An Analysis of Sand from Green Turtle Nesting Beaches on Ascension Island

Abstract

Sand samples from most of the beaches on Ascension Island which are used by green turtles (Chelonia mydas) were collected and analyzed for organic, water and calcium carbonate content, pH, color and grain size distribution. Color, grain size distribution and water content varied to such an extent that Ascension beaches encompass the ranges of these parameters for green turtle nesting beaches surveyed in other parts of the world. A brief nesting survey and examination of nesting records kept by Mariculture, Ltd. suggested less frequent nesting on beaches near civilization, where human disturbance was high. There was no correlation between any other beach parameter and nesting frequency. We conclude that in the absence of disturbance or competition, green turtles have a wide tolerance of physical conditions on their nesting beaches.