The accelerated development of high-density brackishwater shrimp farming necessitates the importance of bioremediation. Seaweeds have the potential to reduce nutrients from aquaculture systems and provide extra income when species of economic importance are used. Identification of suitable seaweed species which is locally available in abundance with bioremediation capacity in brackishwater system is paramount, and the present study addresses this issue. An exploratory monthly survey was undertaken in three brackishwater systems in Chennai coast viz. Muttukadu lagoon, Vennangupattu Lake and Pulicat Lake from March 2018 to February 2019 which led to a focus on species of the family Gracilariaceae. Identification of the species through taxonomical and molecular observations confirmed that seaweed from Muttukadu lagoon and Vennangupattu Lake is Agarophyton tenuistipitatum and that from Pulicat Lake is Hydropuntia edulis. Evaluation of the bioremediation potential of these two species indicated that they were similar with respect to ammonia and phosphate reduction efficiency whereas the specific growth rate of A. tenuistipitatum was significantly higher than H. edulis. Furthermore, the nutrient reduction efficiency and specific growth rate was significantly higher at biomass density of 3.5 and 4.5 g L⁻¹ compared to 1.5 and 2.5 g L⁻¹. It could therefore be concluded that A. tenuistipitatum could be utilised for bioremediation as well as culture in brackishwater system at a biomass density ranging from 3.5 to 4.5 g L⁻¹.

高密度咸淡水对虾养殖业的加速发展需要生物修复的重要性。当使用具有经济重要性的物种时，海藻具有减少水产养殖系统养分并提供额外收入的潜力。识别在微咸水系统中具有丰富生物修复能力的本地可用海藻种类至关重要，本研究致力于解决这一问题。在钦奈海岸的三个咸淡水系统中进行了一项探索性的每月调查。从2018年3月至2019年2月，穆图卡杜泻湖，Vennangupattu湖和Pulicat湖都集中在禾本科科的物种上。通过分类学和分子观察鉴定该物种，证实了Muttukadu泻湖和Vennangupattu湖的海藻是Agarophyton tenuistipitatum和来自Pulicat湖的Agarophyton tenuistipitatum是可食的水tia。对这两种物种的生物修复潜力的评估表明，它们在氨和磷酸盐还原效率方面相似，而特异曲霉的比生长速率显着高于可食紫苏。此外，营养物的还原效率和特定生长率显著更高是在3.5和4.5克L-的生物量密度^-1相比1.5和2.5克L- ^-1。因此可以得出结论，A。tenuistipitatum可用于微咸水系统的生物修复和培养，生物量密度为3.5至4.5 g L ^-1。