Change the world

03/02/2025

An article entitled "Groundwater Sources: Microbiolite seeps harnessed to monitor aquifer health" on Nelson Mandela University research on the coast linked to Nelson Mandela Bay’s water resources, has been published in the Water Research Commission's Water Wheel newsletter as the cover story. 

 

Drs Carla Dodd and Gavin Rishworth

The article is based on the doctoral research of Mandela University postdoctorate fellow Dr Carla Dodd, who obtained her PhD at the University.

This is a good example of Mandela Science meeting the needs of the community during the drought crisis using innovative ways to measure water resources, said Dr Dodd.

There is more to some of the rock pools along the Nelson Mandela Bay coast than meets the eye.

At a few locations, fresh groundwater from coastal springs flows onto the coast and, with the help of microorganisms, carbonate rocks are formed.

These rock pools are modern examples of ancient ecosystems and scientists have studied these Eastern Cape systems for more than a decade, she said.

Besides being interesting from a biological point of view (for example, some organisms that live in these pools don’t occur anywhere else), researchers now think that these ecosystems can be used to track changes in local groundwater resources, such as those caused by drought conditions or pollution.

This was investigated by a diverse scientific team, led by senior lecturer in Botany Dr Gavin Rishworth, in a recent Water Research Commission project.

The study showed that although there is consistent flow from coastal springs, the relationship between rainfall and the response of the groundwater system is not straightforward and there is a delay between rainfall events and increases in the flowrates of coastal springs.

The chemical signature of the coastal springs also indicates that recent rainfall is not the sole source replenishing the groundwater systems. Coastal springs also reflect the level of human occupancy, with sites closer to residential areas exhibiting higher levels of nutrients in the groundwater than sites further away.

This short-term study is now being expanded into a long-term monitoring programme to help us better understand the connectivity between rainfall, groundwater and coastal ecosystems and its interaction with humans.

Read the full article 

Contact information
Ms Elma de Koker
Internal Communication Practitioner
Tel: 041-504 2160
elma.dekoker@mandela.ac.za