Strength May Lie in Numbers: Intertidal Foraminifera Non-Negligible Contribution to Surface Sediment Reworking

Abstract

The contribution of benthic foraminifera to sediment bioturbation has widely been overlooked despite their huge abundance in intertidal soft sediments. In this preliminary study, we specifically chose to focus on two key species of benthic foraminifera in temperate intertidal mudflats, Quinqueloculina seminula and Ammonia tepida, and first experimentally investigated their individual movements at the sediment surface. We subsequently derived from these observations the individual-level surface sediment reworking rates, and used the actual abundance of these species to extrapolate these rates at the population level. Individual surface sediment reworking rates SSRRi ranged between 0.13 and 0.32 cm2∙ind−1∙day−1 for Q. seminula, and between 0.12 and 0.28 cm2∙ind−1∙day−1 for A. tepida. Population-level surface sediment reworking rates were subsequently estimated as ranging between 11,484 and 28,710 cm2∙m−2∙day−1 for Q. seminula and 27,876 and 65,044 cm2∙m−2∙day−1 for A. tepida...