Time for a U-turn for an ecosystem-based management of shrimp fisheries in the Sea of Marmara

Abstract

This study aims to inform sustainable fisheries management strategies by evaluating the contribution of beam trawl fisheries, mainly targeting deep-water rose shrimp Parapenaeus longirostris, to bycatch in the Sea of Marmara (SoM). Field studies were conducted between May 2022 and April 2023 in collaboration with local fishers operating in shrimp fishing areas in southern SoM. The study encompassed 120 beam trawl surveys covering 8.88 km² across randomly selected stations. Biomass and catch per unit effort were analyzed to quantify catch composition and bycatch levels. Over the study period, 3925 kg of marine organisms representing diverse species were collected, with the target species, deep-water rose shrimp, comprising only 24.6% of the retained catch. The remaining catch consisted of bycatch, including both commercial and non-commercial species, as well as the incidental capture of sensitive taxa. Through field-based assessments, this study highlights the inadequacy of current mitigation efforts to address the destructive nature of the beam trawl fishery in the SoM. Despite gear modification efforts to date to increase selectivity and reduce bycatch, no intervention has been entirely successful in eliminating the ecological footprint. Data-driven insights argue for new management strategies, prioritizing alternative solutions and ecosystem-based fisheries management.

Keywords

• Beam trawl
• Shrimp fishery
• Bycatch
• Fisheries
• Ecosystem-based fisheries management

Supporting Institution

This work was supported by the Scientific and Technological Research Council of Türkiye (TUBITAK) ARDEB 1002 [grant number 122Y004].

Project Number

122Y004

Ethical Statement

Formal consent is not required for this study. No shark and ray individuals were landed during the study. All applicable international, national, and/or institutional guidelines for the care and use of animals were followed. Field studies were carried out with the permission decision dated 17.12.2021 and numbered E-12907815-140.99-3782900 of the Ministry of Agriculture and Forestry.

Thanks

We want to thank the volunteer commercial fishermen in the study area who participated in the sampling studies with their vessels.

Marmara Denizi'nde karides balıkçılığının ekosistem tabanlı yönetimi için U dönüşü zamanı

Abstract

Bu çalışma, esas olarak derin su pembe karidesini (Parapenaeus longirostris) hedef alan trol balıkçılığının Marmara Denizi'ndeki (SoM) hedef dışı av katkısını değerlendirerek sürdürülebilir balıkçılık yönetim stratejilerini bilgilendirmeyi amaçlamaktadır. Güney SoM'daki karides avcılığı alanlarında faaliyet gösteren yerel balıkçılarla iş birliği içinde Mayıs 2022 ile Nisan 2023 arasında saha çalışmaları güney yürütülmüştür. Çalışma, rastgele seçilen istasyonlarda 8,88 km²'yi kapsayan 120 trol araştırmasını içermektedir. Av kompozisyonu ve yan av miktarını belirlemek için biyokütle ve birim çaba başına av miktarları analiz edilmiştir. Çalışma süresince, çeşitli türleri temsil eden 3.925 kg av elde edilmiş olup, hedef tür olan derin su pembe karidesi, toplam avın yalnızca %24,6'sını oluşturmuştur. Geriye kalan av, ticari ve ticari olmayan türler de dahil olmak üzere yan avların yanı sıra tesadüfen yakalanan hassas taksonlardan oluşmaktadır. Saha tabanlı değerlendirmeler yoluyla bu çalışma, SoM'deki algarna balıkçılığının yıkıcı doğasını ele almak için mevcut azaltma çabalarının yetersizliğini vurgulamaktadır. Seçiciliği artırmak ve yan avı azaltmak için bugüne kadar yapılan ekipman değişikliği çabalarına rağmen, ekolojik ayak izini ortadan kaldırmada hiçbir müdahale tamamen başarılı olmamıştır. Veriye dayalı içgörüler, alternatif çözümlere ve ekosistem tabanlı balıkçılık yönetimine öncelik veren yeni yönetim stratejilerine olan ihtiyacı vurgulamaktadır.

Keywords

• Algarna
• Karides balıkçılığı
• Yan av
• Balıkçılık
• Ekosistem temelli balıkçılık yönetimi

