Normandie Univ, UNICAEN, CNRS, BOREA, 14000 Caen, France; UMR BOREA, CNRS-7208, IRD-207, MNHN, UPMC, UCBN, 14032 Caen, France.
Ifremer, LER/N, 14520 Port en Bessin, France.
Harmful Algae. 2017 Sep;68:192-205. doi: 10.1016/j.hal.2017.07.005. Epub 2017 Sep 1.
The population dynamics of different Pseudo-nitzschia species, along with particulate domoic acid (pDA) concentrations, were studied from May 2012 to December 2013 in the Bay of Seine (English Channel, Normandy). While Pseudo-nitzschia spp. blooms occurred during the two years of study, Pseudo-nitzschia species diversity and particulate domoic acid concentrations varied greatly. In 2012, three different species were identified during the spring bloom (P. australis, P. pungens and P. fraudulenta) with high pDA concentrations (∼1400ngl) resulting in shellfish harvesting closures. In contrast, the 2013 spring was characterised by a P. delicatissima bloom without any toxic event. Above all, the results show that high pDA concentrations coincided with the presence of P. australis and with potential silicate limitation (Si:N<1), while nitrate concentrations were still replete. The contrasting environmental conditions between 2012 and 2013 highlight different environmental controls that might favour the development of either P. delicatissima or P. australis. This study points to the key role of Pseudo-nitzschia diversity and cellular toxicity in the control of particulate domoic acid variations and highlights the fact that diversity and toxicity are influenced by nutrients, especially nutrient ratios.
从 2012 年 5 月到 2013 年 12 月，对诺曼底海峡塞纳湾的不同伪菱形藻物种的种群动态以及颗粒态软骨藻酸（pDA）浓度进行了研究。虽然在两年的研究中发生了伪菱形藻属的大量繁殖，但伪菱形藻物种多样性和颗粒态软骨藻酸浓度有很大差异。2012 年，春季爆发中鉴定出三种不同的物种（夜光藻、柔弱伪菱形藻和假菱形藻），pDA 浓度较高（约 1400ng/L），导致贝类捕捞关闭。相比之下，2013 年春季以无毒性事件的纤细伪菱形藻爆发为特征。最重要的是，结果表明，高浓度的 pDA 与夜光藻的存在以及潜在的硅限制（Si:N<1）有关，而硝酸盐浓度仍然充足。2012 年和 2013 年的环境条件截然不同，强调了可能有利于纤细伪菱形藻或夜光藻发展的不同环境控制因素。本研究指出了伪菱形藻多样性和细胞毒性在控制颗粒态软骨藻酸变化方面的关键作用，并强调了多样性和毒性受营养物质的影响，特别是营养物质的比例。
