这项研究提供了第一个证据,表明加拿大北极水域的产毒藻类群落不仅活跃地产生了多种植物毒素,但也正在进入海洋食物网。我们检测到可测量量的健忘症贝类毒素(AST)和麻痹性贝类毒素(PST),以及痕量的其他亲脂性毒素基团,包括果胶毒素,耶烟毒素,和环状亚胺,在2014年和2018年从加拿大博福特海收集的双壳类动物中。北极双壳类动物对AST的积累和保留似乎存在物种特异性差异,Nuculanidae中记录的浓度明显高于Propeamassiidae,可能反映生理和异速差异。我们进一步证实了加拿大西部北极地区普遍存在潜在有毒的分类学上通用的浮游植物群落,其中包括伪硝虫群,P.obtusa,尖锐湿疣,最低原中心,Alexandriumtamarense,和金针菇属。尽管采样时这些物种的实际毒性水平和分布的测量值超出了本研究的范围,我们表明,已知AST生产商的高丰度和竞争成功,伪硝基苯属。,在加拿大北极水域是可能的。2014年,伪硝菌属的强势优势。在几个浅层沿海站观察到,代表近40%的总浮游植物细胞丰度与>106细胞/L在最大叶绿素a的深度。我们进一步描述海洋学条件有利于高丰度的毒素产生藻类,表明温度可能是一个关键因素。即使双壳类组织中测得的AST和PST浓度仍远低于加拿大卫生部监测渔业将关闭的水平,即,5%和4%,分别,它们的存在表明,植物毒素的积累发生在加拿大博福特海的食物网中。然而,植物毒素的产生控制和营养转移机制仍然未知。加拿大北极海洋生态系统正在迅速变化,温度预计将继续升高。鉴于这些变化同时影响多个,并且经常同时发生,初级生产者的种类,适应能力可能在加拿大北极浮游植物群落结构中起重要作用。
This study presents the first evidence that a diverse suite of phycotoxins is not only being actively produced by the toxigenic algal communities in the Canadian Arctic waters, but is also entering the marine food web. We detected measurable amounts of Amnesic Shellfish Toxins (ASTs) and Paralytic Shellfish Toxins (PSTs), as well as trace amounts of other lipophilic toxin groups including pectenotoxins, yessotoxins, and cyclic imines, in bivalves collected from the Canadian Beaufort Sea in 2014 and 2018. There appear to be species-specific differences in accumulation and retention of AST by Arctic bivalves, with significantly higher concentrations recorded in Nuculanidae than Propeamussiidae, likely reflecting physiological and allometric differences. We further confirm the omnipresence of potentially toxic taxonomically-versatile phytoplankton communities in the western Canadian Arctic comprising Pseudo-nitzschia delicatissima group, P. obtusa, Dinophysis acuminata, Prorocentrum minimum, Alexandrium tamarense, and Gymnodinium spp. Although measurements of actual toxicity levels and profiles of these species at the time of sampling fall outside of the scope of this study, we show that high abundance and competitive success of known AST-producers, Pseudo-nitzschia spp., are possible in Canadian Arctic waters. In 2014, a strong dominance of Pseudo-nitzschia spp. was observed at a few shallow coastal stations, representing nearly 40% of the total phytoplankton cell abundances with > 106 cells/L at the depth of maximum chlorophyll a. We further describe oceanographic conditions conducive to high abundances of toxin-producing algae, indicating that temperature is likely a key factor. Even though measured AST and
PST concentrations in bivalve tissue remained well below the Health Canada\'s levels at which monitored fisheries would close, i.e., 5% and 4%, respectively, their presence demonstrate that phycotoxin accumulation is occurring in food webs of the Canadian Beaufort Sea. Yet, the phycotoxin production controls and trophic transfer mechanisms remain unknown. Canadian Arctic marine ecosystems are rapidly changing and temperatures are expected to continue to increase. Given that these changes simultaneously affect multiple, and often co-occurring, species of primary producers, adaptive capacity is likely to play an important role in the structure of phytoplankton communities in the Canadian Arctic.