What causes Hermit Crab species to change?
Contaminants are often carried to coastal zones by stormwater. This stormwater would naturally absorb into the ground if it were not for hard, unnatural surfaces that are a result of urbanisation. Such surfaces include paved areas, roads and roofs, which all act to direct water runoff into stormwater drains and onto intertidal areas. In addition to carrying contaminants, large incursions of freshwater may also have ecological effects on inshore areas by severely depressing normal salinity levels. The striped-leg and yellow-footed hermit crabs have different physiological tolerances to reduced salinity [9] and recent studies have found that striped-leg hermit crabs are more numerous where there is an influence of freshwater, while yellow-footed hermit crabs seem to favor areas where little or no freshwater flows onto the coast [1,10]. Therefore, changes in the relative numbers of these species over time can indicate unnatural freshwater flows and changes in salinity that may have ecolog
