Relationships between Concentrations of Mercury in Largemouth Bass and Physical and Chemical Characteristics of Connecticut Lakes

Abstract

Abstract Concentrations of total mercury were determined for axial muscle tissue of 438 largemouth bass Micropterus salmoides from 46 lakes representing five regions in Connecticut to determine relationships between mercury concentrations and lake characteristics and to assess regional differences in mercury concentrations. Expected concentrations of mercury (EHg) predicted for a length of 356 mm for each population ranged from 0.103 to 0.795 μg/g wet weight. Principal components analysis revealed that, in general, two types of lakes were represented in the data set and were grouped based on hydrologic characteristics. Type-II lakes (artificial impoundments) had a significantly lower mean retention time than type-I lakes (natural drainage lakes) and a significantly larger mean watershed area, watershed area : surface area ratio, watershed area: lake volume ratio, and shoreline development index. Mean EHg was approximately 20% higher in type-II lakes (0.514 μ/g wet weight) than in type-I lakes (0.410 μg/g ...