Understanding the status of key fish stocks in the Turkish Black Sea: A graphical approach to sustainable management

Mahir Demir

doi:10.12714/egejfas.42.2.03

EN TR

Understanding the status of key fish stocks in the Turkish Black Sea: A graphical approach to sustainable management

Abstract

Fish stocks are critical components of aquatic ecosystems, providing essential food sources for humanity and supporting the complex balance of marine food webs. Effective management of these resources is crucial for meeting global food demands and preserving aquatic biodiversity. In this study, we assess fishing pressures—categorized as low, high, and extreme—on six key fish stocks in the Turkish waters of the Black Sea: horse mackerel (Trachurus mediterraneus), the Black Sea anchovy (Engraulis encrasicolus), sprat (Sprattus sprattus), whiting (Merlangius merlangus euxinus), bluefish (Pomatomus saltatrix), and the Atlantic bonito (Sarda sarda) and provide important findings to protect fish stocks. By applying dynamic modeling and stability analysis solely to landing data, we create graphical representations that illustrate the current trends of these stocks, through growth and fishing mortality curves. Our findings reveal that although certain stocks have shown an upward trend over the past 15 years, they remain exposed to high levels of fishing mortality. To support sustainable management, this study establishes the Maximum Sustainable Yields (MSYs) for each stock based on their present conditions and identifies stable equilibrium points where stocks can be sustained over the long term. This method also provides an opportunity to analyze state of fish stocks when only landing data is available.

Keywords

Karadeniz'deki önemli balık stoklarının durumunun anlaşılması: Sürdürülebilir yönetim için grafiksel bir yaklaşım

Öz

Balık stokları, su ekosistemlerinin temel bileşenleridir; insanlık için çok önemli bir gıda kaynağı sağlarken, besin zincirinin karmaşık dengesine de katkıda bulunurlar. Bu balık stokların etkin bir şekilde yönetimi, gıda taleplerini karşılamak ve denizlerdeki biyolojik çeşitliliği korumak açısından kritik öneme sahiptir. Bu çalışmada, Türkiye'nin Karadeniz kıyısındaki altı ana balık stoğu – istavrit (Trachurus mediterraneus), hamsi (Engraulis encrasicolus), çaça (Sprattus sprattus), mezgit (Merlangius merlangus euxinus), lüfer (Pomatomus saltatrix) ve palamut (Sarda sarda) – düşük/yüksek/aşırı avlanma seviyelerine göre incelenmiştir ve bu stokların korunmasına dair önemli bulgular sunulmuştur. Sadece av istatistikleri kullanılarak dinamiksel bir inceleme ve denge analiziyle, balık stoklarının mevcut dinamiklerini grafiksel temsiller kullanarak analiz ettik. Bu grafikler, balık stoklarının büyüme eğrileri ve balıkçılık kaynaklı avlama (ölüm) eğrilerine dayanarak oluşturulmuştur. Araştırmamız, bazı stoklarda son 15 yılda artış eğilimi gözlense de hala yüksek düzeyde avlanma oranına maruz kaldıklarını ortaya koymaktadır. Bu sorunu ele almak için çalışmamız, her bir balık stoğunun mevcut durumuna bağlı olarak Maksimum Sürdürülebilir Verim (MSV) değerlerini belirlemekte ve bu stokların uzun vadede sürdürülebilir kalabileceği denge noktalarını tespit etmektedir. Bu yöntem, avlanma verileri dışında herhangi bir veri bulunmadığında balık stoklarını analiz etme fırsatı da sunmaktadır.

Anahtar Kelimeler

Etik Beyan

No ethical approval is required for this study.

Kaynakça

Akkuş, G., & Gücü, A.C. (2022). A comparative assessment of the Black Sea anchovy stock using holistic production and analytical age structure models. Acta Biologica Turcica, 35(3), A5, 1-12.
Aslan, I.H., Demir, M., Wise, M.M., & Lenhart, S. (2022). Modeling COVID-19: Forecasting and analyzing the dynamics of the outbreak in Hubei and Turkey. Mathematical Methods in the Applied Sciences, 45(10), 6481 – 6494. https://doi.org/10.1002/mma.8181
Bellard, C., Bertelsmeier, C., Leadley, P., Thuiller, W., & Courchamp, F. (2013). Impacts of climate change on the future of biodiversity. Ecology Letters, 16(4), 487–95. https://doi.org/10.1111/j.14610248.2011.01736.x
Botsford, L.W., Castilla, J.C., & Peterson, C.H. (1997). The management of fisheries and marine ecosystems. Science, 277(5325), 509-15. https://doi.org/10.1126/science.277.5325.509
Bouch, P., Minto, C., & Reid, D.G. (2021). Comparative performance of data-poor CMSY and data-moderate SPiCT stock assessment methods when applied to data-rich, real-world stocks. ICES Journal of Marine Science, 78, 264–276. https://doi.org/10.1093/icesjms/fsaa220
Beverton, R.J.H., & Holt, S.J. (1957). On the dynamics of exploited fish populations. Fisheries Investigations, 19, 1-533.
Cheikh, B.B., Mohamed Ahmed, J., Jilali, B., Fambye N., Ad, C., & Jo, G. (2024). Overexploitation of round sardinella may lead to the collapse of flat sardinella: What lessons can be drawn for shared stocks. Fisheries Research, 269,106873. https://doi.org/10.1016/j.fishres.2023.106873
Damir, N., Coatu, V., Danilov, D., Lazar, L., & Oros, A. (2024). From Waters to Fish: A Multi-Faceted Analysis of Contaminants’ Pollution Sources, Distribution Patterns, and Ecological and Human Health Consequences. Fishes, 9(7), 274. https://doi.org/10.3390/fishes9070274

