Abstract Seawater desalination via reverse osmosis (SWRO) is highlighted as one of the most feasible solutions for obtaining freshwater. However, brine produced by SWRO is generally discharged to the subtidal area potentially causing detrimental effects on benthic organisms. In this study, we evaluated for the first time, ecophysiological and cellular responses of brown macroalgae as diagnosis tools to assess environmental impacts of desalination, through transplantation experiments with the cosmopolitan brown alga Ectocarpus. Transplants located at 10 and 30 m from the discharge point of a desalination plant located in Antofagasta, Chile, showed impaired photosynthetic parameters (ETR, Fv/Fm, αETR and ETRmax) and oxidative stress responses like accumulation of H2O2 and enhanced lipid peroxidation. Also, increased salinity produced high accumulation of ascorbate but a decrease in glutathione content. Also, genes encoding for enzymes related to salinity tolerance, SOS2, and oxidative stress, SOD, APX, PRX and GR, were highly up-regulated in transplanted Ectocarpus, especially at 10 m from the brine discharge. Altogether, our results demonstrate that Ectocarpus is a sensitive species to brine impacts, and that the transplantation method combined with its physiological and molecular responses are reliable tools to incorporate in environmental monitoring plans to address for desalination brine impacts on coastal ecosystems.

中文翻译：

---

世界性棕色巨藻 Ectocarpus 的生态生理学和细胞应激反应作为评估海水淡化影响的生物监测工具

摘要 反渗透海水淡化（SWRO）被强调为获得淡水的最可行的解决方案之一。然而，SWRO 产生的盐水通常排放到潮下区，可能对底栖生物造成不利影响。在这项研究中，我们通过世界性褐藻 Ectocarpus 的移植实验，首次评估了褐藻的生态生理和细胞反应作为评估海水淡化对环境影响的诊断工具。位于智利安托法加斯塔海水淡化厂排放点 10 和 30 m 处的移植显示光合参数（ETR、Fv/Fm、αETR 和 ETRmax）和氧化应激反应（如 H2O2 积累和脂质过氧化增强）受损。还，盐度增加导致抗坏血酸的大量积累，但谷胱甘肽含量降低。此外，与耐盐性、SOS2 和氧化应激、SOD、APX、PRX 和 GR 相关的酶的编码基因在移植的 Ectocarpus 中高度上调，尤其是在距盐水排放 10 m 处。总而言之，我们的结果表明 Ectocarpus 是对盐水影响的敏感物种，并且移植方法与其生理和分子反应相结合是纳入环境监测计划以解决海水淡化对沿海生态系统影响的可靠工具。特别是在距盐水排放口 10 m 处。总而言之，我们的结果表明 Ectocarpus 是对盐水影响的敏感物种，并且移植方法与其生理和分子反应相结合是纳入环境监测计划以解决海水淡化对沿海生态系统影响的可靠工具。特别是在距盐水排放口 10 m 处。总而言之，我们的结果表明 Ectocarpus 是对盐水影响的敏感物种，并且移植方法与其生理和分子反应相结合是纳入环境监测计划以解决海水淡化对沿海生态系统影响的可靠工具。