Coral Reef Ecosystems

This research group, led by Dr. Stuart Sandin, studies coral reef ecosystems to answer fundamental questions of population biology, trophic dynamics, and spatial ecology.

Marine ecosystems offer unique opportunities to study basic principles of ecology, complementing insights gained from terrestrial systems. Coral reefs, in particular, facilitate detailed study of population dynamics and species interactions. We focus our efforts to understand the role that reef fish play in controlling ecosystem dynamics, with specific interests in predator-prey and competitive interactions.

Given the conservation significance of coral reef ecosystems, we make efforts to link our research with tangible problems that are of interest to the management community. We are currently applying ecological studies to answer two core questions:

  • What type of management maximizes the long-term yield of tropical reef fisheries?
  • Which members of the reef community are most valuable for buffering coral reef ecosystems from the growing effects of global climate change?

Growth and Productivity of Coral Reef Fish

A long history of targeted fishing has reduced the prominence of apex predators in the sea. However, historical studies and surveys of remote island areas reveal that marine predators can dominate marine ecosystems. On coral reefs, the biomass of predatory fishes (including sharks, snappers, and groupers) can exceed that of prey fishes creating an inverted trophic pyramid. Thermodynamic constraints assure that such a ‘top-heavy’ trophic structure can only be supported through a ‘bottom-heavy’ pattern of productivity, with lower trophic level organisms growing more quickly than the apex predators. The outstanding questions remain, what are the detailed patterns of productivity that support predator-heavy reef communities, and what are the functional consequences associated with removing apex predators?


Fish, Benthos, and Microbes – The Trifecta of Coral Reefs

There are thousands of species that share coral reefs, and these species interact in countless ways. Because of the many relationships among these species, the overall ‘health’ of a coral reef cannot be assessed by focusing only on one group of organisms. Fish depend on the many species living on the bottom (including corals, seaweed, and the many mobile invertebrates) for shelter and food. The species living on the bottom (composing the so-called ‘benthos’) survive because marine bacteria maintain stable water chemistry. But the individual health of species on the benthos and of fish can be compromised by dramatic changes of the microbial community.

100 Island Challenge