High oxygen solubility at cold-water temperature is frequently considered to be responsible for an apparently elevated level of antioxidant protection in marine ectotherms from polar environments. However, tissue oxidative stress is in most cases a function of elevated or variable pO2, rather than of an elevated tissue oxygen concentration. This review summarizes current knowledge on pro- and antioxidant processes in marine invertebrates and fish, and relates reactive oxygen species (ROS) formation in polar ectotherms to homeoviscous adaptations of membrane and storage lipids, as well as to tissue hypoxia and re-oxygenation during physiological stress.

/pdf/formation-of-reactive-species-and-induction-of-antioxidant-3ybs5nz7m2.pdf

Formation of reactive species and induction of antioxidant defence systems in polar and temperate marine invertebrates and fish

Blue mussels (Mytilus edulis spp.) as sentinel organisms in coastal pollution monitoring: A review

http://retina.umh.es/docencia/metodologia/trabajosambientales/1075.pdf

Cadmium and copper display different responses towards oxidative stress in the kidney of the sea bass Dicentrarchus labrax.

1. Determination of Total Lipid, Lipid Classes, and Fatty Acids in Aquatic Samples.- 1.1. Introduction.- 1.2. Results and Discussion.- 1.2.1. Sampling and Storage.- 1.2.2. Lipid Extraction.- 1.2.3. Determination of Total Lipid.- 1.2.4. Determination of Lipid Classes.- 1.2.5. Determination of Fatty Acids and Carbon Number Profiles.- 1.3. Conclusion.- References.- 2. Fatty Acids as Trophic and Chemical Markers in Freshwater Ecosystems.- 2.1. Introduction.- 2.2. Nomenclature.- 2.3. Characteristics of Fatty Acid Markers for Trophic Studies.- 2.4. Primary Sources and Trophic Transfer of Fatty Acids.- 2.4.1. Fatty Acid Composition of Algae and Cyanobacteria.- 2.4.2. Fatty Acids as Trophic Markers of Algae and Cyanobacteria.- 2.4.3. Fatty Acid Composition of Bacteria.- 2.4.4. Fatty Acids as Trophic Markers of Bacteria.- 2.4.5. Fatty Acid Markers from Allochthonous Sources.- 2.4.6. Fatty Acids as Trophic Markers in Vertebrates.- 2.5. Research Needs.- 2.6. Conclusions.- References.- 3. Irradiance and Lipid Production in Natural Algal Populations.- 3.1. Introduction.- 3.2. Metabolism and Reallocation.- 3.2.1. Lipids in Relation to Other Macromolecular Classes.- 3.2.2. Diel Versus Light-Phase Allocation and Synthesis.- 3.2.3. Budgets for Overnight Activity.- 3.2.4. Reallocation Among Lipid Classes.- 3.3. Irradiance and Lipid Synthesis.- 3.3.1. Photosynthetic Parameters.- 3.3.2. Light Saturation Parameter, Ik.- 3.3.3. Production Efficiency Parameter, ?.- 3.3.4. Areal Lipid Production.- 3.3.5. Implications of the Irradiance Response.- 3.4. Conclusions.- 3.5. Research Directions.- References.