Effects of burrowing by the fiddler crab, Uca pugnax (Smith)

Abstract

Quantitative measurements were made of the burrowing activities of the fiddler crab ( Uca pugnax ). The rate of burrow appearance and disappearance, and average burrow volume and surface area, were measured in a set of quadrats. In a year, the population of crabs in the quadrats—42 crabs m −2 —can turn over approximately 18% of the upper 15 cm of sediment in a salt marsh (15 cm was the maximum burrow depth). Burrows increased the surface area by 59%. Burrowing may, therefore, significantly affect the composition and chemistry of salt marsh sediments.