Project Number

122Y004

References

1. Akçay, İ., Yücel, M. (2023). Distinct patterns of sedimentary phosphorus fractionation and mobilization in the seafloor of the Black Sea, Marmara Sea and Mediterranean Sea. Science of the Total Environment, 863: 160936. doi: 10.1016/j.scitotenv.2022.160936.
2. Akoglu, E., Saygu, İ., Demirel, N. (2024). Decadal changes in the Sea of Marmara indicate degraded ecosystem conditions and unsustainable fisheries. Frontiers in Marine Science, 11: 1412656. doi: 10.3389/fmars.2024.1412656.
3. Arslan İhsanoğlu, M., İşmen, A. (2020). Biological traits and population dynamic of Parapenaeus longirostris (Lucas, 1846) in the Marmara Sea, Turkey. Ege Journal of Fisheries and Aquatic Sciences, 37: 275-283. doi: 10.12714/egejfas.37.3.10.
4. Bayhan, Y.K., Çiçek, E., Ünlüer, T., Akkaya, M. (2006). Catch and by-catch composition of the shrimp fishery by beam trawl in the southeastern Marmara Sea. Ege Journal of Fisheries and Aquatic Sciences, 23: 277-283.
5. Bilecenoğlu, M. (2024). Diversity of fishes along the coast of Türkiye. Turkish Journal of Zoology, 48: 589-616. doi: 10.55730/1300-0179.3197.
6. Bjordal, A. (2002). The use of technical measures in responsible fisheries: regulation of fishing gear. FAO Fisheries Technical Paper No: 424. Rome, 231 pp.
7. Bök, T.D., Göktürk, D., Kahraman, A.E., Alıçlı, T.Z., Acun, T., Ateş, C. (2011). Length-weight relationships of 34 fish species from the Sea of Marmara, Turkey. Journal of Animal and Veterinary Advances, 10: 3037-3042. doi: 10.3923/javaa.2011.3037.3042.
8. Bök, T.D., Goktürk, D., Kahraman, A.E. (2011). Bycatch in 36 and 40 mm PA Turkish twin rigged beam trawl codends. African Journal of Biotechnology, 10: 7294-7302.

