Long-Term (2001-2011) Temperature, Salinity and Chlorophyll-a Variations at a Southeastern Coastal Site of the Black Sea

Year 2013, Volume: 13 Issue: 1, - , 01.02.2013

Ali Alkan Bayram Zengin Serkan Serdar Temel Oğuz

https://doi.org/10.4194/1303-2712-v13_1_08

Abstract

Long-term measurements of temperature, salinity and chlorophyll-a concentration at a coastal site off Trabzon in the southeastern Black Sea document their monthly-to-interannual variabilities during 2001-2011. The data point to a general trend of warming with either negligible or absence of the Cold Intermediate Layer except for the relatively cold period of 2002-2004. The warming trend appears to be a continuation of the one started during the early 1990s. The data further documents enhanced anticyclonic type mesoscale features of the circulation system and its impacts on the local startification characteristics in terms of ventilation of the subsurface waters. The surface chlorophyll measurements show a rather sporadic relatively high plankton production events identified by the values greater than 2.0 mg m. More importantly, relatively high chlorophyll concentrations prevail below the surface mixed layer up to 50 m depth throughouıt the years. The mesoscale physical processes occasionally spread this productivity well below the euphotic zone and support biological production at oxygen deficient waters of the upper layer water column. The data further point to quasi-lateral, most likely isopycnal, intrusions and ventilation of subsurface waters.

Keywords

Black sea, temperature, salinity, chlorophyll, cold intermediate layer, pycnocline, primary production. Karadeniz'in Güneydoğu Kıyısal Alanında Uzun Dönemli (2001-2011) Sıcaklık, Tuzluluk ve Klorofil-a Değişimleri

Long-Term (2001-2011) Temperature, Salinity and Chlorophyll-a Variations at a Southeastern Coastal Site of the Black Sea

Abstract

Bu çalışmada, Güneydoğu Karadeniz’in Trabzon kıyılarında 2001-2011 dönemine ait uzun dönemli sıcaklık, tuzluluk ve klorofil-a konsantrasyonlarının aylık ve yıllık değişimleri incelenmiştir. Sıcaklık verileri, 2002-2004 göreceli soğuk dönem dışında, soğuk ara tabaka suyu oluşumunun yokluğu veya çok belirgin olmamasını göstermekte ve genel bir ısınma eğilimini işaret etmektedir. Söz konusu ısınma eğilimi 1990'lı yıllarda görülen ısınmanın devamı niteliğindedir. Bulgular, çalışma bölgesinde belirgin orta-ölçekli su sirkülasyonu hareketlerinin varlığına işaret etmektedir. Bu döngüler yaratmış oldukları dikey hareketler nedeniyle yaklaşık 100 m derinliğe kadar yöresel su kütlelerinin tabakalaşma özelliklerini etkileyebilmektedir. Yaklaşık 2 metre derinlikte gerçekleştirilen klorofil ölçümleri ise genellikle 2.0 mg m’den büyük değerlerle tanımlanan göreceli yüksek plankton üretimlerine işaret etmektedir. Yüksek klorofil tabakası yıl boyunca yüzeyin hemen altındaki 50 m derinliğe kadar olan tabakada yer almakta, ancak orta ölçekli aktivitelere bağlı olarak zaman zaman daha derinlerdeki üretimi destekleyebilmektedir.

Keywords

Karadeniz, sıcaklık, tuzluluk, klorofil, soğuk ara tabaka, piknoklin, birincil üretim.

