Seasonal variation of absorption by particles and colored dissolved organic matter (CDOM) in Funka Bay, southwestern Hokkaido, Japan

详细信息    查看全文

• 作者：Sasaki ; Hiroaki ; Miyamura ; Tsuyoshi ; Saitoh ; Sei-ichi ; Ishizaka ; Joji
• 关键词：absorption ; CDOM ; degradation ; phytoplankton ; package effect
• 刊名：Estuarine, Coastal and Shelf Science
• 出版年：2005
• 出版时间：August, 2005
• 年：2005
• 卷：64
• 期：2-3
• 页码：447-458
• 全文大小：997 K

文摘

Between November 2000 and October 2001, the seasonal variation in absorption by particles (phytoplankton and detritus) and colored dissolved organic matter (CDOM) was measured in Funka Bay (a subarctic coastal region of Japan). In autumn–winter, chlorophyll a concentration (Chl a) near the euphotic zone remained very low (<1.0 mg m⁻³) but markedly increased in spring (16.8 mg m⁻³). Chlorophyll-specific absorption coefficient for phytoplankton (a_ph(λ)) was high during summer and low during the spring bloom. This is because the package effect was greater during the spring bloom due to the presence of large diatoms, while small phytoplankton dominated during summer. Absorption at 440 nm by CDOM was higher than that of phytoplankton and detritus, except during the spring bloom, and the relative contribution of CDOM absorption to the total absorption coefficient was >50 % . CDOM and detritus absorption did not increase with increasing Chl a, but it showed a time lag between the spring bloom. It is suggested that phytoplankton degradation started after the spring bloom; detritus absorption increased and, then, CDOM absorption increased. River runoff was not a significant influence in Funka Bay, therefore, CDOM production may be mainly related to microbial activity.