A cross-sectional environmental assessment of the ecological integrity of key driver components (Water Quality, Sediment, and Habitat) in the uMngeni, Thukela, Umvoti, Umdloti, and Umfolozi rivers, KwaZulu-Natal.

Sibonelo Thanda Mbanjwa

doi:10.51168/sjhrafrica.v6i6.1837

Authors

Sibonelo Thanda Mbanjwa Mangosuthu University of Technology P.O. Box 12363 Jacobs 4026 Durban, South Africa

DOI:

https://doi.org/10.51168/sjhrafrica.v6i6.1837

Keywords:

Ecological integrity, Water quality, Sediment contamination, Habitat assessment, KwaZulu-Natal rivers, South African Scoring System (SASS5), Index of Habitat Integrity (IHI), Land use impact, River health, Environmental monitoring

Abstract

Background
Freshwater ecosystems in KwaZulu-Natal are increasingly threatened by urbanization, agriculture, and industrial activities. These pressures undermine ecological integrity by affecting water quality, sediment characteristics, and habitat structure. The uMngeni, Thukela, Umvoti, Umdloti, and Umfolozi Rivers hold critical ecological and socio-economic value, yet comprehensive assessments of their environmental condition remain limited.

Methods
A cross-sectional environmental assessment was conducted across five major rivers between March 2024 and October 2024, with sampling sites positioned upstream, midstream, and downstream to capture spatial variability. Water quality parameters (pH, dissolved oxygen, turbidity, nitrates, phosphates, and heavy metals) were measured using standard methods. Sediment samples were analysed for particle size distribution, organic content, and contaminants. Habitat integrity was assessed using the South African Scoring System (SASS5) and the Index of Habitat Integrity (IHI). Data were analysed using descriptive statistics and multivariate techniques.

Results
The assessment revealed varying levels of ecological degradation. Downstream sections of the uMngeni and Umvoti Rivers showed poor water quality, with elevated nutrient levels and low dissolved oxygen. Sediment contamination by organic matter and heavy metals was prominent near urban and industrial zones. Habitat integrity scores were lowest in areas affected by agricultural runoff and informal settlements. The Umdloti and Umfolozi Rivers showed relatively better ecological conditions, though signs of degradation were still evident.

Conclusion
The study highlights significant ecological stress in KwaZulu-Natal’s rivers, particularly due to declining water quality and habitat degradation. Spatial trends reveal a strong association between land use activities and ecosystem health, emphasizing the need for urgent intervention.

Recommendation
To protect freshwater ecosystems, authorities should enhance river monitoring programs, enforce pollution control measures, and implement habitat rehabilitation. A collaborative, catchment-based management approach involving communities, industries, and conservation stakeholders is essential for sustainable riverine ecosystem protection.

Author Biography

Sibonelo Thanda Mbanjwa, Mangosuthu University of Technology P.O. Box 12363 Jacobs 4026 Durban, South Africa

Dr. Sibonelo Thanda Mbanjwa is a dedicated lecturer in the Department of Nature Conservation at Mangosuthu University of Technology (MUT), South Africa. He holds a Ph.D. in Environmental Science and specializes in biodiversity conservation, sustainable development, and environmental education. Dr. Mbanjwa is deeply committed to community engagement, student mentorship, and the integration of indigenous knowledge systems into conservation practices. His work bridges academia and practical application, empowering students and communities through innovative teaching, research, and outreach initiatives.

References

Artiola, J.F., Pepper, I.L. & Brusseau, M.L. (2004). Environmental Monitoring and Characterization. Elsevier Academic Press.

https://doi.org/10.1016/B978-012064477-3/50003-5

Brand, R.C., Smith, J.A. & Jones, L.M. (1967). Water Quality Assessment in Southern Africa. Pretoria: Water Research Commission.

Carminati, A. (2008). Soil-Plant Water Relations: A Hydrological Perspective. Springer.

Cheesman, J. (2005). Water Management in Arid Regions. Oxford University Press.

