The Groot River that runs through Meiringspoort is part of the greater Gouritz system which is the largest river system within the Cape Fold Ecoregion. The Groot River is home to four of the eight indigenous freshwater fish species that occur in the Gouritz system. The Groot River within Meiringspoort, is located partially within the Swartberg Nature Reserve, a Cape Floristic Kingdom World Heritage Site and a nationally important fish sanctuary in the National Freshwater Ecosystem Priority Areas (NFEPA) Atlas. The indigenous fish fauna of the Groot River consists of four species, namely the small-scale redfin P. asper, the slender redfin P. tenuis, the chubbyhead barb Enteromius anoplus and the Cape kurper Sandelia capensis.

A freshwater fish survey was conducted in the poort following a report of the presence of alien and invasive sharptooth catfish in the river. CapeNature faunal ecologists sampled seven sites in three days and detected healthy populations comprising several size classes for all three indigenous minnow species. The trip also yielded the first State of Biodiversity Report record for the indigenous moggel Labeo umbratus in the Groot River. On a less positive note, the presence of invasive sharptooth catfish was confirmed at half of the sites surveyed. Based on the presence of a mainly subadult population, it is evident that the catfish are breeding in the Groot River. The results of this study will serve to inform not only long-term monitoring but also provide a basis for future conservation interventions to ensure the survival of the indigenous fish fauna of this very special river.