Increase in understanding of environmental status and functioning of the BS ecosystem
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1) The document discusses various aspects of the Black Sea ecosystem including zoobenthos distribution and species numbers, the decline of the Phyllophora seaweed field and its impact on other species, plankton populations and their seasonal changes, and nutrient fluxes in the water. 2) It notes that zoobenthos species numbers can vary greatly over short distances, and the Phyllophora field originally supported many species but seaweed numbers declined in the 1980s while sediment deposition increased. 3) Plankton populations vary seasonally, and while phytoplankton biomass has decreased since the early 1990s, the dominance of mixotrophic dinoflagellates resembles past eutroph
Increase in understanding of environmental status and functioning of the BS ecosystem
- 1. 15 Years of UNDP/GEF in the Black Sea Region, Final Seminar, 14-15 February 2008, Istanbul
- 2. Zoobenthos (1) Macro- and meio-benthos Standardised macro-methods manual Excellent overview of data analysis options in research cruise reports and Todorova & Konsulova presentation (univariate and multivariate approaches) Ecological indices represent the best forward for result presentation
- 3. Zoobenthos (2) No. of species distribution:
- 6. Zoobenthos (5) AMBI geographic distribution
- 7. Zoobenthos (6) Zoobenthos is not evenly distributed over short distances. Thus: •Both abundance and biomass of individual species vary substantially between replicates •The total number of species can vary greatly between replicates •30 nautical miles offshore of Constanta, the number of macrozoobenthos species varied between 5 and 14 in individual replicates, with a total number of 25 species in 5 replicates WARNIN G
- 8. Phyllophora field (1) The Phyllophora field once provided a habitat for 118 species of invertebrates and 47 species of fish In 1964, 32 macro-algal species were recorded, but this had halved by 1986 3 years later only a quarter of the species recorded in the 1960s were present However, in 2004, a slight increase in macroalgal species numbers was recorded when compared to the 1989 situation
- 9. Phyllophora field (2) 1979 2002 Shading by phytoplankton
- 10. Phyllophora field (3) Sediment deposition rates - Danube Prodelta 0 10 20 30 40 50 60 70 80 1960 1962 1964 1966 1968 1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 T,mlntons 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 CRSMAR,gcm-2 y-1 Sediment Discharge 3y AVG Annual Sediment Discharge CRS MAR
- 12. Phyllophora field (5) Relatively low levels of zoobenthos occur in the Phyllophora field, but often with a high number of species, particularly of macrozoobenthos While one species dominates, this dominance is much less complete than in the other polygons and indicative of higher biodiversity Large numbers of ascidians actively process high organic flux from water column, preventing sediment enrichment
- 13. Phyllophora field (6) Originally Phyllophora nervosa dominated Phyllophora brodiaei in southern part of field, but rarely dominant. Ph. pseudoceranoides has not been recorded since 1989 Now filamentous reds (Polysiphonia) and greens (Ectocarpus, Desmarestia) cover 70-80% bed Phyllophora (and other seaweeds) reduce internal loading of nutrients
- 14. Plankton Manuals written; equipment provided Plankton populations change quickly (on a seasonal basis) Participating scientists asked to present results in relation to long-term monitoring data Phytoplankton biomass and abundance have been on a decreasing trend since the early 1990s Species richness and other univariate indices are in favour of the “recovery phase” of the NW Black Sea ecosystem
- 16. Phytoplankton (2) However, the dominance of mixotrophic/ heterotrophic dinoflagellates strongly resembles the “eutrophication phase” Concern over colonisation by invasive species (Alexandrium cysts – 2006) In the 1960s, the phytoplankton population was dominated by diatoms and dinoflagellates Now “others” constitute a much greater proportion – the ecology is changing
- 17. Zooplankton (1) Two patterns of vertical distribution: •Maximum close to the thermocline where Noctiluca dominates •Maximum in surface waters Copepods, Cladocera, Meroplankton, Appendicularia and Chaetognatha predominate in Northern Shelf waters Further south, Noctiluca dominates Improved diversity in northern (Ukrainian) waters Mnemiopsis/Beroe battle continues
- 18. Zooplankton (2) Long-term summer abundance of Cladocera and Copepoda (Cape Galata):
- 19. Nutrients and Fluxes (1) Annual water transport across the shelf/open sea boundary: 0 4 8 1 2 m o n t h s 8 0 1 0 0 1 2 0 1 4 0 volume
- 20. Nutrients and Fluxes (2) Annual water transport across the shelf/open sea boundary: Peaks in October
- 21. Nutrients and Fluxes (3) Annual DIN fluxes across the shelf/open sea boundary: Ammonium Nitrate Nitrite
- 22. Nutrients and Fluxes (4) Surface trackers following anticyclonic eddy: A= Release point B = Cape Kaliakra C = fishing vessel route
- 23. Nutrients and Fluxes (5) The nitrate maximum defines the oxycline boundary in deep regions of the Sea Phosphate conc’s increase within the oxycline and the upper suboxic zone Surface conc’s low, but may be locally elevated