Lysosomal Membrane Stability of Mussel (Mytilus galloprovincialis Lamarck, 1819) as a Biomarker of Cellular Stress for Environmental Contamination.

The lysosomal membrane stability (LMS) of hemocytes in wild mussels (Mytilus galloprovincialis) as a biomarker of cellular stress for chemical pollution was tested by neutral red retention time (NRRT) assays. To assess the environmental contamination in the study area, seawater quality and pollutant bioaccumulation throughout the soft tissue of mussels were investigated. The samples were collected in July 2022 at four sites on the Romanian Black Sea coast considered to be differently affected by contamination. To support the suitability of LMS as a biomarker of contaminant-induced stress, the contaminant body burdens of the mussels were compared with the NRRT values. The results showed a significantly reduced NRRT in all investigated locations, particularly in port areas (mean retention time between 11 and 14 min). The elevated bioaccumulation of organochlorinated pesticides (OCPs) and polychlorinated biphenyls (PCBs) and low NRRTs were observed at the most contaminated sites (i.e., ports). The low lysosomal stability reflected stress and damage in the hemocytes of mussels and could be related to the body burdens of contaminants. LMS is an effective indicator of health status in mussels and could be considered a sensitive biomarker of cellular stress induced by contaminant exposure.

Assessment of the environmental quality of coastal sediments by using a combination of in vitro bioassays.

The environmental quality of marine sediments collected in the area of influence of the Po and Danube Rivers was assessed by using a battery of bioassays based on the use of PLHC-1 cells, zebrafish-Pxr-transfected COS-7 cells, and sea bass ovarian subcellular fractions. This allowed the determination of multiple endpoints, namely, cytotoxicity, oxidative stress, induction of CYP1A, activation of zebrafish Pxr and inhibition of ovarian aromatase. Organic extracts of sediments influenced by the Danube River and collected near harbors and urban discharges showed significant cytotoxicity, CYP1A induction and inhibition of aromatase activity. An analogous response of CYP1A induction and zfPxr activation was observed, which suggests the existence of common ligands of AhR and PXR in the sediment extracts. The study highlights the usefulness of the selected bioassays to identify those sediments that could pose a risk to aquatic organisms and that require further action in order to improve their environmental quality.

Biochemical biomarker responses to pollution in selected sentinel organisms across the Eastern Mediterranean and the Black Sea.

Pollution effects were assessed by means of biochemical biomarkers (catalase, glutathione S-transferase and acetylcholinesterase activities, and metallothioneins content) in five species at selected coastal sites across the Eastern Mediterranean and the Black Sea. The mussel Mytilus galloprovincialis, a well-established sentinel species, was investigated in the Adriatic Sea, Aegean Sea, and Black Sea. The mussel Brachidontes pharaonis and the striped red mullet Mullus surmuletus were used in the Levantine Sea where M. galloprovincialis is not present. The white seabream Diplodus sargus sargus and the gastropod Rapana venosa were additionally sampled in the Adriatic and the Black Sea, respectively. Mussels showed catalase, glutathione S-transferase, and acetylcholinesterase responses to pollution in most geographical areas while the response of metallothioneins was restricted to a few sites. R. venosa showed marked responses of catalase and metallothioneins whereas both fish species did not generally exhibit variations in biomarker values among sites. The approach based on the reference deviation concept using the "Integrated Biological Responses version 2" index was useful for the interpretation of overall biomarker responses.

Bioaccumulation of heavy metals in marine organisms from the Romanian sector of the Black Sea.

The aim of this research was to study the accumulation of heavy metals (cadmium - Cd, lead - Pb, chromium - Cr, nickel - Ni, and copper - Cu) from water and sediments into living tissues of relevant marine species from different trophic levels of a food web, representative for shallow waters of the Romanian Black Sea Coast where the main anthropogenic impacts exist. The heavy metals concentrations were analysed by using an Atomic Absorption Spectrometer with graphite furnace, the results being further used to calculate the bioconcentration factors for a few key taxa like green and red algae, molluscs and fishes. Seven sampling sites influenced by anthropogenic pollution sources (municipal wastewater treatment plants and diffuse sources) were considered and a total of 300 samples were analysed for the period 2011-2012, this being the first unitary study for the Romanian Black Sea marine ecosystem. In 2011 and 2012 there were no significant differences between the sampling areas considering the heavy metals concentrations in water. For the sediments significant differences were observed between sampling sites for some heavy metals, namely Pb in 2011 and Pb, Cu and Cd in 2012, the highest concentrations being registered in the southern sector of the Romanian Black Sea shore, where the anthropogenic pollution sources are represented by the harbour and wastewater treatment plants. The values of the bioaccumulation factors (BCFsed) shows that algae are good accumulators for Cu>Pb>Ni>Cr>Cd, in comparison with BCFwater where the order of heavy metal accumulation was different: Cr>Ni>Pb>Cd>Cu. Molluscs have higher bioconcentration factors for Cu and Cd for sediments and for Cu and Ni for water. Rapana venosa accumulated more Cd and Cu. For fishes, Pb, Cu and Ni had the highest values in the tissues of benthonic species Mullus barbatus. In bivalve molluscs and fishes, in the majority of cases, there were not recorded exceeding mean concentrations as compared to the maximum allowed concentrations for Cd and Pb.