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responsive to contamination due for instance to nanoparticles (Bilberg et al. 2011; Buffet
et al. 2011; Chen et al. 2011; Barros Amorim and Scott-Fordsmand 2012; Truong et al. 2012),
phytoestrogens (Clotfelter et al. 2006), antibiotics (Yu et al. 2011), brominated flame retar-
dants (BDE-47, Chen et al. 2012) or nonylphenols (Cailleaud et al. 2011).
10.2 Physiological Mechanisms Inducing Behavioral Impairments
Sensory systems are key for normal behavior since detection of environmental toxicants—
but also natural compounds emitted by prey, congeners, and predators—govern avoidance
ability and inter- and intraspecific relationships, particularly reproduction. Many studies
have shown important links between hormones and behavior. Thus, it is highly prob-
able that endocrine disruptors (Chapter 8) can have behavioral effects. Behavior is also
influenced by the levels of neurotransmitters including the core damage biomarker AChE
(Chapter 4). Energy-consuming locomotion activities are needed for the implementation
of most behaviors; thus, it is expected that contaminants that impair energy metabolism
(Chapter 11) probably influence behavioral responses.
10.2.1 Disruption of Sensory System Function
When exposed to an environmental contaminant, an organism will react differently
depending on its ability (or lack thereof) to detect the presence of this compound (Figure
10.1). Once detected, avoidance (escape, valve closure in bivalves) allows a reduction of
exposure, limiting noxious effects and improving survival. In the absence of detection and
appropriate behavioral responses, organisms endure maximal exposure that can lead to
lethal effects and reduced longevity.
Communication by chemosignals is often based on pheromones that can be chemically
similar to internal chemical messengers such as steroids or neuropeptides. Production
Environmental disturbance
Detection
Avoidance
No avoidance
No exposure
Reduced exposure
Maximal exposure
Sublethal effects
Lethal effects
No toxic effects
Reduced longevity
Short-term survival
Long-term survival
FIGURE 10.1
Different types of responses of organisms exposed to contaminants in their medium and consequences for their
health and survival.
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