Toxicity of inorganic aluminium at spring snowmelt—In-stream bioassays withbrown trout (Salmo trutta L.)
2012 (English)In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 437, 422-432 p.Article in journal (Refereed) Published
Although the acid load has decreased throughout Scandinavia, acidic soils still mobilise aluminium (Al) thatis harmful to brown trout. We hypothesise that there are thresholds for Al toxicity and that the toxicity can betraced from the water content to gill accumulation and the consequential physiological effects. During snowmelt,yearlings were exposed to a gradient of pH and inorganic monomeric Al (Ali) in humic streams to studythe toxic effects and mortality. Gill Al and physiological blood analyses [haemoglobin (Hb), plasma chloride(P-Cl) and glucose (Glu)] were measured. As the water quality deteriorated, Al accumulated on the gills; Hband Glu increased; P-Cl decreased, and mortality occurred. Moribund fish had significantly increased gill Aland Hb, suggesting that respiratory disturbances contributed to mortality. Decreased P-Cl and plasmaavailability indicated an ion regulatory disturbance and possibly circulatory collapse. Ali should be lessthan 20 μg/L, and pH higher than 5.0, to sustain healthy brown trout populations. These thresholds can beused to fine-tune lime dose, as both Ali and pH levels have to be balanced to prevent harm in the recoveringaquatic biota. Although Al is tightly linked to pH, local variation in Al availability in soil and bedrock affectsthe Al release and subsequent toxic Ali episodes in some catchment areas.
Place, publisher, year, edition, pages
2012. Vol. 437, 422-432 p.
Acidification, Brown trout, Thresholds Ali & pH, Gill accumulation Al, Blood physiology, Liming strategy
Research subject Applied Environmental Science
IdentifiersURN: urn:nbn:se:su:diva-80527DOI: 10.1016/j.scitotenv.2012.08.006ISI: 000310941000048OAI: oai:DiVA.org:su-80527DiVA: diva2:556261