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Riverside talks: A tale of three rivers
By Dr Joh Henschel, Manager, SAEON Arid Lands Node
Three intrepid canoeists of TriWaters are paddling 2 500 km across South Africa - from the source of the Vaal River, where they started on 16 January to the Orange River Mouth, where they intend arriving on 4 April 2015.
The canoeists, a South African, Franz Fuls, Australian, Brett Merchant and Canadian, Troy Glover, passed through Barkly West on February 20 and Douglas on February 26, where they presented riverside talks to 100 learners and other members of the local community. The talks were hosted by SAEON and sponsored by the Northern Cape Department of Environment and Nature Conservation, GWK and Northern Cape Tourism.
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The water body from the source of the Vaal River to the ocean via the Orange River is the largest continuous water body within the borders of South Africa. The Northern Cape Province is relatively dry and few rivers run through it, with the bulk of the province’s water coming from the Vaal and Orange rivers after they have passed through more populated areas.
Indicators of river health
The TriWaters team is collecting diatom samples for SAEON at 61 sites along the entire 2 500 km stretch as indicators of river health. Diatoms are tiny algae that cling to stones and river sediments, collectively appearing like a green smudge, but individually too small to identify by naked eye. These micro-algae allow the detection of water quality changes integrated over time and at a fine scale. Diatoms are sensitive to salinity, which is an increasing problem in the lower reaches of the Orange River.
This project follows in the tracks of a similar SAEON project, the Gariep Mega-transect, conducted two years previously along the length of the Senqu and Orange rivers.
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The samples now being collected by TriWaters will be analysed to determine if the water quality in the Vaal and Orange rivers has deteriorated over time and will also assist in identifying possible pollution sources. Such long-term environmental monitoring by SAEON is part of its efforts to track global change and local environmental changes across South Africa.
Riverside talks
Members of SAEON’s Arid Lands Node joined the canoeists on both occasions to inform farmers, learners and other members of the local community about river health and effective ways of monitoring it. The riverside talks along the shores of the Vaal and Orange before and after the confluence* - three interconnected water bodies - featured interactive demonstrations aimed at schools, other guests and the media.
"Educating learners about the health of river systems not only assists in saving water and protecting the environment, but it can also be a lot of fun,” said Omphile Khutsoane, education officer of SAEON’s Arid Lands Node. “We thoroughly enjoy broadcasting this important message to our communities."
The demonstrations included the use of MiniSASS, a "light" version of the Stream Assessment Scoring System (SASS), which is used as a bio-monitoring tool to gauge river health by looking at macroinvertebrates (tiny aquatic animals). MiniSASS is being promoted by the Wildlife and Environmental Society of South Africa (WESSA) for use by schools and communities across the country to assess the state of our river systems. This is a good example of citizen science, where communities collect scientific data that can be valuable to scientists and managers alike, to ensure sustainable utilisation of natural resources.
Monitoring long-term changes in river health
Provided there is enough water left in these rivers for another group of enthusiastic, energetic canoeists to paddle its length, the successors of the TriWaters team can collect the next set of samples in a few years’ time. This would enable SAEON to monitor changes in river health over time.
The enthusiastic engagement of the TriWaters team gives hope that it will be possible for our rivers to have a healthy future, brimming with life, with people reaping the many crucial benefits of water, thanks to increased scientific knowledge, public awareness and sound natural resource management.
* TriWaters: Three rivers meet at the confluence near Douglas: the Gariep coming in from the west, meets the Vaal coming in from the east, to continue as the Orange, which flows further westward through the arid wilderness of the southern Kalahari region and Namaqualand in the Northern Cape Province to meet with Namibia. From here it flows westward for 550 km, forming the international border between the province and Namibia's Karas Region.
