Many studies have been conducted to measure mercury (Hg) levels in fish, but little information exists on

Question:

Many studies have been conducted to measure mercury (Hg) levels in fish, but little information exists on Hg concentrations in marine mammals. The article “Factors Influencing Exposure of North American River Otters Otters…to Mercury Relative to a Large-Scale Reservoir in Northern British Columbia, Canada” (Ecotoxicology 2019: 343–353) describes a study in which river otters living in five Canadian reservoirs were tested for Hg concentration (mg/kg). The accompanying summary information was extracted from a graph in the article.

Hg concentration distributions at all five reservoirs were heavily right-skewed.
a. Why should we hesitate to perform one way ANOVA on the Hg concentration data?
b. Consider the transformation y = ln(concentration). Estimated summary information appears above, and taking the logarithm greatly reduces skewness. Apply the ANOVA F test to the transformed data, and report your findings at the .05 significance level.
c. Apply Tukey’s method to the log transformed data, if appropriate.