ix
‘Water’ is life and must be saved and conserved. Having its origin in water,
life has evolved itself into an enchanting world of rich and bewilderingly
diverse fl ora and fauna. The dependence of the living world, notably man, on
the biological wealth of rivers, lakes, seas and oceans cannot be overemphasised and perhaps does not need any explanation. As such, there is a need to
deepen our understanding of the aquatic environment with regard to its
physical, chemical and biological characteristics and interactions. The aquatic
ecosystems perform many important environmental functions, e.g. recycling
of nutrients, recharging of groundwater, augmentation and maintenance of
stream fl ow and recreation of people, to name a few. Wetlands are among the
most productive and biologically diverse aquatic ecosystems. Wetlands have
been rendering many goods and services. One of the important benefi ts
provided by wetlands in improving water quality is by fi ltering sediments and
nutrients from surface water. Wetlands act as natural purifi cation mechanisms, enhancing the water quality in the vicinity. Wetland vegetation plays a
major role in removing 90 % of dissolved nutrients, and, to some extent,
heavy metals. Apart from these, the socio-economic values provided by wetlands through water supply, fi sheries, fuelwood, medicinal plants, livestock
grazing, agriculture, energy resource, wildlife resource, transport, recreation
and tourism, etc., are signifi cant. The functional properties of wetland
ecosystem demonstrate clearly its role in maintaining the ecological balance.
But the wetlands are very fragile ecosystems. Unplanned and improperly
planned developmental works coupled with rapid increase of population have
led to the decline of water bodies, both lentic and lotic. Increased demand for
drainage of wetlands has been accommodated by channelisation, resulting in
further loss of stream habitat. This has been leading to aquatic biota becoming either extinct or imperilled in increasing number and to the impairment of
many benefi cial uses of water, including drinking, swimming and fi shing.
Various anthropogenic activities have altered the physical, chemical and
biological processes within aquatic ecosystems. Failure to restore these
ecosystems will result in sharply increased environmental costs later, in the
extinction of species or ecosystem types and in permanent ecological damage.
Further, restoration with an ecosystem view point helps in correcting point
and non-point sources of pollution. This along with regulations and planning
for wildlife habitat and fi shes helps in arresting the declining water quality
and the rate of wetland loss. These rate of restoration goals require profound
Pref ace
‘Water’ is life and must be saved and conserved. Having its origin in water,
life has evolved itself into an enchanting world of rich and bewilderingly
diverse fl ora and fauna. The dependence of the living world, notably man, on
the biological wealth of rivers, lakes, seas and oceans cannot be overemphasised and perhaps does not need any explanation. As such, there is a need to
deepen our understanding of the aquatic environment with regard to its
physical, chemical and biological characteristics and interactions. The aquatic
ecosystems perform many important environmental functions, e.g. recycling
of nutrients, recharging of groundwater, augmentation and maintenance of
stream fl ow and recreation of people, to name a few. Wetlands are among the
most productive and biologically diverse aquatic ecosystems. Wetlands have
been rendering many goods and services. One of the important benefi ts
provided by wetlands in improving water quality is by fi ltering sediments and
nutrients from surface water. Wetlands act as natural purifi cation mechanisms, enhancing the water quality in the vicinity. Wetland vegetation plays a
major role in removing 90 % of dissolved nutrients, and, to some extent,
heavy metals. Apart from these, the socio-economic values provided by wetlands through water supply, fi sheries, fuelwood, medicinal plants, livestock
grazing, agriculture, energy resource, wildlife resource, transport, recreation
and tourism, etc., are signifi cant. The functional properties of wetland
ecosystem demonstrate clearly its role in maintaining the ecological balance.
But the wetlands are very fragile ecosystems. Unplanned and improperly
planned developmental works coupled with rapid increase of population have
led to the decline of water bodies, both lentic and lotic. Increased demand for
drainage of wetlands has been accommodated by channelisation, resulting in
further loss of stream habitat. This has been leading to aquatic biota becoming either extinct or imperilled in increasing number and to the impairment of
many benefi cial uses of water, including drinking, swimming and fi shing.
Various anthropogenic activities have altered the physical, chemical and
biological processes within aquatic ecosystems. Failure to restore these
ecosystems will result in sharply increased environmental costs later, in the
extinction of species or ecosystem types and in permanent ecological damage.
Further, restoration with an ecosystem view point helps in correcting point
and non-point sources of pollution. This along with regulations and planning
for wildlife habitat and fi shes helps in arresting the declining water quality
and the rate of wetland loss. These rate of restoration goals require profound
Pref ace