Conservation And Rehabilitation Of Flood Plain

CONSERVATION & REHABILITATION OF FLOODPLAIN WETLANDS IN INDIA Ambarish.P.Gop. FRM 221 CIFE

Floodplain, 

Flat region of a valley floor located on either side of a river channel. A floodplain is built of sediments deposited by the river that flows through it and is covered by water during floods when the river overflows its banks. During most floods, just a portion of the floodplain is covered with water and only during infrequent, very large floods is the whole floodplain covered. Floodplains tend to develop on the lower and less steep sections of rivers.

INTRODUCTION Low lying alluvial lands bordering rivers created by sedimentation from the movement of river and its meanders.  Generally fringe the main river channel  Directly or indirectly associated with river systems- Ganga, Brahmaputra, Tapti, Narmada, Godavari, Krishna and Cauvery  Area- 4.1 lakh ha comprising natural 1.5 lakh ha and manmade 2.6 lakh ha 

FORMATION OF FLOODPLAINS Floods play a central role in creating and shaping floodplains  During a flood, the flow of a river is both deeper and faster, allowing it to carry more sediment  As the flood recedes, the depth and speed of the river diminishes and the river deposits some of its load of sediment  . Since floodplains are constructed of the material being carried by the river, they are composed of relatively fine sediment  Most floodplains are composed of sand, silt, and clay  floodplains of gravel occur where the water flows especially fast. 

WETLANDS AND THEIR FUNCTIONS Natural ecosystems in a floodplain referred as floodplain wetlands such as ox bow lakes and tectonic depression  Beels -W. Bengal, Assam  Maun and chaur- Bihar  Pat-Manipur  Tal- Utterpradesh 

FUNCTIONS Recharging of ground water  De- charging of ground water  Trapping of sediments  Anchoring of shoreline  Removal and detention of nutrients  Supporting food chain  Habitat for fish , bird and wild life  Recreation and navigation 

HUMAN USE OF FLOODPLAINS 

  



The sediment brought down from mountains and deposited in floodplains provides a fertile soil in which to grow crops. Each new flood brings a fresh supply of sediment and nutrients, which acts as a natural fertilizer The rivers also provide a ready supply of water. This is particularly important in arid regions . Floodplains also provide easy routes for communication and so promote trade between the coast and the upper part of the river valley. The floodplains of large rivers are also particularly suitable for irrigation because the flatness of the floodplain enables water to be easily moved from one place to another in irrigation canals and ditches.

ISSUES AND THREATS  Effective

conservation of physical entity of wetlands  Conservation and sustainable use of resources  Maintenance of ecological balance  Restoration of biological damage  Developing suitable & effective management package  Creation of awareness among people about the implication of ecological degradation

THREATS Encroachment for arable lands and human settlement  High rate of siltation  Eutrophication  Pollution  Biotic communities like aquatic macrophytes  Over exploitation for short term gains 

STATUS OF FLOODPLAIN FISHERIES Productive potential- 1000-2000 kg/ha  Present yield 160 kg/ ha- Assam  350 kg/ha –West bengal  Smaller and forage fishes –more than 50%  IMC – 5-10%only 

TYPES OF FLOODPLAINS Ox-bow lake or channels -Open/live lakes - closed or dead lakes  Shallow depressions by seismic activities  Swamps or wet lands 

PRESENT STATUS

PROSPECTS FOR DEVELOPMENT  Macro-level

planning;  Transfer of scientific technologies need be strengthened  Environmental awareness  fishermen cooperatives must be strengthened  Credit and subsidy schemes should be strengthened  Fishermen should be trained properly

CONTD… Micro level planning  Holistic approach of development is a must  Required and timely arrangement of finance  Proper monitoring of the projects  Available technologies - Development of culture based fishery -management of capture fishery -Fish husbandry based fishery development

DEVELOPMENT OF CULTURE BASED FISHERY Selection of species in tune with the biogenic capacity  Stocking of appropriate size  Stocking in appropriate density  Stocking sp. in correct ratio and capture of sp at right size 

MANAGEMENT OF CAPTURE FISHERY Proper identification and protection of breeding grounds  Ensuring free and smooth migration of brooders  Stringent steps to protect brood stock and juveniles  Keeping a strict vigil on over fishing 

FISH HUSBANDRY IN FLOOD PLAIN WET LANDS Selection of right site  Proper design of the pen culture  Suitable preparation of the enclosed pen area  Proper selection of sp. To be cultured  Rational stocking of proper size fish/prawn seed and  Rational supplementary feeding 

FLOODPLAIN LAKES-PROBLEMS Massive stands of aquatic macrophytes  Inadequate proliferation of pelagic communities like plankton  Greater colonization of benthic fauna at bottom  Presence of forage& smaller spp with low economic value  Irrational & reckless fishing practices  Encroachment of wetlands 

FISHERIES ENHANCEMENT IN FLOODPLAIN LAKES Stock enhancement  Species enhancement  Environment enhancement  Management enhancement  Introduction of new culture systems 

CONSTRAINTS  Lack

of knowledge on modern fishery mgt among target groups  Inadequate training support  Weak extension network  High rate if illiteracy among target groups  Paucity of quality fish seed and feed  Inadequate financial support  Irrational leasing policy  Poor functioning of co-operatives  Conflicts among user groups

THRUST AREAS FOR FISHERIES DEVELOPMENT Increasing fish production & productivity by bringing more lakes under scientific management  Conservation of physical and biological properties  Strict vigil on introduction of alien sp.  Diversification of activities such as shrimp farming in pens  Integrating fisheries development of wetlands with other facets of agriculture 

MACROPHYTE MANAGEMENT IN FLOODPLAINS The control of weeds should not be attempted in an isolation, it should from the well thought and properly designed strategy to improve the ecosystem  Manual removal is preferred  bio control of weeds should be encouraged  Integration of duck farming with fisheries  Pen and cage culture is the best option 

MANAGEMENT PROBLEMS IN PEN CULTURE Damage of pen screen (constructional defects or installation defects  Overtopping and escape of fish from the bottom  Algal clogging  Fish disease due to high organic load 

ORNAMENTAL FISHERY RESOURCES Problems; There have not been efforts to design collection methods, gears , acclimatization etc.  Dependence of wild stock may soon deplete the natural population  Proper breeding and rearing technologies have not been worked out  Unauthorized introductions may contaminate our water 

CONTD… Future strategies; Potential ornamental sp. Should be identified and properly catalogued  Studies on distribution, ecology, biology, breeding and maintenance in aquaria should be intensified  Studies on disease and health  Prevention of unauthorized introductions  Use of modern techniques to establish sp of doubtful varities 

CONCLUSION The view that fishery has a negative impact on such ecosystems is not true  Those flood plains where fishery activity is being practiced regularly have better environment  Thick stands of macrophyte create creating hostile aquatic regimes for many organisms  The question of conserving biodiversity becomes irrelevant if wetlands are lost  Fishery development following scientifically based norms may play a pivotal role in conserving the floodplains 

HOW CAN WE PROTECT OUR REMAINING WETLANDS? Through conservation programs.  Wetland conservation encompasses the protection, enhancement and use of wetland resources according to principles that will assure their highest long-term social, economic and ecological benefits.  It is recognized that some wetlands should be protected and managed in their natural state; some actively managed to allow sustained, appropriate use of wetland renewable resources; and some developed for their non-renewable resource values 

THANK YOU FOR YOUR ATTENTION