Mercury concentrations in largemouth bass (Micropterus salmoides), white bass (Morone chrysops), and white crappie (Pomoxis annularis) from six Dallas-Fort Worth area reservoirs

Largemouth bass (Micropterus salmoides) are routinely monitored for mercury (Hg) in Texas reservoirs. Other piscivorous game-fish that may have high concentrations of Hg, such as white bass (Morone chrysops) and white crappie (Pomoxis annularis), are monitored less frequently because they are difficult to capture. I examined Hg concentrations in largemouth bass, white bass, and white crappie from six Dallas-Fort Worth area reservoirs: Benbrook Lake, Eagle Mountain Lake, Grapevine Lake, Lake Lewisville, Joe Pool Lake, and Lake Ray Hubbard were examined. Fish were collected using electroshocking, trap nets and hook and line. For all species Hg concentrations were positively correlated with total length. Hg concentrations of each species were significantly different between reservoirs, indicating that some reservoirs were more contaminated with Hg than others. In the majority of reservoirs Hg concentrations in largemouth bass did not differ from Hg concentrations in white bass and white crappie. These data suggest that Hg concentrations in largemouth bass may be representative of Hg concentration in other piscivorous game-fish and is an appropriate indicator species for monitoring studies.