Sentinel Species - Ecological Biomarkers: Indicators of Ecotoxicological Effects - page 178

(a)

4%

2%

Bivalves

Gastropods
Chitons
Cephalopods

29%

65%

3% 6% 3%

(b)

Phyllopods
Cladocerans
Copepods
Amphipods
Decapods

18%

70%

(c)

19%

Oligochaetes
Polychaetes

81%

FIGURE 7.7
Percentages of species of mollusks (a), crustaceans (b), and annelids (c) in which metallothionein induction by
metals has been shown. (After Amiard, J.C. et al., Aquat. Toxicol ., 76, 160-202, 2006.)

Although mollusks are often recommended for use to estimate lysosomal membrane
integrity, DNA strand breaks, or MT concentrations, they are, on the other hand, of less
interest in investigations, for example, of the catalytic activity of P450. Other taxa are
then recommended such as particular teleost fishes: red mullet ( Mullus barbatus ) or bass
( Serranus spp.) (UNEP/RAMOGE 1999). In reverse again, although only few data for gluta-
thione- S -transferase (GST) are supplied by fish (Roméo et al. 1994; Castro et al. 2004), GST
is successfully used as biomarker of exposure in mollusks (Roméo et al. 2003; Buffet et al.
2011) and annelids (Durou et al. 2007; Buffet et al. 2011). In a recent review, Amiard-Triquet
et al. (2012) have highlighted the importance of polychaetes in ecotoxicological studies,
because of the robustness of many polychaete worms, and because many biomarkers mea-
sured in these animals have proven to be generally more sensitive to pollution factors than
to natural factors (e.g., salinity of the studied area, size of the worms), thereby avoiding
many of the problems caused by so-called “confounding factors.” Amiard-Triquet et al.
(2012) conclude that ragworms of the family Nereidae appear to represent the most com-
monly used taxon of polychaetes for the determination of biomarkers.
On the other hand, mixed populations may supply different data to those obtained on
isolated organisms. Chapman et al. (1982), using mixed populations of freshwater oligo-
chaetes ( Limnodrilus hoffmeisteri and Tubifex tubifex ), demonstrated that mixed populations
of these two species showed higher tolerance to cadmium, mercury, and sodium penta-
chlorophenol, but lower tolerance to anoxia, than isolated populations. Similar conclusions
were reached by Keilty et al. (1988), who showed that, during contamination of sediment
by endrin, L. hoffmeisteri benefits from the presence of the oligochaete Stylodrilus herin-
gianus , with a decrease of its mortality, an increase of its mass, and a stimulation of its
bioturbatory activity.