Improving the quality of water in the Great Barrier Reef in northeastern Australia requires around $11,571 billion over the next decade, according to a government study released on Thursday.These initial figures were part of a study carried out by a group of water quality and economic experts. Due to lack of time, the study numbers were not included in a report on the waters of the Great Barrier Reef published last week, ABC Australia reported.Australian Prime Minister Malcolm Turnbull has allocated an additional fund of some $124 million in the budget for the fiscal year starting July 1.The Labour Party, which is seeking to secure a win in the upcoming parliament elections on July 2, has promised around $254 million to save the Great Barrier Reef, a World Heritage Site, which is undergoing the most severe coral bleaching in its history.The greatest threat to the quality of the waters of the Great Barrier Reef comes from pesticides and sediments, which block sunlight, and excess nutrients such as nitrogen, which make the corals more susceptible to bleaching.The health of the Great Barrier Reef, which has 400 types of corals, 1,500 species of fish and 4,000 varieties of molluscs, began to deteriorate in the 1990s due to the twin impact of the warming of seas and the increase in their acidification due to more carbon dioxide in the atmosphere.