Mangroves 3
Transcript of Mangroves 3
-
8/2/2019 Mangroves 3
1/24
Environment Management
Project on
Mangroves around the world
Importance and Why to protect
-
8/2/2019 Mangroves 3
2/24
MangrovesAn Introduction
A mangrove is a tree, shrub, palm or ground fern,
generally exceeding one half metre in height, that
normally grows above mean sea level in the intertidal
zone of marine coastal environments and estuarinemargins.
A mangrove is also the tidal habitat comprising such
trees and shrubs
The term "mangrove" comes to English from Spanish
word mangueand english word grow
-
8/2/2019 Mangroves 3
3/24
Ecosystem
Though the trees themselves are few in species, the
ecosystem that these trees create provides a home for
a great variety of other organisms.
Protection from strong winds & waves
Soil stabilization & erosion protection
Nutrient retention and water quality improvement
through filtration of sediments and pollutants Protection of associated marine ecosystems
-
8/2/2019 Mangroves 3
4/24
Evolution of Mangroves
Evolved around 114 million years ago Indo-Malaysian area is considered as cradle of
evolution of mangrove system
Mangroves of West Africa and Americas contain
fewer but similar colinizing species.
Asia, India, and East Africa contains much full range
of mangove species
At present, Indo-Pacific region is also known asluxuriant Mangroves
Sunderbans of India and Bangladesh forms the single
largest block of mangroves of the world
-
8/2/2019 Mangroves 3
5/24
Where do Mangroves occur?
The richest mangrove communities occur in tropicaland sub-tropical areas
The best mangroves are found in Asia especially in
India and Bangladesh Sunderbans are the largest forest mangrove in the
world both in size as well as biodiversity
Total area of Mangroves is about 6,740 sq. km7%
of the worlds total area of mangroves 80% of the mangroves are present in the east coast
Remaining 20% are scattered on the west coast fromKutch to Kerela
-
8/2/2019 Mangroves 3
6/24
Importance of Mangroves
Buffer between land and sea
Play an invaluable role as nature's shield againstcyclones, ecological disasters and as protector ofshorelines
Harbour a variety of lifeforms like invertebrates, fish,
amphibians, reptiles, birds and even mammals liketigers
Save the marine diversity, which is fast diminishing
Purify the water by absorbing impurities and harmful
heavy metals and help us to breathe a clean air byabsorbing pollutants in the air.
Potential source for recreation and tourism
Saviors in todays scenario of global warming
-
8/2/2019 Mangroves 3
7/24
Mangroves vegetation
The mangrove flora of the world is represented by
about 65 species.
The Indian mangroves are represented byapproximately 59 species (inclusive of some
mangrove associates) from 29 families.
-
8/2/2019 Mangroves 3
8/24
Few commonly found plant species in
Mangrove ecosystem are:
Rhizophora apiculata (Red Mangrove): It grows well in sheltered areasrather than open seas exposed to the wave action.
Rhizophora mucronata (Red Mangrove): It is often notice as a front
mangrove plant where the shore is well protected. It has a high growth rate
and is economically important. The species is quite similar to R. apetala
Bruguiera gymnorhiza (Broad leaf orange mangrove): Roots arecharacteristically thick, rope-like and filled with air. They are called "cable
roots".
Parviflora (Small leaf orange mangrove): Essentially a back mangrove
species. It is a useful tree for commercial extraction of tannin. The leaves
are supposed to be used for treating high blood pressure. Sonneratia alba (Mangrove Apple): It prefers non swampy intertidal
zones and prefers open areas with some wave action. It has thick, pointed
and long pneumatophores. The apple like fruits are edible and used in
pickles.
-
8/2/2019 Mangroves 3
9/24
Ceriops tagal (spur mangrove): A widely distributed species with a high
tolerance for salinity.
Avicennia marina: Avicennia spp have the highest salt tolerance of
mangrove trees. One of the dominant species found throughout thecoastline.
Avicennia officinalis: Of the three dominant species of Avicennia this is
the tallest. The wood is used as timber and fuel. Extraction of tannin is still
done at some places. Leaves useful as fodder for cattle.
Acanthus ilicifolius (Shore purslane): One may notice this attractiveplant in the back mangrove zones. Its shrubby nature and spiny leaves
make it an outstanding species.The blue flowers are also a source of nectar
for honey bees. The flowers and leaves are used for decoration in Kerala.
