Thursday, November 5, 2009

hypox expedition to a methane seep area at the Crimean Shelf

From 4. to 6.9.2009 the Ukranian hypox partner "Institute of Biology of the Southern Seas" (IBSS) conducted a land-based expedition to a shallow methane seep area at Tarkhankut Cape (NW Crimea peninsula, Black Sea).

Fig. 1: The site (photograph: Sergei Konovalov)

Video: methane seeping from the seafloor (Maksim Gulin)

The work was centered at effects of methane seeping on water column oxygen concentration, sediment biogeochemistry and benthic communities. Sampling and measurements were conducted by divers. Voltammetric microprofiles of diverse constituents (O2, Fe2+, Mn+, H2S, various other sulfur compounds...) were measured immediately on the beach. Analyses of meiofauna distributions and other sediment parameter are currently performed at IBSS.

Fig. 2: Sediment coring (photograph: Sergei Konovalov)

Fig. 3: Voltammetric profiling on the beach (photograph: Vitaly Timofeev)

First results indicate that hypoxic conditions may be present in the bottom waters where gas seeping occurs. Microbial mats found at the surface of the seafloor. For the first time it was observed that fishes fed on the mats or the associated fauna leading to dispersal of parts of the mats into the water column.

Fig. 4: The IBSS team: Sofia Konovalova, Sergey Konovalov, Vitaly Timofeev, Maksim Gulin, Natasha Orekhova (left to right)

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