The Coral Triangle: A Hotspot for Submarine Groundwater Discharge

Coral reefs are some of the most biologically diverse habitats in the world. They provide economic value to many coastal communities through fisheries and tourism. Coral reef ecosystems are especially valuable in the Coral Triangle (CT), an area in the western Pacific Ocean. Several local and regional studies have focused on geochemical and ecological research in the CT. Studies focusing on hydrologic connections and inputs from land to sea are much less common, although these have implications for coastal water quality and ecosystem health. This research explores the global patterns of submarine groundwater discharge (SGD) and investigates the spatial connection between SGD rates and coral reefs. We hypothesized that SGD rates are higher in the CT versus the rest of the world. To test this hypothesis, global SGD data from two previous studies (Luijendijk et al., 2020; Zhou et al., 2019) were analyzed. The analysis included the use of GIS software and statistical methods. Student T-tests and Mann-Whitney U-tests were performed on the data to determine statistical differences between SGD values in the CT versus those outside. Results from both the Zhou et al. and Luijendijk et al. data demonstrate that SGD values are higher in the Coral Triangle than in the rest of the globe. Future work will explore the spatial relationship between volcanoes and coral reefs to determine whether volcanic activity correlates with SGD. The findings will help establish the environmental context under which the coral reefs of the CT thrive and identify potential threats to these crucial ecosystems.