Juan Carlos was born in Caracas, Venezuela. He did his undergraduate degree in the Universidad Central de Venezuela (UCV), where he was awarded a degree in Ecology. His undergraduate thesis was studying the effects of freshwater and sediments discharges on a marginal coral community in the central coast of Venezuela. Juan started a PhD at the University of Queensland in 2006 co-supervised by Prof Ove Hoegh-Guldberg (University of Queensland) and Prof. Rob van Woesik (Florida Institute of Technology), studying the ecological dynamic of coral reefs in response to subtle disturbances. His project is part of the GEF-Coral Reef Target Group and is based on Heron Island, Great Barrier Reef.
Coral reefs are under constant and increasing stress as a consequence of a variety of factors (e.g. over-fishing, agricultural runoffs, global warming, ocean acidification). Under these adverse conditions detecting the effect of environmental stress on coral communities as early as possible over the degradation process becomes crucial for the management of coral reef ecosystems. The parameter most widely used as a proxy for coral reef status is coral cover. However, is it possible to detect the effect of environmental stress (either anthropogenic or natural) using coral cover before the perturbation produced by that stress becomes catastrophic? In this study we explored the response of four coral taxa populations to a mild thermal stress event in summer 2006 on Heron Island. We compared the dynamics of coral cover after the event, with the dynamics of different demographic parameters of these four populations. Our results suggest that the response of coral cover dynamics to mild thermal stress seems to be much slower than population demographic dynamics. Following that result we ranked the four populations studied in relation to its sensitivity to thermal stress and found that Pocillopora damicornis was the most sensitive of these taxa. We propose that changes in demographic parameters in sensitive taxa like P. damicornis can be used for early detection of the effect of thermal stress in coral communities representing a useful tool for the future management of coal reef ecosystems.