Direct linkage between dimethyl sulfide production and microzooplankton grazing, resulting from prey composition change under high partial pressure of carbon dioxide conditions.
Oceanic dimethyl sulfide (DMS) is the enzymatic cleavage product of the algal metabolite dimethylsulfoniopropionate (DMSP) and is the most abundant form of sulfur released into the atmosphere. To investigate the effects of two emerging environmental threats (ocean acidification and warming) on marine DMS production, we performed a large-scale perturbation experiment in a coastal environment. At both ambient temperature and ∼ 2 °C warmer, an increase in partial pressure of carbon dioxide (pCO2) in seawater (160-830 ppmv pCO2) favored the growth of large diatoms, which outcompeted other phytoplankton species in a natural phytoplankton assemblage and reduced the growth rate of smaller, DMSP-rich phototrophic dinoflagellates. This decreased the grazing rate of heterotrophic dinoflagellates (ubiquitous micrograzers), resulting in reduced DMS production via grazing activity. Both the magnitude and sign of the effect of pCO2 on possible future oceanic DMS production were strongly linked to pCO2-induced alterations to the phytoplankton community and the cellular DMSP content of the dominant species and its association with micrograzers.
School of Environmental Science and Engineering, Pohang University of Science and Technology , Pohang 790-784, Korea.
Ki-Tae
KT
Park
Kitack
K
Lee
Kyoungsoon
K
Shin
Eun Jin
EJ
Yang
Bonggil
B
Hyun
Ja-Myung
JM
Kim
Jae Hoon
JH
Noh
Miok
M
Kim
Bokyung
B
Kong
Dong Han
DH
Choi
Su-Jin
SJ
Choi
Pung-Guk
PG
Jang
Hae Jin
HJ
Jeong
D000818:Animals; D001272:Atmosphere; D002245:Carbon Dioxide / Q000032:analysis*; D010313:Partial Pressure; D010839:Phytoplankton / Q000378:metabolism / Q000502:physiology; D012623:Seawater / Q000737:chemistry; D013440:Sulfides / Q000378:metabolism*; D013452:Sulfonium Compounds; D013455:Sulfur / Q000378:metabolism; D015048:Zooplankton / Q000378:metabolism / Q000502:physiology*
D013440:Sulfides; D013452:Sulfonium Compounds; D002245:Carbon Dioxide; D013455:Sulfur; C068078:dimethylpropiothetin; C004784:dimethyl sulfide