Photosynthesis-irradiance relationship of phytoplankton and primary production in the vicinity of Kuroshio warm core ring in spring |
| |
Authors: | Ken Furuya Osamu Hasegawa Takashi Yoshikawa Satoru Taguchi |
| |
Institution: | (1) Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, 113-8657 Tokyo, Japan;(2) Faculty of Engineering, Soka University, Tangi, Hachioji, 192-0003 Tokyo, Japan |
| |
Abstract: | The light-saturated maximum value (P
B
max) and initial slope (α) of the photosynthesis-irradiance (P-E) curve were examined in a warm streamer, a cold streamer and
a warm core ring off the Sanriku area in the subarctic western North Pacific Ocean during an ADEOS/OCTS Sanriku field campaign
in early May 1997. BothP
B
max and α were within the ranges of temperate populations. A regional difference was apparent inP
B
max: populations in the warm streamer tended to show higher value ranging between 1.92 and 4.74 mgC (mgChla)−1h−1 than those in the cold streamer and the warm core ring (1.35–2.87 mgC (mgChla)−1h−1). A depth variation was also observed in α in both the warm streamer and the warm core ring: shallow populations tended to
have lower α than deep populations. The depth variations in bothP
B
max and α resulted in a lower light intensity of the light saturation in a deeper population than that of a shallower one. These
depth-related variations in the P-E parameters were likely a manifestation of “shade-adaptation” of photosynthesis. Photoinhibition
was not observed over in situ surface light intensity varying below ca 1600 μmol photon m−2s−1. Water-column primary productivity was biooptically estimated to be 233 to 949 mgC m−2d−1 using vertical distributions of the P-E parameters, chlorophylla, phytoplankton light absorption and underwater irradiance. Applicability of surface data sets for estimation of water-column
productivity is discussed. |
| |
Keywords: | Photosynthesis primary production phytoplankton P-E curve subarctic Pacific warm core ring ADEOS/OCTS |
本文献已被 SpringerLink 等数据库收录! |
|