School of Life Sciences

Son Fulfils Promise Made to Dying Father

Mr Bayanda Sonamzi was awarded his MSc degree in Ecological Sciences from UKZN – fulfilling the commitment he made to his dying father.

Said Sonamzi: ‘My late father, Mr Mthumeni “Ncanes” Sonamzi, was and still is my hero. To him I say:  RIP Sir… I’ve done what I promised you on your death bed.’

Describing UKZN as one of the best universities in South Africa, he said ecology – his area of specialisation – involved the study of organisms (living things) and their interactions with their surroundings. ‘It is very difficult to quantify these processes accurately, especially in aquatic environments such as rivers which are highly dynamic systems. If the right methods are applied, plants and animals can tell us a whole lot about their environment and how changes in such environments affect them.’

Supervised by Professor Colleen Downs, Sonamzi’s MSc project used remote measuring methods (FISHTRAC) to quantify the activity of the African tigerfish, largescale yellowfish and purple labeo as a response variable to a suite of water quality constituents (physical and chemical) as well as flow in the Olifants River in the Kruger National Park.

‘Telemetry is relatively new in southern Africa and it is exciting to see the traction it’s gained over the past several years. I feel honoured to be part of this cutting-edge and technology-based development,’ he said.

Sonamzi explained that when the activity of biological organisms was used as a response variable to external triggers, it was known as a behavioural response. ‘Behavioural response provides an instant result of the current situation as opposed to other measurables such as physiology,’ he said.

Sonamzi found that tigerfish were susceptible to predation by fish eagles in very low flow conditions owing to the restricted movement in isolated pools. Largescale yellowfish appeared happy in medium to medium-low flows while low pH levels made them reduce their activity. Purple labeo showed little movement in temperatures lower than 16.5 degrees Celsius, and were active during the day and rested at night. They were also very strong swimmers and able to navigate in fast flowing water.

Sonamzi found evidence of predation on largescale yellowfish and tigerfish but not on purple labeo, possibly owing to its high mobility.

‘This opportunity of measuring animal behaviour in real time and remotely in their natural environment will enable managers to identify behaviours of potential concern associated with water quality, flow and natural environmental pressures such as predation,’ said Sonamzi. ‘With this knowledge, managers can then direct intervention measures to where they are needed, at the time they are needed, thereby saving costs on unnecessary site visits.’

Sonamzi explained that identifying “cut-off” water flow conditions for fish could help in reserve determination studies, for example, deciding how much water could safely be taken out of the Olifants River without adversely harming the river and its users.

‘This will then ensure that humans continue to benefit from the socio-economic services derived from rivers.’

Sonamzi said that growing up as a little boy, he was very inquisitive and always questioned why things worked the way they did. At university, he excelled in biology-related modules, especially Zoology. ‘It just tickled my fancy and it was at this point that I realised: “Why not do what excites me? This will be my motivation to succeed.”’

Sonamzi hopes to venture into the corporate world and put the skills he has learned into practice. He thanked his wife for her positive impact and sacrificial support during his studies.

‘I thank God, the creator of the universe for his grace upon my life. He chose me among many and seated me with the kings. May his holy name be glorified!’

Words: Sally Frost

Photograph:  Supplied