Sediment reworking by a sand bubbler crab, Scopimera globosa, on a Korean tidal flat

Abstract

Bioturbation, especially sediment reworking by the macroinvertebrates results from activities such as feeding and burrowing, is one of the major process that affects the physical, chemical, and biological characteristics of marine sediments. Given the importance of sediment reworking, this study was designed to evaluate the sediment reworking rate of a sand bubbler crab, Scopimera globosa, which is one of the dominant species in the upper tidal flats on the west coast of Korea, based on quantification of pellet production and burrow sediment production during summer and fall surveys. The density of individuals, the morphometric dimensions of the crab and its pellets were significantly higher, longer and heavier in fall than in summer. Daily pellet production and burrow sediment production were much higher in fall than in summer, mostly due to an increase in daytime production on pellet production and nighttime production on burrow sediment production. The sediment reworking rate of Scopimera was notably higher in fall than in summer and depended on its density as well as the sediment reworking rate per individual. The overall sediment reworking rate of Scopimera was 214 cm yr-1 based on its density in this study area.. Given the importance of sediment reworking, this study was designed to evaluate the sediment reworking rate of a sand bubbler crab, Scopimera globosa, which is one of the dominant species in the upper tidal flats on the west coast of Korea, based on quantification of pellet production and burrow sediment production during summer and fall surveys. The density of individuals, the morphometric dimensions of the crab and its pellets were significantly higher, longer and heavier in fall than in summer. Daily pellet production and burrow sediment production were much higher in fall than in summer, mostly due to an increase in daytime production on pellet production and nighttime production on burrow sediment production. The sediment reworking rate of Scopimera was notably higher in fall than in summer and depended on its density as well as the sediment reworking rate per individual. The overall sediment reworking rate of Scopimera was 214 cm yr-1 based on its density in this study area.