Reducing discards in trammel net fisheries with simple modifications based on a guarding net and artificial light: contributing to marine biodiversity conservation




experimental fishing, discard reduction, trammel net fisheries, Mediterranean Sea, cuttlefish


Experimental fishing trials with standard (control) and modified trammel nets were conducted to assess the possible reduction of discards. The standard trammel net was the commercial net used in the area (80 mm stretched mesh inner panel) targeting Sepia officinalis. This configuration produced 19% discards in weight. The modifications researched were of two kinds: a “guarding net” consisting of a 2.5-mesh-high (200 mm stretched mesh) net between the footrope and the trammel net and artificial lights of two colours (white or green) mounted on the floating ropes. Catches were identified, measured and categorized (commercial, discards and reason for discarding), and the different configurations were tested for statistical differences. Our results show that trammel net deployments with guarding net produce 32% higher catches of commercial species and as much as 95% higher catches of the target cuttlefish. Artificial lights produced a low but significant increase in total catches of commercial species of 13%, with no differences due to light colour. The amount of discards in deployments with guarding net was 6%, i.e. ca. 1/4 of the amount produced by the standard configuration. The effect of lights on discard reduction was not significant.


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Arimoto T., Glass C.W., Zhang X. 2010. Fish vision and its role in fish capture. In: He P. (ed.), Behavior of marine fishes: capture processes and conservation challenges. Wiley-Blackwell, Ames, Iowa, pp. 25-40.Ben-Yami M. 1988. Attracting fish with light. FAO, Rome.

Clarke K.R., Gorley R.N. 2006. PRIMER v6: User Manual/Tutorial. PRIMER-E, Plymouth, 192 pp.

European Commission (EC). 2002. Communication from the Commission to the Council and the European Parliament on a Community Action Plan to reduce discards of fish (COM (2002) 656 final), 21 pp. 2002-656-EN-F1-1.Pdf

Erzini K., Gonçalves J.M.S., Bentes L., et al. 2006. Size selectivity of trammel nets in southern European small-scale fisheries. Fish. Res. 79: 183-201.

Gonçalves J.M.S., Stergiou K.I., Hernando J.A., et al. 2007. Discards from experimental trammel nets in southern European small-scale fisheries. Fish. Res. 88: 5-14.

Gonçalves J.M.S., Bentes L., Coelho R., et al. 2008. Non-commercial invertebrate discards in an experimental trammel net fishery. Fish. Manag. Ecol. 15: 199-210.

Griffiths R.C., Robles R., Coppola S.R., et al. 2007. Is there a future for artisanal fisheries in the western Mediterranean? Rome, FAO-COPEMED, 106 pp.

Guyader O. (co-ordinator). 2007. Small-scale coastal fisheries in Europe. Final Report of the project. European Commission FISH/2005/10.

Gullestad P., Blom G., Bakke G., et al. 2015. The "Discard Ban Package": Experiences in efforts to improve the exploitation patterns in Norwegian fisheries. Mar. Pol. 54: 1-9.

Inada H., Arimoto T. 2007. Trends on research and development of fishing light in Japan. J. Illum. Engng. Inst. Jpn. 91: 199-205.

Maynou F., Recasens L., Lombarte A. 2011. Fishing tactics dynamics of a Mediterranean small-scale coastal fishery. Aquat. Liv. Res. 24: 149-159.

Metin C., Gökçe G., Aydın ?., et al. 2009. Bycatch reduction in trammel net fishery for prawn (Melicertus kerathurus) by using guarding net in ?zmir bay on Aegean coast of Turkey. Turk. J. Fish. Aquat. Sci. 9: 133-136.

Rossetti I., Vannucci A., Sartini M., et al. 2006. Pesca di mazzancolla, Penaeus kerathurus (Forsskål, 1775), con reti da posta presso la marineria artigianale di Viareggio (Mar Ligure sud-orientale). Biol. Mar. Mediterr. 13: 284-285.

Sartor P., Silvestri R., Sbrana M., et al. 2007. Sperimentazione di accorgimenti tecnici per la riduzione dello scarto nella pesca con reti da posta lungo il litorale livornese. Biol. Mar. Mediterr. 14: 360-361.

Sartor P., Li Veli D., De Carlo F., et al. 2018. Reducing unwanted catches of trammel nets: experimental results of the "guarding net" in the caramote prawn, Penaeus kerathurus, small scale fishery of the Ligurian Sea (Western Mediterranean). Sci. Mar. 82S1.

Stergiou K.I., Moutopoulos D.K., Soriguer M.C., et al. 2006.Trammel net catch species composition, catch rates and métiers in southern European waters: A multivariate approach. Fish. Res. 79: 170-182.

Szynaka MJ, Bentes L, Monteiro P, et al. 2018. Reduction of by-catch and discards in the Algarve small-scale coastal fishery using a monofilament trammel net rigged with a guarding net. Sci. Mar. 82S1.



How to Cite

Martínez-Baños P, Maynou F. Reducing discards in trammel net fisheries with simple modifications based on a guarding net and artificial light: contributing to marine biodiversity conservation. scimar [Internet]. 2018Dec.30 [cited 2023Nov.28];82(S1):9-18. Available from:




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