such as shooting turtles and seabirds, raiding nests and fishing with explosives. The collection of rare medicinal plants, collecting of wood, and hunting for the wildlife trade are common threats to the biodiversity of the entire region, including these islands. Coral habitats are threatened by pollution, over-exploitation of fish and invertebrates, and the use of explosives and poisons as fishing techniques. A 2014 United Nations Environment Programme (UNEP) report said: "Sand is rarer than one thinks". The average price of sand imported by Singapore was US$3 per tonne from 1995 to 2001, but the price increased to US$190 per tonne from 2003 to 2005. Although the Philippines and China had both ratified the UNCLOS III, in the case of and Johnson South Reef, Hughes Reef, Mischief Reef, the PRC dredged sand for free in the EEZ the Philippines had claimed from 1978 arguing this is the "waters of China's Nansha Islands". Although the consequences of substrate mining are hidden, they are tremendous. Aggregate particles that are too fine to be used are rejected by dredging boats, releasing vast dust plumes and changing water turbidity. John McManus, a professor of marine biology and ecology at the Rosenstiel School of Marine and Atmospheric Science, said: "The worst thing anyone can do to a coral reef is to bury it under tons of sand and gravel ... There are global security concerns associated with the damage. It is likely broad enough to reduce fish stocks in the world's most fish-dependent region." He explained that the reason "the world has heard little about the damage inflicted by the Peoples Republic of China to the reefs is that the experts can't get to them" and noted "I have colleagues from the Philippines, Taiwan, PRC, Vietnam and Malaysia who have worked in the Spratly area. Most would not be able to get near the artificial islands except possibly some from PRC, and those would not be able to release their findings." History Records show the islands as inhabited at various times in history by Chinese and Vietnamese fishermen. In 1888 the Central Borneo Company were granted a lease to work guano 'on Sprattly island and Amboyna Cay' During the Second World War troops from French Indochina and Japan were in occupation. However, there is no record of large settlements on the islands until 1956, when Filipino adventurer Tomás Cloma, Sr., decided to "claim" a part of