Research

Modern Animals-Sediment Interactions
In addition to studying the ancient record of animal-seafloor interactions, we actively work in modern sedimentary systems. The 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. Recent field work includes coring sediments in Long Island Sound, Connecticut; the Skidaway-Ogeechee estuary system, Georgia and the Exumas, the Bahamas.

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.
Sinking into the mud while coring for sediment samples. Raccoon Key, GA.

Cored sediments can be x-rayed, producing high-resolution images of sediment fabric from which the intensity of bioturbational disruption (and identify of bioturbators) can be determined. Ogeechee estuary system, GA.