The GEEP Workshop: mesocosm exposures

Hepatic ethoxyresorufin 0-de-ethylase (EROD) and benzo(a)pyrene hydroxylase (B(a)PH) activity in flounder Platichthys flesus increased along a pollution gradient in Langesundfjord, examined during the GEEP Workshop. EROD activity in fish from a reference site was around 100 pm01 min-' mg microsomal protein-', increasing 5-fold at 2 moderately polluted sites and a further 2-fold at a more highly polluted site. B(a)PH activity was around 30 pm01 min-' mg protein-' in fish from the reference site, and was more than doubled at the polluted sites. Liver residue concentrations of several industrially-derived chlorinated hydrocarbons also increased along the pollution gradient. The data support the conclusion that fish hepatic mono-oxygenase activity may indicate exposure to organic pollutants in the field. Exposure of flounder to diesel oil and copper in mesocosms over several months dld not induce EROD or B(a)PH. Enzyme activities were all below those at the field reference site (EROD and B(a)PH around 70 and 20 pm01 min-' mg proteln-' respectively). Total PAH concentrations in liver (fluorescence measurements) did not vary with treatment, suggesting that the expenmentally exposed fish &d not accumulate inducing compounds.

Section: Methodsmentioning

confidence: 99%

Hepatic microsomal mono-oxygenase activity in flounder Platichthys flesus from polluted sites in Langesundfjord and from mesocosms experimentally dosed with diesel oil and copper

Addison¹,

Edwards²

1988

“…from field sites in Langesundfjord (Norway), an area contaminated by metals and organic xenobiotics of industrial origin (Follum & Moe 1988), and from NIVA mesocosm facilities at Solbergstrand (near Oslo), where a contaminant gradient had been simulated in experimental basins (Bakke et al 1988). Briefly, the M. edulis were sampled according to the following schedule.…”

Section: Mytilus Edulis Were Collected During August 1986mentioning

confidence: 99%

“…The 4 experimental basins were dosed for 15 wk from April 1986 with differing concentrations of the same mixture of diesel oil (water accommodated fraction) and copper (C: control, L: low, M : medium and H: high dose), see Bakke et al (1988). High dose levels were chosen to impact the organisms strongly, while C, (Pauley 1967).…”

Section: Mytilus Edulis Were Collected During August 1986mentioning

confidence: 99%

Histopathological changes related to chemical contamination in Mytilus edulis from field and experimental conditions

Auffret¹

1988

This comparative histopathological study, carried out at the GEEP Workshop, assesses tissue changes in mussels Mytilus edulis from a contaminated Norwegian fjord and from mesocosm basins where a contaminant gradient had been simulated. Parasitism by larval trematodes was observed in both circumstances, but was not related to contaminant levels. Mussels from the field exhibited granulocytomas in their interstitial tissues, with a greater incidence at polluted sites than at a reference site, suggesting that granulocytomas could be a consequence of chronic pollutant exposure. This pathological condition was not observed in experimentally treated mussels, which nevertheless had severe tissue alterations, especially in digestive tubules and gills, under exposure to high levels of a diesel oil and copper mixture. It is concluded that this type of histopathological analysis can provide useful information on the health of mussels, and that this information can be used successfully in the comparison of field samples.

“…that potentially confound comparisons of different experimental treatments. In the existing experimental design, 4 basins were used, each of which contained one single experimental treatment (control or one of three concentrations of pollutants), Bakke et al (1988). A better experimental design.…”

Section: Evaluation: Comparisons Of Techniquesmentioning

confidence: 99%

“…Where possible, this will best be achieved by some comparison of experimentally polluted sites with control, unpolluted samples. Ideally, this would be done in a properly controlled and replicated field experiment to remove interference from naturally confounding variables (or in suitable laboratory conditions such as the Solbergstrand mesocosms; see Bakke et al 1988, Warwick et al 1988, and other papers in this MEPS SPE-CIAL). Alternatively, prior knowledge of well-established causal links between pollutants and their known effects would suffice to demonstrate that pollutants caused the observed dfferences.…”

Section: Introduction: the Rationale For Studies Of Pollution In The Seamentioning

confidence: 99%

Towards an ecological framework for investigating pollution

Underwood¹,

Peterson²

1988

215

129

Three aspects of the study of effects of pollution in marine systems are discussed. First is the evaluation of relative sensitivities and reliabilities of different methods of detecting pollution, includ~ng a brief contrast of processes operating in mesocosms and in the field. Second is the problem of interpretation of pollution, i e determining the importance of the observed effects of pollution to the biological system. Species selected for detecting pollution may not provide useful information about the econoinic effects on explo~ted parts of natural systems, nor about trophic structure of a community, nor about future sizes of populations of important species. The choice of appropriate species a s indicators or detectors of pollution also requires determination of how representative they are of other species likely to b e affected by pollution. Finally, there is the problem of prediction of future consequences of pollution. Some methods used to detect pollutants might b e useful a s early warnings of future deleterious effects, although the usefulness of these measures may b e lessened by the decoupling of reproductive rates of many marine invertebrates from the eventual recruitment to adult populations. Other measures such as patterns in whole assemblages of species can usually only detect pollutants after sufficient time has elapsed for populations to have changed. Nevertheless, these offer more direct measurements of the importance of pollution to the continued functional well-being of the system. A mixture of different types of measures allows the best synthesis of predictive power while providing the most useful information for interpretation of the consequences of pollution to a marine system.