Biology Reference
In-Depth Information
Chlorpyrifos
AChE inhibitor
Exposure
Cadmium
To xic metal
Swimming
ability
Behavior
Hyperactivity
Breakdown of
mysid swarms
More noticeable to
predators
Favor predation
Displacement from areas
of optimum feeding
Ecological
consequences
Ecological death
FIGURE 10.4
Ecological consequences for estuarine mysid crustacean Neomysis integer from exposure to realistic concentra-
tions of contaminants. (After Roast, S.D. et al., Aquat. Toxicol. , 47, 227-241, 2000; Roast, S.D. et al., Aquat. Toxicol. ,
52, 217-227, 2001.)
2+
L -1 ) (Asthaus 1992, quoted in Roast et al. 2001). Swimming was also disturbed in N. integer
exposed to the organophosphate pesticide chlorpyrifos (Roast et al. 2000). After 7 days of
exposure to 0.038 μg L -1 , hyperactivity was observed, and individuals swimming forward
into a slow current (3 cm s -1 ) were more numerous than in control conditions. The authors
concluded that swimming behavior of mysids would be disturbed at concentrations cor-
responding to freshwater quality standards (in the absence of water quality criteria for
the protection of aquatic life in estuaries). Using both laboratory and stream microcosm
studies, Nørum et al. (2010) showed effects of the pyrethroid lambda-cyhalothrin on drift
behavior in three species of freshwater macroinvertebrates. Low observed effect concen-
trations (LOECs) determined for Leuctra nigra (1 ng L -1 ), Gammarus pulex (10 ng L -1 ) and
Heptagenia sulphurea (100 ng L -1 ) were all within expected environmental concentrations.
In the nematode Caenorhabditis elegans , exposure to sulfamethoxazole, one of the most com-
mon existing antibiotics in the environment, at environmentally relevant concentrations,
Yu et al. (2011) have shown that behavior indicators exhibited a better sensitivity than
growth indicator. They also demonstrated that behavior toxicity was transferable to the
progeny, at least to the next generation.
Carrying out experiments over a duration significant compared to the life span of the
species of interest, and/or tests that take place at a key stage of the life cycle, can also
contribute to improving environmental realism. For instance, the possible sublethal altera-
tions in smolt physiology and behavior due to PCB (Aroclor 1254) exposure of Atlantic
salmon ( Salmo salar ) have been examined by Lerner et al. (2007) in fish exposed as yolk-sac
larvae or as juveniles just before the parr-smolt transformation in April. After exposure,
yolk-sac larvae were reared at ambient conditions for 1 year, until the peak of smolting
the following May. These authors indicate that the effects of exposure may vary according
to developmental stage. Exposure in the freshwater environment can inhibit preparatory
the Thames (0.53 μg Cd (aq)
2+ L -1 ), the Schelde (0.3 μg Cd (aq)
2+ L -1 ), and the Rhine (0.18 μg Cd (aq)
 
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