Tributyltin canned
WWF 17 Sep 08;
A milestone in the protection of the oceans was reached today as a global ban on tributyltin (TBT) - one of the most toxic chemicals deliberately released into the sea - entered into force.
The International Convention on the Control of Harmful Antifouling Systems for Ships obliges its signatories to ensure that no vessels using TBT-containing paint go under their flag or call at their ports.
“TBT belongs not in the sea but in the poison cupboard, and this agreement will help put it firmly back there,” says Stephan Lutter, International Policy Officer with WWF Germany.
But take-up of the agreement has been slow, with many of the large shipping states having yet to sign and implement the agreement into their national legislation. Whereas WWF is applauding the commitment of the 34 states that have ratified the agreement so far, the conservation organisation urges all 168 member states of the International Maritime Organization (IMO) to join.
TBT is an organic additive often used in marine antifouling paints, as it swiftly kills organisms such as barnacles, algae and mussels which naturally attach themselves to hard surfaces, including on the sides of ships, thus ensuring their smooth passage through the water and reducing fuel consumption.
The problem is that TBT leaks out from the paint and into the surrounding water, affecting marine life and seeping into the food chain.
Heard of sea snails changing sex, or oysters seeing their hard shell going all soft and mushy? These are but two known adverse TBT effects on marine species. The decline of commercially harvested oysters along the Atlantic coast of France and the UK has been attributed to TBT contamination. TBT has also been found far from shipping lanes in albatrosses, whales and fish.
But we have probably only begun to see the long term effects of TBT on marine ecosystems, as the poison is stored in sediment and re-enters the food chain when the sea bottom is stirred up by passing vessels in ports and shallow areas.
WWF has been lobbying for the ban of TBT for more than a decade. At the end of the 1990’s, WWF, together with some leading shipping companies and paint manufacturers, initiated the 2003 Group, whose members voluntarily banned the use of TBT on their vessels and develop toxics-free alternatives.
Scandinavian Wallenius Wilhelmsen Logistics (WWL) banned the use of TBT in hull paint on all vessels in 2000.
“There are better alternatives which balance the need for antifouling with environmental stewardship. It is our responsibility to use them,” says Melanie Moore, WWL’s Global Head of Environment.
