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Size selectivity of redfish (Sebastes spp.) in the Northeast Atlantic using grid-based selection systems for trawls

Published online by Cambridge University Press:  16 May 2013

Bent Herrmann ,
Manu Sistiaga ,
Roger B. Larsen  and
Kåre N. Nielsen
Bent Herrmann*
Affiliation:
SINTEF Fisheries and Aquaculture, Fishing Gear Technology, Willemoesvej 2, 9850 Hirtshals, Denmark
Manu Sistiaga
Affiliation:
SINTEF Fisheries and Aquaculture, Brattørkaia 17C, 7010 Trondheim, Norway
Roger B. Larsen
Affiliation:
University of Tromsø, Breivika, 9037 Tromsø, Norway
Kåre N. Nielsen
Affiliation:
University of Tromsø, Breivika, 9037 Tromsø, Norway
*
a Corresponding author: bent.herrmann@sintef.no
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Abstract

Using experimental data and a model to predict size selection based on morphological data, we investigated size selection of redfish (Sebastes spp.) in the grid-based selection systems used in Northeast Atlantic trawls. We found that not all redfish make physical contact with the spacing between the bars in the sorting grids while they pass in the direction of the codend, and therefore the escapement of some undersized redfish depends on size selection in the codend. We estimate that most of the escapement in the combined selection system (consisting of a 55-mm grid and a diamond mesh codend) happens through the grid. We demonstrated that for one of the two grid systems investigated the increase in size selection obtained experimentally by increasing grid-bar spacing is well in line with what could be expected based on the morphology of redfish. However, the size selection observed experimentally was significantly lower than the size-selective potential of the grids estimated based on the morphology of redfish. By computer simulations, we show that a possible explanation for this difference could be that not all redfish that attempt to escape through the grid make their attempt with an optimal angle of attack.

Keywords

Trawl fisheriesFishing gearSorting grid system, SelectivityAngle of attackRedfishSebastes
Type
Research Article
Information
Aquatic Living Resources , Volume 26 , Issue 2 , April 2013 , pp. 109 - 120
Copyright
© EDP Sciences, IFREMER, IRD 2013

