Macroalgae are one of the main producers in marine environments. However, only a few toxicity test methods have been established that use reference strains of macroalgae to evaluate the effects of chemicals on the growth and reproduction of macroalgae to monitor water quality. We selected reference strains of Chlorophyta, Ulva aragoënsis; Phaeophyceae, Ectocarpus siliculosus; and wakame, Undaria pinnatifida, as test species to establish a microplate-based method to investigate the toxicity of potassium dichromate, 3,5-dichlorophenol, and two common herbicides (diuron and simazine). We determined the growth of the three macroalgae in their early life stages and during the sporangia formation stage in E. siliculosus under laboratory conditions. We observed that the growth and sporangia formation in these algae were impaired in a dose-dependent manner. Additionally, we investigated the sensitivity of these macroalgae by comparing the toxicity values of toxicants used in this study with those obtained from a database. Compared to other microalgae and plant species, macroalgae showed a relatively high sensitivity to organic compounds, including herbicides. Growth tests using U. aragoënsis and E. siliculosus produced reliable results at 0–32 and 25–32 practical salinity units (PSU), respectively. The tests established in this study could test the toxicity of chemical substances in macroalgae and are thus expected to contribute to a better understanding of the environmental risks of chemical substances on aquatic biota. The tests could be applied to all effluent toxicity tests used for the management of seawater and brackish water quality.

大型藻类是海洋环境中的主要生产者之一。然而，目前仅建立了少数毒性测试方法，使用大型藻类的参考菌株来评估化学品对大型藻类生长和繁殖的影响，以监测水质。我们选择了绿藻门石莼 ( Ulva aragoënsis)的参考菌株；褐藻纲，Ectocarpus siliculusus；和裙带菜，裙带菜，作为试验物种，建立了基于微孔板的方法来研究重铬酸钾、3,5-二氯苯酚和两种常见除草剂（敌草隆和西玛嗪）的毒性。我们在实验室条件下测定了三种大型藻类在早期生命阶段和E. siliculusus孢子囊形成阶段的生长情况。我们观察到这些藻类的生长和孢子囊形成以剂量依赖性方式受到损害。此外，我们通过将本研究中使用的毒物的毒性值与从数据库中获得的毒物的毒性值进行比较，研究了这些大型藻类的敏感性。与其他微藻和植物物种相比，大型藻类对有机化合物（包括除草剂）表现出相对较高的敏感性。使用U. aragoënsis和E. siliculosus进行的生长测试分别在 0-32 和 25-32 实际盐度单位 (PSU) 下产生了可靠的结果。本研究建立的测试可以测试化学物质对大型藻类的毒性，从而有望有助于更好地了解化学物质对水生生物群的环境风险。该测试可应用于用于海水和苦咸水水质管理的所有废水毒性测试。