The causes and consequences of marine extinction
Marine environments extend over 70% of the Earth’s surface and contain tremendous biodiversity. It has commonly been assumed that marine species are so widespread and numerous that they are less vulnerable to extinction. However, recent studies have documented large-scale declines of many marine species and the fossil record provides overwhelming evidence of past extinction. Marine sedimentary records can preserve ecological, evolutionary, and environmental information with considerable fidelity and are thus natural laboratories for investigating the impacts of environmental change on marine benthos over a range of spatial and temporal scales. In our lab we investigate the characteristics of marine organisms that have led to elevated extinction risk throughout Earth history and use this information to identify taxa and regions in the modern oceans that may be more vulnerable to current and future environmental change. See Publications for additional information.
Anthropogenic impacts on coastal ecosystems in the Gulf of Mexico
The Mississippi River watershed drains 40% of the continental United States and is home to approximately 70 million people. The river’s delivery of nutrients has supported tremendous primary production in the northern Gulf of Mexico for millennia. Farming and other human activities have enhanced delivery of nitrogen and phosphorous to these coastal ecosystems, further spurring primary production. How has anthropogenic nutrient enrichment and associated hypoxia affected marine biotas across the northern Gulf? By comparing live populations of marine mollusks with the remains of historical populations preserved in seafloor sediments, our lab is working to answer this question. Specifically, we are 1) measuring the pace of life history adaptation in response to anthropogenic nutrient enrichment, (2) establishing historical baselines for the diversity and abundance of Gulf mollusks on the continental shelf prior to the onset of industrial agriculture and commercial fishing, and (3) assessing the taphonomic condition and ecological fidelity of historical death assemblages. This work is currently funded by a CAREER award from the National Science Foundation (link) . See Publications for additional information.