Large numbers of people are gathered on the shores of Mauritius, trying to help contain an oil spill that is threatening the island's ecosystem. More than 1,000 tonnes of fuel has seeped from the bulk carrier MV Wakashio into the azure sea off southeast Mauritius. But another 2,500 tonnes remain aboard the stricken vessel, which ran aground on a reef on July 25 but only started oozing from a crack in the hull in the past week.