Abstract The main meteorological and oceanographic drivers shaping phytoplankton community structure and dynamics are investigated in two wide-open bays influenced by coastal upwelling. Local processes influencing the proliferation of harmful algal bloom species were also investigated. The work was developed during one year in Lisbon Bay (central-west coast) and in Lagos Bay (south coast), both located on the upwelling shadow of prominent headlands. In both bays, the results indicated a bi-modal annual pattern in phytoplankton biomass, and phytoplankton concentration maxima, between spring and late-summer, were associated with high diatom abundances. In Lagos Bay, higher dinoflagellate abundances were observed from spring to autumn, while in Lisbon Bay these were recorded from late-summer to autumn. The coccolithophores were a frequent group all year round in Lisbon Bay, which contrasts with Lagos Bay where they were the least frequent group. The phytoplankton community structure showed significant spatial and seasonal differences. The community succession pattern indicated the existence of four biological seasons in Lisbon Bay and at the offshore site in Lagos Bay. By contrast, the nearshore site in Lagos Bay was characterized by having no significant differences between summer and autumn. Differences in HAB species/groups were also observed between the bays. In general, HABs occurred at higher concentrations and were more persistent in Lagos Bay. In both bays, winter assemblages were influenced by water column mixing processes, although precipitation was also relevant in Lagos. Upwelling was a key driver of the spring phytoplankton community in Lagos Bay, while in Lisbon Bay other factors seemed to drive the spring phytoplankton assemblages. Both summer and autumn communities were related to thermal stratification. In autumn, the occurrence of reversal circulation patterns also played an important role in shaping the phytoplankton communities, especially in Lagos Bay. Overall, this study revealed differences on phytoplankton community patterns in two wide-open bays, shaped by the local environmental variables.

中文翻译：

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伊比利亚上升流系统中两个开阔海湾的浮游植物群落

摘要 在受沿海上升流影响的两个开阔海湾中，研究了影响浮游植物群落结构和动态的主要气象和海洋驱动因素。还研究了影响有害藻华物种增殖的局部过程。这项工作是在一年内在里斯本湾（中西部海岸）和拉各斯湾（南部海岸）开发的，两者都位于突出的海岬上升流的阴影上。在这两个海湾中，结果表明浮游植物生物量呈双峰年度模式，春季和夏末之间的浮游植物浓度最大值与高硅藻丰度有关。在拉各斯湾，从春季到秋季观察到较高的甲藻丰度，而在里斯本湾，则从夏末到秋季记录到这些。球石藻常年在里斯本湾频繁出现，而在拉各斯湾，它们是最不常见的群体。浮游植物群落结构呈现出显着的空间和季节差异。群落演替模式表明里斯本湾和拉各斯湾近海地点存在四个生物季节。相比之下，拉各斯湾近岸站点的特点是夏季和秋季没有显着差异。在海湾之间也观察到了 HAB 物种/组的差异。总的来说，HAB 浓度较高，在拉各斯湾的持久性更强。在这两个海湾，冬季组合都受到水柱混合过程的影响，尽管拉各斯的降水也与此相关。上升流是拉各斯湾春季浮游植物群落的主要驱动力，而在里斯本湾，其他因素似乎推动了春季浮游植物群落。夏季和秋季群落都与热分层有关。秋季，逆循环模式的出现也对浮游植物群落的形成起到了重要作用，尤其是在拉各斯湾。总体而言，这项研究揭示了两个开阔海湾中浮游植物群落模式的差异，这是由当地环境变量塑造的。尤其是在拉各斯湾。总体而言，这项研究揭示了两个开阔海湾中浮游植物群落模式的差异，这是由当地环境变量塑造的。尤其是在拉各斯湾。总体而言，这项研究揭示了两个开阔海湾中浮游植物群落模式的差异，这是由当地环境变量塑造的。