Presentation on theme: "Recent data on the Black Sea small pelagic fish condition G. E. Shulman, V. N. Nikolsky, O. A. Yunev, T.V. Yuneva, A. M. Shchepkina Institute of Biology."— Presentation transcript:
Recent data on the Black Sea small pelagic fish condition G. E. Shulman, V. N. Nikolsky, O. A. Yunev, T.V. Yuneva, A. M. Shchepkina Institute of Biology of the Southern Seas, Sevastopol, Ukraine
Temperature and Food Supply are two the most important environmental factors that cause stock and population condition of mass small pelagic fish in the Black Sea: sprat Sprattus sprattus phalericus and anchovy Engraulis encrasicolus ponticus (Shulman et al., 2009).
The Black Sea surface water temperature increases last decade due to global warming (Nikolsky et al., 2009).
The temperature increase strongly affects on fat content of cold-tolerated sprat as an indicator of fish food supply. This effect is negative because decreases the energy potential of sprat population.
6 7 8 9 10 11 12 13 14 15 16 1955- 1964 1965- 1973 1980- s 200420052006200720082009 Fat content indicator, % But this has positive influence on fat accumulation in warm-tolerated anchovy.
We tried to connect primary food base (phytoplankton concentration) of the Black Sea pelagic ecosystem and total abundance of anchovy and sprat stocks during last 5 decades.
For this aim we compared phytoplankton concentration in Pre-Danube shallow region of largest primary productivity (TU Black Sea International data base) with stock value of anchovy + sprat (Prodanov et al., 1997; Shlyahov, Chashchin, 2004).
Data for stock value for last years are absent but there is high correlation between stock values and landing of small pelagic fish for the period 1967-1992 years (Yunev et al, 2009).
We revealed close correlation between phytoplankton biomass and fish stock values (Yunev et al, 2009).
Characteristics of the pelagic ecosystem of the Black Sea (mean data for the interannual study periods) This relationship (Q – factor, see table) is a good indicator for estimation of connection between small pelagic fish abundance and state of primary fodder base in The Black Sea ecosystem. Parameter Interannual period 0IIIIIIIVVVI 1967-19721973-19791980-19831984-19881989-19921993-19981999-2004 Stock of small pelagic fishes, thousand tons 57012581877162464013001570 Phytoplankton biomass, thousand tons 397100427403602180514151574 Q-value 1.441.250.690.450.350.921.00
Reserve (triacylglycerols, TAG) and structural (phospholipids, PL) content in sprat body during feeding period 2006-2009 (Yuneva et al., 2009). C20:5ω3 and C22:6ω3 fatty acid content in sprat body during feeding period 2006-2009
C22:6 3 essential fatty acid content in Black Sea anchovy in Turkey and Crimea waters during feeding period 2005-2009 C22:6 3
200620082007 Sprat diet composition during feeding period in spring-summer 2006-2008
Hypothetical influence of diet composition changes on sprat metabolism and behavior: Role of essential C22:6ω3 and C20:5ω3 fatty acids (Yuneva, unpublished data).
Shulman G.E. et al. Influence of global climatic changes and regional anthropogenic factors on the Black Sea sprat and anchovy condition. In: Trophic Relationships and Food Supply of Heterotrophic Animals in the Pelagic Ecosystem of the Black Sea (Eds: G.E. Shulman et al.), Commission on the Protection of the Black Sea against Pollution, Istanbul, Turkey, 2009, 273 – 281. Nikolsky V. N. et al. Interannual changes of lipid content in the Black Sea sprat. Ibidem, 227 – 245. Prodanov K. et. al. Environmental management of fish resources in 6the Black Sea and their rational exploitation // GFCM Stud. Rev. – 1997. – v. 68. – 178 p. Shlyahov V.A., Chashchin A.K. On state of stocks of main industrial fish in 2000 and perspectives their catch in 2002 // Main results of complex investigations of YugNIRO in Azov – Black Sea basin and World Ocean: YugNIRO Proceedings – 2004. – vol. 45. – 11 – 20. (in Russian) Yunev O.A. et al. Relationship between the Abundance of Small Pelagic Fishes and the Phytoplankton Biomass as an Indicator of the State of the Pelagic Ecosystem of the Black Sea // Doklady Biological Sciences, 2009, vol. 428, 454 – 457 Yuneva O.A. et al. Lipid composition of the Black Sea sprat In: Trophic Relationships and Food Supply of Heterotrophic Animals in the Pelagic Ecosystem of the Black Sea (Eds: G.E. Shulman et al.), Commission on the Protection of the Black Sea against Pollution, Istanbul, Turkey, 2009, 246 – 263. Literature