Research

Modern Animal-Sediment Interactions
In addition to studying the ancient record of animal-seafloor interactions, we actively work in modern sedimentary systems and conduct experimental perturbations of living animal and microbial communities. One objective of this modern work is to provide an actualistic and more quantitative framework for the interpretation of the sedimentary record of biotic-environmental coevolution. This work includes study of modern bioturbated sediments (in both siliciclastic and carbonate depositional systems) in order to calibrate proxies for mixed layer depth and measure the impact of bioturbation upon sulfur, carbon, phosphorus and trace metal cycling—integrating textural (x-radiographic) characterization of sediments with paleoecology, sedimentary geochemistry and diagenetic modeling. We are also actively investigating the impact of thermal and oxygen stress on coastal seafloor communities of bioturbating animals. Recent field work includes Long Island Sound, Connecticut; the Skidaway-Ogeechee estuary system, Georgia; the Exumas, the Bahamas; and Willapa Bay, Washington.

Crustacean trackways and polychaete trails in the intertidal zone. Guanacaste, Costa Rica.
Fecal matter of a burrowing hemichordate, alongside the star-shaped burrow of a nereid polychaete. Ripple troughs hold lags of calianassid shrimp fecal pellets. Raccoon Key, GA.
Luminophores in incubation experiments reveal how bioturbating animal communities respond to warming mimicking marine heat waves.
Modern intertidal flats in Willapa Bay, western Washington.
Sinking into the mud while coring for sediment samples. Raccoon Key, GA.