IPMA, I.P. - Instituto Português do Mar e da Atmosfera, Rua Alfredo Magalhães Ramalho, 6, 1495-006 Lisbon, Portugal; MARE - Centro de Ciências do Mar e do Ambiente, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisbon, Portugal.
IPMA, I.P. - Instituto Português do Mar e da Atmosfera, Rua Alfredo Magalhães Ramalho, 6, 1495-006 Lisbon, Portugal.
Harmful Algae. 2019 Jun;86:20-36. doi: 10.1016/j.hal.2019.03.003. Epub 2019 May 6.
The benthic genus Ostreopsis contains toxic-bloom forming species and is an important cause of concern in warm-temperate and tropical waters. On the coast of Portugal, NE Atlantic, the occurrence of Ostreopsis cf. siamensis and Ostreopsis cf. ovata has been reported since 2008 and 2011, respectively. This work aims to understand the favorable conditions for high concentrations of Ostreopsis cells in the plankton at two sites, Lagos and Lisbon Bays, located in the South and West coast of Portugal, respectively. This study is based on weekly Ostreopsis abundance data in the plankton, from 2011 to 2017, daily satellite and in situ sea surface temperature (SST), and meteorological and sea state parameters, namely wind stress and significant wave height. The molecular identification of local Ostreopsis spp. is also presented. The maximum cell densities occur between late-summer and autumn. The distribution range of Ostreopsis cf. ovata is restricted to the South coast, while Ostreopsis cf. siamensis has a wider distribution range, being also present on the West coast. In the study period, there was only one occurrence of Ostreopsis spp., in Lagos Bay, with concentrations within the alert phase of monitoring. In Lagos Bay, high Ostreopsis spp. concentrations were related with positive SST anomalies. These high concentrations were often recorded after a period of almost 2-weeks to more than 4-weeks of low sea state (<0.6 m), followed by short time events of onshore wind and moderate waves (0.6-1 m). The former conditions are interpreted as favoring bloom development on the substrate and the latter as causing the re-suspension of Ostreopsis cells in the water column. In Lisbon Bay, O. cf. siamensis occurred in the plankton in few occasions and no clear relation could be established with the studied environmental variables. It is here hypothesized that the recent records of O. cf. siamensis in Lisbon Bay may correspond to an early colonization stage of an invasion process. Knowledge gained on Ostreopsis dynamics along the Portuguese coast can be used for both the improvement of benthic harmful algal blooms (BHABs) monitoring in the region and as a basis to design forecasting models.
底栖物种牡蛎含有毒性的生物，并在暖温带和热带水域引起了人们的广泛关注。在葡萄牙东北海岸，自 2008 年和 2011 年以来，分别报道了牡蛎 cf. siamensis 和牡蛎 cf. ovata 的出现。本研究旨在了解葡萄牙南海岸拉各斯湾和西海岸里斯本湾两个地点浮游生物中牡蛎高浓度的有利条件。本研究基于 2011 年至 2017 年每周的浮游生物牡蛎丰度数据、每日卫星和现场海面温度 (SST) 以及气象和海况参数，即风应力和显著波高。还介绍了当地牡蛎 spp. 的分子鉴定。最大细胞密度出现在夏末至秋季。牡蛎 cf. ovata 的分布范围仅限于南海岸，而牡蛎 cf. siamensis 的分布范围更广，也存在于西海岸。在研究期间，只有一次在拉各斯湾发现了牡蛎 spp.，其浓度处于监测的警戒阶段。在拉各斯湾，高牡蛎 spp. 浓度与正 SST 异常有关。这些高浓度通常在低海况 (<0.6 m) 持续近 2 周至 4 周后记录，随后是短时间的向岸风和中浪 (<0.6-1 m)。前者的条件被解释为有利于基质上的浮游生物生长，后者则导致牡蛎细胞在水柱中重新悬浮。在里斯本湾，牡蛎 cf. siamensis 偶尔出现在浮游生物中，与研究的环境变量之间没有建立明确的关系。在这里假设，最近在里斯本湾记录的牡蛎 cf. siamensis 可能对应于入侵过程的早期定植阶段。在葡萄牙沿海获得的牡蛎动态知识可用于改善该地区的底栖有害藻华 (BHAB) 监测，并作为设计预测模型的基础。
