The Bahamas: Physical Geography and Environment
The physical setting
The Bahamas is an archipelago of roughly 700 islands and 2,000 cays lying in the Atlantic Ocean, north of Cuba and east of Florida - not in the Caribbean Sea, which is a favourite exam trap. Only a small number of islands are permanently inhabited. The islands sit on two shallow limestone platforms, the Great Bahama Bank and the Little Bahama Bank, separated by deep channels. Mount Alvernia on Cat Island is the highest point at only about 63 metres, so the landscape is low and flat.
Limestone and water
The rock is mainly limestone built from coral, shells and sand. Because limestone is porous, rainfall soaks straight through instead of running off. That is why the islands have almost no surface rivers; water is stored underground in a freshwater lens and reached by wells. The same dissolving action creates caves, sinkholes and inland blue holes. Fresh water is therefore a limited resource and is easily polluted.
Climate and hazards
The climate is tropical to subtropical, with a wet season (roughly May to October) and a dry season, steady north-east trade winds, and a hurricane season from June to November. Hurricanes, storm surge, coastal erosion, sea-level rise, coral bleaching, sand mining, mangrove clearance and invasive species such as the lionfish are the main environmental threats. Protected areas include the Exuma Cays Land and Sea Park and Inagua National Park.
Rule of thumb
When asked to explain any Bahamian physical feature, trace it back to limestone: porous rock means no rivers, underground water, caves and blue holes. When asked why the islands are vulnerable, link low elevation and coastal settlement to storm surge and sea-level rise.