Bonaire and Curacao are situated in the southern Caribbean approximately 100 km north of Venezuela. They are in the so-called “ABC” islands-Aruba, Bonaire and Curacao-and form the Netherlands Antilles together with Curacao and the windward islands of St. Maarten, Saba and St. Eustatius. Separated from the South American continental shelf they are oceanic isles surrounded by deep water.
The Reefs at Risk analysis suggests that almost two-thirds of the 210 sq km of reefs around Bonaire and Curacao are threatened by human activities. The most pervasive threats are marine-based pollution and coastal development each threatening about 45 percent of reefs. Overfishing threatens about one-third of the reefs. No threat was found from sedimentation.
Bonaire is 40 km long by 11 km at its widest point. Klein Bonaire, a small uninhabited islet lies 750 m off the western shore.  Both Bonaire and Klein Bonaire are surrounded by continuous fringing coral reefs from the shoreline seaward to depths of 70 m, covering an area of some 26 sq km. The reefs are much better developed on the leeward side than they are on the windward side, particularly in shallow water. There are unusual shallow water spur and groove formations on the north at Boca Bartol, and Playa Benge. The leeward (western) shore has large coral heads several meters in diameter. 
Bonaire’s industrial base is confined to the transshipment of oil, the production and transportation of salt, and the refining of rice.  The major impacts on the marine ecosystem are direct and indirect results of tourism. Most of the tourist activity associated with Bonaire’s reefs is confined to scuba diving. Dive tourism began in 1963 and by 1994, visitation had risen to approximately 57,000, of whom 25,000 were divers.  The direct impacts include occasional illegal anchoring, groundings, and direct contact damage by divers and snorkellers. Indirect results, which are a greater threat and more pervasive, include increased nutrient loading from hotels and increased sedimentation through land clearance and poor construction practices. 
Fishing is essentially a small-scale artisanal activity, but some of Bonaire’s reefs are over-fished as shown by an absence of grouper, conch, and lobster, and by reduced snapper populations. Parrotfish are not generally targeted by fisherman and are still plentiful.  The Bonaire National Marine Park is in the process of setting up Fish Protected Areas to prevent further overfishing.
The Bonaire National Marine Park, surrounding the entire coastline down to a depth of 60m, was established in 1979 and declared a national park in 1999. The park is protected under island legislation and has been under continuous active management since 1991. Managed by STINAPA, Bonaire, a local NGO, management activities include infrastructure and moorings maintenance, outreach and education, research, monitoring, and law enforcement. Monitoring is carried out by visiting scientists, park staff, and volunteers. An annual diver admission fee of US$10, which has been universally well received by divers, was introduced in 1992, allowing the Marine Park-with the support of the local dive industry-to be self financing since that time.
Curacao is completely surrounded by fringing reefs, which are much better developed on the leeward side than on the windward side, particularly in shallow water. 
Massive coastal development, which is linked to tourism, is an increasing threat to Curacao’s marine ecosystems; increased sewage discharge and sedimentation due to deforestation are considered the biggest problem.  Large oil refineries have been operating since the early 1920s at Curacao and have brought significant oil pollution to the island. The Curacao reefs have also experienced the effect of several boat groundings: for instance in June 1995 a small freighter ran aground leading to the destruction of reefs. 
Heavy fishing pressures have reduced fish populations, and few large fishes, lobsters, or conchs are seen on the reefs. Large groupers and full-size parrotfish are very rare; however, snappers and small parrotfish are still fairly frequent. 
Massive coral bleaching has been documented for Curacao reefs in 1987, 1990, and 1995, and several diseases have had detrimental effects in the 1980s and 90s.