Wetlands are defined as lands covered with water all or part of the year. They are characterized by three factors: hydrology, hydric soils, and hydrophytic vegetation. Wetlands provide many benefits including pollutant filtration, flood control, habitat provision, and biological productivity. However, over 50% of the world's original wetlands have been lost due to human activities like development, agriculture, and pollution. This has negative environmental consequences like increased flooding and loss of biodiversity. India contains many types of wetlands, but they cover only an estimated 3% of the country's land area. Conservation efforts aim to protect remaining critical wetlands and involve local communities.

1. Wetlands
'nature's kidneys’

2.  Definition of wetland(s)
-Lands covered with water all or part of a year
-Interface between Terrestrial and aquatic ecosystems
- They have been called as 'nature's kidneys’
 Characteristics of wetlands
• There are three characteristics that describe a wetland:
1. Hydrology
– There must be water at or near the surface of the land for a
designated amount of time.
2. Soils
– Must be hydric or saturated with water to create an anaerobic
(oxygen-free environment).
3. Plants
– Must be “wetland plants,” meaning that they require lots of
water and the anaerobic conditions that the hydric soil creates.
(Smith & Smith, 2001)

3. Hydrology
Two components of hydrology
1. Physical
Characteristics
– Precipitation, surface
and subsurface flow,
direction, chemistry,
and kinetic energy of
the water.
2. Hydroperiod
– Duration, frequency,
depth, and flood
season

4. Classification of wetland on the basis of hydrology
• Basin Wetlands (lakes and ponds)
– Physical: Water flow is vertical
(precipitation)
– Hydroperiod: Long with floods during
periods of high rainfall.
• Riverine Wetlands (periodically flooded
banks of rivers and streams)
– Physical: Water flow is both vertical
and horizontal (precipitation and
stream/river flow)
– Hydroperiod: Have short periods of
flooding with stream/river flow.
Basin Wetlands
Riverine Wetlands

5. Classification of wetland on the basis of hydrology
• Fringe Wetlands (along
coastal areas of large lakes
and oceans)
– Physical: Water flow is
both vertical and
horizontal (precipitation
and tidal flow)
– Hydroperiod: May be
short and regular. Is not
seasonal like basin
wetlands.

6. Three types of soils
1. Sandy soils
– Contain mineral grains ranging from 0.05-2 mm
in diameter.
2. Silt soils
– Soils that have grains ranging from 0.002-0.05
mm in diameter.
3. Clay soils
– Contain mineral grains smaller than 0.002 mm in
diameter.
Soil

7. Soil Properties
• Sandy soils
– Has good drainage and aeration
– Does not store water well
– Is not suitable for most plants
• Silt Soils
– Soils made from minerals
– Granule sizes are between sandy and
clay.
– Also known as “rock flour” or “stone
dust” when produced by glaciers
• Clay soils
- Hold water very well
- Do not drain water easily
- Do not have space for air
- Is not suitable for most plants
Sandy soils
Silt Soils
Clay soils

8. Wetland Plants
Native vs. Exotic
• If a plant is native to a particular area, then it is
originally from that area
– Native plants provide food and habitat for native animals.
Without this, the native animals may be forced to migrate to
areas.
– Native plants also keep local genes viable and in the gene
pool.
• Exotic plants were not originally in the area and have
been carried to the area in some way.
– Exotic plants can become invasive where they dominate the
ecosystem preventing opportunities for growth for the native
plants.
– Exotic plants also out grow native plants because they have no
native predators.
– Invasive exotic species are the second leading cause of native
species extinction (habitat loss being number one).

9. Benefits of Aquatic Plants
• Primary Production
– Wildlife Food
– Oxygen Production
• Shelter
– Protection from predation for small fish
• Fish Spawning
– Several fish attach eggs to aquatic macrophytes
– Some fish build nests in plant beds
• Water Treatment
– Wetland plants are very effective at removing
nitrogen and phosphorous from polluted waters
Phytoremediation

10. Submerged macrophytes can provide shelter for young fish as well as
house an abundant food supply.

11. Some fish will attach their
eggs to aquatic vegetation.
Alligators also build nests
from vegetation.

12. Wetland Life – The Protists
• One celled organisms (algae, bacteria)
– Often have to deal with a lack of oxygen
• Desulfovibrio – genus of bacteria that can
use sulfur, in place of oxygen, as a final
electron acceptor
– Produces sulfides (rotten-egg smell)
• Other bacteria important in nutrient cycling
– Denitrification

13. Phytoplankton
• Single celled
• Base of aquatic food web
• Oxygen production
Photosynthesis:
Solar Energy + CO2 + H20  C6H12O2 + O2
CO2 + H20  H2CO3
 H+ + HCO3
-  2H+ + CO3
2-
As CO2 is removed from the water pH increases.

