Aggregation and sedimentation of Thalassiosira weissflogii (diatom) in a warmer and more acidified future ocean.
Increasing Transparent Exopolymer Particle (TEP) formation during diatom blooms as a result of elevated temperature and pCO2 have been suggested to result in enhanced aggregation and carbon flux, therewith potentially increasing the sequestration of carbon by the ocean. We present experimental results on TEP and aggregate formation by Thalassiosira weissflogii (diatom) in the presence or absence of bacteria under two temperature and three pCO2 scenarios. During the aggregation phase of the experiment TEP formation was elevated at the higher temperature (20°C vs. 15°C), as predicted. However, in contrast to expectations based on the established relationship between TEP and aggregation, aggregation rates and sinking velocity of aggregates were depressed in warmer treatments, especially under ocean acidification conditions. If our experimental findings can be extrapolated to natural conditions, they would imply a reduction in carbon flux and potentially reduced carbon sequestration after diatom blooms in the future ocean.
Molecular Life Science Research Center, Jacobs University Bremen, Bremen, Germany.
Shalin
S
Seebah
Marine Science Institute, University of California Santa Barbara, Santa Barbara, California, United States of America.
Caitlin
C
Fairfield
Molecular Life Science Research Center, Jacobs University Bremen, Bremen, Germany.
Matthias S
MS
Ullrich
Marine Science Institute, University of California Santa Barbara, Santa Barbara, California, United States of America.
Uta
U
Passow
D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism*; D017377:Diatoms / Q000502:physiology*; D005068:Eutrophication / Q000502:physiology*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D009792:Oceans and Seas
D002245:Carbon Dioxide