References

• Alkan, A. 2002. The investigation on the seasonal changes of some physical parameters in the water column of Southeastern Black Sea. MSc. thesis. Trabzon. Karadeniz Technical University. BSC 2008. State of the Environment of the Black Sea (2001-2006/7). The Commission on the Protection of the Black Sea Against Pollution Publication, Istanbul, 448 pp.
• Bilio, M. and Niermann, U. 2004. Is the comb jelly really to blame for it all? Mnemiopsis leidyi and the ecological concerns about the Caspian Sea. Marine Ecology Progress Series, 269: 173-183.
• Chikina, M.V. and Kucheruk, N.V. 2005. Long-term changes in the structure of coastal benthic communities in the Northeastern part of the Black Sea: influence of alien species. Oceanology, 45(1): 176–182.
• Cochrane, K. and de Young, C. 2008. Ecosystem approach to fisheries management in the Mediterranean. Options Mediterraneennes, 62 (B): 71-85.
• Daskalov, G.M., Grishin, A.N., Rodionov, S. and Mihneva, V. 2007. Trophic cascades triggered by overfishing reveal possible mechanisms of ecosystem regime shifts. Proceedings of the National Academy of Sciences, 104: 10518– 105
• Daskalov, G.M. 2003. Long-term changes in fish abundance and environmental indices in the Black Sea. Marine Ecology Progress Series, 255: 259-2
• Gucu, A.C. 2002. Can overfishing be responsible for the successful establishment of Mnemiopsis leidyi in the Black Sea? Estuarine, Coastal and Shelf Science, 54: 439-451.
• Gunduz, M. and Ozsoy, E. 2005. Effects of the North Sea Caspian pattern on surface fluxes of EuroAsian-Mediterranean seas. Geophysical Research Letters, 32: L21701.
• Ilyin, Y.P. 2010. Observed long-term changes in the Black Sea physical system and their possible envronmental impacts. In: F. Briand (Ed.), CIESM Workshop, Monographs No 39. Climate Forcing and its Impacts on the Black Sea Marine Biota, Monaco: 35-44.
• Ivanov, L. and Panayotova, M. 2001. Determination of the Black Sea anchovy stocks during the period 1968-1993 by Ivanov's combined method. Proceedings of the Institute of Oceanology, Bulgarian Academy of Sciences; 3: 128-154.
• Kara, A.B., Barron, C.N., Wallcraft, A.J., Oguz, T. and Casey, K.S. 2008. Advantages of fine resolution SSTs for small ocean basins: Evaluation in the Black Sea. Journal Of Geophysical Research, 113: 8013, doi:1029/2007JC004569.
• Kazmin, A.S. and Zatsepin, A.G. 2007. Long-term variability of surface temperature in the Black Sea, and its connection with the large-scale atmospheric forcing. J. Mar. Syst., 68: 293–301.
• Knudsen, S. and Toje, H. 2008. Post-Soviet transformations in Russian and Ukrainian Black Sea fisheries: socio-economic dynamics and property relations. Southeast European and Black Sea Studies, 8: 17-32.
• Knudsen, S., Zengin, M. and Kocak, M.H. 2010. Identifying drivers for fishing pressure. A multidisciplinary study of trawl and sea snail fisheries in Samsun, Black Sea coast of Turkey. Ocean and Coastal Management, 53: 252-269.
• Korotaev, G., Oguz, T., Nikiforov, A. and Koblinsky, C. 2003. Seasonal, interannual and mesoscale variability of the Black Sea upper layer circulation derived from altimeter data. J. Geophys. Research, 108(C4), 3122.
• Mee, L.D., Friedrich, J. and Gomoiu, M.T. 2005. Restoring the Black Sea in times of uncertainty. Oceanography, 18:32–43.
• Niermann, U. 2004. Mnemiopsis leidyi distribution and the effect on the Black sea ecosystem during the first years of invasion in comparison with other gelatinous biomass. In: H. Dumont, T.A. Shiganova and U. Niermann (Eds.), The aquatic invasions in the Black, Mediterranean and Caspian Seas: The ctenophores Mnemiopsis leidyi and Beroe in the Ponto-Caspian and other aquatic invasions. Kluwer Academic Publishers, Dordrecht: 3-32.
• Oguz, T., La Violette, P. and Unluata, U. 1992. Upper layer circulation of the southern Black Sea: Its variability as inferred from hydrographic and satellite observations. J. Geophys. Research, 97(C8): 12569-12584.
• Oguz, T. and Salihoglu, B. 2000. Simulation of eddydriven phytoplankton production in the Black Sea. Geophys. Res. Letters, 27(14): 2125-2128.
• Oguz, T., Dippner, J.W. and Kaymaz, Z. 2006. Climatic regulation of the Black Sea hydrometeorological and ecological properties at interannual-to-decadal time scales. J. Mar. Syst., 60: 235-254.
