Effects of pollution and parasites on biomarkers of fish health in spottail shiners Notropis hudsonius (Clinton)

Abstract

Seven biomarkers in 204 spottail shiners Notropis hudsonius were examined for effects of pollution and parasites on fish health at localities along the St Lawrence River, Canada. The number of pigmented macrophage centres and pigmented macrophages in the spleen was significantly higher at polluted localities receiving urban and industrial effluents than at reference localities, indicating that they were good indicators of exposure to pollution in spottail shiners. Seven of the nine species of parasites found in 1þ year fish showed significant correlations with biomarkers. More parasites (18 species) but fewer correlations with biomarkers were observed in 2þ year fish, indicating that parasite effects were more pronounced in young spottail shiners. A significant negative relationship was observed between condition factor and Neoechinorhynchus rutili in 1þ year fish, suggesting its potential pathological significance in young spottail shiners. High abundance of Plagioporus sinitsini was associated with higher spleen macrophage counts and lower indices of condition at polluted localities. Furthermore, infection by P. sinitsini in polluted conditions appeared to have a greater negative effect on fish health than either stressor alone, providing further evidence that parasites should be considered when examining effects of pollution on fish health. # 2007 Crown Copyright

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“…Only a small amount of studies quantitatively investigated such kind of parameters . Because changes in PMQ may be good biomarkers of anthropogenic impacts on ichthyofaunal health (Hinton et al, 1992;Wolke 1992;Thilakaratne, Mclaughlin and Marcogliese 2007;Balamarugan et al, 2012), in depth studies of the normal ranges and influences of endogenous factors are essential for each bioindicator species. Here we discovered that the amounts (relative and total volumes) of barbel spleen PMQ were positively correlated with age, which is in line with previous reports (Blazer et al, 1987;Agius and Roberts 2003;Iwanowitcz et al, 2012).…”

Parasite fauna of Etheostoma nigrum (Percidae: Etheostomatinae) in localities of varying pollution stress in the St. Lawrence River, Quebec, Canada

“…Various locations are exposed to differing amounts of these contaminants. Within this system, effects of pollution have been examined on immune response, stress response, and parasitism in spottail shiners (Notropis hudsonius) and yellow perch (Perca flavescens) Marcogliese et al 2005Marcogliese et al , 2006Thilakaratne et al 2007;Dautremepuits et al 2009); however, no effects of pollution have been measured for a benthic fish in this river. Effects of pollutants on benthic fish may be of particular interest because of the close proximity of these fish to the sediments; similar studies have been conducted on flatfish in marine environments (e.g.…”

Effects of a major municipal effluent on the St. Lawrence River: A case study

“…However, macrophage number in the spleens of spottail shiners increase with infection intensity of the gall bladder trematode Plagioporus sinitsini (Fig. 4b) in polluted waters, including those downstream of the municipal effluents, but not at reference sites (Thilakaratne et al 2007). In that same study, fish condition also decreased with infection intensity, but again only at polluted sites.…”

“…In some cases, the parasites implicated did not appear to be measurably pathogenic in reference waters. Pigmented macrophages and their aggregates typically are found in greater numbers in fish tissues such as liver and spleen in polluted conditions (Agius and Roberts 2003), including spottail shiners downstream of Montreal (Thilakaratne et al 2007). These cells and their aggregates are responsible for a variety of functions including detoxification, scavenging of materials, and responding to foreign particles or infectious agents (Agius and Roberts 2003).…”