Ecological Turnover of Shallow Water Carbonate Producers Following the Paleocene-Eocene Thermal Maximum

Abstract:

Modern coral reef ecosystems are under threat from global climate change (and associated, synergistic stresses) and local environmental degradation. Therefore, it is important for ecologists to understand how ecosystems adapt and recover from climate change. The fossil record provides excellent case studies of similar events, such as the Paleocene-Eocene Thermal Maximum (PETM). Although Paleocene and Eocene shallow water carbonates have not received the same degree of attention as the deep-water record, the PETM provides an opportunity to study the role of alternative stable states in maintaining the health and diversity of shallow water carbonate environments. It is generally accepted that during the PETM there is a transition from reef systems to foraminiferal shoals as the dominant shallow water carbonate producers. In fact, previous work has documented this interval as one of the major metazoan reef collapses of the Phanerozoic. This study fills an important gap in the shallow-water PETM record by quantitatively measuring the changes in carbonate production and ecology of 15 localities as they shift from coral reefs to foraminiferal shoal. The quantitative and semi-quantitative analysis is accomplished by using data from the PaleoReefs database and a simple carbonate production calculation to estimate the productivity of the shallow water system. Ecological data are gathered through a literature review of the localities. The results of this study will enable a better understanding of how modern reefs may react to global climate and environmental change.