The Florida Fish and Wildlife Conservation Commission’s Florida Marine Research Institute (FWC-FMRI) has
examined total mercury levels in muscle tissue from a variety of economically and ecologically important species
as part of an ongoing study to better understand mercury contamination in marine fishes.The FWC-FMRI Mercury
Program is one of the most comprehensive programs in the United States for monitoring mercury levels in
marine and estuarine fishes. Because mercury, a toxic metallic element, has been shown to bioaccumulate in fish
tissue, humans consuming fish can potentially consume significant levels of mercury.We examined the concentration
of total mercury in 6,806 fish, representing 108 species from 40 families. Species represented all major trophic
groups, from primary consumers to apex predators.The majority of individuals we examined contained low concentrations
of mercury, but concentrations in individual fish varied greatly within and among species. Species
with very low mean or median mercury concentrations tended to be planktivores, detritivores, species that feed
on invertebrates, or species that feed on invertebrates and small fish prey.Apex predators typically had the highest
mercury concentrations. In most species, mercury concentration increased as fish size increased. Sampling
in Florida waters is continuing, and future research relating mercury levels to fish age, feeding ecology, and the
trophic structure of Florida’s marine and estuarine ecosystems will help us better understand concentrations of
this element in marine fishes. (64pp.
