Extremely irregularly-karstified aragonitic limestone at Pain Pond, northeastern San Salvador Island, eastern Bahamas.

Several categories of karst (dissolutional features in soluble rocks such as limestone) exist on islands in the Bahamas. Common small-scale karst features include phytokarst and solution tubes. Large-scale karst features include flank margin caves, pit caves, banana holes, lake drains, and blue holes.

The karstified limestones shown above are located along the shores of Pain Pond, a small lake in the northeastern part of San Salvador Island. This island has numerous inland bodies of water (see map - newton.newhaven.edu/sansalvador/ssmap_11x17.PDF). Christopher Columbus remarked upon them during his visit in October 1492. These ponds and lakes can have freshwater, brackish water, hyposaline water, normal marine-salinity water, or hypersaline water. Many of these lakes have aquatic biotas quite distinctive from adjacent lakes.

Pain Pond is a small lake having a lake drain/conduit on the eastern side, along a “swiss-cheese limestone” rocky shoreline. The water’s salinity is near-normal marine, around 36 ppt. I measured 36 to 37 ppt salinity on 24 March 1999.

Easily observed organisms here include Cerithium snails, Arenicola cristata (Atlantic lugworm) egg masses, and Cyprinodon variegatus sheepshead minnows.