Fatty acid profile of the sea snail Gibbula umbilicalis as a biomarker for coastal metal pollution

Metals are among the most common environmental pollutants with natural or anthropogenic origin that can be easily transferred through the food chain. Marine gastropods are known to accumulate high concentrations of these metals in their tissues. Gibbula umbilicalis ecological importance and abundant soft tissues, which enables extent biochemical assessments, makes this particular organism a potentially suitable species for marine ecotoxicological studies. Fatty acids are carbon-rich compounds that are ubiquitous in all organisms and easy to metabolize. Their biological specificity, relatively well-studied functions and importance, and the fact that they may alter when stress is induced, make fatty acids prospect biomarkers. This work aimed to assess fatty acid profile changes in the gastropod G. umbilicalis exposed to three metal contaminants. After a 168 h exposure to cadmium, mercury, and nickel, the following lipid related endpoints were measured: total lipid content; lipid peroxidation; and fatty acid profile (FAP). The analysis of the FAP suggested an alteration in the fatty acid metabolism and indicated a link between metals exposure and homeoviscous adaptation and immune response. In particular, five fatty acids (palmitic, eicosatrienoic, arachidonic, eicosapentaenoic, and docosahexaenoic acids), demonstrated to be especially good indicators of G. umbilicalis responses to the array of metals used, having thus the potential to be used as biomarkers for metal contamination in this species. This work represents a first approach for the use of FAP signature as a sensitive and informative parameter and novel tool in environmental risk assessment (ERA) of coastal environments, using G. umbilicalis as model species.