Multiscale approach of fish responses to different types of environmental contaminations: a case study.
In order to study the responses of wild fish to environmental contaminations, different sites (two references and three contaminated) were sampled across the Walloon hydrographical network (southern Belgium). The status of fish communities was characterized according to an index of biotic integrity (IBI). Furthermore, population structure, reproductive parameters and biochemical assays were performed on chub (Leuciscus cephalus) as sentinel species. The results showed impaired responses in fish sampled downstream paper mill effluents (BKME), in a polychlorinated biphenyls (PCB) contaminated site, and in a river receiving pesticides (i.e. atrazine and hexachlorocyclohexane). High level of hepatic 7-ethoxyresorufin-Odeethylase (EROD) activity were evidence of direct toxicant exposure, while population structures showed unbalanced size-frequency distributions. Moreover, in the pesticide contaminated site, a higher proportion of atretic oocytes was found in females and abnormally high plasma alkali-labile phosphorus (ALP) values were noticed in males, compared to reference sites, suggesting that chubs were exposed to estrogenic compounds. IBI scores from both sites were also lower than in reference sites. On the other hand, no particular response was found in hepatic glutathione-S-transferase (GST) activities, hepatic heat-shock protein HSP70 concentrations and plasma sex steroids (estradiol-17beta, 11-ketotestosterone and testosterone) in chubs from any sites. By using a multiparametric approach, a better understanding of response mechanisms to pollution in fish may be achieved in order to improve the ecological status of river ecosystems.
Mayon
Nicolas
N
Unité de Recherches en Biologie des Organismes (URBO), Facultés Universitaires N.D. de la Paix, Namur, Belgium.
Bertrand
Arnaud
A
Leroy
Delphine
D
Malbrouck
Christelle
C
Mandiki
S N M
SN
Silvestre
Frédéric
F
Goffart
Anne
A
Thomé
Jean-Pierre
JP
Kestemont
Patrick
P
D000704:Analysis of Variance; D000818:Animals; D001530:Belgium; D003530:Cyprinidae / Q000502:physiology*; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D017753:Ecosystem; D005982:Glutathione Transferase / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D010575:Pesticides / Q000032:analysis / Q000633:toxicity*; D011078:Polychlorinated Biphenyls / Q000032:analysis / Q000633:toxicity*; D011157:Population Dynamics; D012098:Reproduction / Q000187:drug effects / Q000502:physiology; D018571:Sentinel Surveillance; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*
D018840:HSP70 Heat-Shock Proteins; D010575:Pesticides; D014874:Water Pollutants, Chemical; D011078:Polychlorinated Biphenyls; D019363:Cytochrome P-450 CYP1A1; D005982:Glutathione Transferase