Biodiversity and species-environment relationships of freshwater zooplankton in tropical urban ponds

Urbanisation affects not only large ecosystems but also small ones, such as ponds, through changes in environmental parameters. It consequently impacts the biodiversity of all organisms, including zooplankton. However, disturbances due to urbanisation may have different levels of impact on ecosystems. We therefore aimed to determine how different degrees of disturbance and environmental parameters affect zooplankton species diversity and which zooplankton species could indicate the disturbance degree and water quality of tropical urban ponds. We recorded 63 species, namely, 46 species of rotifers and 17 species of cladocerans. The overall species diversity tended to decrease from the low to the high disturbance areas. The level of disturbance, temperature, salinity, phycocyanin and vegetation affected the zooplankton species composition. More common species were found in the low disturbance areas, and among the few species in the highly disturbed areas, the distribution was more specific. We therefore propose that rotifer and cladoceran species be used as bioindicators to indicate water quality and the degree of disturbance. Our study provides significant insights into the relationship between zooplankton and environmental factors in oriental tropical regions and presents a framework for identifying crucial species associated with levels of disturbance, particularly in the habitats of Oriental Asia.