Daskalov, G.M. (2002). Overfishing drives a trophic cascade in the Black Sea. Marine Ecology Progress Series, 225, 53 63. https://doi.org/10.3354/meps225053
Daskalov, G.M., Demirel, N., Ulman, A., Georgieva, Y., & Zengin, M. (2020). Stock dynamics and predator-prey effects of Atlantic bonito and bluefish as top predators in the Black Sea. ICES Journal of Marine Science, 77(7-8), 2995-3005. http://doi.org/10.1093/icesjms/fsaa182
Demirel, N., Zengin, M., & Ulman, A. (2020). First large-scale eastern Mediterranean and Black Sea stock assessment reveals a dramatic decline. Frontiers in Marine Science, 7(103). https://doi.org/10.3389/fmars.2020.00103
Demir, M., (2019). Optimal Control Strategies in Ecosystem-Based Fishery Models, Ph.D dissertation, University of Tennessee in Knoxville. Available from: https://trace.tennessee.edu/utk_graddiss/5421
Demir, M., & Lenhart S. (2020). Optimal sustainable fishery management of the Black Sea anchovy with food chain modeling framework. Natural Resource Modeling,33, e12253. https://doi.org/10.1111/nrm.12253
Demir, M., & Lenhart, S. (2021). A spatial food chain model for the Black Sea anchovy, and its optimal fishery. Discrete and Continuous Dynamical Systems Series B, 26(1), 155 171. https://doi.org/10.3934/dcdsb.2020373
Demir, M. (2023). Importance of stability analysis for sustainable fisheries in the absence of important data. Acta Aquatica Turcica, 19(1), 071-087. https://doi.org/10.22392/actaquatr.1179986
Demir, M. (2024). Predator effect of Atlantic bonito on the Black Sea anchovy and their sustainable and optimal fishery. Turkish Journal of Fisheries and Aquatic Sciences, 24(3), TRJFAS23861. https://doi.org/10.4194/TRJFAS23861
Dick, E.J., & MacCall, Alec D. (2011). Depletion-based stock reduction analysis: A catch-based method for determining sustainable yields for data-poor fish stocks, Fisheries Research, 110(2), 331-341, ISSN0165-7836. https://doi.org/10.1016/j.fishres.2011.05.007
FishBase, Estimation of Life history key facts. Accessed February 7, 2025. https://www.fishbase.se/manual/key%20facts.htm?utm_source=chatgpt.com
Fox, W.W. (1970). An exponential surplus-yield model for optimizing exploited fish populations? Transactions of American Fisheries Society, 99 (1), 80–88.
Froese, R., Demirel, N., Gianpaolo, C., Kleisner, K.M., & Winker, H. (2017). Estimating fisheries reference points from catch and resilience. Fish and Fisheries, 18(3), 506–526. https://doi.org/10.1111/faf.12190
Froese, R., Winker, H., Coro, G., Palomares, M.L., Tsikliras, A.C., Dimarchopoulou, D., Touloumis, K., Demirel, N., Vianna, G.M.S., Scarcella, G., Schijns, R., Liang, C., & Pauly, D. (2023). New developments in the analysis of catch time series as the basis for fish stock assessments: The CMSY++ method. Acta Ichthyologica et Piscatoria, 53, 173-189. https://doi.org/10.3897/aiep.53.105910
Gücü, A.C., Gen, Y., Dagtekin, M., Saknan, S., Ak, O., & Ok, M. (2017). On Black Sea anchovy and its fishery. Reviews in Fisheries Science and Aquaculture, 25, 149 162. https://doi.org/10.1080/23308249.2016.1276152
Hilborn, R. (2012). Overfishing: What everyone needs to know. New York: Oxford University Press USA, OSO. http://dx.doi.org/10.1080/03632415.2014.903839
Jenkins, D.G., & Quintana-Ascencio, P.F. (2020). A solution to minimum sample size for regressions. PLoS ONE, 15(2), e0229345. https://doi.org/10.1371/journal.pone.0229345
John, Fox (2015). Applied Regression Analysis and Generalized Linear Models. SAGE Publications (Book). ISBN: 1483321312, 9781483321318
Kasapoğlu, N. (2018). Age, growth, and mortality of exploited stocks: anchovy, sprat, Mediterranean horse mackerel, whiting, and red mullet in the southeastern Black Sea. Aquatic Sciences and Engineering, 33(2), 39-49. https://doi.org/10.18864/ase201807
Kot, M. (2001). Elements of mathematical ecology. Cambridge University Press.
Llope, M., Daskalov, G.M., Rouyer, T.A., Mihneva, V., Chan, K.S., Grishin, A. N., et al. (2011). Overfishing of top predators eroded the resilience of the Black Sea system regardless of the climate and anthropogenic conditions. Global Change Biology, 17, 1251 1265. https://doi.org/10.1111%2Fj.1365-2486.2010.02331.x
