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Invasive alien species continue to spread and proliferate in waterways worldwide, but environmental drivers of invasion dynamics lack assessment. Knowledge gaps are pervasive in the Global South, where the frequent heavy human‐modification of rivers provides high opportunity for invasion. In southern Africa, the spatio‐temporal ecology of a widespread and high‐impact invasive alien snail, Tarebia granifera, and its management status is understudied. Here, an ecological assessment was conducted at seven sites around Nandoni Reservoir on the Luvuvhu River in South Africa. The distribution and densities of T. granifera were mapped and the potential drivers of population structure were explored. T. granifera was widespread at sites impacted to varying extents due to anthropogenic activity, with densities exceeding 500 individuals per square meter at the most impacted areas. T. granifera predominantly preferred shallow and sandy environments, being significantly associated with sediment (i.e., chlorophyll‐a, Mn, SOC, SOM) and water (i.e., pH, conductivity, TDS) variables. T. granifera seemed to exhibit two recruitment peaks in November and March, identified via size‐based stock assessment. Sediment parameters (i.e., sediment organic matter, sediment organic carbon, manganese) and water chemistry (i.e., pH, total dissolved solids, conductivity) were found to be important in structuring T. granifera populations, with overall snail densities highest during the summer season. We provide important autecological information and insights on the distribution and extent of the spread of T. granifera. This may help in the development of invasive alien snail management action plans within the region, as well as modelling efforts to predict invasion patterns elsewhere based on environmental characteristics.

Satellite remote sensing techniques have been proved to be capable of quantifying chlorophyll-a (Chl-a) levels by estimating algal concentrations in water bodies. harmful algal blooms (haBs) pose a significant threat to many water bodies in South africa. this study aimed at using a remote sensing solution to estimate chlorophyll concentrations in water bodies of vhembe district municipality using landsat 8 oli. this study seeks to provide quantitative water quality information for the vhembe region's water bodies from a time series of satellite remotely sensed data and in-situ laboratory data. the 30 meters spatial resolution multispectral landsat 8 oli for 2016, 2017 and 2018 were used to derive Chl-a estimate at three water bodies, namely, nandoni, albasini and vondo reserviors. the Chl-a concentrations obtained from landsat 8 (oli) satellite were compared with the laboratory analysis using the Kappa coefficient statistical analysis. this study show that landsat derived chl-a estimates have a high positive correlation of 80-90% accurate with field measurements. in all the reservoirs, it was detected that there is low content of haBs and thus the water bodies are in good condition since the chl-a concentrations were very low. in conclusion, it can be stated that landsat 8 oli sensor can be used to map and monitor inland water bodies dominated by algal blooms to a certain extent.

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