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Information × Registration Number 0213U005186, 0112U004316 , R & D reports Title Scientific expertise of the risks to existence and growth of biological communities in the Black Sea ecosystem as well as fields of gashydrates prospective exploration and mining, and also in the highly productive areas of methane gas seeps and redox-chemocline popup.stage_title Head Gulin M.B., Registration Date 04-04-2013 Organization Kovalevsky Institute of biology of southern seas NAS Ukraine popup.description2 Within the fields of active gas discharge from the seabed (gas seeps) in the Black Sea, active migrations of polychaetes, crustaceans etc. were detected. Organic matter value could reach up to the 328 mg/g of dry weight; while at the reference areas it does not exceed 36 mg/g in average. Maximum level of oxygen concentration was observed during the dark time - 2.7 mg/l. Conversely, at noon [O2] has been decreased sharply to 0.6 mg/l, but in some cases - down to anoxia. Redox-potential in the gas seeps during the day was decreased to -363 mV. In the oxygen-deficient sediments near the methane seeps, one of the dominating microzoobenthos group it was ciliate genus Euplotes. Oxygen optimum for these organisms was equal to the 0.6 mg/l. Under long-term anoxia (more than 2 weeks), the death of all these ciliates was observed. Product Description popup.authors В.П. Чекалов popup.nrat_date 2020-04-02 Close