In response to C. Pickering, concerning heavy metal loading in fish
species. In the St. Johns River in Florida, mercury seems to be the
most pressing problem. We appear to have high background levels of
mercury in the sediments in our swamp-fed systems here. Even in
relatively isolated areas of the Everglades. How much is too much?
Mercury complexes with the high organic content of our sediments down
here and moves up the trophic levels.