Toxic species of the diatom genus Pseudo-nitzschia, observed worldwide from coastal waters to the open ocean, produce the neurotoxin domoic acid (DA). DA is an important environmental and economic hazard due to shellfish contamination with subsequent effects on higher trophic levels. Previous research has demonstrated that, among other environmental factors, salinity influences the abundance and toxicity of Pseudo-nitzschia. In this study, the environmental factors driving the growth of Pseudo-nitzschia and the production of dissolved DA (dDA) in North Inlet estuary were examined. The effect of salinity on the growth inhibition of phytoplankton induced by the initial presence as well as by an addition of dDA was also assessed. Initially, the diatom abundance was negatively correlated with the abundance of Pseudo-nitzschia and with the concentration of dDA. With the addition of a concentrated solution of dDA, the percent inhibition of cryptophytes and diatoms was significantly correlated with salinity and suggested a higher sensitivity to dDA at extreme salinities. These results emphasize the importance of salinity in assessing the properties of DA and potentially of other phycotoxins on phytoplankton.

从沿海水域到公海在世界范围内观察到的硅藻属假性尼兹菌属的有毒物种产生神经毒素多摩酸（DA）。由于贝类受到污染，DA对营养和环境造成重大危害，进而对较高营养水平产生影响。先前的研究表明，除其他环境因素外，盐度还会影响拟南芥的丰度和毒性。在这项研究中，环境因素推动了拟南芥的生长并检查了北入口河口的溶解DA（dDA）的产生。还评估了盐度对初始存在以及添加dDA诱导的浮游植物生长抑制的影响。最初，硅藻的丰度与假性尼兹菌的丰度和dDA的浓度呈负相关。通过添加dDA的浓溶液，隐藻类和硅藻的抑制百分率与盐度显着相关，并表明在极端盐度下对dDA的敏感性更高。这些结果强调了盐度在评估DA和浮游植物上其他植物毒素的特性方面的重要性。