climate change. Phytoplankton is a key component in the base of the oceanic food chain and oceanographers have hypothesized a link between oceanic chlorophyll and fisheries production for some time. The degree to which phytoplankton relates to marine fish production depends on the number of trophic links in the food chain, and how efficient each link is. Estimates of the number of trophic links and trophic efficiencies from phytoplankton to commercial fisheries have been widely debated, though they have been little substantiated. More recent research suggests that positive relationships between and fisheries production can be modeled and can be very highly correlated when examined on the proper scale. For example, Ware and Thomson (2005) found an r2 of 0.87 between resident fish yield (metric tons km-2) and mean annual concentrations (mg m-3). Others have found the Pacific's Transition Zone Chlorophyll Front (chlorophyll density of 0.2 mg m-3) to be defining feature in loggerhead turtle distribution. References External links SeaWiFS Project Home Page OceanColor Website Earth observation satellite sensors Satellite meteorology NASA spin-off technologies Oceanographic instrumentation