Spatial distribution of the protist community in the southern part of the Okhotsk Sea off Hokkaido during summer
Spatial distribution of the protist community in the southern part of the Okhotsk Sea off Hokkaido during summer
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DOI：
10.1007/s10872-021-00630-5
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发表时间：
2022-01-27
影响因子：
2.3
通讯作者：
Yamaguchi, Atsushi
中科院分区：
文献类型：
--
作者：
Hamao, Yusuke;Matsuno, Kohei;Yamaguchi, Atsushi
北海道附近的鄂霍次克海南部渔业资源丰富，初级生产量高。浮游植物群落已被描述的几项研究的基础上的大小分级叶绿素a浓度和初级生产，但是，纳米和微型原生生物群落的物种组成的细节还没有得到很好的调查。我们评估了2019年夏季北海道外鄂霍次克海南部地区纳米和微型原生生物群落的空间分布及其与水文的关系。共鉴定出硅藻19属42种，甲藻7属，纤毛虫、寡毛纤毛虫和硅鞭藻1属。它们的空间分布在不同类群之间表现出明显的差异。聚类分析的基础上的原生生物细胞密度确定了六组地理上区分的分布。硅藻优势群落分布在北海道沿岸的冷水带和大豆暖流沿着。微鞭毛藻群落主要分布在近海。本文报道了几种有害硅藻（Pseudonitzschia pseudodelicatissima）和甲藻（Alexandrum spp.）在若奈的冷水带占主导地位我们认为，冷水的上升流可能会增加有害物种的丰度，对海洋生态系统或渔业资源产生不可估量的负面影响。总之，夏季原生生物群落的物种组成和丰富度与北海道外鄂霍次克海南部的不同水团密切相关。
The southern part of the Okhotsk Sea off Hokkaido has rich fishery resources supported by high primary production. The phytoplankton community has been described by several studies based on size-fractionated chlorophyll a concentration and primary production; however, the details of the species composition of nano- and micro-protist communities have not been well investigated. We evaluated the spatial distribution and relationship with hydrography of nano- and micro-protist communities in the southern region of the Okhotsk Sea off Hokkaido during the summer of 2019. Forty-two species of diatoms from 19 genera, dinoflagellates from 7 genera, tintinnid ciliates, oligotrich ciliates, and 1 genus of silicoflagellates were identified. Their spatial distribution showed distinct differences among the taxa. Cluster analysis based on the protist cell density identified six groups with geographically well-distinguished distributions. Diatom-dominant communities were distributed in the Cold Water Belt and Soya warm current along the coastal area of Hokkaido. Nanoflagellate-dominated communities were distributed in the offshore area. Some harmful species of diatoms (Pseudonitzschia pseudodelicatissima) and dinoflagellates (Alexandrium spp.) were dominant in the Cold Water Belt off Wakkanai. We suggest that the upwelling of cold water could increase the abundance of harmful species, with immanent negative impacts on marine ecosystems or fishery resources. In summary, the species composition and abundance of the summer protist community was strongly related to different water masses in the southern part of the Okhotsk Sea off Hokkaido.