- 4. Lipids in Freshwater Zooplankton: Selected Ecological and Physiological Aspects.- 4.1. Introduction.- 4.2. Usefulness of Areal Energy Reserve Estimates.- 4.3. Time Course of Lipid Deposition/Loss.- 4.4. Lipids as Indices of Stress.- 4.4.1. Ratio of Storage to Membrane Lipids.- 4.4.2. Maternal Lipid Investment.- 4.4.3. Visible Lipid Energy Stores.- 4.4.4. Fatty Acid Composition and Abundance.- 4.5. Ultraviolet Radiation and Zooplankton Lipids.- 4.6. Research Needs and Suggested Future Directions.- 4.6.1. Geographical Disparities.- 4.6.2. Physicochemical Disparities.- 4.6.3. Essential Fatty Acids.- 4.6.4. Effects of Temperature Changes.- 4.6.5. Diapause.- 4.6.6. Lipids as Allelopathic Compounds and Chemical Feeding Deterrents.- 4.7. Conclusions.- References.- 5. Lipid Dietary Dependencies in Zooplankton.- 5.1. Introduction.- 5.2. Methods.- 5.2.1. Microparticle Preparation.- 5.2.2. Dietary Supplement Experiments.- 5.2.3. Characterization of the Natural Algal Diet.- 5.2.4. Algal Counting and Autoradiography.- 5.3. Results.- 5.3.1. Supplement Experiments with Natural Populations.- 5.3.2. Lake Waynewood Experiment: October 1989.- 5.3.2.1. Algal Diet.- 5.3.2.2. Response byDaphnia.- 5.4. Discussion.- References.- 6. Seasonal Dynamics of Lipids in Freshwater Benthic Invertebrates.- 6.1. Introduction.- 6.2. Results and Discussion.- 6.2.1. Slope and Profundal Zones.- 6.2.1.1. Crustacea: Amphipoda.- 6.2.1.2. Mysidacea.- 6.2.2. Shelf and Nearshore Zones.- 6.2.2.1. Crustacea: Amphipoda.- 6.2.2.2. Annelida: Oligochaeta.- 6.2.2.3. Insecta.- 6.2.2.4. Mollusca: Bivalvia.- 6.3. Research Needs.- 6.4. Conclusions.- References.- 7. Ecological Role of Lipids in the Health and Success of Fish Populations.- 7.1. Introduction.- 7.2. Results and Discussion.- 7.2.1. Overwinter Starvation and Survival.- 7.2.2. Energy Allocation Strategies.- 7.2.3. Reproductive Development and Early Life History.- 7.2.4. Lipids and Environmental Stress.- 7.2.4.1. Contaminant Effects.- 7.2.4.2. Thermal Effects.- 7.2.4.3. Other Stressors.- References.- 8. Lipids and Essential Fatty Acids in Aquatic Food Webs: What Can Freshwater Ecologists Learn from Mariculture?.- 8.1. Introduction.- 8.2. Results and Discussion.- 8.2.1. Some Important Lipids and Fatty Acids.- 8.2.1.1. Essential Fatty Acids.- 8.2.1.2. Lipid Classes.- 8.2.2. Methodological Considerations.- 8.2.3. Physiological Requirements of Marine Animals.- 8.2.3.1. General Evaluation of EFA Requirements.- 8.2.3.2. Anabolic Processes and Growth.- 8.2.3.3. Membrane Transport and Metabolism.- 8.2.3.4. Regulation of Metabolism.- 8.2.3.5. General Considerations and Concluding Remarks.- 8.2.4. Methods for Evaluation of EFA Requirements.- 8.2.5. Symptoms of EFA Deficiency.- 8.2.6. Fatty Acid Transport and Metabolism in Food Webs.- 8.2.6.1. Algae.- 8.2.6.1.1. Lipids of Algae.- 8.2.6.1.2. Essential Fatty Acids of Algae.- 8.2.6.1.3. Conclusion.- 8.2.6.2. Zooplankton.- 8.2.6.2.1. Lipid Content and Lipid Composition.- 8.2.6.2.2. Fatty Acids of TAG-Zooplankton.- 8.2.6.3. Fish.- 8.2.6.3.1. Lipid.- 8.2.6.3.2. Fatty Acid Composition.- 8.2.6.4. General Conclusions.- 8.2.7. Relevance of Mariculture Research.- 8.2.8. Evaluation of Ecological Effects of Essential Fatty Acids.- 8.3. Concluding Remarks.- References.- 9. Influence of Lipids on the Bioaccumulation and Trophic Transfer of Organic Contaminants in Aquatic Organisms.- 9.1. Introduction.- 9.1.1. Sources of Contaminant Gain and Loss in Aquatic Systems.- 9.1.2. Organism Adiposity and Internal Distribution of Contaminants.- 9.1.3. Nonlipid Factors Affecting Internal Distributions.- 9.2. Prediction of Bioconcentration and Bioaccumulation.- 9.2.1. Bioconcentration.- 9.2.2. Bioaccumulation.- 9.3. Factors Affecting Prediction.- 9.3.1. Methods for Measuring Lipid Content.- 9.3.2. Lipid Composition and Bioaccumulation.- 9.4. Mimicking Bioconcentration with Semipermeable Membrane Devices.- 9.5. Toxicity and the Role of Lipid.- 9.5.1. Release of Sequestered Contaminant During Metabolism.- 9.5.2. Lipids and Membrane Narcosis.- 9.5.3. Effect of Toxins on Lipid Metabolism and Function.- 9.6. Relevance of Food Chain Transfer to Bioaccumulation.- 9.6.1. Relevance of Trophic Transfer to Bioaccumulation...- 9.6.2. Role of Lipids in Food Chain Accumulation.- 9.6.2.1. Fugacity Model.- 9.6.2.2. Mechanism for Trophic Transfer.- 9.6.3. Factors Affecting Trophic Transfer.- 9.6.3.1. Assimilation Efficiency.- 9.6.3.2. Miscellaneous Factors Affecting Assimilation.- 9.7. Biomagnification and Organism Lipids.- 9.7.1. Is Biomagnification Real?.- 9.7.2. A Lipid-Based Model for Biomagnification.- 9.7.3. Current Issues in Biomagnification and Relationship to Lipids.- 9.8. Lipids and Transgenerational Transfer of Contaminants.- 9.9. Conclusions.- References.- 10. Lipids in Water-Surface Microlayers and Foams.- 10.1. Introduction.- 10.2. Basic Physicochemistry of Surface Microlayers.- 10.3. Basic Structure of Foams.- 10.4. Sampling Techniques.- 10.5. Physicochemical Processes at the Surface Microlayers.- 10.6. Lipids in the Water-Surface Microlayers and Foams.- 10.6.1. Total Lipids and Major Lipid Classes.- 10.6.2. Fatty Acids.- 10.7. Research Needs.- 10.8. Final Remarks.- References.- 11. Comparison of Lipids in Marine and Freshwater Organisms.- 11.1. Introduction.- 11.2. Discussion.- 11.2.1. Lipid Classes.- 11.2.2. Sterols and Cholesterol.- 11.2.3. Wax Esters and Triacylglycerols.- 11.2.4. Fatty Acids.- 11.2.5. Furan and Some Other Unusual Fatty Acids.- 11.2.6. Ether Lipids.- 11.2.7. Prostanoids.- 11.3. Conclusions.- References.

