Cooperative effect of crude oil and low salinity on the digestive glands lipid composition of the White Sea blue mussels Mytilus edulis

Abstract

The response of the organism to the pollutant impact is influenced by a variety of abiotic and biotic environmental factors that may have a synergistic or antagonistic effect on the biodegradation, accumulation, distribution and elimination of the xenobiotics. It is known that lipophilic organic contaminants including oil hydrocarbons can be accumulated in lipid-rich tissues of marine animals, thus causing changes in biosynthesis and transport of phospholipids and triacylglycerols, as well as in the physical state of biological membranes. The cooperative effect of crude oil and low salinity on digestive gland lipid composition of the White Sea blue mussels Mytilus edulis L. was studied in aquarium experiment. Low salinity (15‰) impact reflects on the lipid composition indicating high energy costs directed to acclimation of the mussels to new environmental conditions. However, the response of the lipid composition on the crude oil effect is almost not dependent on the ambient salinity, and is mainly determined by exposure duration to crude oil and its dose in aquarium water. On the third experimental day a significant increase in the cholesterol/phospholipids ratio and the subsequent its recovery to initial level possibly indicate the development of the protective compensatory mechanisms to provide low permeability of cell membranes in digestive glands under crude oil pollution. It was observed that the leading factor contributing the lipid composition modifications in blue mussel digestive glands is crude oil effect, mainly in its higher concentrations.