Positive correlation between the number of shells or skeletal elements of a species preserved in the sedimentary record and the abundance and distribution of the once-living population can be an important assumption in paleoecological analysis. The assumption was tested for the large gastropod Strombus gigas (queen conch) in and around 2 nursery grounds in the central Bahamas. Concentrations of shell fragments on the surface of the sediment measured in 1990 were closely correlated (r = 0.998 and 0.928) with mean live conch abundance monitored regularly at 13 stations during the 2 previous years. Projections from field experiments on shell decomposition rates indicated that the shell remains of S. gigas last for at least a decade on the sediment surface. The direct relationship between shell remains and living populations integrated over time permits interpretation of historic changes in populations. Furthermore, time-averaging qualities of the death assemblages provide an integration of distribution and abundance patterns on an ecological time scale useful in learning the relationships between the environment, the species and its management.
Death assemblage . Gastropod . Paleoecology . Strombus gigas . Taphonomy
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