Enclosure (1) TO COMDTINST 16478.12
Tampa Bay
The Tampa Bay Prototype investigation discovered large numbers of discarded
batteries at several AtoNs, and a very high percentage of these were broken.
The sediment mercury concentrations reflected this condition; at most of the
AtoNs sampled, the nearfield sediment concentrations were above the measured
and the literature reported background levels (CNMS 1992). (Figure 3-3).
Also, at approximately half the AtoNs the concentrations were above the more
protective ecological benchmark for sediment dwelling organisms (ER-L).
Although concentrations found in animals were less than the FDA action level
indicating risk to human health, metal concentrations in sediments indicated
some potential risk to marine organisms in small localized areas close to high
concentrations of batteries. Levels adjacent to batteries frequently exceeded
concentrations usually associated with ecological effects (Long and Morgan,
1991) and always exceeded the most conservative concentrations considered to
be associated with effects on sediment dwelling animals. Within 10 meters of
AtoNs mercury levels did not exceed levels generally associated with effects
but frequently were above the most protective ecological benchmarks. Beyond
10 meters no elevated levels were noted.
Sediment mercury concentrations in the eastern portion of the Tampa Bay system
(Hillsborough Bay), have been previously documented as having a high
3-3
Previous Page
