An Underwater Laboratory at the Fraser River Delta



Deltas, home to more than 500 million people and the site of vital wetland ecosystems across the world, are of tremendous economic importance to many countries. The physical dynamics at river mouths determines how sediment particles and contaminants are dispersed offshore by mechanisms that include waves, currents, and gravity flows, but how and when particular mechanisms operate are often inferred rather than known. Thus, scientists' understanding of sediment and contaminant dispersal mechanisms is only rudimentary. The problems lie in the intermittent operation of the different mechanisms, which occur on tidal, seasonal, and interannual time scales, and the difficulty of making long time series measurements at high sampling rates in these challenging oceanographic environments.