Environmental Engineering Reference
In-Depth Information
communities in moving to replacement food sources, such as sorghum,
cassava, wheat, pumpkins, sweet potatoes, and madumbes, a wild taro.
If they fail to do so, the existing structure of local livelihoods and reli-
ance that many families have on subsistence farming may be destroyed.
Similarly, poor traditional fi shing communities will likely see their way
of life and sources of nutrition and income threatened by climate impacts
on water conditions, fi sh stocks, and biodiversity. In Durban, the extent
to which the aquatic environment will be affected by climate-induced
changes such as sea-level rise is of particular concern because the city
has 98km of coastline, eighteen major river catchments, and sixteen
estuaries. It is likely that changes in the sea level will result in increased
coastal erosion, saltwater intrusion into estuaries and groundwater,
raised groundwater tables, and increased vulnerability to storm events
(Department of Environmental Affairs and Tourism 2006). Fluctuations
in rainfall will also change the amount of freshwater runoff.
Such changes are signifi cant in the marine environment, because any
reduction in freshwater fl ow has direct impacts on estuaries and the
marine biota that utilize these systems, such as estuarine-dependent fi sh
species (Department of Environmental Affairs and Tourism 2006).
Reduced freshwater fl ow also decreases the extent to which wastewater
discharges are diluted before they reach estuaries, thereby increasing the
concentration of pollutants in the coastal zone and limiting the capacity
of estuarine systems to support natural biota (Department of Environ-
mental Affairs and Tourism 2006).
In turn, variations in water conditions are highly problematic for
maintaining existing fi sh stocks in Durban, with acute health and social
consequences for the fi shing communities engaged in and dependent on
subsistence fi shing. This situation is exacerbated by the fact that fi sh
stocks have already been badly affected by offshore line fi shing, rock and
surf angling, and estuarine fi shing (Environmental Management Depart-
ment, n.d.). Many of these traditional communities have high levels of
poverty and rely on local fi sheries both for their livelihood and survival
(Branch et al. 2002). Any danger to key ecosystems, such as estuarine
and inshore marine environments, puts these subsistence-level communi-
ties at long-term risk of disappearing.
In sum, climate change pressures are likely to translate into local
extinctions and range shifts for the surviving species, with species required
to move into the more transformed landscapes of the city where habitat
availability is restricted. The extent to which species in Durban can adapt
and ecosystems will shift, disintegrate, or reorganize due to climate
