Abstract-There is widespread concern over the presence of Hg in fish consumed by humans. While studies have been focused on determining the Hg concentration in sport fish and some commercial fish, little attention has been directed to canned tuna; it is widely held that concentrations are low. In the present study, the amount of Hg present in canned tuna purchased in Las Vegas, Nevada, USA, was examined, and the brand, temporal variation, type, and packaging medium impacts on Hg concentrations in tuna were explored. A significant ( p < 0.001) brand difference was noted: Brand 3 contained higher Hg concentrations (x standard deviation (SD) (0.777 AE 0.320 ppm) than Brands 1 (0.541 AE 0.114 ppm) and 2 (0.550 AE 0.199 ppm). Chunk white tuna (0.619 AE 0.212 ppm) and solid white tuna (0.576 AE 0.178 ppm) were both significantly ( p < 0.001) higher in mean Hg than chunk light tuna (0.137 AE 0.063 ppm). No significant temporal variation was noted, and packaging had no significant effect on Hg concentration. In total, 55% of all tuna examined was above the U.S. Environmental Protection Agency's (U.S. EPA) safety level for human consumption (0.5 ppm), and 5% of the tuna exceeded the action level established by the U.S. Food and Drug Administration (U.S. FDA) (1.0 ppm). These results indicate that stricter regulation of the canned tuna industry is necessary to ensure the safety of sensitive populations such as pregnant women, infants, and children. According to the U.S. EPA reference dose of 0.1 mg/kg body weight per day and a mean Hg value of 0.619 ppm, a 25-kg child may consume a meal (75 g) of canned chunk white tuna only once every 18.6 d. Continued monitoring of the industry and efforts to reduce Hg concentrations in canned tuna are recommended. Environ. Toxicol. Chem. 2010;29:237-242. # 2009 SETAC

The intersection of wildlife and people on roads raises two critical issues: the barrier and mortality effects of roads on wildlife and risks to people from animal-vehicle collisions (AVCs). Road mitigation decisions are typically made at the discretion of transportation departments that are mandated to primarily address motorist safety. Therefore, prioritization of road sections for mitigation currently focuses on identification of spatial clusters of AVCs. We sought to understand if AVC clusters align with multispecies connectivity across roads to accurately identify multipurpose mitigation hotspots. We developed a decision-support tool based on weighted priorities for mitigation planning across 7,900 km of roads over an 84,000-km 2 area of southern Alberta, Canada. To assess alignment, we built functional connectivity models for four focal species (prairie rattlesnake, grizzly bear, mule deer, and pronghorn) and a species-neutral structural connectivity model. We integrated AVC risk and wildlife connectivity indices into Mitigation Priority Indices that varied the weighting of individual indices. Our results demonstrated poor spatial alignment between road sections of high motorist safety risk and those of high value for wildlife connectivity. Transportation planning would benefit from integrating motorist safety risk and wildlife management needs to prioritize mitigation neighborhoods along roadways.

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