BBSR 2001 Annual Report - Bermuda Institute of Ocean Sciences

Protecting theWorld’s MarineEnvironmentsBBSR has long been at the forefront of research into the impactsof pollutants on corals. This research history led to theestablishment in 1998 of the International Center for Ocean andHuman Health at BBSR, which examines both health of the oceanand health from the ocean (such as the potential forpharmaceutical development from marine organisms).Dr. Richard Owen describes the studieshe and the ecotoxicology group atBBSR are conducting to identify newpollution threats to corals. As Dr.Owen explains, one such threat, froman increasingly used additive to marineantifouling paints, may require urgentattention on a global basis if we are toprotect the future of the world’s coralreefs.PRIOR TO THE EARLY1990s,compounds called organotins werecommonly used in antifouling paintson ships’ hulls. However, research intothe ecological effects of organotins suchas tributyl tin (TbT) soon showed thatthese compounds were extremely toxicto marine organisms, particularlyaffecting the reproductive systems ofshellfish. In the early 1990s, TbT wasbanned for use on boats under 25m inlength. A full International MaritimeOrganization ban on the use of TbT onall shipping comes into force in 2003.The industry responded bydeveloping new antifouling paints,using so called “booster biocides”formulated with copper to preventfouling. Of these, two herbicides,Irgarol 1051 and diuron, have becomecommon in boat paints. While globalusage patterns are hard to evaluate, arecent study in the United Kingdomfound that 80 percent of antifoulingpaints on the market contained eitherIrgarol 1051 or diuron. Theseherbicides are designed to leach slowlyfrom the paint to prevent buildup ofbiofilms on boat hulls. A consequenceof this is a strong potential forcontamination of coastal waters bythese herbicides, which are moderatelysoluble and environmentally persistent,with Irgarol 1051, for example,reported to have a half-life in seawaterof between 100 and 200 days.While there were a number ofstudies showing considerablecontamination of coastal waters inEurope by Irgarol 1051, the distributionof this herbicide in tropical waters wasuntil very recently unknown. Workundertaken by BBSR and funded by theBermuda Government showedsubstantial Irgarol 1051 contaminationthroughout the inshore waters ofBermuda. BBSR has also sampled otherareas, such as the Florida Keys and St.Croix, U.S. Virgin Islands, which also