The productive but highly exposed coastline of the southern Benguela eastern boundary upwelling system offers limited natural environment for aquaculture. Saldanha Bay located on the west coast of South Africa is one of the few embayments on the coastline that provides a productive and relatively sheltered environment suitable for the cultivation of shellfish. Consequently, bivalve culture in South Africa is centered in Saldanha Bay and is presently targeted for expansion. Pseudo-nitzschia blooms including toxin-producing species are shown to contribute significantly to the phytoplankton of Saldanha Bay specifically in spring and summer. Their dominance at this time of the year, when upwelling is strongest, fits the ecological profile of Pseudo-nitzschia occurring during periods of high turbulence and nutrients. Multiple Pseudo-nitzschia blooms were sampled under varying environmental conditions and the strength of the relationship between Pseudo-nitzschia cell abundance and particulate domoic acid (pDA) content, reflecting bloom toxicity, varied greatly. This variability is the result of the combined influence of species and strain composition of the Pseudo-nitzschia assemblage and the effect of environmental conditions on toxin production. Elevated levels of pDA were associated with higher concentrations of cells of the P. seriata complex differentiated by frustule width (>3 µm). P. australis was identified as a toxin-producing species and a prominent member of the P. seriata complex. Low DA levels in shellfish in Saldanha Bay are considered a function of low cellular domoic acid (cDA). Silicate limitation has emerged as an important factor inducing DA production in Pseudo-nitzschia species. The high ratio of silicate to nitrate in Saldanha Bay provides a plausible explanation for the low toxin content of Pseudo-nitzschia blooms in the bay and the consequent low risk posed by these blooms to the aquaculture sector.

南部本格拉东部边界上升流系统的高产但高度裸露的海岸线为水产养殖提供了有限的自然环境。位于南非西海岸的萨尔达尼亚湾（Saldanha Bay）是海岸线上为数不多的几个隔离带之一，可提供适于贝类养殖的生产性且相对庇护的环境。因此，南非的双壳类养殖以萨尔达尼亚湾为中心，目前正以扩张为目标。包括产毒物种在内的假性紫罗兰绽放被证明对Saldanha湾的浮游植物有重要贡献，特别是在春季和夏季。当上升势最强时，它们在一年中这个时候的优势符合伪尼茨基亚的生态特征发生在湍流和营养丰富的时期。在不同的环境条件下采样了多个假奈茨海藻大花，并且反映了大花毒性的假奈瑟茶细胞丰度与颗粒状多聚酸（pDA）含量之间的关系强度存在很大差异。这种变异性是假想球虫菌种和菌株组成的综合影响以及环境条件对毒素产生的影响的结果。pDA水平升高与通过平头肌宽度（> 3 µm）分化的疟原虫假单胞菌复合物细胞浓度更高有关。澳洲假单胞菌被鉴定为产生毒素的物种，是P. seriata复合体的重要成员。Saldanha湾贝类中的低DA水平被认为是低细胞性海藻酸（cDA）的功能。硅酸盐的限制已成为诱导假性尼兹菌属物种中DA产生的重要因素。Saldanha湾中硅酸盐与硝酸盐的比例很高，这可能解释了该海湾假拟南芥开花的毒素含量低，以及这些开花对水产养殖部门造成的低风险。