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new freshwater ecosystem ATLAS shows which
rivers and wetlands to keep in a natural condition
In brief
South Africa’s freshwater ecosystems are
under increasing pressure and cannot
all be kept in a good condition. In this
project, the CSIR and a number of partners
carefully mapped those which should be
protected. Experts believe that if the rivers
and wetlands that have been identified as
priority areas are kept in a good condition,
it will help support the sustainability of the
entire network of freshwater ecosystems in
South Africa.
The challenge
Water is South Africa’s lifeblood. It
influences the well-being of the country’s
people and water shortages or a decline
in water quality will hamper economic
development. Water is intrinsically linked
with the ecosystems through which it
passes, and deteriorating ecosystems will
adversely affect the quantity and quality
of water. In recent years, numerous studies
have found that more than half of the
ecosystems associated with rivers are
classified as threatened.
While there is widespread agreement
on the importance of sustainable water
resource development and freshwater
biodiversity conservation as a national
priority, the question remains: How many
and which rivers and wetlands do we have
to maintain in a natural condition to sustain
economic and social development and
still conserve our freshwater biodiversity
The National Freshwater Ecosystem Priority
Areas project (NFEPA) addressed this
question.
CSIR research
One of the most important considerations
in tackling this challenge was that of
cooperation: No single entity is responsible
for decisions on freshwater-related matters;
progress in managing and conserving
freshwater ecosystems is dependent on
cooperation.
Many different players were therefore
involved, including government departments
and their regional and provincial
counterparts as well as conservation groups
and universities. In addition to the project
team and reference group, the project also
relied on the participation of well over 150
stakeholders, representing approximately
1000 person years of collective experience
in either aquatic science or biodiversity
planning.
What makes an area a priority
The criteria for identifying freshwater priority
areas were based on earlier work in which
government departments had agreed on
a vision for managing and conserving
freshwater ecosystems. These criteria were
reviewed during regional expert review
workshops. The underlying principle is
that by conserving habitat, species are
conserved, so a representative part of all
river, wetland and estuary ecosystems has
to be conserved.
Other criteria included:
• Areas where populations of threatened
or near-threatened freshwater fish
occurred
• Areas that are considered high water
yield or high groundwater recharge
areas
• Free-flowing rivers, which are rivers
that have not been dammed and of
which there are very few left globally
• Connectedness, as ecosystems that
are connected are most likely to
support biodiversity.
Once the criteria had been established, the
process of collecting data sets began. The
team used the best existing and available
data sources. This typically included data
from the river health programme, the
reserve determination data of the then
Department of Water Affairs and Forestry,
as well as the ecostatus data for the present
ecological status of rivers. These data
Conservation scientist and GIS specialist,
Dr Jeanne Nel of the CSIR, pictured in
the Upper Berg river with Dean Impson of
Cape Nature, one of many contributors in
this project.
sets were converted to a spatial format,
and taken to freshwater experts in six
different regions of the country for review.
Refinements were made to these input data
and priorities were determined using a
conservation planning algorithm that seeks
to find the most spatially efficient solution to
achieving all the criteria.
These priority areas were then taken to
a national review workshop in which the
same experts from the different regions, and
managers, gathered to review the priority
outputs. Refinements, with appropriate
reasons, were made to the priority areas
to produce Freshwater Ecosystem Priority
Areas maps (‘FEPA maps’) for the 19
different Water Management Areas of
South Africa.
Key findings
• Only 35% of the length of SA’s
mainstem rivers is in a good condition,
compared to 57% of the tributaries.
• 57% of river ecosystems and 65% of
wetland ecosystems are threatened.
• Only 22% of South Africa’s river length
has been identified as freshwater
ecosystem priority areas and this puts
conservation and development aims
within reach.
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