at McMurdo. The pollution ended in 2003 when a $5 million waste treatment plant went online. Other documented bay water contaminants include leakage from an open dump at the station. The dump introduced heavy metals, petroleum compounds, and chemicals into the water. A study by the Australian Institute of Marine Science found that anti-fouling paints on the hulls of icebreakers are polluting McMurdo Sound. Such paints kill algae, barnacles, and other marine life that adhere to ship hulls. Scientists found that samples taken from the ocean floor contained high levels of tributyltin (TBT), a component of the anti-fouling paints. "The levels are close to the maximum, you will find anywhere, apart from ship grounding sites", said Andrew Negri of the institute. Ships, aircraft, and land-based operations in McMurdo Sound all present hazards of oil spills or fuel leaks. For instance, in 2003, the build-up of two years of difficult ice conditions blocked the U.S. tanker MV Richard G. Matthiesen from reaching the harbor at McMurdo Station, despite the assistance of icebreakers. Instead shore workers rigged a temporary fuel line over the ice pack to discharge the ship's cargo. The ship pumped more than of fuel to storage facilities at McMurdo. Officials balance the potential for fuel spills inherent in such operations against the critical need to keep McMurdo Station supplied with oil. A fuel tank spill in an unrelated onshore incident in 2003 spilled roughly of Diesel fuel at a helicopter pad at McMurdo Station. The 1989 grounding of the Argentinean ship Bahía Paraíso and subsequent spillage of of oil into the sea near the Antarctic Peninsula showed the environmental hazards inherent in supply missions to Antarctica. Zoologist Clive Evans from Auckland University described McMurdo's harbor as "one of the most polluted harbors in the world in terms of oil", according to a 2004 article by the New Zealand Herald. Cleanup Efforts Modern operations in McMurdo Sound have sparked surface cleanup efforts, recycling, and exporting trash and other contaminants by ship. The U.S. National Science Foundation began a 5-year, $30-million cleanup program in 1989, according to Reuters News Agency. The concentrated effort targeted the open dump at McMurdo. By 2003, the U.S. Antarctic Program reported recycling approximately 70% of its wastes, according to Australia's Herald Sun. The 1989 cleanup included workers testing hundreds of barrels at the dump site, mostly full of fuels and human waste, for identification before they