Histopathology alterations and histochemistry measurements in mussel, Mytilus edulis collected offshore from an aluminium smelter industry (Norway).

Histopathological characteristics of specific organs express condition, and represent time-integrated impacts on the organism stemming from alterations at lower levels of biological organisation. As integrative parameters, histochemical investigations have proved to be sensitive tools to detect effects of chemical compounds. The objective of this study was to determine changes in the tissues of mussels collected at a PAH contaminated site compared to a reference site using histopathological and histochemical parameters: lipofuscin (LF) accumulation in mussel digestive gland, and lysosomal membrane stability (LMS), and using additional information provided by body burden analysis to compare the sensitivity of these parameters. The histochemical measurements for both LF and LMS gave a clear indication of a high level of stress in animals from the PAH contaminated site. This LF accumulation in lysosomes is the result of peroxidation of autophagocytosed proteins associated with protein aggregates and oxidatively damaged organelles. These measurements were able to detect the effects of PAHs, and showed a strong relationship with the body burden results.

Preliminary study of responses in mussel (Mytilus edilus) exposed to bisphenol A, diallyl phthalate and tetrabromodiphenyl ether.

Environmental pollutants with hormonal activity including bisphenol, diallyl phtalate and tetrabromodiphenyl ether, have the potential to alter gonadal development and reproduction in aquatic wildlife. Little is known about the biological impact of environmentally relevant concentrations in mussels. To investigate some aspects of their potential estrogenic action, mussels were continuously exposed during 3 weeks. Gonadal development and vitellogenin like protein levels were examined. Bisphenol (50 microg/l) induced the expression of phospho-proteins in females and spawning in both sexes. Diallyl phthalate and tetrabromodiphenyl ether decreased phospho-protein levels in both sexes and induced spawning in males. Moreover, severe damaging effects on ovarian follicles and ovocytes were observed in both bisphenol A- and tetrabromodiphenyl ether-exposed female mussels.

Scale of classification based on biochemical markers in mussels: application to pollution monitoring in Mediterranean coasts and temporal trends.

A battery of biochemical parameters was used to evaluate the response of mussels to a contaminated coastal environment. A multimarker approach was developed, establishing a scale for the classification of the water quality in European coastal sites (BIOMAR European programme). This study allows the evaluation of the temporal trends of this scale when applied to selected sites of European Mediterranean coast (BEEP Biological Effects of Environmental Pollution in Marine Coastal Ecosystems: European programme). Acetylcholinesterase activity (AChE) is highly sensitive to organophosphorus and carbamate insecticides and, to some extent, also to heavy metals. Catalase activity (CAT) and lipid oxidation (evaluated as malonedialdehyde) are markers of oxidative stress, glutathione S-transferase (GST) activity is related to conjugation of organic compounds and benzo(a)pyrene hydroxylase activity (BPH) is a marker of effect of certain planar organic compounds (e.g. polycyclic aromatic hydrocarbons, PAHs). These parameters were measured either in gills (AChE, GST) or digestive gland (BPH, GST, CAT, MDA). For each biomarker, a discriminatory factor was calculated (maximum variation range/confidence interval) and a response index was allocated. For each site, a Multimarker Pollution Index (MPI) was calculated as the sum of the response index of each of the five more discriminating biomarkers. As the result of our calculation method, the quality of the coastal environment at each site can be classified according to a five levels scale. Samples collected for five cruises in May 2001, 2002, 2003, and September 2001 and 2002 showed MPI evolutions. The results show that water quality can be classified from class 1 (clean areas in some sites of France, Italy and Spain) to class 4 (high pollution in main harbours). Results of the use of the biomarker scale in WP3 (Work Package Concernant Biomonitoring Programmes in Mediterranean Sea) during the BEEP programme make a strong contribution to the establishment of standardized strategies and methods for internationally agreed protocols for biomarker-based monitoring programmes. In comparison with scale pollution methodology used in the BIOMAR programme, the main contribution of BEEP was (1) to select from discriminatory analysis the biomarkers to be included in calculation of scale pollution; (2) to improve the use of the biomarker index in order to identify the main contaminants by analysis of individual contributions to the MPI; and (3) to apply methodology for temporal trends at sampled sites.

Biochemical and histological responses in mussel (Mytilus edulis) exposed to North Sea oil and to a mixture of North Sea oil and alkylphenols.

Several environmental chemicals are suspected to be responsible for adverse health effects on the reproductive system in various organisms. During this work, environmentally relevant concentrations of North Sea oil were used alone or in combination with alkylphenols and additional PAH to study the effect on vitellogenin-like protein expression and gonadal development in mussels. North Sea oil (0.5 ppm) induced the expression of phospho-proteins in both sexes indicating that some compounds are oestrogen-mimics. This induction was not seen in samples dosed with the mixture but signs of toxic effects were observed in the gonads. Indeed, numerous degenerating ovarian follicles in females and foci, similar to vertebrate melanomacrophage centres, were observed in testes.