He thanked his family and supervisors for their support.

During the course of his postgraduate research, van Zyl monitored the efficacy of a lowland instream barrier on the lower uThukela River to understand the importance of river connectivity.

Pietermaritzburg-born and bred, van Zyl jumped at the chance to pursue an MSc in his hometown under the supervision of Pietermaritzburg academics Professor Colleen Downs, Dr Celine Hanzen and Dr Matthew Burnett, who he regards as accomplished researchers with great enthusiasm for making a positive change in the natural environment.

His research involved using Passive Integrated Transponder (PIT) telemetry to track fish movements through a fishway on the lower uThukela River.

‘The fishway, which is basically an artificial river, is intended to allow fish to move freely past the barrier created by the weir,’ explained van Zyl. ‘Species such as freshwater eels, gobies and some mullet species rely on connectivity between freshwater and saltwater environments to complete their life cycles, which can be facilitated by fishways and other fish passage structures when artificial barriers like dams or weirs are built.’

Van Zyl said that fish passage science in South Africa is still emerging, with designs mainly based on those from countries in the Northern Hemisphere that have little understanding of how local fish species will react.

His research required setting up a PIT monitoring antenna at the upstream end of the fishway, tagging multiple species of fish downstream of it with PIT tags (microchips similar to those implanted in pet cats and dogs), and then monitoring whether the tagged fish were able to navigate the fishway successfully.

‘A successful navigation occurred when a tagged fish moved through the PIT antenna,’ said van Zyl. ‘My research showed which species of fish managed to navigate the fishway, the timing of their migrations, and the effectiveness of the fishway.

‘Furthermore, we were able to determine fish species’ presence and their associated habitat uses at sites across the study area, and how that information correlated to previous studies in the region.’

Van Zyl added that the results of the study provide important information for water resource managers.

‘Having always had a fascination for aquatic organisms, particularly fish, this MSc opportunity meant that I could work under the Aquatic Ecosystem Research group in Professor Colleen Downs’ lab, where I was exposed to many of the freshwater ecosystems in the province. Much of the research that the group focuses on is important to help improve the state of freshwater ecosystems in KwaZulu-Natal, a topic which I am passionate about.’

Van Zyl, whose undergraduate degree was in Engineering, is currently working as a civil engineer with the aim of being professionally registered. ‘Ideally, once registered, I would like to open my own engineering consultancy which specialises in the design and construction of various fish passage solutions across Africa that are effective in their design. This would enable me to combine my qualifications into a niche, but much needed, profession,’ he said.

Not surprisingly for a fishway expert, van Zyl spends his free time fishing. ‘I feel most at home with a rod in my hand, stuck in the bush, without any cell reception, connecting to our natural environment.’

Words: Sally Frost

Photograph: Sethu Dlamini