Academic Scientific JournalsThe effects of two different net modifications on reducing discards in the trammel net fishery for prawn in Mersin Bay
DOI:
https://doi.org/10.26881/oahs-2023.3.09Keywords:
by-catch, discards, greenhouse plastic film, greenhouse shade cloth, Mersin Bay, trammel netAbstract
The discarded species caught in prawn trammel nets damage the nets and cause a serious labor loss problem for fishers. In the present study, a 15 cm high greenhouse plastic film and a greenhouse shade cloth net were fitted between the lower parts of the nets and the lead collars to reduce discards in the trammel net fishery. The modified nets were tested in Mersin Bay with twenty-one fishing operations between September and December 2021. The results showed that, compared to commercial trammel nets, the nets equipped with greenhouse plastic film and greenhouse shade cloth did not significantly reduce the catch of the target species green tiger prawn (Penaeus semisulcatus). However, the total number of discards significantly decreased. The discard rates in the commercial net, greenhouse plastic film net, and greenhouse shade cloth net were 45%, 26%, and 22%, respectively. Furthermore, when the incomes from the nets’ hauls were calculated, the net equipped with greenhouse garden film and the net equipped with greenhouse shade cloth generated 24.77% and 14.41% more profit than the commercial net, respectively.
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References
Aydın, I., Gökçe, G., & Metin, C. (2013). Using guarding net to reduce regularly discarded invertebrates in trammel net fisheries operating on seagrass meadows (Posidonia oceanica) in İzmir Bay (Eastern Aegean Sea). Mediterranean. Marine Science, 14(2), 282-291. https://doi.org/10.12681/mms.425.
Bayhan, Y. K., & Gökçe, G. (2010). Shrimp fishery in northeast Mediterranean Sea and technical specifications of the shrimp nets. Journal of FisheriesSciences.Com, 4(2), 129- 135, (in Turkish) https://doi.org/10.3153/jfscom.2010012.
Bayhan, Y. K., Çiçek, E, Ünlüer, T., & Özdöl, M. (2022). Catch Composition and Abundance of Shrimp Species in the Bottom Trawl Fishery from Northeast Mediterranean, Türkiye. Journal of Marine Sciences and Fisheries, 5(2), 150- 159. (in Turkish) https://doi.org/10.46384/jmsf.1181780.
Borges, L. (2015). The evolution of a discard policy in Europe. Fish and Fisheries, 16(3), 534-540. https://doi.org/10.1111/faf.12062.
Bozaoğlu, A. S. (2012). Determination of By-Catch and Reduction in Trammel Net Fishery for Prawn in Mersin Bay. PhD Thesis, Mersin University, Mersin (in Turkish).
Catanese, G., Hinz, H., Gil, M. D. M., Palmer, M., Breen, M., Mira, A., Pastor, E., Grau, A., Campos-Candela, A., Koleva, E., Grau, A. M., & Morales-Nin, B. (2018). Comparing the catch composition, profitability and discard survival from different trammel net designs targeting common spiny lobster (Palinurus elephas) in a Mediterranean fishery. PeerJ, 6, e4707. https://doi.org/10.7717/peerj.4707.
Eryaşar, A. R., Ceylan, Y., Özbilgin, H., & Bozaoğlu, A. S. (2020). Are Cloth Tarpaulin Mounted Nets Effective for Discard Reduction in Trammel Nets? Turkish Journal of Fisheries and Aquatic Sciences, 21(2), 63-71. https://doi.org/10.4194/1303-2712-v21_2_02.
FAO. (2018). The State of Mediterranean and Black Sea Fisheries. General Fisheries Commission for the Mediterranean Rome.
GFCM. (2021). New programme to empower small-scale fishers https://www.fao.org/gfcm/news/detail/fr/c/1392277/.
Gökçe, G. (2004). Research on reduction of non-target species in shrimp trammel nets. PhD Thesis, Ege University Natural Science Institute, Izmir (in Turkish).
Gökçe, G., Bozaoğlu, A. S., Eryaşar, A. R., & Özbilgin, H. (2016). Discard reduction of trammel nets in the Northeastern Mediterranean prawn fishery. Journal of Applied Ichthyology, 32, 427–431. https://doi.org/10.1111/jai.13015.