Aegiceras corniculatum (River mangrove): A densely flowering shrub.
Salt tolerance of this species is comparatively low and grows only in theareas where there is good mixing of freshwater at least for a few months. It
seeds profusely between January and March and fruits are curved and very
finely pointed. The nectar produces fine quality honey.
-
8/2/2019 Mangroves 3
10/24
Phoenix padulosa (Sea Date): This palm species is also called as sea date
and is a relative of the common date. In Sunderbans, this species forms a
major zone along the upper reaches of the delta. It is used as a fuel and its
trunk is used for constructing traditional hutment. It grows naturally onlyon the East Coast.
Nypa fruticans (Golpatta): This is a characteristic palm species and
resembles a shrunken coconut tree. It prefers well consolidated but moist
tidal zones with a low to medium level of salinity preferably with
freshwater mixing. Heritiera fomes (Sundari): This plant is locally called as sundari in W.
Bengal. The name Sunderban perhaps has been derived from the abundance
of this species in the Gangetic delta. It produces timber of excellent quality
which is said to be more expensive than teak.
-
8/2/2019 Mangroves 3
11/24
Coastal Regulation Zone (CRZ) Rules 2011.
CRZDefinition
Coastal regulation zone is the boundary from the high tide line up to 500min the landward side area between the low tide line. In the case of rivers,
creeks and backwaters, the distance from the high tide level shall apply to
both sides and this distance shall not be less than 100m or the width of the
creek, river or backwater whichever less is.
There are four categories of CRZs.CategoryI (CRZ I)
Areas which are ecologically sensitive and important such as national
parks, areas close to breeding and spawning grounds to fish and other
marine life. Historically important and heritage areas, area rich in genetic
diversity, areas likely to be inundated due to rise in sea level consequentupon global warming and such other areas as notified by government from
time to time.
-
8/2/2019 Mangroves 3
12/24
Mangroves around the world
The countries with the largest area of mangroves are:
1) Indonesia
2) Brazil
3) Australia
4) Nigeria
5) Mexico
Estimates of mangrove diversity indicate that there are 16-24
families and 54-75 species worldwide. The greatest mangrove
species diversity exists in SE Asia.
Only 12 mangrove species are found in the Americas, with 4
of these occurring along portions of the SE USA (Florida)
coast.
http://mangroveactionproject.org/mangroves/origin-of-mangroveshttp://mangroveactionproject.org/mangroves/origin-of-mangroves -
8/2/2019 Mangroves 3
13/24
Sundarban Forest The Sundarbans is the largest mangrove forest in the world
300 species of trees and herbs
425 species of wildlife including the Royal Bengal Tiger exist.
It lies in south-east of Calcutta .
It covers some 10,000 sq.km. of mangrove forest and water (of which some
40% is in India and the rest in Bangladesh)
It is a part of the worlds largest delta (80,000 sq. km.) formed fromsediments deposited by three great rivers, the Ganges, Brahmaputra and
Meghna.
The three sanctuaries are intersected by a complex network of tidal
waterways,
mud flats, small islands of salt tolerant mangrove forests.
The area is flooded with brackish water during high tides which mix with
freshwater from inland rivers.
The Sundarbans has experienced balanced growth of flora and fauna in
association with the fresh water of the Ganges and the salty sea water of
theBay of Bengal.
-
8/2/2019 Mangroves 3
14/24
The Sundarbans mangrove area of India and Bangladesh when
taken together forms one of the worlds largest single patches.
Tidal waves are a regular phenomenon and may be up to 7.5m
high About half of the Sundarbans is under water and the rest of the
landscape
Rainfall is heavy and humidity high (80% on average) due to
proximity of the Bay of Bengal. The entire mangrove forest extends over an area of 4,262
sq.km. of which 2,320 sq.km. is forest and the rest is water and
it is called Sundarban, locally known as sundari.
It is classified moist tropical seral forest, comprising beachforest and tidal forests.
-
8/2/2019 Mangroves 3
15/24
This mangrove forest generally bears the salt-tolerant
forest ecosystem excepting some amongst which
about 856.7 million Sundari (Heritiera fomes) trees
are less salt-tolerant.
