Marine phytoplankton metabolism is affected by higher ocean temperatures, which trigger an increase in the rate of protein synthesis, reports a study published online this week in Nature Climate Change. These findings indicate that there is a previously unrecognized direct response to water temperature, with implications for marine biogeochemical cycling.
Thomas Mock and colleagues use a range of techniques to investigate the effect of temperature on marine phytoplankton growth strategies, metabolism and chemical composition. They find that although protein synthesis is increased under high temperatures, the number of ribosomes-the protein builders-and associated ribosomal RNAs decreases. Ribosomes are phosphate rich, and a decrease will therefore lead to higher nitrogen/phosphate ratios in the organisms. This change in nutrient ratios will increase the demand for nitrogen, causing shifts towards nitrogen limitation, which would lower productivity and have implications for the marine carbon cycle.