Mercury accumulation by largemouth bass (Micropterus salmoides) in recently impounded reservoirs.

Mercury levels of largemouth bass from three reservoirs in the southeastern United States were highest in the younger, relatively oligotrophic reservoirs and were significantly lower in an older, more eutrophic reservoir in the same drainage system. The reservoir with the highest mercury levels in bass is the reservoir farthest upstream, and is not subject to inputs of municipal or industral wastes. The source of mercury in these reservoirs appears to be the soil which formed theri original sediments. Preliminary data indicate that mercury levels in largemouth bass in these systems decline as the reservoirs age. televated mercury levels in fish appear to be a transitory phenomenon in newly impounded, relatively oligotrophic reservoirs.

Wildlife and environmental health: raccoons as indicators of zoonoses and pollutants in southeastern United States.

Inasmuch as terrestrial fauna are an integral part of our natural environment and are directly exposed to disease and pollutants, it follows that certain wild populations could serve to detect subtle alterations within ecosystems. A collection of studies on raccoons is presented to stimulate other researchers to develop the potential of our wildlife resources as monitors of environmental health. Raccoons have been used as serologic sentinels for St Louis encephalitis and Venezuelan equine encephalomyelitis. Studies suggest that the raccoon may be used as an indicator of leptospirosis, tularemia, and some enteric bacteria and viruses. Base line surveys have defined (1) residue levels of organochlorine and organophosphate compounds and (2) body burdens of mercury, cesium-137, and strontium-90. Physiologic responses, parasite burdens, and reproductive processes are also considered as measures that may reflect pertinent information about environmental health.