Communities are concerned about various aspects such as water quality, especially since those such as Elim largely depend on groundwater for domestic and agricultural use, said Prof Dominic Mazvimavi, Director of the Institute.
The Nuwejaars Catchment is a two-and-a-half-hour drive from Cape Town, within the Cape Agulhas Municipality. This region lies at the interface between the southern African winter rainfall zone and the seasonal rainfall zone. It is the southernmost promontory of the Fynbos Biome and is a hotspot of biodiversity and endemism with about 100 plant species that occur nowhere else on earth. The catchment has some of the longest rainfall records in South Africa which, combined with the multimillion-Rand hydrological monitoring infrastructure installed by the Institute, makes this an invaluable living laboratory for research, teaching, management and community engagement.
At IWS’s recent community engagement session, the programme included an overview of the Nuwejaars Wetlands Special Management Area (NWSMA) activities and the current and past catchment research.
“The objective here was to present an overview of management and research activities in the Nuwejaars catchment area (Elim, Napier, and Bredasdorp) where the Institute is looking to increase the understanding of surface water, groundwater and ecosystem linkages.
“We want to understand how water users are affected and which factors affect these linkages.
It is a multi-disciplinary approach to research since water issues cut across various disciplines,” said Professor Michael Grenfell, chair of the event.
In the session held at the Black Oystercatcher Restaurant outside Elim, the IWS could share their research findings with the community and answer questions about hydrological processes, water use by alien vegetation, water quality, and plant and animal life.
In the Nuwejaars catchment, alien vegetation is encroaching on mountainous areas and forming dense corridors along riparian zones. This poses an environmental threat. A number of previous studies have demonstrated that alien invasions negatively impact the environment, including a reduction in annual flows, a decline in groundwater levels, and an increase in soil nitrate levels. Prior studies focused mainly on other Acacia species (A. meansii, A. saligna). The least studied Acacia longifolia is found on the mountainous parts and riparian zones of the catchment. Research led by a PhD candidate, Ms Yonela Mkunyana (pictured), under the supervision of Professor Dominic Mazvimavi (UWC), Dr Sebinasi Dzikiti (CSIR), and Professor Timothy Dube (UWC), is the first to quantify and compare the water use rates of A. longifolia across different elevations and locations in the catchment.
Mkunyana presented her findings on the spatial coverage of invasive alien plants and their water uses. Additionally, water use rates from indigenous fynbos vegetation were presented as part of this PhD study. Her study found that clearing activities in the catchment should not only prioritise the wetlands adjacent to rivers and streams known as riparian zones. Potential water savings can also be achieved by clearing the mountainous parts where invasive alien plant species have formed dense thickets.
Professor Jenny Day, an extraordinary Prof at IWS at UWC, is a freshwater ecologist. Her presentation revealed that only three native freshwater fish species occur in the Nuwejaars River catchment and Agulhas Plain areas found near the coastal towns of Arniston and Bredasdorp in the Overberg.
“Four species found in the rivers in the region are alien. The fish of particular concern to researchers and conservationists is the Sharptooth Catfish (Clarias Gariepinus) which they fear could pose a disastrous threat to indigenous fish species in the area.”
The work by Prof Day with PhD researcher James Machingura, studied the aquatic species found in the Nuwejaars River and linked species variation with water quality changes from the headwaters to lowlands. The water chemistry component that Prof Day - along with PhD researcher, Errol Malijani - studied looked at the hydrochemical traces that linked surface water and groundwater within the Nuwejaars catchment.
Professor Thokozani Kanyerere and Dr Sumaya Clarke gave an overview of groundwater flows and aquifer characteristics in the catchment. Prof Kanyerere highlighted the role of geology in groundwater quality, as well as the linkages between geological faults and the locations of springs in the area.
Participants at the engagement were organisations with a shared interest in research that informs water resources management. They included SANParks, the Department of Water Affairs, the Council for Scientific and Industrial Research (CSIR), the South African Environmental Observation Network (SAEON), Breede-Gouritz Catchment Management Agency (BGCMA), the Nuwejaars Wetlands Special Management Area (NWSMA) and community organisations.
Grenfell said their research projects here involved setting up weather stations, measuring surface water and groundwater levels, and monitoring water quality and the animal and plant life of the region.
Community engagement sessions revealed key issues that would be helpful in future research, such as leveraging local insights into management problems and alien vegetation clearing needs and finding ways to sustain monitoring activities with community assistance.
“The community’s insights and inputs would prove valuable going forward. Our community engagement aimed to identify remaining gaps in knowledge and further research or management interests, including all participants and stakeholders in the process.”
“We hoped to identify ways in which interested citizens and all participants can participate in research and management activities,” he said.
A member of the Bredasdorp community, Ian Fortuin, was present as the director of a non-profit organisation, Overberg Eco Rangers, working with the youth in environmental education and exposing them to the environment and nature. Their activities include alien-clearing, plant identification, beach clean-ups, and building hiking trails. They work closely with SANParks and Cape Nature, and the organisation is pleased to potentially be included in UWC research activities.
Nadier Roos, a former UWC student who graduated in 2014, is a teacher in Bredasdorp involved with the now-defunct SANParks Junior Ranger Programme. He and Fortuin started the Overberg Eco Rangers, an ecosystem regeneration programme removing alien vegetation, while building an outside classroom for the youth. “We are open to connections such as these. It is a good opportunity for the youth to become aware of the institution,and link with and engage in opportunities it offers,” said Roos.
Grenfell said the research activities here are just a few of several studies by IWS.
“The Institute has various active research projects across the Western Cape and projects as far afield as KZN, Mpumalanga and Limpopo, and Windhoek, Namibia, and receives funding from the Water Research Commission (WRC), the National Research Foundation (NRF), charitable trusts and several European government funding streams.”
See the gallery below for images from the event