Untitled

Abstract

The following biomarkers were investigated in stream populations of juvenile brown trout (Salmo trutta f. fario) and gammarids (Gammarus pulex) to determine if crayfish mortality could have been confounded by pollutants: (1) alterations of fish liver ultrastructure, (2) fish gill and kidney histopathology, (3) stress protein (hsp70) expression in fish liver and gills and in gammarids, and (4) changes in various blood parameters of brown trout. In addition, the following measurements were conducted in parallel with the biological sampling: (a) chemical analyses including several pesticides, organochlorines, PCBs, and PAHs in sediment and tissue samples of brown trout and crayfish (Astacus astacus), and (b) limnochemical analyses of nutrients, electrolytes, dissolved oxygen content, temperature and pH. Biomarkers together with chemical and limnochemical analyses concomitantly indicated moderate pollution of the stream at all sampling sites. Biological data indicated a transient, episodic event at one sampling site resulting (a) in altered stress protein levels in gills and livers of trout and in whole gammarids as well as (b) in elevated numbers of macrophages in liver tissue. Biomarker responses provided spatial and temporal evidence that a contaminant release was associated with the crayfish mortalities observed in this stream system.

Impact of season on liver mitochondrial oxidative stress and the expression of HSP70 in grey mullets from contaminated estuary

“…The observed result was supported by a previous study which reported that the contaminant release was associated with the altered HSP70 expression levels in the liver and gill of the cray fish living in the polluted stream system (Triebskorn et al 2002). On further analysis of the results obtained, the mtHSP70 level in the Ennore estuary fish showed a significant seasonal variation (33% increase) when compared to Kovalam estuary sample which shows only 24% increase during summer season.…”

Synergistic Effects of Toxic Elements on Heat Shock Proteins

“…Apart from the synergistic effects of toxicants, environmental factors such as temperature (Figure 5) [103], salinity [104], and oxygen supply [105] also influence the expression of HSPs and may also have a synergistic effect in combination with toxicants, thus making their consideration as biomarkers doubtful. For example, Cd exposure increased the HSP70 concentrations in marine clams, whereas salinity markedly lowered the same level in that species.…”

“…These results qualify HSP70 as a biomonitor for environmental pollution provided that essential environmental parameters such as pH and temperature are kept constant [108]. Apart from temperature and pH, much similar emphasis has also been placed on the analysis of nutrients, electrolytes, and dissolved oxygen content [105]. …”

“…Some examples exist where toxicity stress alters the HSP levels in some organs (e.g., in gills and livers in case of trout) and in some cases whole of the organism as in gammarids [105]. Such studies and those that have contradicted the validity of HSPs as biomarker for ERA can still help us in the selection of organisms.…”

Nonspecific stress response to temperature increase in Gammarus lacustris Sars with respect to oxygen-limited thermal tolerance concept

“…Among the NCSR components, high attention was given to the antioxidant enzymes (Almeida et al, 2002), heat shock proteins, such as HSP70 (Triebskorn et al, 2002), lipid and fatty acid composition (Bergé & Barnathan, 2005), lipid peroxidation products (Valavanidis et al, 2006), enzymes and products involved in energy metabolism including anaerobiosis (Almeida et al, 2002), gene expression (Lee et al, 2008), etc.…”