Effect of mareb crude oil, dispersed oil and dispersant (OSD) on filtration rates of the clams Tivela ponderosa under laboratory conditions

摘要

This study includes laboratory experiments of filter-feeding activity of bivalves Tivela ponderosa . The filtration rate of bivalves Tivela ponderosa was controlled hourly at 5 th and 10 th day (every two and six hours). The bivalve Tivela ponderosa is exposed to 0.5 ml, 1.0 ml and 1.5 ml/l of three chemicals test (Crude oil, Crude oil with Dispersant and Dispersant OSD) in addition to liter of seawater through experimental time. Results of the study showed that the Dispersant had a less effect than Crude oil or a mixture of oil with dispersant. A mixture of oil with dispersant is more effect on filter-feeding activity of Tivela ponderosa . There are no mortalities during the early 5 days for the three different chemicals test. Bivalves are usually increased in her activity during the first 2 hours and decreased during the next 6 hours of the experiments. The filtration rate of exposed clams was reduced in comparison with the control especially in the presence of polluted chemicals. The condition index of the exposed clams significantly reduced with respect to the control index, which indicated that the treated clams had an uncomfortable condition with low food intake and high energy demand to counteract the toxic effect of toxic chemicals.