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Less than 1% of the worlds water is currently available for human use
and as the global population rises, the demand and competition for these
freshwater resources is rapidly increasing. Rivers and lakes are exploited
to support our freshwater needs for agriculture and industry, as well
as providing a vital source of drinking water.
However, freshwater ecosystems also support a great amount of wildlife,
which are becoming increasingly threatened and their habitats degraded,
as a result of human activity on and around these ecosystems. There is
little emphasis on the conservation of rivers and lakes, yet species dependent
on freshwater ecosystems are the worlds most endangered group of plants
and animals. The threats jeopardizing the future of freshwater ecosystems
include:
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Deforestation of drainage basins causes sedimentation, degrades rivers
and can have unexpected consequences for freshwater biodiversity.
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Chemical
waste and industrial pollutants pumped into local waterways and river systems
degrades habitats and kills aquatic life. |
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Household
waste not disposed of properly eventually finds its way to waterways which
pollutes rivers and also suffocates and entangles aquatic animals.
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Dams
alter the flow of waterways disrupting the natural levels of water reaching
the ecosystems and obstruct fish breeding migrations. |
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Overexploitation
of rivers and lakes disrupts ecosystem balance and reduces fish populations
to levels at which they cannot recover |
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Fertilisers
and pesticide run off from agricultural land polluting river systems. This
promotes algal overgrowth, decreasing the oxygen levels of the water, killing
fish and aquatic life. |
