Coral reefs are among the most diverse and productive ecosystems on earth, and are threatened worldwide by the activities of humans. For reef ecologists, these changes are unprecedented, but there is abundant evidence for rapid ecological change on reef systems from the fossil record. These past examples can be studied from many time intervals and regions, and together form a set of replicated "natural experiments" in which ancient ecosystems responded to various types of environmental change. My research program is to study these past experiments to understand the biological consequences of past changes and help predict how modern reef systems might respond to ongoing and future global environmental change.
Working on exposures of Early Miocene reef rocks on Gunung Eso, Java.
One region of particular interest is the 'coral triangle' that today contains the highest diversity of marine life on Earth. To better understand how environmental changes have shaped this biota, I will be co-ordinating multi-disciplinary group of researchers from 12 institutions to produce an integrated study of Oligocene and Miocene basins in Java and Kalimantan. The project has been funded as an EU Marie Curie Initial Training Network. The goal of this study is to determine the environmental and biotic effects of the initial closure of the Indonesian Throughflow (ITF) to deep-water circulation during the Late Oligocene or Early Miocene. By restricting flow of water from the tropical west Pacific into the Indian Ocean, the ITF plays an important role in determining global climate. This interval is characterised by both an apparent increase in regional reef-building and the diversification of reef-corals and mollusks leading to the development of the present-day 'coral triangle'. Is it a coincidence that this global biodiversity hotspot occurs in a geologically dynamic region that also contains a major control of the global climate?
Our first network activity is the International Symposium on Southeast Asian Gateway Evolution jointly hosted by NHM and Royal Holloway, University of London that will be held in September 2009.
Diploastrea crassolamellata from the Late Oligocene Antigua Fm.
The Caribbean Basin contains several time intervals of accelerated change during the past 30 million years that can be used as case studies to understand how reef biota respond to environmental changes on regional scale. Analysis of large collections of fossil corals identified using an up-to-date taxonomic framework and with newly interpreted stratigraphy indicates that extensive development of Caribbean coral reef ecosystems after the Eocene was limited to two intervals of the Cenozoic. Late Oligocene and Quaternary episodes of large-scale reef construction were interrupted by a long interval without major constructional reef buildups.
Acropora saludensis from the Late Oligocene Antigua Fm.
Surprisingly, the changing diversity of reef coral species does not exactly mirror this broad pattern. Although major extinctions occurred twice, the first is associated with the Early Miocene decline of reef building and the second is nearly contemporaneous with the Early Pleistocene renewal of extensive reef development. Moreover, regional diversity of reef-corals is inversely related to reef building during the past 30 million years, so that extensive Late Oligocene and Quaternary reefs were constructed by relatively few species, but the more diverse Late Pliocene coral biota was not building reefs. Instead, rich Pliocene coral communities were living in coral meadows, sea grass beds, and other soft bottom and reef-marginal settings. These counter-intuitive results suggest that past environmental conditions that were conducive to the development and maintenance of high diversity of reef-corals are not the same that encourage regional reef growth. Researchers and managers developing strategies to manage coral reef ecosystems during the coming decades might need to choose between encouraging reef development or maximizing diversity of reef-corals.
A syntype of Psammoseris hemispherica Gray (BMNH 18126.96.36.199).
The field of scleractinian coral taxonomy is in the midst of a revolution as we incorporate new data resulting from advances in molecular systematics and the application of new technologies for extracting new kinds of morphological characters from coral skeletons. One important goal of this effort is the production of a rigorous framework providing well-circumscribed taxon concepts to allow consistent identification of corals for use by non-taxonomist colleagues. We are using collaborative web-based tools at Corallosphere.org that enable registered contributors to compile, review, and edit nomenclatural data, taxonomic diagnoses, and synonyms. Users may contribute images of types and entries into an illustrated glossary of morphological terms. All users are able to post comments, and a formal peer-review mechanism helps to ensure high-quality content. The aim is to produce a system that will help remove the taxonomic impediment that is currently slowing progress towards an improved understanding of the biology, ecology, and evolutionary history of the Scleractinia.
Fossils can provide useful information to understand biotic responses to environmental change. © Image courtesy of Caitlin Kelly
I am a founding member of the NHM 'High Water Club', an informal group of museum researchers, curators, and public engagement staff interested in finding new uses for NHM collections, expertise, and data to address questions related to environmental change. With support from the NHM Strategic Innovation Fund, we are currently engaged in a pilot study to identify collections areas likely to be useful for this purpose.