Climate change due to global warming is predicted to
cause an annual temperature rise of 0.4 degrees
Celsius in Bangladesh and result in greater frequencyand intensity of cyclonic storms.
The sea level is also predicted to rise by 4 millimetres
every year. These phenomena will result in an
increase in salinity and a decrease in the sweet waterflow in the Sundarbans.
But the balance is now being threatened and siltation
is increasing due to decreasing downstream flow of
rivers running through and around.
-
8/2/2019 Mangroves 3
16/24
Goa Mangroves
Out of Goas total land area of 370000ha, the mangrove area is500 ha having declined sharply from a recorded 20 000 ha in
1987. Some 178 ha of the best mangrove area at Chorao, Goa
has been declared as Reserved Forest under the Indian Forest
Act, 1927 to protect and conserve the mangrove forests. In 1988, this area was declared a bird sanctuary under the
Wildlife (Protection) Act, 1972.
Afforestation work to restore degraded mangrove areas started
in Goa in 1985-1986; By the end of 1996-1997 the programme had covered 876 ha.
-
8/2/2019 Mangroves 3
17/24
Andaman and Nicobar islands
It comprise 572 islands in the Bay of Bengal, with a total area
of about 825 000 ha. The coastline is about 1 962 km. The areaunder mangroves is 96 600 ha (Government of India, 1997).
The Middle Andaman Islands comprise an area of 99 800 ha,
of which 23 400 ha or 23.4 percent are covered with
mangroves Limited extraction did not cause any damage to the
government mangrove forests, but in the revenue areas (areas
managed in such a way as to allow local people to benefit from
extraction of forest products) the destruction of mangroves isconspicuous.
In 1987, the Andaman and Nicobar Administration has
banned extraction of mangrove wood due to growing
awareness about conservation of mangroves.
-
8/2/2019 Mangroves 3
18/24
Mangroves in mumbai
Major mangroves are seen today in Mumbai are
Vasai Creek,
Thane Creek,
Manori and Malad,
Mahim - Bandra,
Versova,
Siwari,
Mumbra - Diva
and few more places.
-
8/2/2019 Mangroves 3
19/24
Importance of Mangroves for Mumbai
Mangroves represent the spirit of Mumbaithey are plucky
survivors.
But each day, millions of citizens in Mumbai pass these
hardy plants imagining they are little more than dirty,muddy weeds growing pointlessly along the shoreline.
Mangroves maintain the integrity of Mumbais shoreline
The Koli community in Mumbai worships mangroves
-
8/2/2019 Mangroves 3
20/24
Mangrove Destruction in Mumbai
Rapid developments like housing, industrialization,pollution and increasing population of Mumbai has resulted
into degradation of mangroves.
There are two important creeks, Vasai Creek towards north
and Thane Creek toward south where luxuriant mangrove
patches are still left.
Mumbai High Court has ordered freeze on destruction of
mangrove forests in Maharashtra and has banned
construction within 50 metres of them
-
8/2/2019 Mangroves 3
21/24
Protection is possible only through the participation
of the local community and by building up pressure
groups for ensuring management of this ecosystem
and strict implementation of the legal provisions bythe Government.
Residents associations & NGOs in Mumbai are
coming together to spread this awareness
-
8/2/2019 Mangroves 3
22/24
Threats to Mangrove ecosystem
Land reclamations for construction activity, aquaculture,agriculture, tourism
Industrial and domestic pollution
Port development
Dumping of all kinds of waste and debris
Deforestation for fuel wood
Over harvesting of marine resources
-
8/2/2019 Mangroves 3
23/24
Recommendations
The existing forest rules should be strictly enforced tomangroves in order to avoid exploitation.
Collection of mangrove products may be regulated byappropriate rules.
Conversion of mangrove lands for other purpose mustbe strictly prohibited.
Coastal Area development should be associated withmangroves land.
Budgetary provisions may be provided in themaritime states for surveillance, watch and ward ofwetland ecosystems.
-
8/2/2019 Mangroves 3
24/24
Regular monitoring of the state of art of mangroves
by government organization, Universities and similar
agencies.
A forestation program may be maintained for
transplantation in the appropriate areas.
National Policy on mangrove ecosystem management
may be strengthened/ formulated for protection ofmangroves.
Awareness campaign on conservation and
management of mangroves. Mangroves should be a part of curriculum/syllabus of
education at various levels.