Ancient 'Dinner Plate' Tool Finds New Life in Ocean Science.
A Secchi disk, a simple 19th-century tool historically called a "dinner plate" by sailors, is still useful in monitoring phytoplankton abundance in the open ocean. A research team compared the performance of Secchi disks with modern methods and found that Secchi disks performed almost as well as satellites and high-performance chromatography. This means that Secchi measurements going back more than a century can help scientists understand long-term changes in the ocean. Secchi disks are still used all around the world to monitor ocean biomass and water quality, and the findings support their continued use.