Management of wetlands by biomanipulation studies

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Management of wetlands by biomanipulation studies

  1. 1. MANAGEMENT OF WETLANDS BY Presentation by Livi Wilson and Jitendra Kumar College of Fisheries, KVAFSU, Mangalore, Karnataka jitenderanduat@gmail.com jitenderanduat@gmail.com BIOMANIPULATION STUDIES
  2. 2. NEED FOR WETLAND MANAGEMENT Natural wetlands –ECOLOGICAL ENGINEERS for waste water treatment  They function as filters, sinks, transformation sites for chemicals  Natural wetlands have been severely altered by the chronic exposure to pollutants, especially nutrients. jitenderanduat@gmail.com 
  3. 3. EFFECTS OF INCREASED NUTRIENT & TURBIDITY LEVELS • Decreased biomass of large-bodied zooplankton • Elevated biomass of planktivorous & benthivorous fish jitenderanduat@gmail.com • Shifts from submerged macrophyte dominance to phytoplankton dominance
  4. 4. EFFECTS OF EUTROPHICATION Increase in algal biomass ,including toxic cyanobacteria  As a consequence ,colour,taste & odour due to dissolved organic carbon & cyanobacterial blooms cause major water quality problems  cause enormous treatment cost jitenderanduat@gmail.com 
  5. 5. CONT….  jitenderanduat@gmail.com Cyanobacterial blooms can cause serious health problems including hepatoentritis,liver damage, promotion of tumour growth,gastroenteritis,hepatitis,renal malfunctioning & haemorrhaging. Burch(1993)
  6. 6. BIOMANIPULATION Increasing grazing pressure on phytoplankton Increase water clarity & promote the growth of aquatic macrophytes jitenderanduat@gmail.com Reduce grazing pressure on zooplankton
  7. 7. BIOMANIPULATION A new tool for water management (Gulati et al. 1990).  Biomanipulation is a widely accepted & frequently applied eco-technology to improve the environmental quality of standing waters  Based on the concept of cascading trophic interactions in aquatic food web  Introduced by Shapiro in 1975 jitenderanduat@gmail.com 
  8. 8. INCREASING POPULARITY OF BIOMANIPULATION IS DUE TO Absence of toxic chemicals High effectiveness jitenderanduat@gmail.com Low cost Absence of machinery
  9. 9. BIOMANIPULATION jitenderanduat@gmail.com Adjusting the biological community to achieve a desired outcome
  10. 10. DESIRED OUTCOME INCLUDES Less turbid water Removal of pest species jitenderanduat@gmail.com Reduced phytoplankton blooms
  11. 11. DISCRETE MECHANISMS BEHIND BIOMANIPULATION  Macrophytes jitenderanduat@gmail.com Biomanipulation can be considered in the theoritical context of two alternative stable state equilibrium ,as the extreme perturbation required to move from a phytoplankton dominated state to one dominated by macrophytes Aquatic macrophytes have been identified as a key component for the long term success of biomanipulation management
  12. 12. CONT… Macrophytes stabilize the sediment preventing resuspension of nutrients as well as utilizing nutrients for their own growth.  Algal blooms is repressed by the macrophytes which can keep the water clear for a long period during the year  Aquatic macrophytes such as Characeae can colonize large parts of the benthos  Once established Characeae is suggested to have a high resistance to the negative effects of fluctuating phytoplakton turbidity  jitenderanduat@gmail.com
  13. 13. FISH In Europe most turbid water lakes are dominated by bream,roach,common carp …  While clear water are dominated by pike,eel.European catfish,redfin perch…  Redfin perch have also been identified as a potential contributor to the turbid water state as their feeding eliminates large filter feeding cladocerans allowing phytoplankton to flourish jitenderanduat@gmail.com 
  14. 14. CONT… In another Matveev et.al (1994) experiments with mosquito fish (Gambusia holbrooki) determined that the species directly stimulated the growth of the phytoplankton by excretion  Hence biomanipulation can be defined more broadly as a removal or biomass reduction of any undesirable fish, irrespective of the impact on the zooplankton grazing, then a reduction in phtoplankton biomass could be expected. jitenderanduat@gmail.com 
  15. 15. BENTHIVOROUS FISH A reduction in benthivorous fish is also suggested to have a favorable impact on the biomanipulation process(Lamarra 1975)  They stir up the bottom when feeding  Enhancing turbidity  Impairing the colonization & growth of macrophytes  Complete removal of Characeae  jitenderanduat@gmail.com
  16. 16. BENTHIVOROUS FISH They stir up the bottom when feeding Impairing the colonization & growth of macrophytes Complete removal of Characeae Enhancing turbidity Loss of stability jitenderanduat@gmail.com A reduction in benthivorous fish -a favorable impact on the biomanipulation process(Lamarra 1975)
  17. 17. PHYTOPLANKTIVOROUS FISH  The role of phytoplanktivorous fish in biomanipulation is gaining acceptance They also improve the water quality jitenderanduat@gmail.com Some fish species can actively eliminate cyanobacterial blooms by grazing directly up on them Eg :silver carp ,bighead carp 
  18. 18. CRITERIA FOR SUCCESSFUL APPLICATION Lake area <4 ha most suitable (Reynolds 1994)  Water depth < 3 m more effective in shallow Zooplankton fauna –Daphnia foremost contributor to the success of biomanipulation  They are recognized as the most significant genus to impact upon algae blooms  When large Daphnia are absent ,zooplankton cannot reduce phytoplankton biomass(McQueen et.al 1986)  jitenderanduat@gmail.com 
  19. 19. REFERENCES  EUTROPHICATION- RESEARCH AND APPLICATION TO WATER SUPPLY DAVID W. SUTCLIFFE AND J. GWYNFRYN JONES Published by the Freshwater Biological Association  Lake restoration and biomanipulation in temperate lakes: relevance forsubtropical and tropical lakes By Erik Jeppesen1.2*, Martin Søndergaard1, Nestor Mazzeo3, Mariana Meerhoff Biomanipulation : a useful tool for freshwater wetland mitigation ? By David G.Angeler jitenderanduat@gmail.com Edited by
  20. 20. jitenderanduat@gmail.com THANK YOU 

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