Aquatic Sciences Meeting, Albuquerque 2001

CS25 Organic Carbon Dynamics

Date: Wednesday, February 14, 2001, Time: 4:15:00 PM

Location: Acoma/Zuni/Tesuque

Hamanaka, J, , Nagoya University, Nagoya , Japan, hamanaka@ihas.nagoya-u.ac.jp

Tanoue, E, , Nagoya University, Nagoya , Japan, tanoue@ihas.nagoya-u.ac.jp

Hama, T, , University of Tsukuba, Tsukuba, Japan, thama@biol.tsukuba.ac.jp

Handa, N, , Aichi Prefectural University, Aichi, Japan, handa@ist.aichi-pu.ac.jp

PRODUCTION AND EXPORT OF PARTICULATE FATTY ACIDS, CARBOHYDRATES AND COMBINED AMINO ACIDS IN THE EUPHOTIC ZONE OF SAGAMI BAY, JAPAN

Dynamics of particulate organic matter (POM) in the euphotic zone was evaluated at molecular level by means of the combination of two methods, 13C-labeling and sediment trap techniques. Determinations of fatty acids, carbohydrates and combined amino acids of photosynthetic products, suspended particles in the euphotic zone and sinking particles out of the euphotic zone, enable us to calculate the biochemical compound-based export efficiency (specific-compound e ratio) as well as organic carbon-based e ratio. Carbohydrates and combined amino acids were separated into two fractions, namely, methanol/water-soluble and -insoluble fractions after organic solvent extraction for fatty acids determination. The specific-compound e ratios of carbohydrates (0.25) and combined amino acids (0.27) in the methanol/water-insoluble fraction were similar to the ratio of bulk organic carbon (0.26). While the ratios of total fatty acids and carbohydrates and combined amino acids in the methanol/water-soluble fraction were exclusively low, being 0.081, 0.078 and 0.064, respectively. These results suggest that the dynamics was quite different among the biochemical compound classes of POM in the euphotic zone. Further discussions are also presented on the source of sinking POM.

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Aquatic Sciences Meeting, Albuquerque 2001

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