The first study about submarine groundwater discharge was done by Sonrel (1868), who speculated on the risk of submarine springs for sailors. However, until the mid-1990s, SGD remained rather unrecognized by the scientific community because it was hard to detect and measure the freshwater discharge. The first elaborated method to study SGD was done by Moore (1996), who used radium-226 as a tracer for groundwater. Since then several methods and instruments have been developed to attempt to detect and quantify discharge rates.