College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, Devon EX4 4QD, United Kingdom.
College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Falmouth, Cornwall TR10 9FE, United Kingdom.
Harmful Algae. 2022 Jan;111:102166. doi: 10.1016/j.hal.2021.102166. Epub 2021 Dec 20.
Harmful algal blooms (HABs) can have severe ecological, societal and economic impacts upon marine ecosystems, human health and the seafood industry. We evaluated changes in marine plankton communities with prevailing physico-chemical conditions throughout an exceptionally warm summer (2018), to elucidate key factors governing HABs and their impacts on shellfish mariculture in the western English Channel. Despite warm, stable weather conditions and widespread seasonal stratification throughout the summer, divergent plankton community compositions were observed at two rope-grown mussel (Mytilus edulis) farms (St Austell Bay and Lyme Bay) and a long-term ecological research LTER site (Plymouth L4). There were significant differences between sites in the abundances of HAB species, including Dinophysis spp. and Karenia mikimotoi, whose cell counts bloomed in excess of UK Food Standards Agency (FSA) advisory 'trigger' levels at Plymouth L4 and St Austell Bay, but not at the Lyme Bay site. The K. mikimotoi bloom occurred over two weeks in August and comprised up to 88% of the standing phytoplankton biomass in St Austell Bay. Dinophysis spp. also bloomed here from May to September, constituting up to 28% of phytoplankton biomass. This protracted bloom resulted in concentrations of Dinophysis toxins 1 & 2 and pectenotoxins and okadaic acid in shellfish, which closed shellfish harvesting operations on farms located in St Austell Bay, and other shellfish sites in the west of the western English Channel (but not in the east of the region). Inter-site differences in the abundances of these and other HAB species were associated with variations in water circulation and co-occurring phytoplankton and zooplankton communities. Furthermore, plankton monitoring data obtained from the L4 site over the past 3 decades showed HAB species (including Dinophysis spp.) with abundances commonly occurring above advisory trigger levels during warmer periods, such as that coinciding with our study. Under projected climate warming these blooms are likely to continue to be governed by regionally distinct patterns of water circulation, which need to be taken into account in marine spatial planning, when assessing the suitability of new shellfish mariculture sites.
有害藻华 (HABs) 会对海洋生态系统、人类健康和海鲜产业造成严重的生态、社会和经济影响。我们评估了整个异常温暖的夏季（2018 年）中，海洋浮游生物群落随流行的理化条件的变化，以阐明控制 HABs 的关键因素及其对英吉利海峡西部贝类养殖的影响。尽管夏季天气温暖、稳定且普遍存在季节性分层，但在两个绳索养殖贻贝（Mytilus edulis）农场（圣奥斯特尔湾和莱姆湾）和一个长期生态研究 LTER 站点（普利茅斯 L4）观察到浮游生物群落组成存在明显差异。在 HAB 物种的丰度方面，站点之间存在显著差异，包括 Dinophysis spp. 和 Karenia mikimotoi，其细胞计数在普利茅斯 L4 和圣奥斯特尔湾超过了英国食品标准局 (FSA) 的咨询“触发”水平，但在莱姆湾站点没有超过。K. mikimotoi 藻华在 8 月持续了两周，在圣奥斯特尔湾的浮游植物生物量中占比高达 88%。Dinophysis spp. 也在 5 月至 9 月在这里爆发，构成浮游植物生物量的 28%。这场持久的藻华导致贝类中 Dinophysis 毒素 1 & 2 和扇贝毒素以及 okadaic 酸的浓度升高，导致位于圣奥斯特尔湾的养殖场和英吉利海峡西部的其他贝类养殖场（但不是在该地区的东部）关闭了贝类捕捞作业。这些和其他 HAB 物种丰度的站点间差异与水环流和共存浮游植物和浮游动物群落的变化有关。此外，过去 30 年来从 L4 站点获得的浮游生物监测数据显示，在温暖时期（如与我们的研究同期），HAB 物种（包括 Dinophysis spp.）的丰度通常高于咨询触发水平。在预测的气候变暖下，这些藻华可能继续受到区域独特的水环流模式的控制，在评估新的贝类养殖地点的适宜性时，需要在海洋空间规划中考虑到这一点。
