15:45 〜 16:00
[ACG38-07] Nutrient budget and cycles of the agricultural system for coral-reef conservation in Ishigaki Island
キーワード：Ishigaki Island, Coral reefs, Nutrient cycle, Agriculture, Livestock
Climate change is the biggest threat to Earth and its ecosystems, with coral reefs particularly at risk due to rising sea temperatures and human activities. Ishigaki Island in Japan, known for its vibrant coral reef communities, is experiencing a decline in coral health and population due to land-based development especially agriculture, and pollution. These activities introduce excess nutrients into the seawater, exacerbating the threat of coral-destructive crown of thorn starfish outbreaks. To protect coral reef communities, it is essential to manage the land-based nutrient loads effectively. This research focuses on quantifying the nutrient budget of Ishigaki Island's agri-food system to identify potential harm to the environment. The nutrient budget involves measuring inputs and outputs to determine if there is a balance, surplus, or deficit. Surpluses indicate a risk of nutrient runoff and emissions, while deficits can lead to soil fertility decline and erosion. This study investigates nutrient dynamics within Ishigaki Island's agri-food system, encompassing inputs like fertilizers, animal feed, and food imports, as well as outputs through exported crops, livestock, and waste, accounting for losses due to volatilization, leaching, and runoff. It also considers recycled nutrients, such as livestock waste returned to cropland. The research aims to assess nutrient utilization efficiency and understand nutrient cycling processes. A scenario analysis based on collected data and nutrient balances will be conducted. Ultimately, the study will offer insights and recommendations to enhance nutrient management practices tailored to Ishigaki Island's unique ecosystem.