engleski

Assessment of metal exposure in industrially/agriculturally impacted freshwater ecosystem using amphipod Gammarus fossarum Koch as a bioindicator

The present study highlights the relevance of the assessment of soluble metal levels in gammarid tissue and its implementation as an early indicator of metal exposure in the freshwater habitats. Physico-chemical water properties in the Sutla River, an industrially/agriculturally influenced catchment in North-Western Croatia, indicated a disturbed ecological status, which also was reflected on the population scale (more than 50 times lower gammarid density in the Sutla River compared to the reference location, Črnomerec Stream). Since total tissue metal concentrations are not fully reliable in the risk assessment of metal exposure (due to internal metal compartmentalization in organisms), metals in the soluble tissue fraction were estimated as indicators of bioavailable metal levels. Among 28 measured metals, significantly higher levels of soluble toxic metals (Al, As, Cd, Pb, Sb, Sn, Sr) were observed in gammarids from the Sutla River compared to Črnomerec Stream. The soluble metal estimates were supplemented with the common multi-biomarker approach: measurement of acetylcholinesterase (AChE) activity, metallothionein (MT) induction and total soluble protein concentrations. Although there was no MT induction, decreased AChE activity and increased total soluble protein concentrations confirmed stressed environmental conditions for biota in the Sutla River. Our results suggest that prior to the observed toxic impact and specific biomarker response, concentrations of soluble metals in organism tissues could be used as an early warning signs of metal impact in freshwater environment.

early indicator ; metallothionein ; acetylcholinesterase ; total water-soluble proteins ; trace-metals

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