School of Marine Science, University of Maine, Orono, ME, 04469, USA.
School of Marine Science, University of Maine, Orono, ME, 04469, USA; State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, 36 Baochubei Road, Hangzhou, 310012, China.
Harmful Algae. 2019 Nov;89:101670. doi: 10.1016/j.hal.2019.101670. Epub 2019 Oct 18.
Climate driven increases in ocean temperature and pCO have the potential to alter the growth and prevalence of future Harmful Algal Blooms (HABs), but systematic studies on how climate drivers influence toxic algal species relative to non-toxic phytoplankton are lacking. In particular, little is known about how future climate scenarios will affect the growth of the toxic dinoflagellate Alexandrium catenella, which is responsible for the paralytic shellfish poisoning (PSP) events that threaten the health and economy of coastal communities in the Gulf of Maine and elsewhere. The growth responses of A. catenella and two other naturally co-occurring dinoflagellates in the Gulf of Maine-Scrippsiella sp., and Amphidinium carterae-were studied in mono and mixed species cultures. Experimental treatments tested the effects of elevated temperature (20 °C), lower pH (7.8), and the combination of elevated temperature and lower pH on growth rates relative to those in near-current conditions (15 °C; pH 8.1). Growth rates of A. catenella decreased under elevated temperature and lower pH conditions, a response that was largely attributable to the effect of temperature. In contrast, growth rates of Scrippsiella sp. and A. carterae increased under elevated temperature and lower pH conditions, with temperature also being the primary driver of the response. These trends did not change substantially when these species were grown in mixed cultures (A. catenella + Scrippsiella sp., and A. catenella + A. carterae), indicating that allelopathic or competitive interactions did not affect the experimental outcome under the conditions tested. These findings suggest that A. catenella blooms may become less prevalent in the southern regions of the Gulf of Maine, but potentially more prevalent in the northeastern regions of the Gulf of Maine with continued climate change.
气候驱动的海洋温度和 pCO2 升高有可能改变未来有害藻华（HAB）的生长和流行，但关于气候驱动因素如何影响有毒藻类物种相对于非毒性浮游植物的系统研究还很缺乏。特别是，对于未来气候情景将如何影响有毒甲藻亚历山大藻（Alexandrium catenella）的生长，人们知之甚少，而这种藻正是导致麻痹性贝类中毒（PSP）事件的原因，这些事件威胁着缅因湾和其他地方沿海社区的健康和经济。本研究在单一和混合物种培养物中研究了缅因湾的亚历山大藻（A. catenella）以及另外两种自然共存的甲藻——斯克里普斯藻（Scrippsiella sp.）和 Amphidinium carterae——的生长反应。实验处理测试了高温（20°C）、低 pH 值（7.8）以及高温和低 pH 值组合对生长速率相对于当前条件（15°C；pH 8.1）的影响。在高温和低 pH 值条件下，亚历山大藻的生长速率下降，这种反应主要归因于温度的影响。相比之下，在高温和低 pH 值条件下，斯克里普斯藻和 A. carterae 的生长速率增加，温度也是反应的主要驱动因素。当这些物种在混合培养物中生长时（A. catenella + Scrippsiella sp.，以及 A. catenella + A. carterae），这些趋势并没有发生实质性变化，这表明在测试条件下，没有种间的化感或竞争相互作用影响实验结果。这些发现表明，随着气候变化的持续，亚历山大藻的爆发可能在缅因湾的南部地区变得不那么普遍，但在缅因湾的东北部地区可能更为普遍。
