"Swiss cheese limestone" along the rocky shore of 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.

Bahamian islands are often said to be composed of swiss cheese, in reference to the significant degree of macroscale dissolutional porosity in the limestone bedrock. The holes seen in the aragonitic limestone shown above were produced by dissolution in a freshwater-salt water mixing zone. The water filling these holes (just discernible in the photo) is close to marine salinity (I measured 36 to 37 ppt salinity on 24 March 1999). During storms and hurricanes, meteoric water having little to no salinity mixes with the salty water of the adjacent pond. Mixing zone waters have high aggressivity, in terms of calcium carbonate dissolution. This results in "swiss cheese limestone".