9. Carpentieri, P. (2019). Monitoring discards in Mediterranean and Black Sea fisheries: methodology for data collection. FAO Fisheries Technical Paper No: 639. Rome, 96 pp.
10. Chen, E.Y.S. (2021). Often overlooked: understanding and meeting the current challenges of marine invertebrate conservation. Frontiers in Marine Science, 8: 690704. doi: 10.3389/fmars.2021.690704.
11. Çıra, E., Tosunoğlu, Z. (2001). An overview of trawl selectivity by the wievpoint of fisheries management. Ege Journal of Fisheries and Aquatic Sciences, 18: 583-591.
12. Daban, B., İşmen, A., Şirin, M., Yığın, C.Ç., Arslan İhsanoğlu, M. (2021). Analysis of demersal fish fauna off the Sea of Marmara, Turkey. COMU Journal of Marine Sciences and Fisheries, 4: 20-31. doi: 10.46384/jmsf.912403.
13. Davies, R.W.D., Cripps, S.J., Nickson, A., Porter, G. (2009). Defining and estimating global marine fisheries bycatch. Marine Policy, 33: 661-672. doi: 10.1016/j.marpol.2009.01.003.
14. Demirel, N., Akoğlu, E., Ulman, A., Ertor-Akyazi, P., Gül, G., Bedikoğlu, D., Yıldız, T., Yilmaz, N. (2023). Uncovering ecological regime shifts in the Sea of Marmara and reconsidering management strategies. Marine Environmental Research, 183: 105794. doi: 10.1016/j.marenvres.2022.105794.
15. Ebert, D.A., Dando, M., Fowler, S. (2021). Sharks of the World: A complete guide. 608 pp, New Jersey, Princeton University Press. doi: 10.1515/9780691210872.
16. FAO (2022). The state of Mediterranean and Black Sea fisheries 2022. General Fisheries Commission for the Mediterranean. Rome, 188 pp.
17. Favaro, B., Rutherford, D.T., Duff, S.D., Côté, I.M. (2010). Bycatch of rockfish and other species in British Columbia spot prawn traps: Preliminary assessment using research traps. Fisheries Research, 102: 199-206. doi: 10.1016/j.fishres.2009.11.013.
18. Froese, R., Pauly, D. FishBase version (04/2025), (2025). Accessed Date: 10.06.2025, https://www.fishbase.org is retrieved.
19. Gillett, R. (2008). Global study of shrimp fisheries. FAO Fisheries Technical Paper No: 475. Rome, 331 pp.
20. Guijarro, B., Ordines, F., Massutı, E. (2017). Improving the ecological efficiency of the bottom trawl fishery in the Western Mediterranean: It’s about time!. Marine Policy, 83: 204-214. doi: 10.1016/j.marpol.2017.06.007.
21. He, P., Chopin, F., Suuronen, P., Ferro, R.S.T., Lansley, J. (2021). Classification and illustrated definition of fishing gears. FAO Fisheries and Aquaculture Technical Paper No. 672. Rome, 110 pp. doi: 10.4060/cb4966en.
22. Hilborn, R., Amoroso, R., Collie, J., Hiddink, J.G., Kaiser, M.J., Mazor, T., McConnaughey, R.A., Parma, A.M., Pitcher, C.R., Sciberras, M., Suuronen, P. (2023). Evaluating the sustainability and environmental impacts of trawling compared to other food production systems. ICES Journal of Marine Science, 80: 1567-1579. doi: 10.1093/icesjms/fsad115.
23. Ismen, A., Yigin, C.C., Inceoglu, H., Arslan, M., Daban, B., Kale, S., Kocabas, E., Sirin, M. (2013). Chondrichthyan bycatches in the beam trawl shrimp fishery of the Marmara Sea. Commission International Pour l'exploration Scientifique de la Mer Méditerranée, 40: 487.
24. Kalogirou, S., Pihl, L., Maravelias, C.D., Herrmann, B., Smith, C.J., Papadopoulou, N., Notti, E., Sala, A. (2019). Shrimp trap selectivity in a Mediterranean small-scale-fishery. Fisheries Research, 211: 131-140. doi: 10.1016/j.fishres.2018.11.006.
25. Kalogirou, S., Dimitriadis, C., Maravelias, C.D., Poursanidis, D., Margaritis, M., Miliou, H., Pihl, L. (2022). Bycatch dynamics from a small-scale shrimp trap fishery in the Mediterranean Sea. Diversity, 14: 292. doi: 10.3390/d14040292
26. Karadurmuş, U. (2022). Current status, management, and future prospects of whiting (Merlangius merlangus) in the sea of Marmara. Acta Aquatica Turcica, 18: 314-331. doi: 10.22392/actaquatr.1059877.
27. Karadurmus, U., Sarı, M. (2022). Marine mucilage in the Sea of Marmara and its effects on the marine ecosystem: mass deaths. Turkish Journal of Zoology, 46: 93-102. doi: 10.3906/zoo-2108-14.
28. Karadurmus, U., Sarı, M. (2024). Distribution and diversity of elasmobranchs in the Sea of Marmara: A 2023 status report. Aquatic Conservation: Marine and Freshwater Ecosystems, 34: e4121. doi: 10.1002/aqc.4121.
29. Karadurmus, U., Dereli, H., Aydın, M. (2025). Distribution and population structure of discarded Parastichopus regalis (Holothuroidea) from the shrimp trawling fishery in the Sea of Marmara. Turkish Journal of Fisheries and Aquatic Sciences, 25: TRJFA25576. doi: 10.4194/TRJFAS25576.
30. Karakulak, F.S., Kahraman, A.E., Yıldız, T., Uzer, U., Doğru, S. (2024). A complete overview of fisheries in the Sea of Marmara. In: “Ecological Changes in the Sea of Marmara”, (Editors: E. Isinibilir, A.E. Kideys, A. Malej), pp. 779-818, İstanbul University Publication, İstanbul. doi: 10.26650/B/LSB21LSB37.2024.023.024.
31. Nelson, J.S. (2006). Fishes of the World (4th ed). 601 pp, New York, Wiley.
32. Özalp, H.B. (2021). First massive mucilage event observed in deep waters of Çanakkale Strait (Dardanelles), Turkey. Journal of the Black Sea/Mediterranean Environment, 27: 49-66.
33. Öztürk, B. (2009). Investigations of the rose shrimp Parapenaeus longirostris (Lucas, 1846) in the Northern Marmara Sea. Journal Black Sea/Mediterranean Environment, 15: 123-134.
34. Özvarol, Y. (2016). Selectivity of lessepsian fish, Randall’s threadfin bream (Nemipterus randali Rusell, 1986) in the Gulf of Antalya, Eastern Mediterranean. Scientific Papers Animal Science, 59: 330-335.
35. Sarı, M., Karadurmuş, U. (2024). Post-mucilage status of the teleost fish assemblages in the Sea of Marmara. Turkish Journal of Zoology, 48: 154-164. doi: 10.55730/1300-0179.3170.
36. Slack-Smith, R.J. (2001). Fishing with traps and pots. FAO Training Series No: 26. London, 62 pp.
37. Suuronen, P., Chopin, F., Glass, C., Løkkeborg, S., Matsushita, Y., Queirolo, D., Rihan, D. (2012). Low impact and fuel efficient fishing-Looking beyond the horizon. Fisheries Research, 119-120: 135-146. doi: 10.1016/j.fishres.2011.12.009.
38. TÜİK, Fisheries statistics. Turkish Statistical Institute, (2022). Accessed Date: 10.06.2025, https://biruni.tuik.gov.tr/medas/?kn=97&locale=tr is retrieved.
39. Ulman, A., Zengin, M., Demirel, N., Pauly, D. (2020). The lost fish of Turkey: A recent history of disappeared species and commercial fishery extinctions for the Turkish Marmara and Black Seas. Frontiers in Marine Science, 7: 650. doi: 10.3389/fmars.2020.00650.
40. Wheeler, C.R., Gervais, C.R., Johnson, M.S., Vance, S., Rosa, R., Mandelman, J.W., Rummer, J.L. (2020). Anthropogenic stressors influence reproduction and development in elasmobranch fishes. Reviews in Fish Biology and Fisheries, 30: 373-386. doi: 10.1007/s11160-020-09604-0.
41. Zengin, M., Kaykaç, H., Tosunoğlu, Z., Yıldız, T., Uzer, U. (2022). Selectivity characteristics of the sorting grid in shrimp beam trawls used to reduce bycatch in the Sea of Marmara. Acta Aquatica Turcica, 18: 535-549. doi: 10.22392/actaquatr.1164735.