Marine Ecosystems under Toxic Pressure - Vulnerability of Coastal Ecosystems and Adaptation - page 40

the sum of their components, and the challenge to come is to
understand the sometimes subtle but important integration of the
indirect influence of contaminants in a realistic approach to exposure.
Experiments in micro- and meso-cosmes constitute necessary tools
for studying the combined effects of different environmental stresses;
although there is disagreement and debate concerning the modeling
methods for the analysis and interpretation of these data [LIE 11,
VAN 12]. Long-term ecotoxicological experiments that integrate the
combination of climate evolution and environmental variations on a
credible scale would permit more reliable predictions of the impact of
toxic products in the context of climate change. Three approaches
seem particularly promising:
- studying the potential of species to adapt, with the help of genetic
analyses (variability and correlations);
-to carry out experiments (in a controlled setting) on
microevolution;
-to compare populations tolerant to climate changes with
populations resistant to toxic substances [SCH 11].
Marine ecosystems have been living under toxic pressure, probably
for decades, but the level of this pressure has increased considerably
with the rapid expansion of synthetic chemistry and the production of
manufactured goods from the middle of the 20th Century. If marine
life has developed with ingenious mechanisms enabling it to regulate,
indeed to use, metals that are a constituent of the Earth's crust, it is not
necessarily the same for the new, synthetic organic molecules, which
are endlessly renewed, with which it is faced today. The formidable
distances over which these substances are transported, physically or
biologically, separate the origins and impacts of these pollutions in
space and time. Everything should be done to reduce contamination
on such a vast scale in environments that have a heritage value and are
rich in practical uses.
But, we also have a lot to learn about the dynamics of these marine
ecosystems that have developed strategies of maintenance, indeed of
development. Life is fundamentally fluid, “unpredictable and