First application of biomarkers approach in the zooplanktonic copepod Acartia latisetosa for the early management and conservation of transitional waters ecosystems

Abstract

1 - A very new and useful strategy for ecotoxicological studies is the application of biomarker techniques in zooplanktonic bioindicators. In fact an evidence of alteration at this level of the food chain, first or second, can be used as an early warning sign of risk to the health of an entire TW ecosystem, enabling local authorities to intervene promptly to avoid bioaccumulation and biomagnification phenomena. Ecological characteristics of this kind of environments are low biodiversity and peculiar spatial and seasonal distribution with high abundance peaks. These are favourable conditions in accordance with the biomarkers test protocols. Specific biomarkers of exposure and/or effects can be used giving informations about the kind of contaminant involved. 2 - The zooplanktonic organisms with largest distribution in all the TW environments are the copepods, so, in the field, it is possible to use a suite of biomarkers in a copepod species collected in a study area and in a reference site, not polluted, in order to evaluate its environmental "health status". 3 - The aim of this study was to propose a suite of biomarkers (BPMO activity, EROD activity, NADPH-cytochrome C reductase, NADH-cytochrome C reductase, NADH-ferricyanide reductase, total proteins, esterases, porphyrins) and residue concentration (heavy metals) in the zooplanktonic copepod Acartia latisetosa, as a multi-disciplinary diagnostic tool for assessment of the health status of a TW environment in which the species was sampled. This was Lago Faro (Messina, Italy), a lake suspected of being polluted, respect to Lago Verde, a small brackish lake of a natural marine reserve (Marinello, Messina, Italy). 4 - The results show inductions of MFO activity (EROD, NADH-Cytochrome C reductase, NADH-ferricyanide reductase) and inhibition of acetylcholinesterase activity in A. latisetosa sampled in Lago Faro, suggesting contamination with xenobiotic lipophilic compounds and neurotoxic substances. But, in contrast with what was expected, samples collected in the reference lake were high in porphyrins and heavy metals. 5 - The results show and confirm that biomarkers in zooplankton species can be used to study early the "health status" of different TW environments.