South African National Parks (SANParks) scientists are keeping a close eye on the Olifants River in the Kruger National Park after satellite observations showed the rapid buildup of algal bloom. This could be highly destructive to fauna and flora in the river.
Algal blooms form in water which is rich in nutrients, and generally occur when algae multiplies very quickly. The algae need nitrogen, phosphorous, iron, and warmer waters to thrive.
The river forms part of the Great Limpopo Transfrontier Park and the water quality, as well as the effect it has on the health of the aquatic ecosystem, is being carefully monitored.
Rapid build-up of a potential harmful algal bloom
According to SANParks, recent satellite observations suggest the rapid build-up of a potential harmful algal bloom in the lower Olifants River, as it flows through a deep gorge with a large Nile crocodile population, before it enters the large Massingir Dam in the Republic of Mozambique.
“The scientists have embarked on a detailed monitoring programme to assess the impacts from this algal bloom on the crocodile population and the aquatic ecosystem more broadly,” said SANParks in a statement.
They say conditions arose from a combination of several factors, these include very high lake levels in Massingir Dam following the good summer rains, increased water clarity allowing mono-cellular algae to access sunlight and build up large biomass; high nutrient inputs (pollution) from upstream catchment areas; and the warm early winter temperatures experienced that increase surface water temperature.
“SANParks is also keeping park and catchment management partners informed in South Africa and Mozambique and through this collaboration intends to mitigate negative impacts of this event on the health of ecosystem of the Olifants River and those that depend on its resources downstream.”
Danie Pienaar, the Head of Conservation and Area Integrity Management in Kruger National Park, said: “We have learned valuable scientific lessons about the mechanisms giving raise to Pansteatitis outbreaks and the impact on the park’s crocodile population following the outbreak of this disease in 2008-2009. This time we are at least forewarned and will do proactive monitoring and research to track the situation together with our Mozambican colleagues”.