One of the best records of past ocean temperatures can be found in the shells of marine creatures called foraminifera. Known as “forams” for short, these single-celled plankton build microscopic calcite shells. When forams die, their shells fall to the ocean floor and accumulate in sediments that provide a record of past climate. The surface-feeding plankton are natural thermometers because the chemical makeup of foram shells is linked to the environmental conditions they grow in.
Visit Website | Image credit: Dr. Jennifer Fehrenbacher, Oregon State University