Mainali, K.P., Warren, D.L., Dhileepan, K, McConnachie, A., Strathie, L., Hassan, G., et al. (2015). Projecting future expansion of invasive species: comparing and improving methodologies for species distribution modeling. Global Change Biology, 21(12), 4293–4684. https://doi.org/10.1111/gcb.13038
Marino, S., Hogue, I.B., Ray, C.J., & Kirschner, D.E. (2008). A methodology for performing global uncertainty and sensitivity analysis in systems biology. Journal of Theoretical Biology, 254(1), 178-196. https://doi.org/10.1016%2Fj.jtbi.2008.04 .011
Nastase, A., & Paraschiv, G. (2024). Recent findings on the pollution levels in the Romanian Black Sea. Sustainability, 16(22), 9785. https://doi.org/10.3390/su16229785
Neubert, M. G. (2003). Marine reserves and optimal harvesting. Ecology Letters, 6(9), 843–849
Nogrady, B. (2023). Controlling pollution and overfishing can help protect coral reefs but it’s not enough. Nature, 620(7974), 479-479. https://doi.org/10.1038/d41586-023-02512-w
Özsandikçı, U. (2020). Estimation of exploitable sprat (Sprattus sprattus, Linnaeus, 1758) biomass along Black Sea coasts of Turkey (Samsun Region). Journal of New Results in Science, 9(3), 1-8. https://dergipark.org.tr/en/download/article-file/1306269
Patrick, W.S., & Cope, J. (2014). Examining the 10-Year rebuilding dilemma for U.S. fish stocks. PLoS ONE, 9(11), e112232. https://doi.org/10.1371/journal.pone.0112232
Raykov, V.S., & Duzgunes, E. (2017). Fisheries management in the Black Sea—pros and cons. Frontiers in Marine Science, 4: 227. https://doi.org/10.3389/fmars.2017.00227
Salihoglu, B., Arkin, S.S., Akoglu, E., & Fach, B.A. (2017). Evolution of future Black Sea fish stocks under changing environmental and climatic conditions (report). Frontiers in Marine Science, 4: 339. https://doi.org/10.3389/fmars.2017.00339
Schaefer, M.B. (1954). Some aspects of the dynamics of populations important to the management of the commercial marine fisheries? Inter-American Tropical Tuna Commission, 1, 26–56.
STECF (2017). Scientific, Technical and Economic Committee for Fisheries (STECF) Black Sea Assessments. Publications Office of the European Union, Luxembourg, EUR 27517 EN, JRC, page 284 pp.
Sumaila, U.R., & Tai, T.C. (2020). End overfishing and increase the resilience of the ocean to climate change. Frontiers in Marine Science, 7, 523. https://doi.org/10.3389/fmars.2020.00523
TUIK (2023). Turkish Statistical Institute (TUIK). Quantity of harvested marine products and price of harvested marine products. https://biruni.tuik.gov.tr/medas/?kn=97&locale=tr
Winker, H., Carvalho, F., & Kapur, M. (2018). JABBA: just another Bayesian biomass assessment. Fisheries Research, 204, 275–288. https://doi.org/10.1016/j.fishres.2018.03.010
Zengin, M., & Dincer, A. C. (2006). Distribution and seasonal movement of Atlantic bonito (Sarda sarda) populations in the southern Black Sea coasts. Turkish Journal of Fisheries and Aquatic Sciences, 6, 57-62. https://www.trjfas.org/uploads/pdf_267.pdf
Zhou, S., Punt, A.E., Smith, A.D.M., Ye, Y., Haddon, M., Dichmont, C.M., & Smith, D.C. (2017). An optimized catch-only assessment method for data poor fisheries. ICES Journal of Marine Science, 75, 964–976. https://doi.org/10.1093/icesjms/fsx226

Ayrıntılar

Birincil Dil

İngilizce

Konular

Balıkçılık Yönetimi

Bölüm

Araştırma Makalesi

Yazarlar

Mahir Demir ^*
0000-0002-9670-5210
Türkiye

Erken Görünüm Tarihi

14 Haziran 2025

Yayımlanma Tarihi

15 Haziran 2025

Gönderilme Tarihi

17 Aralık 2024

Kabul Tarihi

12 Mart 2025

Yayımlandığı Sayı

Yıl 2025 Cilt: 42 Sayı: 2

DOI

https://doi.org/10.12714/egejfas.42.2.03

IZ

https://izlik.org/JA42SW62BD

Kaynak Göster

RIS / Bibtex

APA

Demir, M. (2025). Understanding the status of key fish stocks in the Turkish Black Sea: A graphical approach to sustainable management. Ege Journal of Fisheries and Aquatic Sciences, 42(2), 105-121. https://doi.org/10.12714/egejfas.42.2.03