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References

Akaike, H., 1974, A new look at the statistical model identification. IEEE Trans. Auto. Control 19, 716–722. CrossRefGoogle Scholar
Angell S., 1999, Development of a flexible selection system for fish trawls. Master thesis. Norwegian College of Fishery Science, University of Tromsø.
Chernick M.R., 2007, Bootstrap methods: A guide for practitioners and researchers, second edition. Wiley Series in Probability and Statistics, Wiley, New York.
Collins L.M., Lanza S. T., 2010, Latent class and latent transition analysis: with applications in the social, behavioral, and health sciences. New York, John Wiley & Sons.
Efron B., 1982, The jackknife, the bootstrap and other resampling plans. SIAM Monograph No 38, CBSM-NSF.
Eigaard, O., Herrmann, B., Nielsen, J. R., 2011, Influence of grid orientation and time of day on grid sorting in a small-meshed trawl fishery for Norway pout (Trisopterus esmarkii). Aquat. Living Resour. 25, 15–26. CrossRefGoogle Scholar
Frandsen, R.P., Herrmann, B., Madsen, N., 2010. A simulation-based attempt to quantify the morphological component of size selection of Nephrops norvegicus in trawl codends. Fish. Res. 101, 156–167. CrossRefGoogle Scholar
Fryer, R.J., 1991, A model of between-haul variation in selectivity. ICES J. Mar. Sci. 48, 281–290. CrossRefGoogle Scholar
Fryer, R.B., Shephard, J.G., 1996, Models of codend size selection. J. Northw. Atl. Fish. Sci. 19, 51–58. CrossRefGoogle Scholar
Herrmann, B., Krag, L.A., Frandsen, R.P., Madsen, N., Lundgren, B., Stæhr, K.J., 2009, Prediction of selectivity from morphological conditions: Methodology and a case study on cod (Gadus morhua). Fish. Res. 97, 59–71. CrossRefGoogle Scholar
Herrmann, B., Sistiaga, M., Nielsen, K.N., Larsen, R.B., 2012, Understanding the size selectivity of red fish (Sebastes spp.) in North Atlantic trawl codends. J. Northw. Atl. Fish. Sci. 44, 1–13. CrossRefGoogle Scholar
ICES, 2011, Report of the ICES-FAO Working Group on Fishing Technology and Fish Behaviour (WGFTFB), 9–13 May 2011, ICES CM 2011/SSGESST:11.
ICES, 2012, ICES Advice 2012, Book 3. ICES, Copenhagen.
Krag, L.A., Herrmann, B., Madsen, N., Frandsen, F., 2011, Size selection of haddock (Melanogrammus aeglefinus) in square mesh codends: A study based on assessment of decisive morphology for mesh penetration. Fish. Res. 110, 225–235. CrossRefGoogle Scholar
Manly B.F.J., 1997, Randomization, bootstrap and Monte Carlo methods in biology – Texts in statistical science. Chapman & Hall.
Millar, R.B., 1993, Incorporation of between-haul variation using boot strapping and nonparametric estimation of selection curves. Fish. Bull. 91, 564–572. Google Scholar
Millar, R.B., Fryer, R.B., 1999, Estimating the size selectivity of towed gears, traps, nets and hooks. Rev. Fish. Biol. Fish. 9, 89–116. CrossRefGoogle Scholar
O’Neill, F.G., Kynoch, R.J., Fryer, R.J., 2006, Square mesh panels in North Sea demersal trawls: separate estimates of panel and cod-end selectivity. Fish. Res. 78, 333–341. CrossRefGoogle Scholar
Pampoulie, C., Danielsdottir, A.K., 2008, Resolving species identification problems in the genus Sebastes using nuclear genetic markers. Fish. Res. 93, 54–63. CrossRefGoogle Scholar
Power, D.J., Ni, I.H., 1985, Morphometric differences between golden redfish (Sebastes marinus) and beaked red fishes (S. mentella and S. fasciatus). J. North Atlant. Fish. Sci. 6, 1–7. CrossRefGoogle Scholar
Sistiaga M., 2010, Selectivity studies in the Barents Sea bottom trawl gadoid fishery: Gear and methods. PhD thesis, University of Tromsø.
Sistiaga, M., Herrmann, B., Larsen, R.B., 2009, Investigation of the paired-gear method in selectivity studies. Fish. Res. 97, 196–205. CrossRefGoogle Scholar
Sistiaga, M., Herrmann, B., Grimaldo, E., Larsen, R.B., 2010, Assessment of dual selection in grid based selectivity systems. Fish. Res. 105, 187–199. CrossRefGoogle Scholar
Sistiaga, M., Herrmann, B., Nielsen, K.N., Larsen, R.B., 2011, Understanding limits to cod and haddock separation using size selectivity in a multispecies trawl fishery: an application of FISHSELECT. Can. J. Fish. Aquat. Sci. 68, 927–940. CrossRefGoogle Scholar
Wienbeck, H., Herrmann, B., Moderhak, W., Stepputtis, D., 2011, Effect of netting direction and number of meshes around on size selection in the codend for Baltic cod (Gadus morhua). Fish. Res. 109, 80–88. CrossRefGoogle Scholar
Wileman D.A., Ferro R.S.T., Fonteyne R., Millar R.B. (Eds.), 1996. Manual of methods of measuring the selectivity of towed fishing gears. ICES Coop. Res. Rep. No. 215.
Zuur, G., Fryer, R.J., Ferro, R.S.T., Tokai, T., 2001, Modelling the size selectivities of a trawl codend and an associated square mesh panel. ICES J. Mar. Sci. 58, 657–671.CrossRefGoogle Scholar