Types

Inland Wetland

Natural

Ponds/Lakes

Water logged

Seasonal

Swamp/Marsh/Fen/Bog

Manmade

Tanks

Ash pond

Reservoirs

Coastal Wetland

Natural

Estuary

Bay

Creeks

Lagoon

Backwater

Coral Reef

Tidal flat (mud deposited by tides)

Mangroves

Salt Marsh

Manmade

Salt Pans

Aquaculture

Hydrophytes - adopted plant life for wetlands

Hydric soils - not enough oxygen available for some plants

Mangroves, Corals and coral reefs;
Sand Dunes, Mudflats
National parks and other protected areas
Salt Marshes;
Turtle nesting grounds;
Horse shoe crabs habitats;
Sea grass beds;
Nesting grounds of birds;

Dominant producer in wetland is Macrophytes but not Phytoplankton whereas in Lake/Marine dominant is Phytoplankton
Montreux Record

Loktak lake in Manipur	Deforestation in catchment area, Infestation of water, pollution, Hyacinth(flowering plants), hydroelectric power plant
Keoladeo National Park, Rajasthan	Shortage of water and unbalanced grazing by invasive growth of grass Paspalum distichum

Chilika Lake was once in Montreux record but not now. It was effected by heavy silting

Sea Grass

Distribution

South East coast of Tamilnadu coast, Lakshadweep islands, few around Andaman & Nicobar islands

Conditions:

Shallow coastal waters
Sandy or muddy bottoms
Calm areas
Clear Water
High Salinity

IUCN has accorded high status for conservation of sea grass

Mangroves

Conditions for mangrove formation

Abundant silt brought down by the rivers [Fine grained substrate]

Lack of sediments favourable for Corals
Calm, Clean and Sandy substratum ideal for Sea Grass

Backshore of accreting(accumulating) sandy beaches
High solar radiation [Only at tropical and subtropical regions]

But Cold water coral reefs are also present

Free from strong wave action and tidal current
Mix of saline and fresh water
Low seasonal variation in temperature
Low oxygen soil

Characteristics

Adapted to high salinity
Ability to absorb fresh water in the anaerobic water logged areas
Stilt roots and Pnuematophores roots to overcome respiratory problems (Adventitious roots)
Leaves are thick and contains salt secreting glands
Lenticellated bank to facilitate more water loss
Viviparity mode of reproduction - seeds germinate in the tree itself
Intricate root system of mangroves makes the forests attractive to fish and other organisms

Distribution in India

In India, Mangroves present in 12 states & UTs - WB, Odisha, AP, TN, Puducherry, Kerala, Karnataka, Goa, Maharashtra, Daman & Diu, Gujarat, Andaman & Nicobar

9 states and 3 UTs
All coastal states have mangrove cover
NOTE: Lakshadweep do not have Mangrove cover
While both Lakshadweep and A&N have corals

West Bengal - Sundarbans

Dominated by Sundri Tree
UNESCO World Heritage site and a biosphere reserve, Ramsar site
Only mangrove reserve in the world to have tigers
This reserve includes o Royal Bengal Tiger Reserve. o Sundarban National Park. o Sajnekhali wildlife sanctuary. o Lothian Island wildlife sanctuary. o Holiday Island wildlife sanctuary

Orissa - Bhitarkanika
AP- Godavari-Krishna delta
TN- Mangroves of Pichavaram and Vedaranyam - Cauvery delta mangroves
Kerala - very sparse and thin
Maharashtra, Goa, Karnataka - degraded and along intertidal region of estuaries and creeks - Ratnagiri mangroves(Maharashtra)
Gujarat- Gulf of Kachchh and Kori Creek
Andaman and Nicobar islands - dense and diverse undisturbed mangrove flora

Uses of Mangroves

Stabilize coastal areas
Provide breeding ground for fishes
Reduce inundation of coastal lowlands
Protect coasts from Tsunami, Hurricanes, Floods
Natural recycling of nutrients
Biodiversity
Fire wood, medicinal plant, oil and edible plants to local people
Carbon sinks: Mangroves & Coastal Wetlands Store 50 Times More Carbon than Tropical Forests by Area.
Protection from cyclones

Protected the WB Sundarbans from deadly Bulbul cyclone

Conservation

Mangroves for the Future initiative

Threats

Commercialisation of Golpata tree in order to produce oil and alcohol for human consumption.
Logging of Sundri trees for timber and pulp.
Artificial Plantation is being done for aesthetic purposes, especially at the tourist spots. These plants can be competitive and pose a threat to the mangrove.
Shrimp culture has grievously threatened the mangroves.
Oil Spillage is one of the major man-made causes of mangrove degradation
Aqua culture and for building embankments and for human settlements
Eco-tourism
Conversion of area for agricultural purposes
Use of chemical pesticides, fertilizers

Recent India state of Forest report shows an marginal increase in Mangrove cover in India
MH is the first state to declare State Mangrove Tree - Mangrove Apple - evergreen mangrove species grows on newly formed mud flats
Coral reefs and Mangroves symbiotic association

Coral Reefs

Basic study in geography notes
Coral is a symbiotic association of Coral and Zooxanthellae(microscopic algae)
Color of the corals is due to color of Zooxanthella algae
Hard Corals(reef making) and Soft Corals(Ex: Sea fans, gorgonians)
Corals reefs are made by tiny animals (corals) called Polyps - Hermatypic corals
Cold water corals and tropical/subtropical corals
Cold water corals - present inside deep water- Rost Reef off Norway is largest cold water coral reef
Globally, there are more cold water coral reefs than tropical reefs
Coral reefs are referred as Tropical Rain forests of Oceans because of its bio diversity and ability to survive in nutrient poor environment
Distribution in India

In India, around 19000 sq kms
Patch Reef - Gulf of Mannar and Palk Bay, Gulf of Katchchh
Fringing Reef - Andamans, Palk Bay (TN)
Barrier Reef - Nicobar and Lakshadweep
Atoll - Lakshadweep and Nicobar
Netrani island of Karnataka, Malwan in Maharashtra are also coral sites in India

Sea grass grow on Kavaratti Atoll and Andaman while mangroves on Andaman and Nicobar
Species biodiversity - Andaman and Nicobar > Lakshadweep > Gulf of Mannar > Gulf of Katchchh

Conditions for coral formation

Refer in geography notes
Free from sediments
Plenty of salty
Temp should not be less than 20 degrees
Will not flourish if there are cold currents
Depth should not be too high [<30 fathoms]
No mixing of cold water and hot water (implies that upwelling is not favourable condition)
Best developed on the sea ward side of reef since tidal waves maintain abundant supply of oxygenated water

Absence of coral reef in northern Indian coast of Bay of Bengal

High influx of fresh water
Sedimentation (silt brought down by rivers)
Heavy Monsoonal rains
High Human presence

Coral Bleaching

Losing color of corals [turns white] because of cell adhesion dysfunction of zooxanthellae
Coral bleach happens

Density of zooxanthellae decline

If 60-90% corals loose zooxanthellae

Concentration of zooxanthellae photosynthetic� pigments falls

Each zooxanthellae lose 50-80% of photosynthetic pigments

Causes

Low or high temperature shocks (major cause)

Corals live in a narrow temperature tolerance limit

Solar irradiance maxima (Photosynthetically active radiation and ultraviolet radiation)
Xenobiotics - external bodies/substances - oil, herbicides, Copper
Epizootics - pathogen induced bleaching
Subaerial exposure - sudden exposure of reef corals to sunlight due to ENSO, low tides etc
Sedimentation
Dredging
Coral mining
Fresh water dilution
Inorganic nutrients- causes increase in density of zooxanthellae but coral resistance decreases and susceptibility to diseases
Overexploitation and over fishing

Worlds coral distribution is generally in eastern margins of continents where there is no upwelling of waters
Conservation

Coral reef is in Schedule I of WPA 1972
Artificial reefs to save Vaan island of TN

TN Govt in collaboration with IIT Madras restoring Vaan island in Gulf of Mannar
It is the first attempt in India to protect and restore a sinking island.
The project has been funded by NAFCC National Adaptation Fund for Climate Change

Functions of Coral reefs

Natural protective barrier against erosion and storm surge
Largest biogenic calcium carbonate producer
They provide substrate for mangroves
Habitat for diverse animals and plants including avifauna

Coral reefs and Mangroves symbiotic association

Mangroves stabilizes shorelines, remove pollutants, improve water quality, provide nursery habitat that maintain fisheries
Corals are correlated with the strength of fisheries and without viable fisheries, coral reef cannot survive.
Coral reefs provide substrate for mangroves

Classification of coral reefs

Fringing reefs

Grow near the coastline around islands and continents.
They are separated from the shore by narrow, shallow lagoons.
Fringing reefs are the most common type of reef that we see.

Barrier reefs

They are also parallel the coastline but are separated by deeper, wider lagoons.
At their shallowest point, they can reach the water’s surface forming a “barrier” to ation.
The Great Barrier Reef in Australia is the largest and most famous barrier reef in the world.

UNESCO World Heritage Listed reef
Coral bleaching due to

Warming sea temperatures due to climate change
Farming run offs
Developmental pressures
Colonization by predatory crown-of-thorns sea fish

Atolls

They are rings of coral that create protected lagoons and are usually located in the middle of the sea.
Atolls usually form when islands surrounded by fringing reefs sink into the sea or the sea level rises around them (these islands are often the tops of underwater volcanoes).
The fringing reefs continue to grow and eventually form circles with lagoons inside.

Patch reefs

They are small, isolated reefs that grow up from the open bottom of the island platform or continental shelf.
They usually occur between fringing reefs and barrier reefs.
They vary greatly in size, and they rarely reach the surface of the water.

Artificial Reef

It is a human made structure, similar to natural coral reef, built with the specific aim of promoting the marine life of an area
Most common forms of artificial reefs are submerged shipwrecks, bridges, lighthouses, etc, which often start functioning as marine habitat after a period of time
In 2017, Tamil Nadu govt in collaboration with IIT Madras have been restoring Vaan Island in Gulf of Mannar by deploying artificial reefs
Aug, 2018, World's largest 3D-printed artificial reef installed in Maldives, for coral reefs survive

Coral restoration in Gujarat using Bio rock technology

When a positively charged anode and negatively charged cathode are placed on the sea floor, with an electric current flowing between them, calcium ions combine with carbonate ions and adhere to the structure (cathode) and result in calcium carbonate formation. Coral larvae adhere to the CaCO3 and grow quickly
Bio rock is the name given to the substance formed by electro accumulation of minerals dissolved in seawater on steel structures that are lowered onto the sea- bed and are connected to a power source.

Coral Triangle

It is a marine area located in the western Pacific Ocean (includes waters of Indonesia, Malaysia, the Philippines, Papua New Guinea, Timor Leste and Solomon Islands)
It is described as world's epicentre of marine diversity.
It houses nearly 600 different species of reef-building corals
one of 3 mega ecological complexes on Earth, together with Congo Basin and Amazon Rainforest

Mangroves vs Corals vs Sea Grass vs Sea Weed

	Mangroves	Corals	Sea Grass	Sea Weed
Gulf of Mannar	NO	Yes (Patch)	Yes	Yes
Gulf of Katchh	Yes	Yes (Patch)	-	Yes
A&N	Yes	Yes Andaman - Fringing Reef Nicobar - Barrier and Atoll	Yes	-
Lakshadweep	No	Yes (Barrier and Atoll)	Yes	-
	All Coastal States	Palk Bay (Patch and Fringing) Netrani Island of KA Malwan of MH
Favorable conditions	Abundant silt brought down by the rivers [Fine grained substrate] High solar radiation [Only at tropical and subtropical regions] Backshore of accreting(accumulating) sandy beaches Free from strong wave action and tidal current Mix of saline and fresh water Low seasonal variation in temperature Low oxygen soil	Free from sediments Temp should not be less than 20 degrees Will not flourish if there are cold currents Depth should not be too high [<30 fathoms] No mixing of cold water and hot water (implies that upwelling is not favourable condition) Best developed on the sea ward side of reef since tidal waves maintain abundant supply of oxygenated water Plenty of salty (High salinity)	Sandy or muddy bottoms Shallow coastal waters Calm areas Clear Water High Salinity
Threats	Commercialisation of Golpata tree in order to produce oil and alcohol for human consumption. Logging of Sundri trees for timber and pulp. Artificial Plantation is being done for aesthetic purposes, especially at the tourist spots. These plants can be competitive and pose a threat to the mangrove. Shrimp culture has grievously threatened the mangroves. Oil Spillage is one of the major man-made causes of mangrove degradation Aqua culture and for building embankments and for human settlements Eco-tourism Conversion of area for agricultural purposes Use of chemical pesticides, fertilizers	Low or high temperature shocks (major cause) Corals live in a narrow temperature tolerance limit Solar irradiance maxima (Photosynthetically active radiation and ultraviolet radiation) Xenobiotics - external bodies/substances - oil, herbicides, Copper Epizootics - pathogen induced bleaching Subaerial exposure - sudden exposure of reef corals to sunlight due to ENSO, low tides etc Sedimentation Dredging Coral mining Fresh water dilution Inorganic nutrients- causes increase in density of zooxanthellae but coral resistance decreases and susceptibility to diseases Overexploitation and over fishing

Four main types of wetlands :

Marsh:

Marshes can often be found at the edges of lakes and streams here they form a transition between the aquatic and terrestrial ecosystems
It is a wetland that is dominated by herbaceous rather than woody plant species.
They are often dominated by grasses, rushes or reeds.
If woody plants are present they tend to be low-growing shrubs.

Swamps

Swamp: A swamp is a wetland that is forested.
Are characterized by slow-moving to stagnant waters.
They are usually associated with adjacent rivers or lakes.
The water of a swamp may be fresh water, brackish water or seawater.
Peat swamp forests are swamp forests where waterlogged soils prevent woody debris from fully decomposing, which over time creates a thick layer of acidic peat.

Bog

A Bog is a landform where peat accumulates with acidic surface water, low in nutrients.
A Bog is dome shaped landform, is higher than the surrounding landscape, and obtains most of its water from rainfall.
The gradual accumulation of decayed plant material in a bog functions as a carbon sink.
The characteristic is acidic surface water, low in nutrients.
These are the features of cold, temperate boreal climate of Northern Hemisphere.

Fen

The difference with Bog is that a Fen is served by both groundwater and rainfall and is therefore, is slightly acidic, neutral or alkaline.
It is relatively rich in minerals.
It is located on a slope, flat or a depression.
They are also features of cold climates such as in Western Europe

Traditional Wetland agriculture in Kerala - Pokkali and in Karnataka - Gazhani
Khazan ecosystems - estuarine agricultural system practiced in low-lying floodplains of Goa - rice and fish fields - tidal influence is regulated by the construction of embankments and sluice gates

Chilika Lake

Asia's largest brackish water lagoon [World's largest is Caspian Sea]
Nalabana Bird Sanctuary inside Chilika Lake

Floating Treatment Wetland

floating treatment

FTWs are buoyant structures or rafts of wetland vegetation that are deployed in water bodies such as ponds and lakes with permanent pool of water.
These plants are perennial non-invasive emergent plants which mimic the functions of natural wetlands
However, in contrast to the traditional wetlands the roots of the plants do not take root in soil however they stay suspended in water column in order to allow plants to adjust to the water fluctuations without any harm
Importance

Helps to purify the lake by breaking down and consuming the organic matter in water with the help of micro-organisms growing in the plant root system of FTW through microbial decomposition
Reduces the biochemical oxygen demand (BOD) of the lake
Reduces the growth of algae by restricting sun rays seeping into the lake
Improves the biodiversity of the lake

Ex: Floating Treatment Wetland (FTW) on Neknampur Lake in Hyderabad

Wetland Ecosystem