Study of Influence of Drilling Wastes on Black Sea Planktonic and Benthic Organisms

Resumo

The aim of this study was to evaluate the impact of modeled drilling wastes on planktonic and benthic organisms of the Tuapse trough of the Black Sea. The extension of shelf turbidity area due to drilling is calculated using VOSTOK software package for water-oil- and water-based drilling muds (WODM and WDM). The maximum impact on the diatom (Phaedactylum tricornutum) population was achieved after 96 h of incubation at 20 mg/liter drilling wastes concentration. Acute lethal effect on water fleas (Daphnia magna) was observed only at high concentrations of suspension of drilling wastes (above 1 g/liter) in the seawater. In real conditions, such a concentration is attained only in the immediate proximity of the waste disposal site. Delayed effects, namely, fertility decline and maturation and growth delay, which resulted from short-term impact in the area of increased turbidity, were established. Mollusks (mussels) exhibited resistance to the impact of drilling wastes, but a marked deterioration occurred in their physiological state.