Metal concentrations in female and male pilot whales biopsied in the Gulf of Mexico. Sample sizes were as follows, for 2011: 2 males and 1 female; for 2012: 9 males and 2 females. Data represented as mean ± standard deviation in units of μg/g tissue. (A,B) Metals with mean skin concentrations less than 2 μg/g for females (A) and males (B), respectively; (C,D) metals with mean skin concentrations between 2 and 20 μg/g for females (C) and males (D), respectively; (E,F) metals with mean skin concentrations greater than 50 μg/g for females (E) and males (F), respectively.