Sentinel Species - Ecological Biomarkers: Indicators of Ecotoxicological Effects - page 155

7
Sentinel S pecies
Brigitte Berthet
CONTENTS
7.1 Concept of Sentinel Species .............................................................................................. 156
7.1.1 Development of Concept and the Species Used ................................................ 157
7.1.2 Criteria for Selection of Sentinel Species ............................................................ 158
7.1.3 Active Biomonitoring ............................................................................................ 160
7.1.3.1 Context ...................................................................................................... 160
7.1.3.2 Implementation of Biomonitoring ........................................................ 161
7.2 Concept of Ecosystem Approach ..................................................................................... 164
7.2.1 Keystone Species .................................................................................................... 164
7.2.1.1 Roles in Food Webs ................................................................................. 165
7.2.1.2 Roles in Biogeochemical Cycles ............................................................ 168
7.2.2 Conservation of Biodiversity ................................................................................ 170
7.2.2.1 Interspecific Variability .......................................................................... 170
7.2.2.2 Intraspecific Variability .......................................................................... 175
7.2.3 Choice of Physical Compartment ........................................................................ 176
7.3 Species Used as Sentinels ................................................................................................. 177
7.4 Conclusions ......................................................................................................................... 179
References ..................................................................................................................................... 180
The increasingly precise techniques of analytical chemistry allow us to identify and to
quantify, in all biological or physical matrices, an increasing number of xenobiotics and
their metabolites, but these measures supply no information about the toxicological or
ecotoxicological risks of such contaminants. For that purpose, toxicity tests, carried out in
the laboratory on a limited number of species, were established, allowing definition of the
nature of the risk as well as any associated dose-effect relationship. However, these tests
do not take into account the influence of the multiple parameters present in the environ-
ment that intervene under natural conditions to affect toxicity: abiotic ecological factors
(such as temperature, salinity, conditions of oxygenation), interspecific variability and the
interactions between species, the heterogeneity of populations in their interactions with
pollutants, or between interactions between pollutants and abiotic factors of the environ-
ment (Smolders et al. 2004). The biological monitoring of the environment, or “biomonitor-
ing,” has the objective of integrating these various aspects, particularly by using sentinel
species as models.
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