Belgian and British fishing grounds on research vessels and/or commercial fishing boats. The project was guided through National Advisory Groups consisting of scientists, fishermen's representatives and practical fishermen. Both the sieve net and the grid are devices that can effectively sort out by-catch fish species, but they have to be rigged properly and blockage due to sea weed or jelly fish may impair their effectiveness. The loss in commercial shrimps in the German, Dutch and UK trials was between 5-20%. However, commercial trials in Belgian waters showed higher losses on average 37% probably caused by the unique Belgian catch composition and seasonal differences. A mesh size of 70mm and a grid bar distance of 20mm demonstrated proper sorting. Some general trends were observed. Grids and sieve nets work well on plaice, flounder, smelt, cod, and to a somewhat lesser extent on dab, bib and whiting. Fishermen expressed a preference for the non-rigid sieve or veil net. |
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