The anti-fouling paint most widely used by shipping fleets around the world is said to be causing damage to many species in every ocean.

A report by the World Wide Fund for Nature (WWF) says the use of the paint, which contains tributyltin (TBT), means that "the world's oceans are being covered in a lethal coat of toxic ship paint".

"Marine life from all around the world, including commercial fish species, is being poisoned, and human health is threatened. All forms of marine life are affected, from molluscs to mammals."

WWF says the report, "the most comprehensive study of its kind", has gathered scientific evidence on the global presence of TBT pollution, which it says persists "on a massive scale".

'Gender bender' chemicals

TBT is one of the so called "gender bender" hormone-disrupting chemicals - it mimics the effects of sex hormones - and causes damage to the nervous and reproductive systems. In United Kingdom waters, it has been blamed for causing female dog whelks to develop penises.

Sea mammals absorb chemicals

WWF says mammals found to be contaminated with TBT include sperm whales, minkes and 12 other whale species, 10 dolphin species, and four kinds of seal. Cetaceans are unable to rid their bodies of TBT. It says studies have shown that sea lions and sea otters are also damaged by TBT.

Bird species affected include the oystercatcher, the Japanese cormorant, a north Pacific albatross, and guillemots in the Baltic. The report says "laboratory tests have found that TBT reduces hatching success and fertility".

In every region tested for TBT, fish were found to be contaminated, including tuna and sharks in the Mediterranean, sea bream, sea bass and Atlantic salmon. High levels have been found in many Baltic fish, especially flounder, herring, eel and sea trout.

Safety limits

The report says the liking for fish in Poland is a particular cause for concern. "Consumption of roach is leading Poles to exceed the tolerable daily intake of TBT.

Concentrations are high worldwide

"As it concentrates in the liver, there is also great concern that consumption of salmon, cod and turbot liver is also greatly exceeding safe limits."

Concentrations of residues have also been found in many fish samples collected from local markets in South and South East Asia and Australia. WWF says organotins (the group of chemicals which includes TBT) can cause hormone damage in humans, and disrupt the functioning of cells which fight infection.

The International Maritime Organisation (IMO) is the UN body responsible for regulating international shipping from a safety and environmental impact perspective.

Voluntary ban

The IMO's marine environment protection committee meets from 28 June to 2 July, and will discuss developing a legal means to enforce an agreement last year to introduce a voluntary ban on the use of TBT paint on ships' hulls by 2003.

TBT is blamed for causing female dog whelks to develop penises

The use of TBT on seagoing vessels shorter than 25 metres has been banned for some years, and WWF says that has meant improvements in coastal waters. But it says there is even greater cause for concern.

"Organotins are now being recorded in wildlife at the top of food chains which spend their lives in deeper water well away from crowded shipping lanes and coastal maritime traffic."