Current state of overfishing and its regional differences in the Black Sea

Long-term (1950-2006) changes of fish landings in combination with some ecosystem indicators are used to evaluate the status and sustainability of the Black Sea fishery. Following the depletion of large pelagic predator and demersal fish stocks during the 1950-1960s, the main fishery was targetted on small and medium pelagics that declined abruptly to similar to 200 kton (kton 10(3) t) at 1989-1991 after a highly productive (similar to 750 kton) but overfished state in the 1980s. Thereafter, total landings in all the Black Sea countries except Turkey remained at most 10% level of the previous phase. For Turkey, only the low cost anchovy fishery was able to maintain at the mean catch size of 368 +/- 74 kton for 1992-2006 that however represented roughly twice of the maximum sustainable catch. The absence of fish within the western, eastern and northern regions and the presence of only a fluctuating heavily exploited anchovy fishery in the southern region during the last 20 years demand an immediate common ecosystem-based fishery management policy and actions by all the coastal states.


Current distribution of the small pelagic fish populations in the North Eastern Levantine Sea in relation to environmental conditions and predicting the impacts of temperature rise on their future distributions
Sakınan, Serdar; Gücü, Ali Cemal; Department of Marine Biology and Fisheries (2014)
Stocks of traditionally targeted fish species are in decline in the north eastern Levant Sea due to overfishing during recent decades, while catch statistics show a simultaneous increase in landings of commercially less valuable small pelagic species. Moreover, the number of species in the eastern Mediterranean is increasing due to Lessepsian migration and the response of native species to the continuous migration of lessepsian species is in question. Additionally, warming associated with climate change is ...
End-To-End Models for the Analysis of Marine Ecosystems: Challenges, Issues, and Next Steps
Rose, Kenneth A.; et. al. (2010-01-01)
There is growing interest in models of marine ecosystems that deal with the effects of climate change through the higher trophic levels. Such end-to-end models combine physicochemical oceanographic descriptors and organisms ranging from microbes to higher-trophic-level (HTL) organisms, including humans, in a single modeling framework. The demand for such approaches arises from the need for quantitative tools for ecosystem-based management, particularly models that can deal with bottom-up and top-down contro...
Assessment of trophic status of the northeastern Mediterranean coastal waters: eutrophication classification tools revisited
Tuğrul, Süleyman; Özhan, Koray; Akçay, İsmail (2019-05-01)
The Eastern Mediterranean and its Cilician Basin offshore waters have oligotrophic features with low nutrient concentrations, low primary production, and high water transparency. However, the wide shelf area of the Cilician Basin is subject to contaminated river inflows with enhanced nutrient loads and direct discharges of urban wastewaters of southern Turkey, leading to develop local eutrophic/mesotrophic conditions in the inner sites of Mersin and Iskenderun Bays on the Cilician Basin. For the assessment ...
Abrupt transition of the northwestern Black Sea shelf ecosystem from a eutrophic to an alternative pristine state
Oguz, Temel; Velikova, Violeta (2010-01-01)
Long-term (1960-2005) ecological data were used to identify a regime shift in the northwestern Black Sea shelf and to assess whether it has recovered from its former eutrophic state. Following the collapse of fish stocks and the population explosion of the ctenophore Mnemiopsis leidyi between 1988 and 1991, anthropogenic P-PO4 loads from the River Danube dropped strongly in 1992-1993. This decline in P-PO4 levels was caused by reductions in fertilizer use and emissions from land-based point sources during t...
Quantification of the Synergistic Effects of Eutrophication, Apex Predator Pressure, and Internal Processes on the Black Sea Ecosystem
Salihoğlu, Barış (2013-12-01)
In the present study, a model of the lower-trophic pelagic food web of the Black Sea is considered in order to provide a quantitative understanding of the marked changes in the food web structure in response to changing top-down and bottom-up control mechanisms due to eutrophication, overfishing, and climatic changes. The simulations consider three particular parameters controlling the changes in the ecosystem structure due to these stressors; (i) the magnitude of the nitrate flux into the euphotic layer fr...
Citation Formats
T. OGUZ, E. Akoğlu, and B. Salihoğlu, “Current state of overfishing and its regional differences in the Black Sea,” OCEAN & COASTAL MANAGEMENT, pp. 47–56, 2012, Accessed: 00, 2020. [Online]. Available: