Mesocosms in Ecotoxicology (1): Outdoor Aquatic Systems

Caquet, Thierry; Lagadic, Laurent; Sheffield, Steven R.

doi:10.1007/978-1-4612-1172-3_1

Cited by 65 publications

(42 citation statements)

References 180 publications

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“…Such variability in survival in mesocosms, either for flounder, (Vethaak et al, 1996) or more generally for many organisms has been observed before. Whilst this variability is a problem for the assessment of effects on community structure and other higher level ecosystem variables, inter-individual variation in organisms, within or between groups is much lower (Caquet et al, 2000). Furthermore, since the higher mortality occurred in one of the clean mesocosms, it is clear that the pollutant status of the sediments is unlikely to be the cause.…”

Section: Discussionmentioning

confidence: 99%

Hepatic gene expression in flounder chronically exposed to multiply polluted estuarine sediment: Absence of classical exposure ‘biomarker’ signals and induction of inflammatory, innate immune and apoptotic pathways

et al. 2010

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The effects of chronic long term exposure to multiply-polluted environments on fish are not well understood, but environmental surveys suggest that such exposure may cause a variety of pathologies, including cancers. Transcriptomic profiling has recently been used to assess gene expression in European flounder (Platichthys flesus) living in several polluted and clean estuaries. However, the gene expression changes detected were not unequivocally elicited by pollution, most likely due to the confounding effects of natural estuarine ecosystem variables. In this study flounder from an uncontaminated estuary were held on clean or polluted sediments in mesocosms, allowing control of variables such as salinity, temperature, and diet. After 7 months flounder were removed from each mesocosm and hepatocytes prepared from fish exposed to clean or polluted sediments. The hepatocytes were treated with benzo(a)pyrene (BAP), estradiol (E2), copper, a mixture of these three, or with the vehicle DMSO. A flounder cDNA microarray was then used to measure hepatocyte transcript abundance after each treatment. The results show that long term chronic exposure to a multiply-polluted sediment causes increases in the expression of mRNAs coding for proteins of the endogenous apoptotic program, of innate immunity and inflammation. Contrary to expectation, the expression of mRNAs which are commonly used as biomarkers of environmental exposure to particular contaminants were not changed, or were changed contrary to expectation. However, acute treatment of hepatocytes from flounder from both clean and polluted sediments with BAP or E2 caused the expected changes in the expression of these biomarkers. Thus transcriptomic analysis of flounder exposed long-term to chronic pollution causes a different pattern of gene expression than in fish acutely treated with single chemicals, and reveals novel potential biomarkers of environmental contaminant exposure. These novel biomarkers include Diablo, a gene involved in apoptotic pathways and highly differentially regulated by both chronic and acute exposure to multiple pollutants.

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Section: Discussionmentioning

confidence: 99%

Hepatic gene expression in flounder chronically exposed to multiply polluted estuarine sediment: Absence of classical exposure ‘biomarker’ signals and induction of inflammatory, innate immune and apoptotic pathways

et al. 2010

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“…To conclude, all these systems can be defined as essential intermediates between singlespecies tests and in situ studies (Caquet et al, 2000) in exploring the effects of toxicants and their potential interaction with environmental factors.…”

Section: Microcosms Mesocosms and Macrocosmsmentioning

confidence: 99%

Herbicide Contamination of Freshwater Ecosystems: Impact on Microbial Communities

Villeneuve¹,

Larroudé²,

Humbert³

2011

Pesticides - Formulations, Effects, Fate

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“…An advantage of experimental ecosystems is that they can be replicated, and several concentrations of a pollutant can be tested simultaneously. The pros and cons of working with model freshwater ecosystems are discussed by Brock et al (1995a), ECETOC (1997), and Caquet et al (2000).…”

Section: Introductionmentioning

confidence: 99%

Threshold Levels for Effects of Insecticides in Freshwater Ecosystems: A Review

2005

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Abstract. A literature review of freshwater (model) ecosystem studies with neurotoxic insecticides was performed to assess ecological threshold levels, to compare these levels with the first tier approach within European Union (EU) administration procedures, and to evaluate the ecological consequences of exceeding these thresholds. Studies published between 1980 and 2001 were reviewed. Most studies covered organophosphates and synthetic pyrethroids in lentic waters. The most sensitive taxa were representatives of crustaceans, insects and fish. Based on toxic units, threshold values were equivalent for compounds with a similar mode of action. This also accounted for the nature and magnitude of direct effects at higher concentrations. Although laboratory single species toxicity tests may not allow predictions on precise ecological effects, some generalisations on effects and recovery can be made with respect to acute standard laboratory EC 50 data. The NOEC ecosystem usually is a factor of 10 or more higher than first tier acceptable concentrations, particularly in the case of single applications and acetylcholinesterase inhibitors. Acceptable concentrations, as set by the EU first tier approach, appear to be protective. Recovery of sensitive endpoints usually occurs within 2 months of the (last) application when peak concentrations remain lower than (0.1-1) · EC 50 of the most sensitive standard test species. The consistency of response patterns found in model ecosystem studies can be useful when estimating the ecological risks of pesticides. The use of an effect classification system was also helpful in evaluating effects.

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Mesocosms in Ecotoxicology (1): Outdoor Aquatic Systems

Cited by 65 publications

References 180 publications

Hepatic gene expression in flounder chronically exposed to multiply polluted estuarine sediment: Absence of classical exposure ‘biomarker’ signals and induction of inflammatory, innate immune and apoptotic pathways

Hepatic gene expression in flounder chronically exposed to multiply polluted estuarine sediment: Absence of classical exposure ‘biomarker’ signals and induction of inflammatory, innate immune and apoptotic pathways

Herbicide Contamination of Freshwater Ecosystems: Impact on Microbial Communities

Threshold Levels for Effects of Insecticides in Freshwater Ecosystems: A Review

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