Sampling Seawater

During a 2017 research cruise in the Mediterranean Sea, MIT-WHOI Joint Program student Mara Freilich and Simón Ruiz from the Mediterranean Institute for Advanced Studies, use an instrument called a CTD (Conductivity-Temperature-Depth) to collect samples of seawater and measure its salinity and temperature at various depths. The CTD also carried sensors that measured levels of nutrients and available light—the ingredients plankton need to grow. Freilich and her advisor Amala Mahadevan have been studying “fronts” in the ocean that form between water masses with different densities. These fronts produce conditions that fuel the growth of plankton. (Photo by Amala Mahadevan, Woods Hole Oceanographic Institution)