The ecological effects of beach sand mining in Ghana using ghost crabs (Ocypode species) as biological indicators

Abstract

Sandy beaches are habitat to many invertebrate biodiversity and threatened vertebrate species. However, extraction of sand is widespread along many developing nations' beaches destroying the ecosystem services the area provides. This study assessed the ecological impacts of beach sand mining on three beaches in the Central Region of Ghana over a four month period, using ghost crabs as a biological indicator. Beaches were categorized as near-pristine, moderately disturbed and highly disturbed. Crab burrows were counted and their diameters measured. Mean burrow density and diameters were significantly higher at the near-pristine site (ANOVA, p < 0.001) compared to the moderately disturbed and highly disturbed beaches, whilst no significant differences occurred between mean burrow densities and diameters at moderately and highly disturbed beaches (ANOVA, p > 0.05). Beach sand mining was found to negatively affect ghost crab populations indicating a critical need for local municipal authorities to identify more sustainable and less damaging sources of sand for the construction industry.