• Oguz, T. and Ediger, D. 2006. Comparison of in-situ and satellite-derived chlorophyll pigment concentrations and impact of phytoplankton bloom on the suboxic layer structure in the western Black Sea during May-June 2001. Deep Sea Research Part II: Topical Studies in Oceanography, 53(17-19): 1923-1933.
• Oguz, T. and Gilbert, D. 2007. Abrupt transitions of the top-down controlled Black Sea pelagic ecosystem during 1960-2000: evidence for regime shifts under strong fishery exploitation and nutrient enrichment modulated by climateinduced variations. Deep-Sea Res.; 54: 220-242. Oguz, T. and Velikova, V. 2010. Abrupt transition of the northwestern Black Sea shelf ecosystem from a eutrophic to an alternative pristine state. Mar. Ecol. Prog. Ser., 405: 231–242.
• Oguz, T., Fach, B. and Salihoglu, B. 2008. Invasion dynamics of the alien ctenophore Mnemiopsis leidyi and its impact on anchovy collapse in the Black Sea. J. Plankton Res., 30: 1385–1397.
• Oguz, T. 2011. Impacts of Climate Change on the Black Sea. In: Climate Change and Marine Ecosystem Research: Synthesis of European Research on the Effects of Climate Change on Marine Environments. Marine Board Special Report, 120-127.
• Oguz, T., Akoglu, E. and Salihoglu, B. 2012a Current state of overfishing and its regional differences in the Black Sea. Ocean and Coastal Management, 58: 47-56.
• Oguz, T., Salihoglu, B., Moncheva, S. and Abaza, V. 2012b. Regional peculiarities of communitywide trophic cascades in strongly degraded Black Sea food web. J. Plankton Res., 34: 3383
• Österblom, H., Gardmark, A., Bergstrom, L., MullerKarulis, B., Folke, C., Lindegren, M., Casini, M., Olsson, P., Diekmann, R., Blenckner, T., Humborg, C., Mollmann, C. 2010. Making the ecosystem approach operational - Can regime shifts in ecological and governance systems facilitate the transition? Marine Policy, 34: 1290–1299.
• Purcell, J.E., Shiganova, T.A., Decker, M.B. and Houde, E.D. 2001. The ctenophore Mnemiopsis in native and exotic habitats: U.S. estuaries versus the Black Sea basin. Hydrobiologia, 451: 145-1
• Shiganova, T.A., Mirzoyan, Z.A., Studenikina, E.A., Volovik, S.P., Siokou-Frangou, I., Zervoudaki, S., Christou, E.D. and Dumont, H.J. 2001. Population development of the invader ctenophore Mnemiopsis leidyi in the Black Sea and other seas of the Mediterranean basin. Mar. Biol., 139: 431-445.
• Shlyakhov, V.A. and Daskalov, G.M. 2008. The state of marine living resources. In: State of the Environment of the Black Sea (2001-2006/7). The Commission on the Protection of the Black Sea Against Pollution Publ., İstanbul: 272-295.
• Sur, H.I., Ozsoy, E., Ilyin, T.P. and Unluata, U. 1996. Coastal deep ocean interactions in the Black Sea and their ecological environmental impacts. Journal of Marine Systems,7: 293-320.
• Vasiliu, D.L., Boicenco, M.T., Gomoiu, L., Lazar and Mihailov M.E. 2012. Temporal variation of surface chlorophyll a in the Romanian nearshore waters. Medit. Mar. Sci., 13(2): 213-226
• Vorobyova, L.V. and Bondarenko, O.S. 2009. Meiobenthic bristle worms (Polychaeta) of the western Black Sea shelf. J. Black Sea/Mediterr. Environ., 15: 109–121.
• Walker, B. and Meyers, J.A. 2004. Thresholds in ecological and social-ecological systems: a developing data base. Ecology and Soci., 9(2): 3.
• Yunev, O.A., Vedernikov, V.I., Basturk, O., Yilmaz, A., Kideys, A.E. et al. 2002. Long-term variations of surface chlorophyll a and primary production in the open Black Sea. Marine Ecology Progress Series, 230: 11-28.
• Yunev, O.A., Shulman, G.E., Yuneva, T.V. and Moncheva, S. 2009. 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, 428: 454–457.
• Zaitsev, Y.P. and Mamaev, V. 1997. Marine biological diversity in the Black Sea: a study of change and decline. GEF Black Sea Environmental Programme. United Nations Publications, New York, 208 pp.
• Zatsepin, A.G., Golenko, N.N., Korzh, A.O., Kremenetskii, V.V., Paka, V.T., Poyarkov, S.G. and Stunzhas, P.A. 2007. Influence of the dynamics of currents on the hydrophysical structure of the waters and the vertical exchange in the active layer of the Black Sea. Oceanology, 47(3): 301–312