Hall, S. J., & Mainprize, B. M. (2005). Managing by-catch and discards: How much progress are we making and how can we do better? Fish and Fisheries, 6, 134–155. https://doi. org/10.1111/j.1467-2979.2005.00183.x.
Jones, B. L., Unsworth, R. K., Udagedara, S., & Cullen-Unsworth L. C. (2018). Conservation concerns of small-scale fisheries: By-catch impacts of a shrimp and finfish fishery in a Sri Lankan lagoon. Frontiers in Marine Science, 52(5), https://doi.org/10.3389/fmars.2018.00052.
Kelleher, K. (2004). Discards in the world’s marine fisheries. An update. FAO Fisheries Technical Paper No. 470 (draft), Rome.
Maynou, F., García‐de‐Vinuesa, A. G., Martínez‐Baños, P., Sánchez, P., & Demestre, M. (2021). Relative catch performance of two gear modifications used to reduce bycatch of undersized fish and shrimp in Mediterranean bottom trawl fisheries. Marine and Coastal Fisheries, 13(5), 518-533. https://doi.org/10.1002/mcf2.10178.
Metin, C., Gökçe, G., Aydin, İ., & Bayramiç İ. (2009). Bycatch reduction in trammel net fishery for prawn (Melicertus kerathurus) by using guarding net in İzmir Bay on Aegean Coast of Turkey. Turkish Journal of Fisheries and Aquatic Sciences, 9(2), 133-136. https://doi.org/10.4194/trjfas.2009.0202.
Roda, M. A. P., Gilman, E., Huntington, T., Kennelly, S. J., Suuronen, P., Chaloupka, M., & Medley P. A. (2019). A third assessment of global marine fisheries discards. Food and Agriculture Organization of the United Nations.
Saidi, B., Enajjar, S., & Bradai, M. N. (2016). Elasmobranch captures in shrimps trammel net fishery off the Gulf of Gabès (Southern Tunisia, Mediterranean Sea). Journal of Applied Ichthyology, 32(3), 421-426. https://doi.org/10.1111/jai.13061.
Sardo, G., Vecchioni, L., Milisenda, G., Falsone, F., Geraci, M. L., Massi, D., Rizzo, P., Scannella, D., & Vitale, S. (2023). Guarding net effects on landings and discards in Mediterranean trammel net fishery: Case analysis of Egadi Islands Marine Protected Area (Central Mediterranean Sea, Italy). Frontiers in Marine Science, 10, 1011630. https://doi.org/10.3389/fmars.2023.1011630.
Sartor, P., Li Veli, D., De Carlo, F., Ligas, A., Massaro, A., Musumeci, C., Sartini, M., Rossetti, I., Sbrana, M., & Viva C. (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). Scientia Marina, 82(S1), 131-140. https://doi.org/10.3989/scimar.04765.15B.
Szynaka, M. J., Bentes, L., Monteiro, P., Rangel, M., & Erzini, K. (2018). Reduction of by-catch and discards in the Algarve small-scale coastal fishery using a monofilament trammel net rigged with a guarding net. ). Scientia Marina, 82(S1), 121-129. https://doi.org/10.3989/scimar.04734.16B.
Thomas, S. N., Edwin, L., & George W. C. (2003). Catching efficiency of gill nets and trammel nets for penaeid prawns. Fisheries Research, 60(1), 141–150. https://doi. org/10.1016/S0165-7836(02)00057-7.
Tiralongo, F., Mancini, E., Ventura, D., De Malerbe, S., Paladini, De Mendoza, F. P., Sardone, M., Arciprete, R., Massi, D., Marcelli, M., Fiorentino, F., & Minervini R. (2021). Commercial catches and discards composition in the central Tyrrhenian Sea: A multispecies quantitative and qualitative analysis from shallow and deep bottom trawling. Mediterranean Marine Science, 22(3), 521-531. https://doi.org/10.12681/mms.25753.
Tsagarakis, K., Palialexis, A., & Vassilopoulou V. (2014). Mediterranean fishery discards: Review of the existing knowledge. ICES Journal of Marine Science, 71(5), 1219- 1234. https://doi.org/10.1093/icesjms/fst074.
TUIK. (2020). Fishery production [www Document]. URL (accessed 6.04.22) (in Turkish)
