Loskop Dam Nature Reserve is beautiful, a hidden gem in the core of the Cultural Heartland. We spend a morning with André Hoffman, River Scientist: Aquatic Systems Scientific Services Mpumalanga Tourism and Parks Agency to explore the wonders of this nature reserve.
Loskop Dam Nature Reserve covers an area of 23 612 ha and lies around the massive Loskop Dam on the Olifants River, 55km north of Middelburg.
The dam is approximately 30km long and supplies water to a vast irrigation scheme in the areas northeast of Loskop, Groblersdal and Marble Hall. The dam has become a favourite for anglers and boat-based game watching can be done and is offered by Forever Loskop.
“Loskop Dam Nature Reserve falls within a transitional zone between the Highveld and Lowveld and the diversity of habitat types present is the main reason for the reserves biodiversity, both terrestrial and aquatic,” André enthusiastically explained.
André said there are 22 indigenous fish species which naturally occur in the dam, one indigenous but extralimital species and four alien and invasive species.
You will find longfin eel, orangefin barb, papermouth, straightfin barb, threesport barb, longbeard barb, shortspine suckermouth, sharptooth catfish, redeye labeo, leaden labeo, rednose labeo, largescale yellowfish, smallscale yellowfish, bulldog, river sardine, silver robber, Mozambique tilapia, Southern mouthbrooder, silver catfish, brown squeaker, redbreast tilapia and banded tilapia.
Moggels are also present; although they are indigenous it is not their natural habitat. Then also swimming in the Loskop waters are the ‘aliens’ carp, Mosquito fish, smallmouth- and largemouth bass.
André’s favourite is Marcusenius macrolepidotus, locally known as the bulldog fish.
“This species is very unusual fish in the sense that they can generate and also receive electrical currents which they use to communicate with each other and can also be used to detect their prey and predators. They are very susceptible to pollution and the impact of alien and invasive predators.”
André is extremely concerned about the waste flowing into the dam. It is on the receiving end from a lot of pollution, but the more biodiverse an ecosystem is, the better is the chance for it to carry out natural processes in spite of the pollution and other stresses and in the end be sustainable, which Loskop is at present.
“Loskop Dam acts as a pollution sump, catching heavy metals and other pollutants in the sediment to provide a better quality of water for the users downstream. But for how long can it go on?” he left a question unanswered.
Pollution from sewage works is a 24/7 problem and from the mines, although more severe, only as pollution plumes. The sewage pollution result in an increase in nutrients causing excessive growth of algae, especially Microcystis species. The algae activity increases the pH of the water up to more than a pH of 12 which the algae favour. When the dam receives a pollution plume from mining, the pH is often less than a pH of 6, causing the Microcystis algae to stress and die, producing a toxin microcystin, which can cause the death of fish and even larger animals such as buffalo if they drink the contaminated water.
“We as humans are ignoring the impacts on the dam because all one sees is the beautiful clear water and the nice fish being caught. But most do not see or realise what is happening. The dam is losing its ability to take the punch and we may reach a point of no return. Pollution must be addressed and the impact of the alien and invasive fish in the dam must be realised before we lose a number of the smaller fish species not seen by the general public.”
André took a few moments and then said, “One can, especially on the dam, surrounded by mountains with at times its waterfalls, creeks and real bushveld and beautiful trees, experience the wonder of God’s creation.”
A lot of research is being done on the reserve and André and the team of conservationists are doing their best to manage the reserve to the best of their ability. The reserve manager can be contacted with regards to the different projects which are running on the reserve. The public are invited to share with them the incredible beauty of the reserve.
