美济礁
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".