Department of Environment, Forestry and Fisheries, Cape Town, South Africa; Department of Biological Sciences, University of Cape Town, Rondebosch, South Africa.
National Marine Information and Research Centre, Swakopmund, Namibia.
Harmful Algae. 2021 Feb;102:101898. doi: 10.1016/j.hal.2020.101898. Epub 2020 Sep 3.
The Benguela Upwelling System (BUS) is subject to a high incidence of HABs. Of the major shellfish poisoning syndromes associated with HABs, Paralytic and Diarrhetic Shellfish Poisoning (PSP and DSP) pose the greatest concern, but as documented herein there are several other HAB organisms that are also present. Blooms of Alexandrium catenella have been recognised as the typical cause of PSP since 1948. In addition to the risk posed to human health A. catenella has also been the cause of large shellfish and bird mortalities. An additional risk of PSP is provided by Alexandrium minutum first detected in Cape Town harbour in 2003. DSP was identified on the South African coast for the first time in 1991. Although several Dinophysis spp. known to cause DSP have been recognized as a component of the plankton of the region, it is accepted that DSP is usually attributed to D. acuminata or D. fortii. In the southern Benguela both Pseudo-nitzschia australis and Pseudo-nitzschia multiseries have been identified and shown to produce domoic acid. Multiple Pseudo-nitzschia spp. have been identified in the northern Benguela with the potentially toxigenic Pseudo-nitzschia pungens and P. australis dominant inshore. The yessotoxin (YTX) producing dinoflagellates Gonyaulax spinifera, Lingulodinium polyedrum and Protoceratium reticulatum are all known to form blooms and YTXs have been the cause of massive mortalities of farmed abalone. Prominent fish-killing blooms include Karlodinium veneficum in the northern Benguela and Karenia cristata in the southern Benguela. Shellfish farms in an embayment of the southern Benguela have suffered reduced growth rates due to the ecosystem disruptive blooms of Aureococcus anophagefferens. High biomass dinoflagellate blooms often attributed to Tripos and Prorocentrum spp. characterise the entire region and major mortalities of marine life are regularly attributed to their decay and the subsequent development of anoxic conditions.
本格拉上升流系统（BUS）经常发生赤潮。在与赤潮相关的主要贝类中毒综合征中，麻痹性贝类毒素和腹泻性贝类毒素（PSP 和 DSP）最为令人担忧，但正如本文所述，还有其他几种赤潮生物也存在。自 1948 年以来，亚历山大藻属的链状亚历山大藻已被确认为 PSP 的典型原因。除了对人类健康构成的威胁外，链状亚历山大藻还导致了大量贝类和鸟类死亡。2003 年在开普敦港首次发现的微小亚历山大藻属也构成了 PSP 的另一个风险。1991 年，南非海岸首次发现腹泻性贝类毒素。尽管已知有几种能导致 DSP 的双鞭甲藻属被认为是该地区浮游生物的一个组成部分，但 DSP 通常归因于 D. acuminata 或 D. fortii。在南部本格拉，已鉴定出并显示出产生软骨藻酸的拟菱形藻属和多列拟菱形藻属。在北部本格拉，已鉴定出多种拟菱形藻属，其中有毒的拟菱形藻属和近岸优势种拟菱形藻属。产生 yessotoxin（YTX）的腰鞭毛藻类旋沟藻、多边膝沟藻和夜光藻都已知会形成赤潮，并且 YTX 已经导致养殖鲍鱼大量死亡。在北部本格拉，主要的鱼类致死性赤潮包括卡尔多尼氏角毛藻，在南部本格拉，主要的鱼类致死性赤潮包括卡氏膝沟藻。南部本格拉一个小海湾的贝类养殖场由于 Aureococcus anophagefferens 破坏生态系统的赤潮而导致生长速度下降。高生物量的腰鞭毛藻类赤潮通常归因于三角藻属和原甲藻属，它们的存在特征遍及整个地区，海洋生物的大量死亡通常归因于它们的腐烂以及随后缺氧条件的发展。
