title: Using molecular biomarkers and traditional morphometric measurements to assess the health of slimy sculpin (Cottus cognatus) from streams with elevated selenium in North-Eastern British Columbia.
abstract: Canadian fish-based environmental effects monitoring programs use individual and population-level endpoints to assess aquatic health. Impacts of coal mining and selenium (Se) exposure were assessed in slimy sculpin (Cottus cognatus) from reference streams located both inside and outside of a coal zone, and from 1 stream with a history of coal mining, using traditional environmental effects monitoring endpoints. In addition, physical characteristics of the streams and benthic macro-invertebrate communities were assessed. To determine whether the assessment of effects could be improved by including molecular markers, real-time polymerase chain reaction assays were optimized for genes associated with reproduction (vtg, esr1, star, cyp19a1, and gys2), and oxidative and cellular stress (sod1, gpx, gsr, cat, and hsp 90). Water Se levels exceeded guidelines in the stream with historical mining (4 μg/L), but benthic macroinvertebrates did not exceed dietary thresholds (2-3 μg/g dry wt). Whole-body Se levels were above British Columbia's tissue guideline in fish from all streams, but only above the draft US Environmental Protection Agency (USEPA) criterion (7.91 μg/g dry wt) at the reference stream inside the coal zone. Some markers of cellular and oxidative stress were elevated in fish liver at the exposed site (sod1, gpx), but some were lower (cat, sod1, gpx, gsr, hsp90) in the gonads of fish inside the coal zone. Some of the differences in gene expression levels between the reference and impacted sites were sex dependent. Based on benthic macroinvertebrate assessments, the authors hypothesize that traditional and molecular differences in slimy sculpin at impacted sites may be driven by food availability rather than Se exposure. The present study is the first to adapt molecular endpoints in the slimy sculpin for aquatic health assessments.
authors.affiliation: Environmental Protection Division, BC Ministry of Environment, Prince George, British Columbia, Canada.
authors.forename: Lana L
authors.initials: LL
authors.lastname: Miller
authors.affiliation: Canadian Rivers Institute and Department of Biology, University of New Brunswick, Saint John, New Brunswick, Canada.
authors.forename: Meghan A
authors.initials: MA
authors.lastname: Isaacs
authors.affiliation: Center for Environmental and Human Toxicology and the Department of Physiological Sciences, UF Genetics Institute, University of Florida, Gainesville, Florida, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Martyniuk
authors.affiliation: Canadian Rivers Institute and Department of Biology, University of New Brunswick, Saint John, New Brunswick, Canada.
authors.forename: Kelly R
authors.initials: KR
authors.lastname: Munkittrick
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism*; D001955:British Columbia; D017753:Ecosystem; D005260:Female; D005786:Gene Expression Regulation; D006066:Gonads / Q000378:metabolism; D006262:Health; D007448:Invertebrates / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D018384:Oxidative Stress; D010473:Perciformes / Q000254:growth & development / Q000378:metabolism*; D012098:Reproduction; D045483:Rivers; D012643:Selenium / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D015415:Biomarkers; D014874:Water Pollutants, Chemical; D012643:Selenium
keywords: Coal mining; Environmental effects monitoring; Real-time polymerase chain reaction; Selenium; Slimy sculpin