Determination of selectivity of cod codends made of netting turned through 90°
Bulletin of the Sea Fisheries Institute 1 (140) 1997, pp. 3-14

Waldemar Moderhak
Sea Fisheries Institute, Kołłątaja 1, 81-332 Gdynia, Poland

Key words: catches, codend, protection, selectivity, turned mesh.

Abstract.
The constantly decreasing fishery resources require taking decisive measures in order to stop, and then, to reverse this unfavorable trend. Since traditional methods of protection are insufficient and far from perfect, research should be undertaken aimed at finding novel conceptions which would assure proper protection, particularly of juvenile fish, and be implemented in commercial catches. In the paper, very promising preliminary results are presented of the tests on a codend with meshes turned through 90°, made of typical netting material of a mesh size of 120 mm, used in the Polish cutter fishery. This codend exhibits better selectivity indices, and retains a smaller number of undersized fish. In 1997, further tests are planned on these types of codends of mesh sizes of 90 and 105 mm.