/pdf/lipids-in-freshwater-ecosystems-3vihdjmdle.pdf

Lipids in freshwater ecosystems

Oxidative stress can take place in marine bivalves under a series of environmental adverse conditions. The study of different systems related to oxidative stress in these organisms can give important information about their physiological status and also about environmental health. Bivalves have been proposed as good sentinel organisms in pollution monitoring studies through the analysis of biochemical biomarkers, and most of the biomarkers analyzed are those related to oxidative stress. However, it is very important to know how other environmental factors not associated to the presence of pollutants might affect these parameters. We have studied a series of mechanisms related to oxidative stress in mussels which inhabit the Brazilian coast, especially in Perna perna species, subjected to different stress conditions, such as the exposure to different contaminants in the laboratory and in the field, the exposure of mussels to air and re-submersion, simulating the tidal oscillations, and in mussels collected at different seasons. Both oxidative damage levels and antioxidant defense systems were strongly affected by the different environmental stress. This review summarizes the data obtained in some studies carried out in bivalves from the Brazilian coast.

Oxidative stress in Perna perna and other bivalves as indicators of environmental stress in the Brazilian marine environment: antioxidants, lipid peroxidation and DNA damage.

Deleterious effects of environmental contaminants could be due to enhanced prooxidant forces overcoming antioxidant defences Before practical biomarkers based on free radical biology will be generally accepted and validated in situ, additional research is required concerning normal physiological and environmental influences on the relevant systems The aims of this study were to evaluate in situ the importance of oxyradical production in the presence and absence of pollutants and to characterize some antioxidant systems in Mytilus edulis L Specimens of M edulis L were transplanted from a reference site (Franquelin) to Baie Comeau (Baie des Anglais), on the North shore of the St Lawrence maritime estuary, where are found aluminium and pulp and paper plants An oxidative stress was observed in mussels submitted to a chronic exposure in the polluted environment Variations of pro-and anti-oxidant molecules involved in oxidative processes were related in part to seasonal and physico-chemical influences Catalase activity, malondialdehyde and glutathione concentrations will be useful as biomarkers of stress in situ since they react to anthropogenic influence and to abiotic factors such as emersion period and temperature

Oxidative processes as indicators of chemical stress in marine bivalves

Effect of the Tidal Cycle on Lysosomal Membrane Stability in the Digestive Gland of Mya arenaria and Mytilus edulis L.

In an attempt to improve our understanding of the transfer process of organic mercury (mainly methyl mercury) from the prey to the consumer, the uptake of mercury in edible muscle of shrimps, Pandalus borealis, from contaminated mussels used as food supplies was studied. Shrimps bioaccumulated rapidly mercury in their abdominal muscle when submitted to a highly contaminated diet (6 μg Hg g⁻¹) but biomagnification was not observed and Hg concentration in shrimps never exceeded 1.8 μg g⁻¹. The assimilation efficiency during the uptake period was estimated to about 42% When shrimps received moderately contaminated diet (2.5–2.9 μg Hg g⁻¹), a two-stage bioaccumulation process was observed in which mercury concentration began to increase in shrimp muscle after 15 days of contaminated diet and at the end of the experiment it seemed to level off. This process can be represented by a two-compartment conceptual model in which mercury rs first eliminated and/or accumulated in the compartment 1 (digestive organs) and then transferred to the compartment 2 (abdominal muscle) following a mechanism and under conditions not yet clearly understood. The use of selenium biologically incorporated into the diet had no apparent effect on the uptake of mercury

Uptake of organic mercury and selenium from food by nordic shrimp Pandalus borealis

Environmental stressors as well as the direct or combined effects of pollutants could be harmful to the populations living in a marine environment and the reproductive and nutritive processes could be impaired in a deteriorating environment. Sublethal effects of pollutants were studied in the blue mussel Mytilus edulis L., a good bioaccumulator of contaminants. Blue mussels of 3.5 cm were sampled on a rocky substrate at Pointe-Mitis (48°40’ N, 68°02’ W) along the coast of the St-Lawrence estuary. Mussels were placed in experimental tanks, fed, supplemented with mineral salts and continuous sea water flow and kept 72 h before the exposure to 0.01 μg 1-1 and 0.3 μg 1-1 methylmercury hydroxide in the presence or absence of selenium, at a concentration of 125μg 1-1, a possible antagonist of methylmercury. The contamination protocol was performed during 45 days and a 14 day period of recuperation was allowed. The stress caused by the transplantation of mussels in the laboratory tanks and/or by the presence of pollutants was evaluated by a general indicator of stress developed in our laboratory, the measure of the lysosomal membrane fragility (LMF) of the digestive gland, according to the method developed by Moore (1976). The effects of contamination on metabolism were measured by the study of the variations of the malate dehydrogenase activity (MDH), a key enzyme of the aerobic metabolism. The first days of the contamination period led to an increased metabolism in the mantle and to a detoxifying mechanism in the hepatopancreas. At days 22 and 29 of the experiment, the affinity of the MDH was greatly decreased with both concentrations of methylmercury and selenium, suggesting a competitive inhibition of the enzymatic activity by the pollutants. LMF increased as the mussels were kept longer in the tanks. Methylmercury increased the stress undergone by the mussels. LMF gives information about the degree of stress of the organism while the biochemical indicator informs about the metabolic effects of sublethal concentrations of pollutants.

Jocelyne Pellerin-Massicotte

Papers

Oxidative processes as indicators of chemical stress in marine bivalves

Effect of the Tidal Cycle on Lysosomal Membrane Stability in the Digestive Gland of Mya arenaria and Mytilus edulis L.

Uptake of organic mercury and selenium from food by nordic shrimp Pandalus borealis

Cellular and biochemical indicators assessing the quality of a marine environment

Seasonal variability in biochemical composition of the polychaete Nereis virens (Sars) in two tidal flats with different geographic orientations