100
Water In Ecosystems: A Non Renewable Resource
This approach makes it possible to clearly determine the link between the
physiological perturbations undergone by cellular cultures or organisms, the
effects noted by simple and reproducible tests, the evidence of structural and
functional disorders present in mesocosms situated in conditions very similar to
those of the natural environment. The different observation scale also highlights
certain effects that are specific to relationships between populations or trophic
levels. These results clearly show the need to tackle simultaneously the structural
and functional aspects, since they are very dependent on each other, just as the fate
of the toxic and its effects over time are equally interdependent ([7], [8]).
Clearly the procedure implied by these methodologies is relatively cumbersome
and costly, but it is entirely complementary to the laboratory approach with its
monospecific tests. The complementarity of these procedures enables ecotoxicology to contribute to the improved protection of aquatic ecosystems by making
it easier to limit pollutions and work out quantities better adapted to needs.
ACKNOWLEDGEMENTS
The author would like to express his thanks to Mrs Dubois for her help in the
translation and in the preparation of the English version of this paper.
KEYWORDS
Ecosystems, pesticide, contamination, aquatic system, water, pollution, ecotoxicology.
REFERENCES
[I]
Ford J., The effects of chemical stress on aquatic species. Composition and community
structure In: Ecotoxicology: Problems and Approaches by Levin S.A., Harwell M.A., Kelly
J.R. and Kimball K.D. (eds) (1989).
[2]
Franco P.I., Giddings J.M., Herbes S.E., Hook L.A., Newbold J.D., Roy W.K., Southworeth
O.R. and Stewart AJ., Effects of chronic exposure to coal-derived oil on freshwater ecosystems. I. Microcosms. Environ. Toxicol. Chern., 3:447-463 (1984).
[3]
Giesy J.R. (ed.), Microcosms in Ecological Research. Conf-78 I 101, U.S. Department of
Energy, Washington, D.C. (1980).
[4]
Giddings J.M., Microcosms for assessment of chemical effects on the prperties of aquatic
ecosystems. pp. 45-94 in J.Saxena (ed.) Hazard Assessment of Chemicals-Current Deve1opmeznt. Vol. II Academic Press, New-York (1983).
[5]
Levin S.A., Harwell M.A., Kelly J.R. and Kimball K.D., (eds), Ecotoxicology: Problems and
Approaches, Springer-Verlag, 547p. (1989).
[6]
Touart L.W., Aquatic Mesocosm Tests to support Pesticide Registrations. EPA. 540/09-88035. US Environmental Protection Agency, Washington, D.C. (1988).
[7]
Weinstein D.A. and Birk E.M., Terrestrial Ecosystem structure and chemical stress.in: Ecology:problems and approaches, Levin S.A. et al. (eds), 181-209 (1990).
[8]
Persoone G. and Janssen C. R., Field validation of predictions based on laboratory toxicity
tests.in. Freshwater field tests for hazard assessment of chemicals (I. Hill et al eds.).CRC
Press, 379-398 (1994).
Water In Ecosystems: A Non Renewable Resource
This approach makes it possible to clearly determine the link between the
physiological perturbations undergone by cellular cultures or organisms, the
effects noted by simple and reproducible tests, the evidence of structural and
functional disorders present in mesocosms situated in conditions very similar to
those of the natural environment. The different observation scale also highlights
certain effects that are specific to relationships between populations or trophic
levels. These results clearly show the need to tackle simultaneously the structural
and functional aspects, since they are very dependent on each other, just as the fate
of the toxic and its effects over time are equally interdependent ([7], [8]).
Clearly the procedure implied by these methodologies is relatively cumbersome
and costly, but it is entirely complementary to the laboratory approach with its
monospecific tests. The complementarity of these procedures enables ecotoxicology to contribute to the improved protection of aquatic ecosystems by making
it easier to limit pollutions and work out quantities better adapted to needs.
ACKNOWLEDGEMENTS
The author would like to express his thanks to Mrs Dubois for her help in the
translation and in the preparation of the English version of this paper.
KEYWORDS
Ecosystems, pesticide, contamination, aquatic system, water, pollution, ecotoxicology.
REFERENCES
[I]
Ford J., The effects of chemical stress on aquatic species. Composition and community
structure In: Ecotoxicology: Problems and Approaches by Levin S.A., Harwell M.A., Kelly
J.R. and Kimball K.D. (eds) (1989).
[2]
Franco P.I., Giddings J.M., Herbes S.E., Hook L.A., Newbold J.D., Roy W.K., Southworeth
O.R. and Stewart AJ., Effects of chronic exposure to coal-derived oil on freshwater ecosystems. I. Microcosms. Environ. Toxicol. Chern., 3:447-463 (1984).
[3]
Giesy J.R. (ed.), Microcosms in Ecological Research. Conf-78 I 101, U.S. Department of
Energy, Washington, D.C. (1980).
[4]
Giddings J.M., Microcosms for assessment of chemical effects on the prperties of aquatic
ecosystems. pp. 45-94 in J.Saxena (ed.) Hazard Assessment of Chemicals-Current Deve1opmeznt. Vol. II Academic Press, New-York (1983).
[5]
Levin S.A., Harwell M.A., Kelly J.R. and Kimball K.D., (eds), Ecotoxicology: Problems and
Approaches, Springer-Verlag, 547p. (1989).
[6]
Touart L.W., Aquatic Mesocosm Tests to support Pesticide Registrations. EPA. 540/09-88035. US Environmental Protection Agency, Washington, D.C. (1988).
[7]
Weinstein D.A. and Birk E.M., Terrestrial Ecosystem structure and chemical stress.in: Ecology:problems and approaches, Levin S.A. et al. (eds), 181-209 (1990).
[8]
Persoone G. and Janssen C. R., Field validation of predictions based on laboratory toxicity
tests.in. Freshwater field tests for hazard assessment of chemicals (I. Hill et al eds.).CRC
Press, 379-398 (1994).