Bali, Indonesia. Among the 13600 islands in Indonesia, Bali is one of the most eye-catching islands. It is located around 8 degrees south latitude in the Indian Ocean and the East of Java Island. The beautiful ocean landscape of Bali has promoted the rapid development of coastal tourism economy, attracting millions of tourists from all over the world every year. Meanwhile, the balance in coastal ecology has constantly been challanged by human economic activities. Therefore, policymakers has regarded the coordination of economic development and environmental sustainability as a primary issue. (Photograph taken by Wanhao Zhang, University College London, UK.)