Dredging Influence on Methane Concentration in the Taganrog Bay

Resumo

The effects of dredging and dumping on methane concentration in water and bottom sediments of the Taganrog Bay (the Sea of Azov) are studied. It is shown that dredging operations are accompanied by the inflow of methane deposited in soil to the water column. This inflow is associated with the resuspension of soils as a result of their loosening, lifting, and loading by the dredger to the barge as well as during their discharge to underwater piles and further erosion and separation of dumping material by waves and seabed currents. In addition to the increase in methane emission to the atmosphere, this is accompanied by a negative impact on the oxygen regime due to the microbial oxidation of methane and other organic and inorganic substances which arrived during soil resuspension. However, due to a relatively small area of the seabed affected by dredging and occupied by underwater dumps as well as due to the active hydrodynamics of waters in general, their influence on methane concentration in water and bottom sediments of the Taganrog Bay is insignificant.