14. General Types of Aquatic Macrophytes
• Submergent – Plants that grow entirely under water. Most are
rooted at the bottom and some may have flowers that extend
above the water surface.
• Floating-leaved – Plants rooted to the bottom with leaves that
float on the water surface. Flowers are normally above water.
• Free Floating – Plants not rooted to the bottom and float on the
surface.
• Emergent – herbaceous or woody plants that have the majority
of their vegetative parts above the surface of the water.

15. Floating-Leaved Plants

16. Free Floating
Plants

17. Emergent
Plants

18. Human-made wetlands
– Aquaculture ponds (e.g., fish/shrimp);
– Irrigated land (rice fields);
– Seasonally flooded agricultural
land (pastures);
– Salt exploitation sites;
– Water storage areas;
– Excavations (gravel/brick/
clay pits);
– Canals and drainage channels;
– Wastewater treatment areas;

19. Description of some wetlands
Freshwater Marshes
• Very diverse group
• Non-tidal, freshwater systems
• Dominated by grasses, sedges, and other
freshwater emergent hydrophytes (non-forested)
• High productivity
• Approximately 20% of world’s wetlands

20. Freshwater Marshes Photo/ Example
Freshwater Marshes

21. Chemical Functions of Wetlands
• Pollution Interception
– Nutrient uptake by plants
– Settle in anaerobic soil and become reduced
– Processed by bacterial action
• Toxic Residue Processing
– Buried and neutralized in soils, taken up by
plants, reduced through ion exchange
– Large-scale / long-term additions can exceed a
wetland’s capacity
– Some chemicals can become more dangerous
in wetlands (Mercury)

22. Mercury Chemistry
• Elemental mercury (Hg0)
– Most common form of environmental mercury
– High vapor pressure, low solubility, does not
combine with inorganic or organic ligands, not
available for methylation
• Mercurous Ion (Hg+)
– Combines with inorganic compounds only
– Can not be methylated
• Mercuric Ion (Hg++)
– Combines with inorganic and organic
compounds
– Can be methylated  CH3Hg

23. Methylation
• Basically a biological process by microorganisms in
both sediment and water
– Mono- and dimethylmercury can be formed
– Dimethylmercury is highly volatile and is not
persistent in aquatic environments
• Influenced by environmental variables that affect both
the availability of mercuric ions for methylation and
the growth of the methylating microbial populations.
– Rates are higher in anoxic environments,
freshwater, and low pH
– Presence of organic matter can stimulate growth
of microbial populations, thus enhancing the
formation of methylmercury

24. Methylmercury Bioaccumulation
• Mercury is accumulated by fish, invertebrates,
mammals, and aquatic plants.
• Inorganic mercury is the dominate environmental
form of mercury, it is depurated about as fast as it is
taken up so it does not accumulate.
• Methylmercury can accumulate quickly but depurates
slowly, so it accumulates
– Also biomagnifies
• Percentage of methylmercury increases with
organism’s age.

26. Chemical Functions of Wetlands
• Waste Treatment
• High rate of biological activity
• Can consume a lot of waste
• Heavy deposition of sediments that bury waste
• High level of bacterial activity that breaks down and
neutralizes waste
• Several cities have begun to use wetlands for waste treatment

27. Biological Functions of Wetlands
• Biological Production
– 6.4% of the Earth’s surface  24% of total
global productivity
– Detritus based food webs
• Habitat
– 80% of all breeding bird populations along with
>50% of the protected migratory bird species
rely on wetlands at some point in their life
– 95% of all U.S. commercial fish and shellfish
species depends on wetlands to some extent

28. What happens when wetlands are destroyed?
• Destruction of wetlands can cause many
problems such as:
– Increased floods
– Water quality problems
– Population decrease in plants and animals that live in
wetlands
Wetland helps
Water storage and purification
Biodiversity protection
Sediment retention
Groundwater replenishment
Climate change mitigation
Recreation/tourism
Cultural value

29. Loss of wetlands
• Building of dams
• Channelization of riverbeds
• Overexploitation of wetlands resources
• Introduction of invasive species
• Developmental activities and population pressure
• Water pollution and dumping of waste
• We have lost an estimated 50% of our
original wetlands in the world.

30. Wetlands in India
 There are 19 different types of wetlands in India.
 It includes mangroves, high-altitude lakes, marshes and ponds.
 It covers an estimated 3 percent of India's land area.
Area Estimates of Wetlands of India (in million ha)
(Source: Directory of Asian Wetlands, IUCN, 1989)

31. Various wetlands in India

32. Various wetlands in India cont..

33. Projects on Wetland Conservation in Uttarakhand
• The two conservation reserves – Jhilmil Jheel in Haridwar and Asan Barrage in
DehraDun districts – are being established under the 2003 parliamentary
amendment made in the Wildlife (Protection) Act 1972 with a view to seek
greater community involvement in protecting extremely critical wildlife.
• FRI Dehradun is engaged in a Wetland Conservation project.
• A special project undertaken by ZSI Northern Regional Circle, Dehradun for
conservation of Swamp Deer.
• Wild life institute of India Dehradun also played a pivotal role in Swamp Deer
conservation

34. THANK YOU