Efeitos das atividades antrópicas sobre populações de caranguejos-fantasmas Ocypode quadrata (fabricius, 1787) em praias arenosas da costa cearense

Abstract

This study evaluated the influence of urbanization and fixed tourist infrastructure (beach shacks) on populations of the ghost crab Ocypode quadrata on sandy beaches of Brazil's semiarid coast. Two complementary approaches were conducted. In Chapter 1, five beaches with varying levels of urban development were assessed using morphological data, anthropogenic impact indicators, and ghost crab population parameters (burrow density and diameter). Despite differences in urbanization, no significant variation in burrow density or diameter was observed, except between Sabiaguaba and Canto Verde beaches. In Chapter 2, intra-beach variation was examined at Praia do Futuro by comparing areas with and without beach shacks. While overall burrow density did not differ, spatial redistribution and significantly larger burrow diameters were found in shack areas, likely reflecting increased food availability. These findings suggest that although burrow density alone may be a limited bioindicator, burrow diameter and spatial distribution reflect adaptive responses to anthropogenic pressures and may support more effective coastal management strategies.