CTD (image) Woods Hole Oceanographic Institution Caption The scientists used a CTD (conductivity, temperature, depth) rosette to collect water samples during a research cruise in October 2011 along a 2,500-mile stretch in the Pacific Ocean, from Hawaii to Samoa. The transect cut across regions with widely different concentrations of nutrients, from areas rich in iron to the north to areas near the equator that are rich in phosphorus and nitrogen but devoid of iron. Credit Photo by Brian Dimento, University of Connecticut Usage Restrictions with proper credit and in a piece featuring the research Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.