OLI Grant: Environmental and Climate Impacts on Coral Productivity in the Gulf of Chiriqui, Panama
Grant Funded: 2005Geochemical measurements from decadal to century scale coral records can yield important information of how coastal ecosystems interact with and respond to the environment. This is particularly relevant in areas within the eastern tropical Pacific, such as along the coast of Panama, which are sensitive to El Nino-Southern Oscillation (ENSO) related sea-surface temperature and salinity anomalies. Previous efforts from this region to understand long-term climate and environmental variability, and their impact on coral health and productivity, have been limited to a single geochemical measurement, oxygen isotopes (d18O). As such, these high resolution coral oxygen isotope records are complicated by the dependence of coralline d18O composition on both temperature and the isotopic composition of the seawater in which it grows. Therefore, the assessment of coral ecosystem health and sustainability along the Pacific coast of Panama depends on our ability to expand our suite of geochemical proxies in order to deconvolve the current trends in temperature-salinity signals in this region.
We request funds from the Ocean Life Institute to initiate a long-term coral research program based out of the Liquid Jungle Lab (LJL) on the Pacific coast of Panama in order to address the research themes set forth by the Institute. Specifically, we propose to collect and analyze coral samples from massive Porites colonies in the Gulf of Chirique. Preliminary reconnaissance surveys of the LJL area indicate several large colonies (up to 1.5 m diameter) growing in shallow water (2-3 m depth). We will explore promising bays known to possess Porites corals on the eastern coast of Coiba Is., where the potential exists for sampling 3 m Porites heads up to 300+ years in age. By making high resolution geochemical measurements in the corals, we propose to reconstruct changes in climatic and environmental conditions throughout the past. Multiple independent proxies measured together on the same samples will allow us to discriminate signatures from changes in environmental variables such as sea-surface temperature (Sr/Ca), sea-surface salinity (Sr/Ca + d18O), runoff and turbidity (Ba/Ca, %Ti, %Al), and nutrient loading (organic d15N) that might not be resolvable with a single proxy (e.g., d18O). Furthermore, resulting data sets will allow us to deconvolve the temperature-salinity signal with increased confidence and to quantify the magnitude of sea-surface temperature and salinity anomalies in the eastern Pacific Ocean driven by ENSO events, as well as seasonal migration of the Intertropical Convergence Zone over the past several decades to centuries. We hope to apply the results from this proposed work to other sites along the coast of Panama in order to understand the interaction and response of the coastal ocean to the effects of microclimates at different local settings. Upon successfully addressing the objectives outlined in this proposal, financial support from the Ocean Life Institute will be used to support highly competitive proposals to federal programs (NSF, NOAA) to establish a long-term coral research program based out of the Liquid Jungle Lab on the Pacific coast of Panama.