Spatiotemporal Response and Phytopotential of <i>Typha domingensis</i> for Management of Aquatic Metal Pollution on the Central African Copperbelt

Anthropogenically accelerated metal pollution of lotic systems draining mining landscapes remains a global concern due to its non-degradability and ecotoxic nature. Nevertheless, the efficacy of macrophytes as indicators and remediators of metal(loid) pollutants in aquatic ecosystems in mining regions is recognised globally. However, in the mineral-rich Central African Copperbelt (CACB), there is limited research on the effectiveness of macrophytes for mining pollution management. Therefore, this study investigated the phytopotential of <i>Typha domingensis</i> Pers. (Typhaceae), as a nature-based approach for managing aquatic metal(loid) pollution on the CACB. A total of 252 samples each for sediment and <i>T. domingensis</i> were collected monthly between May 2022 and April 2023 from seven streams in the Kansanshi sub-catchment of the CACB and analysed to evaluate the spatiotemporal variability of the phytoindication and phytoremediation potential of <i>T. domingensis</i> for As, Cu, Pb and Zn in stream sediments. Metal(loid)s in <i>T. domingensis</i> at 71% of the streams were predominantly accumulated in the below-ground biomass with mean concentrations of 3-6 mg/kg As, 9-259 mg/kg Cu, 25-36 mg/kg Pb and 38-69 mg/kg Zn. The BAF was above 1 for As (0.8-2.6), Pb (10.7-24.3) and Zn (1.4-4.3), indicating <i>T. domingensis</i> as an accumulator of these elements but an excluder for Cu (BAF < 1). Additionally, TF was above 1 for As (1.5-2.0), Pb (1.4-1.5) and Zn (1.0-2.0), indicating the macrophyte's extraction efficacy. For Cu (TF < 1), the limited translocation characterised <i>T. domingensis</i> as a potential metal phytostabiliser. Similar seasonal trends for BAF and TF for As, Cu, Pb and Zn were also observed. Therefore, the spatiotemporal response of <i>T. domingensis</i> as a phytoindicator and phytoremediator of metal contaminants in sediments should be considered in the nature-based management of CACB's aquatic ecosystems.