The community structure of microphytoplankton was assessed along the southeastern Arabian Sea during the early phase of the summer monsoon. The study records an intense coastal upwelling along the southernmost region (off Thiruvananthapuram), which decreased further north. High chlorophyll-a (10.8 mg m-3) and nutrient concentration was recorded in the coastal waters of Thiruvananthapuram. Even though off Mangalore (12° N) and off Goa (15° N) where upwelling was confined to narrow coastal zone, also showed high chlorophyll-a concentration, 3.98 mg m-3 and 6.31 mg m-3, respectively. The upwelled waters were dominated by centric diatoms (Thalassiosira sp.) and the non-upwelled waters (12° N and 15° N) were dominated by dinoflagellates. Microphytoplankton cell density was the highest along off Thiruvananthapuram (4.8×104 cells L-1), with maximum cell density along the coastal waters (1.4×104 cells L-1). Phytoplankton community of upwelled and non-upwelled waters showed significant variations with 60 % similarity between phytoplankton communities of upwelled waters.

中文翻译：

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初夏季风期间阿拉伯海东南部上涌和非上涌水域浮游植物群落结构的变化

在夏季风的早期阶段，沿阿拉伯海东南部评估了微型浮游植物群落结构。该研究记录了沿最南端地区（蒂鲁文南特布勒姆附近）的强烈沿海上升流，并进一步向北下降。特里凡得琅 (Thiruvananthapuram) 沿海水域记录到高叶绿素 a (10.8 mg m-3) 和营养浓度。即使在 Mangalore (12° N) 和 Goa (15° N) 附近上升流仅限于狭窄的沿海地区，也显示出高叶绿素 a 浓度，分别为 3.98 mg m-3 和 6.31 mg m-3。上涌水域以中心硅藻（Thalassiosira sp.）为主，非上涌水域（12° N 和 15° N）以甲藻为主。微浮游植物细胞密度在 Thiruvananthapuram 附近最高（4.8×104 个细胞 L-1），沿海水域的细胞密度最大（1.4×104 个细胞 L-1）。上涌和非上涌水域的浮游植物群落表现出显着差异，上涌水域的浮游植物群落之间的相似度为 60%。