Behind the Paper

Unravelling the long-term river health status of Kruger National Park Rivers using macroinvertebrate-based monitoring

Freshwater ecosystems face severe threats from pollution, habitat loss, and climate change. This study analyzes a decade of biomonitoring data (2010–2019) from Kruger National Park’s four rivers using SASS5, habitat, and physicochemical metrics to assess resilience against upstream human pressures.
THENDO MUTSHEKWA Sep 14, 2025

  • Study Area: Four rivers (Crocodile, Sabie, Olifants, Luvuvhu) flowing west–east across KNP into Mozambique.

  • Methods: Annual sampling (2010–2019) using SASS5 protocol, habitat surveys, and water quality (pH, EC, flow). Macroinvertebrates identified to family level. Data analyzed via ANOVA and mixed-effects models; Present Ecological Status (PES) classification applied.

 

Key Findings:

  • Rivers differed in health: Olifants and Crocodile consistently degraded (classes D–E), while Sabie and Luvuvhu showed better conditions (classes A–C).
  • Macroinvertebrate indices (SASS scores, ASPT) showed strong spatial variation and temporal sensitivity to droughts, floods, and pollution events.
  • Environmental variables, especially electrical conductivity (EC), significantly influenced SASS metrics.
  • Evidence of recovery potential was observed, with some rivers improving downstream within the park, suggesting a refugium effect.

Discussion:

  • Sabie and Luvuvhu rivers displayed resilience and periodic ecological recovery, highlighting the potential role of protected areas in mitigating upstream impacts.
  • Crocodile and Olifants rivers remain heavily modified due to persistent anthropogenic pressures upstream.
  • Long-term monitoring demonstrated that macroinvertebrate communities respond quickly to disturbances and recovery events.

Conclusion:

  • KNP rivers exhibit contrasting ecological conditions, shaped by both natural variability and human pressures.
  • Effective management requires upstream interventions, buffer zones, and potentially freshwater protected areas (FPAs).
  • Sustained biomonitoring is critical for adaptive conservation planning and safeguarding aquatic biodiversity.


    https://doi.org/10.1007/s10661-025-14343-5