PW08 Aquatic Ecotoxicology II
Exhibit Hall
8:00 AM - Wednesday
(PW135) Assessment of selenium toxicosis in northern pike and white sucker exposed to uranium milling effluents.
Muscatello, J1, Janz, D1, 1 University of Saskatchewan, Saskatoon, SK, Canada
ABSTRACT- Northern Saskatchewan, Canada is home to some of the top-producing uranium mines in the world. Effluents from uranium milling operations generally contain elevated concentrations of various metals (e.g., U, Ni, As, Se, Mo) and ions (e.g., sulfate). Selenium is a contaminant of concern in receiving environments and may represent the most toxicologically relevant hazard to fish populations. Most of the cases of Se toxicosis (skeletal curvatures, edema and craniofacial deformities) in native fish populations have been reported from warm-water fisheries. Consequently, the applicability of guidelines and indices developed from warm-water systems to native cold-water fishes, such as those in northern Saskatchewan, is controversial. The objective of this research is to determine potential Se toxicosis in early life stages of two native fish species, northern pike (Esox lucius) and white sucker (Catostomus commersoni), exposed to uranium milling effluents. In Spring 2004, spawning northern pike and white sucker were collected from a reference site and impacted sites downgradient of uranium milling effluent discharge. Eggs and milt were stripped from both species, fertilized in the field, and immediately transported to the University of Saskatchewan. A two-way ANOVA design was employed for each species, with embryos from exposure and reference sites incubated in both reference and exposure water from each site. Throughout the study, fertilization rate, time to hatch, percent hatchability, time to swim-up, and frequency of deformities in developing fish will be evaluated for both species. This research will help to better understand the potential impacts of selenium in native cold-water fishes exposed to uranium milling effluents.
Key words: deformities, selenium, freshwater fish, uranium mine