17
2
Eutrophication: Global Scenario and
Local Threat to Dynamics of Aquatic
Ecosystems
Fareed A. Khan, Fauzia Naushin, Farha Rehman, Ather Masoodi,
Mudasir Irfan, Farah Hashmi and Abid A. Ansari
F. A. Khan () · F. -Naushin · F. Rehman · A. Masoodi · M. Irfan · F. Hashmi
Department of Botany, Aligarh Muslim University,
Aligarh 202002, India
e-mail: fareedkhan.amu2007@rediffmail.com
A. A. Ansari
Department of Biology, Faculty of Science, University of Tabuk,
Kingdom of Saudi Arabia
Abstract
All self-regulated aquatic ecosystems maintain their structural and functional dynamics in
equilibrium. Most natural oligotrophic surface water bodies maintain production: respiration
ratio closer to 1 irrespective of geographical variations. The prevailing environmental gradients govern seasonal, structural and functional dynamics of aquatic ecosystem. During the
past century, major socio-economic changes resulted into adverse alteration in both terrestrial
and aquatic ecosystems. The terrestrial and aquatic ecosystems are not independent of each
other. There is a delicate balance between the two. In the present work, changes in the delicate
balance between seasonal, spatial, littoral dynamics and resulting bio-geo-chemical changes
in the eutrophic water bodies have been highlighted. Seasonal environmental variables are
the forcing factors behind cycling of materials in the water bodies which in turn result into
structural and functional dynamics. Summer season triggers the release of orthophosphates
bound in the sediments and advection brings the free nutrients to upper water surface and
promotes phytoplankton abundance. The rain water input during monsoon may dilute or enrich the water bodies with nutrients subject to the quality of catchment areas. Upwelling and
downwelling and surface run offs are among major drivers of the dynamics of water bodies.
The hydrological characteristics of water bodies vary with the geographical location. Under
extreme polluted conditions, seasonal heterogeneity in nutrient composition of water bodies may not remain maintained except on downstream scale. Phosphorus (P) in runoff from
agriculture land accelerates eutrophication of lakes and streams. Seasonal variation of some
selected macrophytes in a surface water body close to AMU campus has been studied. About
7.56 ha of catchment area of a nearby park forms a source of fertilizer "run off". Qualitative and quantitative seasonal estimates of density and productivity of two indicator species
( Lemna minor, Spirodela polyrrhiza) and physicochemical properties indicated that the water
body is under a fast rate of eutrophication process owing to chemical fertilizer inputs, variables of summer (high wind, high temperature, fast wind speed), winter (low temperature,
reduced rain fall), and monsoon (excessive rainfall).
Keywords
Eutrophication · Fertilizers · Nitrogen · Phosphorus · Phytoremediation
A. A. Ansari, S. S. Gill (eds.), Eutrophication: Causes, Consequences and Control,
DOI 10.1007/978-94-007-7814-6_2, © Springer Science+Business Media Dordrecht 2014
2
Eutrophication: Global Scenario and
Local Threat to Dynamics of Aquatic
Ecosystems
Fareed A. Khan, Fauzia Naushin, Farha Rehman, Ather Masoodi,
Mudasir Irfan, Farah Hashmi and Abid A. Ansari
F. A. Khan () · F. -Naushin · F. Rehman · A. Masoodi · M. Irfan · F. Hashmi
Department of Botany, Aligarh Muslim University,
Aligarh 202002, India
e-mail: fareedkhan.amu2007@rediffmail.com
A. A. Ansari
Department of Biology, Faculty of Science, University of Tabuk,
Kingdom of Saudi Arabia
Abstract
All self-regulated aquatic ecosystems maintain their structural and functional dynamics in
equilibrium. Most natural oligotrophic surface water bodies maintain production: respiration
ratio closer to 1 irrespective of geographical variations. The prevailing environmental gradients govern seasonal, structural and functional dynamics of aquatic ecosystem. During the
past century, major socio-economic changes resulted into adverse alteration in both terrestrial
and aquatic ecosystems. The terrestrial and aquatic ecosystems are not independent of each
other. There is a delicate balance between the two. In the present work, changes in the delicate
balance between seasonal, spatial, littoral dynamics and resulting bio-geo-chemical changes
in the eutrophic water bodies have been highlighted. Seasonal environmental variables are
the forcing factors behind cycling of materials in the water bodies which in turn result into
structural and functional dynamics. Summer season triggers the release of orthophosphates
bound in the sediments and advection brings the free nutrients to upper water surface and
promotes phytoplankton abundance. The rain water input during monsoon may dilute or enrich the water bodies with nutrients subject to the quality of catchment areas. Upwelling and
downwelling and surface run offs are among major drivers of the dynamics of water bodies.
The hydrological characteristics of water bodies vary with the geographical location. Under
extreme polluted conditions, seasonal heterogeneity in nutrient composition of water bodies may not remain maintained except on downstream scale. Phosphorus (P) in runoff from
agriculture land accelerates eutrophication of lakes and streams. Seasonal variation of some
selected macrophytes in a surface water body close to AMU campus has been studied. About
7.56 ha of catchment area of a nearby park forms a source of fertilizer "run off". Qualitative and quantitative seasonal estimates of density and productivity of two indicator species
( Lemna minor, Spirodela polyrrhiza) and physicochemical properties indicated that the water
body is under a fast rate of eutrophication process owing to chemical fertilizer inputs, variables of summer (high wind, high temperature, fast wind speed), winter (low temperature,
reduced rain fall), and monsoon (excessive rainfall).
Keywords
Eutrophication · Fertilizers · Nitrogen · Phosphorus · Phytoremediation
A. A. Ansari, S. S. Gill (eds.), Eutrophication: Causes, Consequences and Control,
DOI 10.1007/978-94-007-7814-6_2, © Springer Science+Business Media Dordrecht 2014