||Herrmann Bent1, Priour Daniel2, Krag Ludvig A.1
||1 : Danish Inst Fisheries Res, DIFRES, North Sea Ctr, DK-9850 Hirtshals, Denmark.
2 : IFREMER, French Inst Res & Explorat Sea, F-29280 Plouzane, France.
||Fisheries Research (0165-7836) (Elsevier), 2007-04 , Vol. 84 , N. 2 , P. 222-232
|WOS© Times Cited
||FEMNET, PRESEMO, T90, Cod end selectivity
||FEMNET, a numerical tool based on the finite element method, was used to estimate the shapes of four different designs of trawl cod-ends during fishing operations. Compared to a traditional diamond-mesh cod-end the design differences were the following: (i) the netting orientation was turned by 90 degrees (T90), (ii) the number of meshes in the circumference was reduced by 50% or (i) and (ii) were combined. The cod-end shape estimates were then entered into the simulation tool PRESEMO, to estimate their influence on the selectivity processes in the cod-end. This enabled us to predict how these design alterations - alone or combined - may act on the selectivity of each cod-end under identical fishing conditions. For instance, we predict that for a I 10 mm diamond-mesh cod-end the 50% retention length (1-50) is increased by nearly 12 cm by both turning the mesh orientation and reducing the number of meshes in the circumference. Of this combined effect we predict that 24% of it is caused by only turning the mesh orientation whereas 71 % of the effect stems from only reducing the number of meshes in circumference. The remaining 5% is due to the interaction between the two factors. (c) 2006 Elsevier B.V. All rights reserved.