Coral reefs are among the most diverse and productive aquatic ecosystems on the planet and directly support the livelihood of more than a ¼ billion people worldwide. Unfortunately, it is now evident that coral reefs are also extremely sensitive to rapid environmental change, and therefore research efforts increasingly focus on the future diversity, function and ultimately sustainability of these ecosystems. The existence of coral reefs is entirely dependent upon a symbiosis between cnidarian reef building corals and a single celled microalga (genus Symbiodinium; generally termed zooxanthellae): Zooxanthellae are endosymbiotic and substantially contribute organic matter to meet the host’s nutritional requirements; thus corals can flourish in otherwise nutrient poor waters. Not all organic carbon generated by the zooxanthellae is ultimately channelled into coral growth and corals can exude half of the organic carbon assimilated by their zooxanthellae as mucus or dissolved sugars, which in turn can support an array of key associated organisms, from bacteria to (food) fish. As such, the long-term diversity and productivity of coral reefs depends on the nature of the symbiosis between corals and zooxanthellae. Scientists are now only just beginning to understand the importance that zooxanthellae diversity plays in regulating how corals respond to changes in their environment at both local (eutrophication, sedimentation, and over- exploitation) and regional-global (climate change) scales. In particular, rapid (anomalous) changes in temperature and light that induce corals to ‘bleach’ (pale) and ultimately die have driven research that has identified ‘stress sensitive’ and ‘stress tolerant’ zooxanthellae (and zooxanthellae-coral interactions). Such novel insights are keys towards the long-term goal of generating a mechanistic understanding of how coral productivity and diversity will respond to predicted environmental (and climatic) change. A number of core research groups worldwide have been independently tackling fundamental aspects of zooxanthellae-coral biology, ecology and biogeochemistry towards this goal. Therefore, the primary aim of this proposal is to build a lasting research network that can better understand how the coral holobiont (animal host, zooxanthellae and associated microbes) interact with one another and their environment to control overall coral and reef productivity.

CESAM members on this project

João Serôdio
Coordinator

Jörg Christian Frommlet
Researcher

Newton Carlos Marcial Gomes
Researcher

Ricardo Jorge Guerra Calado
Researcher

Rui Jorge Miranda Rocha
PhD Student