Release efficiency and selectivity of four different square mesh panel configurations in the Basque mixed bottom trawl fishery




square mesh panel, LED lights, trawl fishery, release efficiency, hake, blue whiting


Reduction of discards from the Basque mixed bottom trawl fishery is a challenge. To improve the selective properties of the gear used by the fleet and supplement codend size selection, a square mesh panel (SMP) installed in the upper panel of the trawl was introduced in 2006. However, recent studies have shown that the release efficiency of this SMP is low due to lack of contact between the fish and the SMP. In this study, we tested the release efficiency of the SMP for four different gear configurations. We tested the effect of adding LED lights at two different positions and altering panel size and panel position in the trawl. The analyses were focused on two species: hake (Merluccius merluccius) and blue whiting (Micromesistius poutassou). The results showed that the position of LED lights did not significantly affect the SMP’s release efficiency for any species. However, increasing panel size had a significant positive effect on the release efficiency of blue whiting, and placing the SMP in the lower panel improved the release efficiency of hake. These results highlight the challenge of simultaneously improving the selective properties of gear for species with different behaviour, especially in mixed demersal fisheries.


Download data is not yet available.


Akaike H. 1974. A New Look at the Statistical Model Identification. In: Parzen E., Tanabe K., Kitagawa G. (eds), Selected Papers of Hirotugu Akaike. Springer Series in Statistics (Perspectives in Statistics). Springer, New York, pp. 215-222.

Alzorriz N., Arregi L., Herrmann B., et al. 2016. Questioning the effectiveness of technical measures implemented by the Basque bottom otter trawl fleet: Implications under the EU landing obligation. Fish. Res. 175: 116-126.

Anonymous. 2016. MEDITS-Handbook Version 8. MEDITS Working Group, pp. 25-31.

Bahamon N., Sardà F., Suuronen P. 2006. Improvement of trawl selectivity in the NW Mediterranean demersal fishery by using a 40 mm square mesh codend. Fish. Res. 81: 15-25.

Bertrand J.A., De Sola L.G., Papaconstantinou C., et al. 2000. An international bottom trawl survey in the Mediterranean: the MEDITS programme. IFREMER Actes Colloq. 76-96.

Brčić J., Herrmann B., Sala A. 2016. Can a square-mesh panel inserted in front of the codend improve the exploitation pattern in Mediterranean bottom trawl fisheries? Fish. Res. 183: 13-18.

Brčić J., Herrmann B., Sala A. 2018. Can a square-mesh panel inserted in front of the cod end improve size and species selectivity in Mediterranean trawl fisheries? Can. J. Fish. Aquat. Sci. 75: 704-713.

De Vos B.I., Döring R., Aranda M., et al. 2016. New modes of fisheries governance: Implementation of the landing obligation in four European countries. Mar. Policy 64: 1-8.

Dorel D. 1986. Poissons de l'Atlantique nord-est: Relations taille-poids. IFREMER Report, 165 pp.

EC. 1996. Council Regulation (EC) No 2406/96 of 26 November 1996 laying down common marketing standards for certain fishery products. OJ L 334, 23.12.1996, pp. 1-15. LEX:31996R2406&from=ES

EC. 2006. Council Regulation (EC) No. 51/2006 of 22 December 2005 fixing for 2006 the fishing opportunities and associated conditions for certain fish stocks and groups of fish stocks, applicable in Community waters and, for Community vessels, in waters where catch limitations are required. OJ L 16, 20.1.2006, pp.1-183. LEX:32006R0051&from=EN

Efron B. 1982. The jackknife, the bootstrap and other resampling plans. SIAM Monograph No. 38, CBSM-NSF.

Engås A., Jørgensen T., West C.W. 1998. A species-selective trawl for demersal gadoid fisheries. ICES J. Mar. Sci. 55: 835-845.

EU. 2013. Regulation (EU) No 1380/2013 of the European Parliament and of the Council of 11 December 2013 on the Common Fisheries Policy, amending Council Regulations (EC) No 1954/2003 and (EC) No 1224/2009 and repealing Council Regulations (EC) No 2371/2002 and (EC) No 639/2004 and Council Decision 2004/585/EC. OJ L 354, 28.12.2013, pp. 22-61. LEX:32013R1380&from=EN

Ferro R.S.T., Jones E.G., Kynoch R.J., et al. 2007. Separating species using a horizontal panel in the Scottish North Sea whitefish trawl fishery. ICES J. Mar. Sci. 64: 1543-1550.

Fryer R.J. 1991. A model of between-haul variation in selectivity. ICES J. Mar. Sci. 48: 281-290.

Glass C.W., Wardle C.S. 1995. Studies on the use of visual stimuli to control fish escape from codends. II. The effect of a black tunnel on the reaction behaviour of fish in otter trawl codends. Fish. Res. 23: 165-174.

Grimaldo E., Sistiaga M., Herrmann B., et al. 2017. Improving release efficiency of cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) in the Barents Sea demersal trawl fishery by stimulating escape behaviour. Can. J. Fish. Aquat. Sci. 75: 402-416.

Hannah R.W., Lomeli M.J., Jones S.A. 2015. Tests of artificial light for bycatch reduction in an ocean shrimp (Pandalus jordani) trawl: strong but opposite effects at the footrope and near the bycatch reduction device. Fish. Res. 170: 60-67.

Herrmann B., Sistiaga M., Nielsen K.N., et al. 2012. Understanding the size selectivity of redfish (Sebastes spp.) in North Atlantic trawl codends. J. Northwest Atl. Fish. Sci. 44: 1-13.

Herrmann B., Wienbeck H., Karlsen J.D., et al. 2014. Understanding the release efficiency of Atlantic cod (Gadus morhua) from trawls with a square mesh panel: effects of panel area, panel position, and stimulation of escape response. ICES J. Mar. Sci. 72: 686-696.

Kim Y.H., Whang D.S. 2010. An actively stimulating net panel and rope array inside a model cod-end to increase juvenile red seabream escapement. Fish. Res. 106: 71-75.

Lomeli M.J., Groth S.D., Blume M.T., et al. 2018. Effects on the bycatch of eulachon and juvenile groundfish by altering the level of artificial illumination along an ocean shrimp trawl fishing line. ICES J. Mar. Sci. 75: 2224-2234.

Nikolic N., Diméet J., Fifas S., et al. 2015. Efficacy of selective devices in reducing discards in the Nephrops trawl fishery in the Bay of Biscay. ICES J. Mar. Sci. 72: 1869-1881.

Rochet M.J., Arregi L., Fonseca T., et al. 2014. Demersal discard atlas for the South Western Waters. 121 pp.

Santos J., Herrmann B., Otero P., et al. 2016. Square mesh panels in demersal trawls: does lateral positioning enhance fish contact probability? Aquat. Living Resour. 29: 302.

Sistiaga M., Brinkhof J., Herrmann B., et al. 2016. Size selective performance of two flexible sorting grid designs in the Northeast Arctic cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) fishery. Fish. Res. 183: 340-351.

Wileman D.A., Ferro R.S.T., Fonteyne R., (ed.). 1996. Manual of methods of measuring the selectivity of towed fishing gears. ICES Coop. Res. Rep. No. 215.



How to Cite

Cuende E, Arregi L, Herrmann B, Sistiaga M, Basterretxea M. Release efficiency and selectivity of four different square mesh panel configurations in the Basque mixed bottom trawl fishery. scimar [Internet]. 2020Mar.30 [cited 2023Mar.31];84(1):39-47. Available from: