Wetlands are areas where water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season. View the presentation to know more!

1. By Abhinandan Krishn Kaul

2. What Are Wetlands?
Wetlands are areas where water covers the soil, or is present
either at or near the surface of the soil all year or for varying
periods of time during the year, including during the growing
season.
 The wetlands ecosystem represents a richly diverse web of
plants and animals interacting together.

3. As Defined By Ramsar Convention-
“Areas of marshes, fen, peat land or water,
whether natural or artificial, permanent
or temporary, with water that is static or
flowing, fresh, brackish or salt, including
areas of marine water the depth of which
at low tide does not exceed six meters”

4. Characteristics-
 Water table sits at or close to the surface of the land.
 Shallow water often covers the area.
 Land supporting aquatic vegetation.
 Substrate of saturated soil and substrates not comprised of soil but
inundated with water during the growing season.
 Water can be freshwater, saltwater, brackish water or flowing water.
 Contain wet soils and typically anaerobic environments, and rooted
plants and other forms of life used to those conditions.

6. A-biotic Factors Of Wetlands-
Water
Weather
Tides
Topography
Sedimentation
Erosion
Turbidity
Temperature
Bedrock
Climate
Human Intrusion

7. Biotic Factors Of Wetlands-
Herbivores
 Producers
 Omnivores
 Carnivores
 Decomposers
 Detritivores

8. Dominant Wildlife in Wetlands-
Wetlands provide extraordinary wildlife diversity.
Fishes
Migratory Birds
Mammals
Amphibians

9. Services Provided By Or Derived From Wetland
Ecosystems-

10. Some Threats facing wetlands-

11. Case Study- Ashtamudi Lake

12. Description
 Ashtamudi Lake in the Kollam District of the Indian state
of Kerala, is the most visited backwater and lake in the
state. It possesses a unique wetland ecosystem and a large
palm-shaped (also described as octopus-shaped) water
body, second only in size to the Vembanad estuary
ecosystem of the state.
 Ashtamudi means 'eight braids' in the
local Malayalam language. The name is indicative of the
lake's topography with its multiple branches. The lake is
also called the gateway to the backwaters of Kerala and is
well known for its houseboat and backwater resorts.

13. History-
The Ashtamudi lake's importance is claimed to be dated to the days
of the Phoenicians and the Romans. Ibn Batuta, during his 24-year
sojourn in the 14th century, is reported to have mentioned about the
Quilon port as one of the five ports for Chinese trade. Links with
Persia (9th century), Chinese mandarin in 1275 AD, Portuguese in
1502 AD, and the Dutch followed British in 1795 AD are recorded
history. Velu Thampi is credited with organizing the rebellion against
the British from this place.
Ibn Batuta Velu Thampi

14. Topography
Quaternary and Tertiary sediments and sedimentary rocks are the formations in
the lake basin and environs. The Quaternary sediments are
of marine and fluvial alluvium of recent age. Tertiary sediments
comprise laterite, sandstones and clays of Warkalai formation.
Geology
Kallada River is a major river discharging into the Ashtamudi Lake.
The Kallada river, which originates near Ponmudi from
the Kulathupuzha hills Western Ghats is formed by the confluence of three rivers-
Kulathupuzha, Chenthurnipuzha, and Kalthuruthipuzha, and after traversing a
distance of about 121 km (75 mi) through virgin forests finally debouches into the
Ashtamudi wetland at Peringalam near Kollam. With a maximum depth of 21 ft
(6.4 m) at the confluence, it is Kerala's deepest estuary.

15. The average annual runoff from the river system into the estuary is reported to be
76 cubic kilometers of freshwater. The basin drainage area is 1,700 km2 (660 mi2)
and with an average annual rainfall of 2400 mm (94 in) it discharges
3.375 km3 (2,740,000 ac·ft) of flow annually. It acts as a flood storage lake thus
protecting the thickly populated city of Quilon (Kollam) and the coastal land. The
Kallada dam built across the Kallada river is 85.3 m high by 35 m long (280 ft by
115 ft) with a reservoir area of 23 km2 (8.9 mi2) with a storage volume of
0.505 km3 (409,000 ac·ft). Though it provides irrigation to 61630 ha for paddy and
upland crops, it has aggravated the salinity ingress into the wetland and the river
due to reduced outflows during summer months.
Ashtamudi Estuary has mangroves Avicennia officinalis, Brugiera
gymnorrhiza and Sonneratia caseolaris as also 43 species of marshy and mangrove associates
including two endangered species Syzygium travancoricum (endangered species according to
the Red Data Book of Indian Plants) and Calamus rotang in the Terrestrial system. These
species offer excellent scope for development of marine bioreserve to promote eco-tourism in
the estuarine of the lake.
Hydrology
Flora

16. The lake supports 57 species of avifauna, of which 6 are migratory and 51 resident
species.
It is also reported that about 40 species of wetland-dependent birds are recorded
in the lake, out of which 45% are long-distance migrants. Terns, plovers,
cormorants, and herons are most abundant birds in the lake. A study report has
identified 45 insect species, including 26 species of butterfly, 5 odonates, 9
hymenopteras, and 2 orthopterans, 1 hemipteran and 2 coleopterans. About 29
zooplankton species have also been identified. The water body is found to have
9 phytoplanktons such as Amphora, Borosigma, Cyclotella, Cymbella,
Gyrozigma, Meloziva, Navicula and Nitzsch.
97 species of fish (42 are typically marine, 3 estuarine, 9 estuarine- riverine, 15 marine-
estuarine) and unique copepod species. It is also a congenial habitat for all species
of penaeid and palaemonid Prawns, edible crabs, paphia malabarica (short neck
Clams) and a variety of fish. The estuary is the source of livelihood for thousands of
fishermen and is stated to be the second biggest fish-landing centre after the
Vembanad estuary
Avifauna
Aqua fauna

17. Economic evaluation
An evaluation of the marketed use benefits of Ashtamudi estuary (valued using market
valuation approach) has assessed the total direct use value at Rs.66.8 million per annum;
coconut husk retting accounts for Rs.5.1 million, Inland navigation service accounts for
Rs.3.7 million and the recreation benefit is assessed at Rs.1.5 million (using the standard
travel cost method). But this is reported to be showing a downward trend, particularly in
fish resources in the estuary.

18. Deterioration of the lake environment
The following are reported to be the
reasons for deterioration of the lake
environment:
 Intense anthropogenic pressure.
 Oil spills from thousands of fishing boats
and from industries in the surrounding area.
 Dwindling of the fragile lake zone due to
conversion/destruction of natural habitats.
 Large quantities of untreated sewage,
disposal of human excreta, and the
pollution from paper mills, industries, etc.
 Many fish species may have become extinct
due to lack of spawning facilities on the
banks of the lake due to canalization of the
lake's banks by walls built of laterite and
granite stones.

19. Restoration plans
 Identify and phase out of the pollution sources.
 Better sanitation, reduction of industrial
growth and reduction of urban waste.
 Address the declining fish stock production
through concerted efforts to conserve the fish
stock.
 Product diversification of coir to ensure better
economic returns to people with the
coordination of self-help groups
 Improved shore protection through mangrove a
forestation.
 Mining to be allowed selectively at village level,
away from the banks of the lake
 Discontinue estuary reclamation