The role of land-use change in coral loss and recovery
Research is increasingly showing that land-based nutrients (from agriculture, sewage, and livestock rearing) and sediments can compromise coral health and reduce coral resilience to climate change impacts. However, the role of land-based pollution in the widespread loss of corals remains underexplored due to a lack of reef water quality monitoring.
Our group is launching projects in the Caribbean and Central Pacific that will utilize coral and reef sediment cores to track nutrient and sediment input to reefs, coral health, and reef ecosystem functioning over the past century, a period of intensifying land use change. Changes in nutrient, freshwater, and terrestrial sediment input will be assessed from geochemical signatures of coral skeletons and related to metrics of coral health. These changes will in turn be related to changes in human dynamics on land, including land use and land cover, population density, and fertilizer usage. This work will quantitatively assess the linkages between land use, reef water quality, and reef ecosystem health and resilience.
Another major aspect of this work is a recently-formed working group led by Katie Cramer and Loren McClenachan that is formulating pathways for integrating long-term ecological data in Caribbean reef fisheries and water quality management. By combining paleoecological, historical, and data from monitoring programs, our group is producing the first region-wide compilation of reef water quality data for the Caribbean to quantify the role of land-based pollution in declines in reef health.