METHANE SEEPS IN THE BLACK SEA: DISCOVERY, QUANTIFICATION AND ENVIRONMENTAL ASSESSMENT

Methane seeps in the Black Sea: discovery, quantification and environmental assessment

Viktor N. Egorov, Yuriy G. Artemov, Sergei B. Gulin, Gennadiy G. Polikarpov

The A.O. Kovalevskiy Institute of Biology of the Southern Seas (IBSS), National Academy of Sciences of Ukraine, 2 Nakhimov Av., Sevastopol, 99011, UKRAINE

Abstract

This review describes methodology and software developments for acoustic data acquisition and determining parameters of gas bubble streams; shows geographical distribution of more than 3000 seeps in the Black Sea; presents data on methane fluxes from the deep-sea mud volcanoes; gives a model for evaluation of gas exchange in the water environment and methane emission from gas seeps to water column and atmosphere; explains modern views on the impact of cold seeps on the hydrochemical characteristics of the marine environment, the vertical water exchange, methanotrophic chemosynthesis and trophic structure of water; reveals a new form of life in the anoxic water column of the Black Sea, which is represented by a symbiotic community of anaerobic archaea and methane oxidizing and sulfate-reducing bacteria; contains estimates of potential environmental hazards due to methane discharge from the bottom of the Black Sea, and outlooks the possible use of cold seeps as a resource factors because they can be indications for shallow or deep hydrocarbon accumulations.

Keywords: Black Sea, gas seeps, methane emission