Temperature controls carbon cycling and biological evolution in the ocean twilight zone

Getting more pumped It is thought that the ocean's biological carbon pump, process transfers organic matter from surface to deep ocean, should be sensitive climate change because temperature controls photosynthesis and respiration rates. Boscolo-Galazzo et al. show efficiency of pump increased over past 15 million years as oceans cooled a reduction in rate breakdown sinking (see Perspective by Bopp). The resulting redistribution nutrients at depth could have affected plankton evolution expanded mesopelagic “twilight zone” ecosystem. Science , this issue p. 1148 ; see also 1099