(Beyond Pesticides, September 12, 2007) Tributyltin (TBT), a cheap, but highly toxic barnacle and algae killer once used on nearly all of the world’s 30,000 commercial ships, will soon be banned once a treaty prohibiting its use is signed by the U.S. The ban on TBT, deemed by the U.S. Environmental Protection Agency (EPA) as the most toxic chemical ever deliberately released into the world’s waters, is endorsed by U.S. and European cruise lines, freighter and container fleets, as well as shipyard and marina operators. The U.S. is expected to sign the treaty in the coming months.
The treaty is overseen by the U.N. International Maritime Organization and was completed in October 2001. However, Washington has yet to endorse the treaty. By 2008, neither the ships of ratifying countries nor foreign vessels that enter their waters will be allowed to have TBT on their hulls without a sealant. Ships found in violation will be put on an international blacklist and barred by other ratifying countries. Along with forbidding the use of TBT on the hulls of marine vessels, the treaty also sets up a system for future testing and curbs on other hull biocides worldwide.
Researchers have linked TBT to adverse environmental and health effects. Studies first linked it to disorders in mollusks in the Arcachon Basin in western France, where shellfish beds adjoined a marina. According to Jill Bloom, an EPA chemical-review manager who worked on the treaty, the most worrisome were “profound reproductive effects” coupled with diminished marine-species populations. The International Maritime Organization (IMO) notes that TBT “persist(s) in the water, killing sea life, harming the environment and possibly entering the food chain… [TBT] has been proven to cause deformations in oysters and sex changes in whelks.”
Opponents of the ban, who point out that TBT has been useful for preventing ships from transporting invasive species such as zebra mussels from one port to another, are concerned that the copper-based alternative barnacle killers will be less effective, due to growing resistance among barnacles.
Since January 2001, major U.S. and European makers have voluntarily stopped producing TBT, even though it continues to be widely used in Asia. In January 2008, whether ratified or not, the European Union would initiate the TBT ban and blacklist system, abetted by hefty fines. According to the Star Telegram, Panama or the Marshall Islands are expected to cast the decisive vote before the U.N. International Maritime Organization.
Source: Star Telegram