MANILA, Philippines — The Philippines on Thursday protested a plan by China to establish a nature reserve in one of the most hotly disputed shoals in the South China Sea, calling it a “pretext to eventual occupation” and demanding that Beijing immediately withdraw the plan. China’s State Council on Wednesday announced the approval of a plan to create a national nature reserve at the Scarborough Shoal. The aim is to protect a coral reef, according to the National Forestry and Grassland