Impact of Organotin on Marine Mammals - October 1998

Impact of Organotin on Marine Mammals - October 1998

Organotin compounds, particularly tributyltin (TBT), have been widely used as antifouling paints for ships, causing significant impacts on marine life. The pollution in major sea routes, such as the North Sea and the Mediterranean, is particularly severe, affecting marine mammals such as dolphins and seals in these areas. TBT remains in water for decades, and due to biomagnification through the food chain, it accumulates in high concentrations in top predators like marine mammals.

Studies have shown that even at low concentrations of 10 nanograms per liter, TBT significantly suppresses the immune system of dolphins, making them more susceptible to infections. In the Mediterranean coastal areas, TBT pollution has been linked to a significant decline in seal populations.

In Japan, TBT contamination in Tokyo Bay and the Seto Inland Sea is also a serious issue, impacting fisheries. Major chemical companies in Japan, such as Sumitomo Chemical and Mitsui Chemicals, have been involved in the production of organotin compounds and are now facing stricter regulations. In the late 1990s, the International Maritime Organization (IMO) proposed a phase-out of TBT, and by 2003, it was completely banned. However, the environmental impact of TBT persists.

The study's most notable finding is that even at low concentrations, TBT can have fatal effects on marine mammals, highlighting the urgent need for continued regulatory measures.