Pollutant bioaccumulation in anchovy (Engraulis encrasicolus) tissue, fish species of commercial interest at the Romanian Black Sea coast

The pollution of the marine ecosystem is a world-wide problem. Heavy metals and organochlorine compounds are among the most harmful elemental pollutants and are of particular concern because of their toxicity to humans. Anchovy (Engraulis encrasicolus, Linnaeus 1758), small pelagic fish with a key ecological role in the marine food web, is an important link connecting the lower and upper trophic levels, being also a valuable species for human consumption. Thus, anchovy samples were collected from different stations along the Romanian Black Sea coast and the analyzed contaminants were organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and heavy metals (Cd, Pb, Ni, Cu and Cr) in muscle tissue. Cd and Pb are the heavy metals that exceeded the allowed levels under the EU legislation (0.3 μg/g), Cd recorded values within the range 0.29-0.51 μg/g (average 0.36 ± 0.09 μg/g) and Pb recorded values within the interval 0.29-1.62 μg/g (average 0.75 ± 0.57 μg/g). Regarding organochlorine pesticides, the highest level was recorded by p,p′-DDE (6.76±1.21 ng/g/dry weight), followed by p,p′-DDD (3.88±0.97 ng/g/dry weight). Among PCB’s, the highest level was recorded by PCB 28 (5.19±1.29 ng/g/dry weight). The results of this study revealed that heavy metals, pesticides and polychlorinated biphenyls values identified in anchovy tissue, species of commercial interest from the Black Sea, are not threatening to human consumers.

Lipids in Marine Ecosystems

Lipids provide the densest form of energy in marine ecosystems. They are also a solvent and absorption carrier for organic contaminants and thus can be drivers of pollutant bioaccumulation. Among the lipids, certain essential fatty acids and sterols are considered to be important determinants of ecosystem health and stability. Fatty acids and sterols are also susceptible to oxidative damage leading to cytotoxicity and a decrease in membrane fluidity. The physical characteristics of biological membranes can be defended from the influence of changing temperature, pressure, or lipid peroxidation by altering the fatty acid and sterol composition of the lipid bilayer. Marine lipids are also a valuable tool to measure inputs, cycling, and loss of materials. Their heterogeneous nature makes them versatile biomarkers that are widely used in marine trophic studies, often with the help of multivariate statistics, to delineate carbon cycling and transfer of materials. Principal components analysis has a strong following as it permits data reduction and an objective interpretation of results, but several more sophisticated multivariate analyses which are more quantitative are emerging too. Integrating stable isotope and lipid data can facilitate the interpretation of both data sets and can provide a quantitative estimate of transfer across trophic levels.