Temporal and spatial variations of selected biomarker activities in flounder (Platichthys flesus) collected in the Baltic proper.

The aim of the study was to examine temporal (monthly) and spatial changes in the activities of a battery of biomarkers and evaluate the influence of gender and environmental factors on those activities. Abiotic factors not correlated with chemical pollution-water temperature, salinity, and oxygen concentration-were evaluated. The activities of the following biomarkers-muscular ChEs (acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)), hepatic ethoxyresorufin-O-deethylase (EROD), glutathione-S-transferase (GST) and catalase (CAT), and gross indices-condition factor (CF), hepatosomatic index (HSI), and gonadosomatic index (GSI)-were measured in individual flounder Platichthys flesus. Female flounder were collected once a month from April 2003 to April 2004 at Sobieszewo (Gulf of Gdansk). In December 2003 flounder of both sexes from nine stations in the Baltic Proper were caught and tested. Strong monthly (attributed mainly to spawning, and less-to pollution) and geographical (attributed to pollution) variations in biomarker activities, as well as gender differences, were demonstrated. Correlations between the enzymes with the abiotic properties of the environment were less important.

Cytogenetic and cytotoxic effects in gill cells of the blue mussel Mytilus spp. from different zones of the Baltic Sea.

Frequency of micronuclei (MN) and other nuclear abnormalities (nuclear buds, bi-nucleated and fragmented-apoptotic cells) was analysed in gill cells of the blue mussel (Mytilus spp.) from selected coastal sites in the Baltic Sea--Kvädöfjärden (Sweden), Klaipeda-Butinge zone (Lithuania), Gulf of Gdansk (Poland) and Wismar Bay (Germany). Samples were collected from 650 specimens during bi-annual sampling campaigns in 2001 and 2002. The lowest frequency of MN (0.37 MN/1000 cells) was found in blue mussels from the reference site (Kvädöfjärden). The highest MN values (up to 6.7 MN/1000 cells) were registered in blue mussels from the Gulf of Gdansk in autumn 2001 and 2002, and at Wismar Bay in spring 2001 (up to 5.06 MN/1000 cells). Gradients of MN incidences were observed when comparing the three studied locations in Wismar Bay, and at the Lithuanian coast before the crude oil spill in the Butinge oil terminal. Moreover, significant seasonal and inter-location differences in the responses were documented (P<0.0001). Nuclear abnormalities were observed most frequently in blue mussels from the Gulf of Gdansk.

Liver histopathology in Baltic flounder (Platichthys flesus) as indicator of biological effects of contaminants.

Results are presented of a study on liver histopathology in Baltic flounder (Platichthys flesus) carried out in 2001 and 2002 in four coastal sampling areas of the Baltic Sea: Kvädöfjärden (Swedish east coast, reference area), Klaipeda-Butinge (Lithuanian coast), Gulf of Gdansk (Polish coast), and Wismar Bay (German coast) within the framework of the EU-funded BEEP project. Liver lesions were diagnosed and categorised using standardised methodologies and, for a spatial and temporal assessment of the prevalence and types of lesions detected, a scoring system was applied, involving the calculation of mean histopathology lesion scores. 83.0% of the 436 female flounder examined (size range: 20-43 cm total length, age range: 2-8 years) were affected by liver lesions, out of which 74.3% were assigned to the category of non-specific, 3.4% to the category of early toxicopathic non-neoplastic, 4.6% to the category of pre-neoplastic and 0.7% to the category of neoplastic lesions. Mean lesions scores were highest in the areas at the Lithuanian and Swedish coast and there is indication of an impact of the age structure of the flounder populations studied, the sampling season as well as of contaminant effects.

Measurements of biomarker levels in flounder (Platichthys flesus) and blue mussel (Mytilus trossulus) from the Gulf of Gdansk (southern Baltic).

In the framework of the EU funded BEEP project a set of biomarkers, gross morphometric indices and tissue concentrations of selected organic pollutants were measured in flounder (Platichthys flesus) and mussels (Mytilus trossulus) collected twice a year (April and October) from three sites in the inner Gulf of Gdansk between autumn 2001 and spring 2003. In flounder, seasonal differences in most biomarkers were observed, but no correlations with tissue pollutant levels could be found. In mussels, highly variable levels in biomarker responses were seen, but no clear seasonal or spatial trends, directly related to tissue concentrations, could be established. The observed biomarkers distribution the study sites are probably mostly caused by interannual, seasonal and individual variability and, in case of flounder, possibly by exchange of stocks between the sampling sites.

Use of biliary PAH metabolites as a biomarker of pollution in fish from the Baltic Sea.

