Mechanisms oftriorganotin toxicity to macroinvertebrates and the role of the biofilm as a controlled release medium

Triorganotins in antifouling coatings effectively prevent macrofouling.
Structure-activity studies suggest that partitioning processes, highly favoring
bioaccumulation of most triorganotin compounds, control the dose and thus
the toxicity to macroorganisms. Organotin-coated surfaces support a well developed
microbial community composed of many species. Bacterial isolates
from painted surfaces displayed resistance to tributyltin, the active agent in the
coatings from which they were obtained. Paradoxically, the biofilm secreted by
bacteria accumulates tributyltin to levels well above water solubility and above
that which would ordinarily be toxic to the contained cells. When bound by
the biofilm, entry of tributyltin may be reduced or prevented, modifying the
response to acutely toxic exposure concentrations. The presence of this biofilm
is hypothesized to act as a secondary controlled-release medium and to reduce
antifoulant release rates.

Florida Atlantic University. Harbor Branch Oceanographic Institute contribution 510

This manuscript is an author version with the final publication available
and may be cited as: Laughlin, R. B., Jr., Cobet, A. B., & Guard, H. E. (1988). Mechanisms of
triorganotin toxicity to macroinvertebrates and the role of the biofilm as a controlled release medium.
In M. F. Thompson, R. Sarojini, & R. Nagabhushanam (Eds.), Marine biodeterioration: advanced
techniques applicable to the Indian Ocean (pp. 757-767). Leiden, The Netherlands: CRC
Press/Balkema.