Comparative effects of environmental conditions, in eutrophic polluted and oligotrophic non-polluted areas of the saronikos gulf (Greece), on the physiology of the copepod Acartia clausi

1. Digestive enzyme activity and the oxygen consumption rate of Acartia clausi from the polluted eutrophic Elefsis Bay and the non-polluted oligotrophic Vouliagmeni-Fleves area were compared. 2. Out of 13 hydrolases whose activity was revealed, 10 had a higher activity in the Elefsis population than in the Vouliagmeni-Fleves one. Only amylase, alkaline phosphatase and esterase lipase had a higher activity in the Vouliagmeni-Fleves population. 3. The high activity of amylase in Vouliagmeni-Fleves population seems to indicate that phytoplankton constitutes the most important part of A. clausi's food. 4. Respiration rate was significantly lower in Elefsis population, irrespective of season. 5. A significant seasonal variation was observed which was greater in the Vouliagmeni-Fleves population, with a 50% decrease in the respiration rate between spring and summer. 6. The obtained results agree with previous literature data and show the physiological characteristics of A. clausi of Elefsis Bay, allowing it to thrive in polluted eutrophic waters. © 1993

Differentiation of physiological aspects of the burrowing shrimp Callianassa tyrrhena in relation to general pollution load

Two aspects of the physiology of the burrowing shrimp Callianassa tyrrhena (Decapoda: Thalassinidea) were studied in order to investigate the effects of the general pollution load: total (TRR) and weight-specific respiration rate (SRR) as well as the digestive enzyme activity of the digestive gland. Callianassa tyrrhena exhibited a very low respiration rate (mean TRR=64.29 μl O2 animal-1 h-1, N=60; mean SRR=0.18 μl O2 mg DW-1 h-1, N=61). The slope of the TRR-DW logarithmic regression (b=0.64) showed that respiration in C. tyrrhena is proportional to body surface. Size is the dominant factor (among size, sex, season and locality) determining the variation in respiration rate. Comparison between the two sites with the different pollution load showed that there were no significant differences in the respiration rates of the same size class and season, except for the youngest animals in summer which showed a significant decrease in their respiration rate at the polluted site. A similar 'inhibitory' effect of pollution has been observed in the activity of the majority of the 19 digestive enzymes tested. Only three, e.g. trypsin, β-galactosidase and α-glucosidase showed an increase in polluted waters. One could suggest, therefore, that C. tyrrhena can be considered to be preadapted to the low oxygen conditions encountered in the sediments, because of its burrowing mode of living

Effets de sédiments contaminés sur les performances physiologiques de juvéniles de turbot, Scophtalmus maximus

Afin de soumettre des juvéniles de turbots à différentes conditions de contamination, des sédiments ont été prélevés dans un port du nord de la France (3 sites), dans un estuaire français anthropisé (la Seine) et dans un site de référence. Après 21 jours d'exposition en laboratoire, les performances physiologiques des poissons ont été analysées. Les résultats montrent une corrélation entre niveau de contamination dans les sédiments et performances physiologiques avec des taux de croissance et des indices de conditions plus élevés dans le site le moins contaminé

Growth, condition indices and biomarker responses of juvenile turbot, Scophtalmus maximus, exposed to contaminated sediment

Since sediments have the potential to form associations with several classes of pollutants, they have been recognized as a possible and significant source of stress for the benthic environment. Flatfish maintain a close association with sediments for food and cover and are therefore more likely to be exposed to contaminated sediments, especially in coastal areas. The assessment of these potential biological effects implies to use adapted biomonitoring tools. The main objective of this study is to assess and compare the response of several biological indicators measured on juvenile turbot (Scophtalmus maximus) exposed to contaminated sediments. Sediments were collected at three stations in a northern France harbour (Boulogne-sur-Mer), in an anthropogenic French estuary (Seine) and in a reference site. Juvenile turbots were exposed to sediments during 7 and 21 days in laboratory conditions. Sediments were analyzed for metals, PAHs and PCBs contamination. Growth and several condition indices were individually measured on tagged fish and metal bioaccumulation was measured in fish gills. The response of some hepatic biotransformation enzymes (EROD, GST) and antioxidant enzyme (CAT) were also analyzed as first indicators of exposure. Results showed a significant correlation between level of contamination and fish biological responses. Indeed, growth rate, morphometric index and the lipid storage index, based on the ratio of the quantity of triacylglycerols on sterols (TAG:ST), were significantly higher in the less contaminated station. The RNA:DNA ratio tend also to decrease with chemical contamination. This decrease of growth and condition indices, associated with a metal accumulation in gills, reflected the adverse effects of contaminated sediment on fish biological performance. In addition, the simultaneous use of several hepatic biomarkers and condition indices could give information on the relevance of molecular biomarker to predict adverse effects of contaminants

Growth and condition indices of juvenile turbot, Scophthalmus maximus, exposed to contaminated sediments: Effects of metallic and organic compounds.

International audienceSince sediments have the potential to form associations with several classes of pollutants, they have been recognized as a possible and significant source of contamination for the benthic environment. Flatfish maintain a close association with sediments for food and cover, and are therefore more likely to be exposed to contaminated sediments, especially in coastal areas (e.g. nursery grounds). The assessment of these potential biological effects involves the use of adapted biomonitoring tools. The main objective of this study was to assess and compare the response of several physiological biomarkers measured on juvenile turbot (Scophthalmus maximus) exposed to contaminated sediments. Sediments were collected from three stations in a harbour in northern France (Boulogne-sur-Mer), in an anthropogenic French estuary (the Seine), and in a reference site (exposed sandy beach of Wimereux). Unexposed lab-reared juvenile turbots were exposed to sediments for 7 and 21 days in laboratory conditions. Sediments were analysed for metals, PAH and PCB contamination. Several fish growth and condition indices were individually analysed in fish according to the chemical contaminant availability in sediment, the metal concentrations in gills and the estimation of PAH metabolites in their bile. Significant decreases in growth rates, morphometric index, RNA:DNA ratio and the lipid storage index, based on the ratio of the quantity of triacylglycerols on sterols (TAG:ST), were observed with increasing level of chemical contamination. This decrease in the fish's physiological status could be related to the significant increase of several metal concentrations in contaminated fish gills and the significant increase of PAH metabolites in bile. In a field situation, such a reduction in growth and energetic status of juvenile fish could dramatically decrease their over-winter survival in contaminated nursery grounds