Paleontologists traditionally look for prominent environmental events to explain pulses of speciation and extinction in the fossil record. But ecological insight suggests that a more complex series of cascading events stretching over a million years or more are most likely responsible, including not only environmental change but also biological interactions and the phenomenon of ‘extinction debt’ developed for conservation biology. I am examining changes in functional biology and life history patterns to better understand the chronology of Caribbean extinctions over the past 5 million years.

Our recent work on bryozoans demonstrates that species richness was similar in both regions 5 million years ago, and the same was apparently true for reef corals.  Ongoing work suggests that the Mediterranean host similar species diversity before it dried up at about the same time. The obvious implication is that the great differences in species diversity today between the Caribbean and Mediterranean versus the Indo-West Pacific is due mass extinction in the Caribbean and Mediterranean rather than, has long been speculated, higher speciation rates in the Pacific.

We have long known that fishing intensified sufficiently by the time of the Roman Empire to drastically deplete Mediterranean fish stocks but have only recently documented the deep historical roots of overfishing worldwide. My group is working to untangle the history of human disturbance and the comparative consequences, of fishing, land use, habitat destruction, pollution, and climate change on Caribbean coral reef ecosystems. The central question is to what extent local management to regulate and diminish fishing, habitat destruction, and pollution on coral reefs can increase their resilience to coral bleaching, disease, and acidification due to the anthropogenic rise in CO2?

The Caribbean is a Mediterranean sea landlocked to the north, west, and south, and isolated from all other tropical oceans for 5 to 3 million years. Biotas in many groups are also deeply divergent as demonstrated especially for reef corals, but also for other groups such as bryozoans. I am interested in the extent to which this isolation has affected the ability of Caribbean biotas to cope with human disturbance. For example, the recent supposedly global extreme coral bleaching events did not occur in the Caribbean, whereas disease outbreaks appear to be more pervasive and fatal to Caribbean invertebrates such as corals and sea urchins than elsewhere in the tropics.