Forecasting Biological and Human Consequences of Climate Change on South East African Coral Reefs and Associated Sediments from the Palaeoclimate Record

Ancient calcifying marine organisms have survived past climate change and provide a geological record of this history.  Extant groups that provide evidence of this at opposite extremes of the biological scale are long-lived corals, colonies of which can survive for centuries, and short-lived foraminifera and coccolithophores, unicellular organism that are the most prolific calcifiers in the sea. Coral systems are particularly important throughout the tropics because of their biodiversity, value for fisheries and ecotourism, and coastal protection.  While corals generate reef structures that provide these essential ecosystem services, they, together with protists and other calcifying organisms, similarly generate marine sediments.  This project examines the past history of coastal accretion on the south east African coast in terms of climate change, and assesses the effects of ocean acidification on the calcifying protists, other sediment-dwelling organisms and corals. Palaeoclimatic records derived from reef sediment and coral cores, as well as from quantitative analysis of calcifying organisms in onshore and offshore sediments, will be compared with current biological and temperature monitoring on the reefs, as well as the determination of aragonite saturation state.  Indicator species of climate change will be sought and tested in laboratory microcosms. The effects of projected changes will be further investigated in terms of reef and adjacent habitat linkages and processes (e.g. coral community structure, reproduction and recruitment), as well as assessments of genetic diversity and resilience.  Finally, all-important human implications of the projected changes will be evaluated in terms of their socio-economic consequences to the livelihood and welfare of coastal communities.