During field campaigns of the BEEP project (Biological Effects of Environmental Pollution in Marine Coastal Ecosystems) in 2001-2002, metabolites of polycyclic aromatic hydrocarbons (PAHs) were determined in bile samples from three fish species, flounder (Platichthys flesus), perch (Perca fluviatilis) and eelpout (Zoarces viviparus), from four separate areas in the Baltic Sea. Two determination methods were applied: fixed wavelength fluorescence (FF) for pyrene-type metabolites and high-performance liquid chromatography with fluorescence detection (HPLC). There was a good correlation between the FF method and 1-OH pyrene determined by HPLC. Normalisation of the FF data for absorbance at 380 nm or bile protein concentrations greatly increased variance in one third and decreased it in two thirds of the cases and resulted in a loss of significant differences (protein normalisation) between the sampling stations, but normalisation of the HPLC data had little effect on the results. The biliary PAH metabolite content was usually higher in males than in females. In perch and eelpout the biliary PAH contents were at similar levels, whereas in flounder the levels were lower. The sampling areas arranged in decreasing order of biliary PAH contents were: Wismar Bay > Gulf of Gdansk > Lithuanian coast > Kvadofjärden (reference area). It is concluded that FF with un-normalised data is a reliable and simple method for monitoring purposes and only one sex of a selected species should be used.

Biomarker responses in flounder (Platichthys flesus) and mussel (Mytilus edulis) in the Klaipeda-Butinge area (Baltic Sea).

During the EU project BEEP a battery of biomarkers was applied in flounder (Platichthys flesus) and the blue mussel (Mytilus edulis) collected at three locations off the Lithuanian coast (Baltic Sea) in June and September 2001 and 2002. The elevated biomarker responses in specimens sampled in September 2001 were apparently related to the extensive dredging activities in the Klaipeda port area and subsequent dumping of contaminated sediments. High concentrations of organic pollutants (organochlorines and PBDEs) were also measured in the tissues of both indicator species. In addition, response levels of genotoxicity, cytotoxicity, immunotoxicity as well as concentrations of PAH metabolites in the bile of flounder showed elevations in 2002 after an oil spill in the Butinge oil terminal in November 2001. In flounder, biomarker measurements 10 months after the spill indicated recovery processes but in mussels a high level of genotoxicity could still be observed 22 months later. The present study illustrates the usefulness of the multi-biomarker approach in the detection of biological effects of pollution in this region of the Baltic Sea.

Hepatic glutathione S-transferase activity in flounder collected from contaminated and reference sites along the Polish coast.

The aim of the present study was to examine the activity of hepatic glutathione S-transferase (GST) in flounder, Platichthys flesus, as a potential biomarker of exposure to xenobiotics present in the environment. The fish were collected along known pollution gradients and from areas regarded relatively free of anthropogenic input. GST was measured spectrophotometrically in each sampled specimen of flounder. The databases from the studies performed by two research institutes were compiled, and generalized linear models were used to analyze the dependence of the enzyme activity on the time and area of sampling and on selected biological parameters of the fish. Fish sex, sampling area, year, month, water temperature, and somatic indices (gonado-somatic index, hepato-somatic index) were significant in the model of GST activity. The three annual datasets showed that the biomarker activities exhibited in the Gulf of Gdansk were significantly different from those measured in the areas off the coast.

Toxicants accumulation rates and effects in Mytilus trossulus and Nereis diversicolor exposed separately or together to cadmium and PAHs.

Two invertebrates, Mytilus trossulus and Nereis diversicolor, were exposed in aquaria to cadmium (50 microg L(-1)) and a mixture of three- to six-ring PAHs (2 microg L(-1) each) for 2 weeks. Organisms of two species were reared in separate tanks or together in the same one. Concentrations of Cd, PAHs and activities of selected biomarkers: catalase (CAT), glutathione S-transferase (GST) and acetylcholinesterase (AChE) were measured within 2 weeks of exposure. When reared separately, higher accumulation rates for cadmium were measured in mussels (16.4 microg day(-1) g(-1) d.w. lipid-free tissue) than in polychaeta (0.7 microg Cd g(-1) d.w day(-1)). When co-exposed, a difference in bioaccumulation was maintained but the accumulation rate in N. diversicolor increased to 1.0 microg Cd g(-1) d.w. day(-1) and decreased to 9.6 microg Cd g(-1) d.w. day(-1) in M. trossulus. On the contrary, faster bioaccumulation rates of PAHs were seen in polychaeta than in mussels when exposed separately (19.3 vs 4.5 microg PAHs day(-1) g(-1) lipid weight) than together (12.0 vs 3.1 microg PAHs g(-1) l.w. day(-1)). Substantial changes in the bioaccumulation patterns of the different M. trossulus organs were observed when both species were reared together. Biochemical responses indicated no effect of the accumulated contaminants on AChE, enhancement of CAT in both species and depletion of GST in Mytilus. The observed differences are discussed in terms of different bioavailability of contaminants, route of uptake and detoxification mechanism, under the two modes of exposure.