Degradation Processes of Phytoplankton in a Eutrophic Bay with Particular Reference to the Chlorophyll a Pigment Composition of Suspended and Sinking Particles
| Autor: | Sakoh, Hiroaki, Matsuda, Osamu, Yamamoto, Tamiji |
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| Jazyk: | japonština |
| Rok vydání: | 1993 |
| Předmět: | |
| Zdroj: | 生物生産学研究. 32(2):79-86 |
| Popis: | 広島湾内にある閉鎖的内湾である江田内湾において、海水中懸濁粒子、沈降粒子および底泥表層を採取し、その光合成色素組成を比較した。クロロフィルa類色素は高速液体クロマトグラフィーを用いてchl.a, chl.aアイソマー、およびフェオ色素に分類した。その結果chl.aの占める割合は沈降粒子に比べて懸濁粒子で高かった。しかし懸濁粒子、沈降粒子ともにchl.aの分解産物であるフェオ色素の占める割合は30%以下と低く、chl.aの分解はあまり進んでいなかった。一方で底泥表層ではchl.aの占める割合は数%と低く、分解が進んでいた。以上のことから江田内湾でのchl.aの分解過程は外洋などと違って、動物プランクトンの摂餌・消化によるものより、植物プランクトンの自然死滅によるものが主であると考えられた。chl.aの分解は水中ではほとんど進まず、底泥表層に堆積してから進むものと考えられた。 Physiological condition of phytoplankton can be estimated from both quantitative and qualitative analyses of photosynthetic pigments. In this study, the process of chlorophyll a degradation in an enclosed eutrophic bay were investigated using high-performance liquid chromatography (HPLC). Chlorophyll a and its derivatives were classified into chi. a, chl. a isomers (chi. a'-1, 2, 3) and pheopigments by the use of reverse-phased HPLC. Resulted pigment compositions were compared between suspended particles, sinking particles and surface sediment in Etauchi Bay. Chl. a was more abundant in suspended particles than in sinking particles, while pheopigments in both particles accounted for only less than 30%. Since it was reported that 66% of chl. a was degraded by grazing of zooplankton, these results indicate that grazing and digestion by zooplankton are not the major process of degradation. Different from open sea, the major degradation process of chl. a in the eutrophic coastal area was concluded to be the natural death of phytoplankton. Because of the shallowness of the area, final stage of the degradation is supposed to occur after sedimentation. |
| Databáze: | OpenAIRE |
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