Cocos Island (Chamorro: Islan Dåno) is an island 1 mile (1.6 km) off the southern tip of the United States territory of Guam, located within the Merizo Barrier Reef, part of the municipality of Merizo. The island is uninhabited, 1,600 meters (5,200 ft) long in a southwest-northeast direction, between 200 m (660 ft) and 300 m (980 ft) wide, and has an area of 386,303 m2 (95.458 acres). It sits atop the southwestern coral reef rim of Cocos Lagoon.
The east coast of the island is a day resort with a pool, volleyball court, cafe, ice cream parlor, restaurant and bar, and water sports equipment rentals. Visitors to the resort can snorkel, dive, kayak, dolphin watch, parasail, jet ski and bike. The west side is public land, part of the Territorial Park System. Ferries run to Merizo, Guam.
During the Spanish times, the island was owned by Don Ignacio Mendiola Dela Cruz (Tu'an). In the late 1920s, the US Government acquired ⅔ of the island via Eminent Domain. In the mid-1930s Don Ignacio sold the remaining ⅓ to a Businessman named Gottwald. A Coast Guard long-range navigation station was built and operated on Cocos Island from 1944-1963. In the late 80's to early 90's, the US Govt. returned the larger portion of the island to the Guam Government, who then turned it into a Park.
Military tests on soil from Cocos Island in late 2005 showed levels of polychlorinated biphenyls (PCBs) contamination 4,900 times higher than the federally recommended level. Tests on twelve species of fish in the lagoon showed all but one of those species had high levels of PCBs. One had 265 times the acceptable level. The contamination most likely originated from transformers and other electrical equipment at the Coast Guard station, but was not tested for earlier.
Officials from the Guam Environmental Protection Agency, Guam Department of Public Health and Social Services, and the Coast Guard announced their findings on 20 February 2006 and warned people not to eat fish caught in the lagoon.