Productivity of picoplankton compared with that of larger phytoplankton in the subarctic region

• Main Authors: Akihiro Shiomoto, Kazuaki Tadokoro, Kojo Monaka, Masaaki Nanba
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1997
• Subjects: Bering Sea; Pacific; Posi; Tive; Subarctic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1033.2074; http://plankt.oxfordjournals.org/content/19/7/907.full.pdf

Abstract We determined the productivity (ug C ug~ ' Chi a h~') of size-fractionated phytoplankton in the northern North Pacific and the Bering Sea in summer and winter. Picoplankton (<2 urn) were more productive than larger sized phytoplankton (2-10 and 10-200 um) in the subtropical region, where the in situ temperature was>lff"C; whereas picoplankton in the subarctic region were similar in productivity or less productive than larger sized plankton, where the in situ temperature was <10°C. The result from the subtropical region in this study agrees with previous results from tropical and sub-tropical waters, which indicate that phytoplankton productivity tends to decrease with increasing cell size. The result from the subarctic region, however, differs from previous results. We observed a posi-tive linear regression for in situ temperature and picoplankton productivity, but this trend was not seen in the larger sized phytoplankton. The results show that the productivity of picoplankton is markedly influenced by in situ temperature compared with that of larger sized plankton. Low tem-perature appears to account largely for the observation that the productivity of picoplankton is not significantly higher than that of larger sized phytoplankton in the subarctic region.