NEWS
Wetlands do the job of
expensive technology,
if we let them
Current Address: Deputy Dean Faculty of Science, Nelson Mandela University
Reprinted From: http://bit.ly/2qVJRCW
Gaathier Mahed
T
he world’s freshwater supplies are
at risk. This is a threat to all life on
the planet. It is therefore no sur-
prise that water purification has turned
into a multibillion-dollar global busi-
ness.
The World Bank estimates that at least
$150 billion a year will be required to
give the entire global population ac-
cess to clean drinking water by 2030.
There is no silver bullet when it comes
to the technology available to tackle
severe water shortages. Several op-
tions therefore need to be explored.
One purification option can be found in
nature – wetlands. Research shows that
wetlands are able to act as filters of wa-
ter in numerous ways. This includes the
uptake of pollutants by plants, soils and
even microbes present in the wetlands.
They are also able to mitigate the ef-
fects of floods and store carbon diox-
ide, while aiding in providing liveli-
hoods and holding cultural importance.
We conducted an analysis of the Rietv-
lei freshwater wetland on the outskirts
of the coastal city of Cape Town, in
South Africa’s Western Cape Province,
to understand the soil, surface and
groundwater, because of the intricate
interplay between water bodies in the
area as well as the reliance of the en-
tire ecosystem on water flow between
them.
We found that the wetland had been
impacted due to water being drained
from it as well as from contamination.
This, in turn, is affecting the well-being
of people, animals and plants that de-
pend on the wetland. Our research
underscores the fact that wetlands are
important for the functioning of eco-
systems and need better care.
Grassroots
Vol 19
No 4
This will help protect the environment
and the earth’s already strained water
resources. geological formation contains a salt
deposit, which is being dissolved in the
groundwater.
What we found These findings shed light on the water
quality in the wetland and show what is
needed to better understand the func-
tioning of wetlands in order to improve
their management.
A number of factors have affected the
Rietvlei body in the past.
One is that it is near residential areas, a
wastewater treatment plant and a pe-
troleum refinery. This has implications
for water in the wetland, due to the dis-
charge from industry and households
as well as consumption upstream.
In addition, the natural water flow in
Rietvlei’s immediate vicinity has been
altered. This is due to the canalisation,
which is the lining of the riverbed and
banks with concrete to form a channel,
of the Diep River as well as the use of
water by farmers in the area.
The amount of water in the river has
been drastically reduced and its quality
has been affected, which has an impact
on plants and animals as well as human
health.
Then there is the issue of contamina-
tion: we found that flooding water
from the river and on the surface in the
rainy season filled the cracks in the soil
formed during the dry season.
The floodwaters flushed salts into the
groundwater through cracks. Water
quality and plant survival are threat-
ened by the salinity.
Other factors have also increased the
amount of salt in the groundwater. One
of them is over-pumping during a re-
cent drought. Cape Town drew large
volumes of groundwater daily and sea-
water may have moved into the wells
to replace it.
Another possibility is that the local
November 2019
Protecting a precious resource
A report, which examined the state and
trends of wetlands around the world,
the Global Wetland Outlook, recently
examined the status of wetlands in line
with the Ramsar Convention – the only
international treaty focused on wet-
lands.
It found that wetland quality and quan-
tity are declining and this has immedi-
ate and long-term effects on biodiver-
sity and human livelihoods.
These include declining food and wa-
ter security.
As a result, many countries are now
employing policy and legislation to
strengthen the application of the Ram-
sar Convention and the United Na-
tions’ Sustainable Development Goals.
Wetlands are sensitive systems that are
affected by human activity. They need
to be protected because they play a
critical role in the ecosystem.
Streets and rivers must be kept clean to
stop pollutants from migrating into riv-
ers and ultimately into wetlands. Indus-
try should be more responsible when
emitting discharge into rivers.
This means stricter rules regarding the
quality of water that is pumped from
industrial processes into the environ-
ment.
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