Charkhabi, A.H., Sakizadeh, M. & Jalali, M. (2008). Assessment of spatial variation of water quality parameters in the most polluted branch of the Anzali Wetland, Northern Iran. Polish Journal of Environmental Studies, 17(4), pp. 639-647.

Cloete, T.E., Nel, L.H. & Theron, J. (2008). Microbial Ecology of South African Rivers. Water Research Commission Report No. 1234/1/08.

Coke, J. (1995). The Impact of Industrial Effluents on Freshwater Systems. Cape Town: Environmental Press.

Cruz, J. (2000). Integrated Water Resource Management: A Global Perspective. UNESCO Publishing.

De Moor, F.C., Day, J.A. & De Moor, I.J. (1999). Guides to the Freshwater Invertebrates of Southern Africa. Volume 7. Pretoria: Water Research Commission.

Dikole, N. (2014). Community Participation in Water Resource Management in South Africa. Johannesburg: University of Johannesburg Press.

Dube, T., Moyo, P. & Ncube, M. (2017). Climate Change and Water Resources in Southern Africa. Harare: African Institute for Environmental Studies.

DWAF (Department of Water Affairs and Forestry). (1996). South African Water Quality Guidelines. Volume 1: Domestic Use. Pretoria: DWAF.

Gallagher, D. & Kleynhans, C.J. (1999). Ecological Risk Assessment of South African Rivers. Pretoria: Water Research Commission.

Kleynhans, C.J. (1996). A Procedure for the Determination of the Ecological Reserve for the National Water Act. Pretoria: Department of Water Affairs and Forestry.

Malherbe, W. (2008). Freshwater Fish Conservation in South Africa. Stellenbosch: University of Stellenbosch Press.

Malherbe, W. (2010). Threatened Freshwater Fish Species in South Africa: A Conservation Assessment. Water SA, 36(1), pp. 1-8.

Munn, R.E., Huel, D. & Smith, K. (2002). Environmental Monitoring and Assessment: Principles and Practice. Dordrecht: Kluwer Academic Publishers.

Naidoo, S. & Glass, N. (2019). Water Quality Challenges in South African Rivers. Johannesburg: Environmental Monitoring Group.

Oberholster, P.J. & Ashton, P.J. (2008). State of the nation report: An overview of the current status of water quality and eutrophication in South African rivers and reservoirs. CSIR Report No. CSIR/NRE/WR/IR/2008/0075/C.

O'Brien, G.C. (2005). Fish Assemblages in South African Rivers: A Review of Current Knowledge. Water SA, 31(3), pp. 273-278.

Oliff, W.D. (1960). Hydrobiological studies on the Tugela River System, Part 1. The main Tugela system. Hydrobiologia, 14, pp. 281-308. https://doi.org/10.1007/BF00162106

Ollis, D.J. (2006). Wetland Delineation and Classification: A South African Perspective. Pretoria: Department of Water Affairs and Forestry.

Serife, A., Yilmaz, M. & Demir, N. (2001). Water Pollution and Its Effects on Aquatic Life. Ankara: Turkish Environmental Foundation.

Uys, M.C., O'Keeffe, J.H. & Bruton, M.N. (1996). National Biomonitoring Programme for Riverine Ecosystems: Ecological Indicators, a Review and Recommendations. Pretoria: Department of Water Affairs and Forestry.

USEPA (United States Environmental Protection Agency). (2001). Water Quality Criteria and Standards Plan: Priorities for the Future. Washington, D.C.: USEPA.

van Vuren, J.H.J. (1997). The Use of Bioassays in the Assessment of the Effects of Pollution on Aquatic Ecosystems. Water SA, 23(2), pp. 127-133.

Weston, D.P. (2011). Ecotoxicology of Aquatic Systems. Boca Raton: CRC Press.

Wiersma, G.B. (2004). Environmental Monitoring. Boca Raton: CRC Press. https://doi.org/10.1201/9780203495476