Effects of Organotin Antifouling Paint Leachates on Pearl Harbor Organisms: A Site Specific Flowthrough Bioassay

Tributyltin (TBT) concentrations in the range of 0.04 to
2.5 \mu
g/l were used for treatments on marine communities at Pearl Harbor, Hawaii. Over an exposure phase of three months and a recovery phase of two months, significant effects were noted on many species of fouling organisms. Four of the six most abundant fouling taxa sustained 100% mortality at
0.5 \mu
g/l TBT. Overall species abundances of fouling organisms were reduced by 50, 60 and 80% by TBT treatments of 0.5, 1.8 and
2.5 \mu
g/l, respectively. TBT concentrations of
0.1 \mu
g/l and higher caused significant reductions in numbers of species and species diversity of organisms that settled on virgin panel surfaces. Significant mortality of oysters (Crassostrea virginica) was observed only in
2.5 \mu
g/l treatments. However, condition indices showed that general health of oysters is markedly reduced by TBT concentrations of
0.1 \mu
g/l and higher.