Interpopulation dynamics betweenAcartia clausi(Copepoda) andNoctiluca scintillans(Dinoflagellata) in the Bosphorus area of the Black and the Marmara Seas

Abstract

The dynamics of abundance and biomass of Noctiluca scintillans (Dinoflagellata) and Acartia clausi (Copepoda) in the Bosphorus area of the Black and Marmara Seas during 2005-2009 has been analyzed. Despite the fact that the more abundant Black Sea zooplankton community permanently enters the Marmara Sea, A. clausi and N. scintillans have formed independent populations in the northeast of the Marmara Sea. This may be confirmed on the one hand by the positive correlations between the numbers of A. clausi and N. scintillans individuals in the Marmara Sea near the Bosphorus Strait and near the Prince Islands and, on the other hand, by a lack of correlation between the abundance of these species in the Marmara Sea and in the Bosphorus area of the Black Sea. The abundance of N. scintillans was 6-10 times lower in the Black Sea near the Bosphorus Strait than that in the Marmara Sea. A high correlation (r = 0.84) between the abundance of N. scintillans and the number of dead A. clausi females near the Bosphorus Strait in the Marmara Sea suggests an important role of necrozooplankton in the development of the dinoflagellate.

Current state and long-term changes in the mesozooplankton community of the Ukrainian and Georgian parts of the Black Sea as indicators of its ecological status

“…He divided the history of the pelagic ecosystem into three periods: period of "ecological norm" (before anthropogenic eutrophication, prior to 1970), period of eutrophication and hypereutrophication (1970-2004 years) and the period of de-eutrophication and establishment of a new "ecological norm" (after 2005). The first period was characterized by dominance of Copepoda (≥ 45% of the total zooplankton biomass) and the following values of the biomass of zooplankton: in spring 150-400 mg/m 3 , in summer 350-900 mg/m 3 , in autumn -150-350 mg/m 3 , the percentage of N. scintillans in total biomass did not exceed 30% (Selifonova, 2009;Nikishina et al, 2011;Isinibilir et al, 2014). During the second period the percentage of Copepoda decreased, the percentage of N. scintillans increased up to 95-98% and total biomass of zooplankton increased in 9-28 times (Polishchuk & Nastenko, 2006).…”

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“…The dinoflagellate Noctiluca scintillans is common in temperate to tropical neritic waters around the world and is known at times to form pronounced red tides (Cardoso, 2008;Turkoglu, 2013). Blooms have been reported from the Marmara Sea including the straits of Istanbul, and Dardanelles (Yılmaz, Okuş, & Yüksek, 2005;Turkoglu, 2013;Isinibilir, Hubareva & Svetlichny, 2014). Noctiluca scintillans observed high biomass in spring and summer periods in Golden Horn (Dorak and Albay, 2016) contributed largely to the decrease of Copepod importance at high salinity locations (in stations GH3 and GH4).…”