Distribution of Mangrove Ecosystem

(A)Worldwide distribution:

       The occurrence of mangroves is largely limited to the regions between 30° north and south of the Equator. The few mangroves out of this area worth mentioning are in the North up to the Bermudas (32°20’N), Japan (31°22’N) as well as in the South, in Australia (38°45’S), New Zealand (38°03’S) and the East Coast of South Africa (32°59’S). There are two center of mangrove diversity- the Eastern group (Australia, Southeast Asia, India, East Africa and the Western Pacific) where the total number of species is approximately 40 and the Western group (West Africa, Caribbean, Florida, Atlantic South America, pacific North and South America) where the number of species is only eight. According to estimate made by F.A.O./ UNDP a total area of 7.1 million hectare is covered under the mangrove formation in the world.


                               

(B) Distribution & Zonation in mangroves in India :
       Total area of mangroves in India is about 6,740 sq. km, which is about 7% of the world's total area of mangroves. Luxuriant patches of mangroves are found on all the other continents but the best mangroves are found in Asia, especially in India and Bangladesh - the Sunderbans are the largest mangrove forest in the world both in size as well as biodiversity.

State/UT wise Mangrove Cover Mangrove Cover Assessment 2001
                                                                                                                       (Area in km2)


SL No. 		State/UT Dence Open Total Percent of Geographical Area
1 Andhra Pradesh 14 319 333 0.12
2 Goa 5 0 5 0.14
3 Gujrat 184 727 911 0.46
4 Karnataka 2 0 2 0.001
5 Maharahstra 90 28 118 0.04
6 Orissa 194 25 219 1.39
7 Tamil Nadu 10 13 23 0.02
8 West Bengal 1651 430 2081 2.34
9 Andaman and Nicobar 709 80 789 9.56
10 Pondichery 0 1 1 0.21
  Total 2859 1623 4482 0.14

Zonation: Every mangrove species has its own level of salinity tolerance. Zonation in mangrove areas is not simple and varies from place to place. In India this zonation is very distinctive in east coast of India & merging in west coast of India. Due to high salinity range Estuaries on east coast show distinct zonation. A very broad and general distinction would be:-

1. Proximal Zone (Front mangroves): This zone is towards water front, subject to regular tidal effect where intensity of soil accumulation and inundation is a continuous process. The mangrove species in this zone are specially adapted with stilt roots, prop roots for stability and anchorage. Main species with these features are Rhizophora Spp. On rocky and coral reef substrata Avicennia Spp, Sonneratia Caseolaris are also found.
2. Middle Zones (Mid mangroves): Above the Rhizophora / Avicennia line luxuriant group of Ceriops and Bruguiera spp. occur, they develop a strong hold fast in the form of knee roots or bent roots as a special adoption for supporting the erect bole.
3. Distal Zone(Back mangroves): Towards island area mangroves like Excoecaris agallocha, Heritiera littoralis and Xylocarnus spp occur. Both Heritiera and Xylocarpus produce buttresses. Generally in this zone the salinity is low as the zone occurs towards hill sides where run off of fresh water is for a prolonged period. The duration of tidal submergence is low in this zone compared to front mangroves

(C)Distribution of Mangrove Ecosystem in Maharashtra

       Maharashtra has 720 km long coastline, which is characterized by pockets of beaches and rocky cliffs flanked by estuaries and patches of mangroves. The Maharashtra coastal zone extends between the latitude 15 52'N and 20 10'N and longitude 72 10'E and 73 10'E and falls under five districts from South to North- Thane, Sindhudurg , Ratnagiri ,  Raigad , Mumbai. The mangroves of Maharashtra are the most diverse among the west coast and as per the Forest Survey of India (FSI) covered 116 sq. km in 2003.The area under mangroves in Maharashtra was 200 km2 in 1972-75, which reduced to 108 km2 in 1997 but increased to 118 km in 2001. According to MMRDA, the mangrove areas in Mumbai have shown significant increase since 1991. The mangroves of Maharashtra are now well protected by law under the CRZ notification.

Maharashtra - Mangrove Cover :

       As per MRSAC, statistics of Mangroves in Maharashtra State –derived from Satellite data in the year 2005 - is summerised in the table bellow-

                                                                                    (Area in km2)                                 

District

Taluka

Mangrove
(Deans)

Mangrove
(Sparse)

Mud flat

Salt pan

Grand Total

Thane

Bhiwandi

4.07

4.53

4.15

0.00

12.75

 

Dahanu

0.32

2.21

26.88

6.10

35.51

 

Kalyan

0.84

0.44

1.47

0.00

2.75

 

Palghar

2.51

13.79

37.75

14.94

69.00

 

Thane

26.82

9.49

16.29

3.69

56.29

 

Vasai

5.82

9.16

21.37

14.59

50.94

Sub-Total

 

40.39

39.61

107.91

39.32

227.24

 

 

 

 

 

 

 

Mumbai City & Suburbs

Andheri

2.14

0.35

0.72

0.00

3.21

 

Mumbai

2.19

0.39

1.83

0.00

4.41

 

Borivali

12.24

5.28

6.88

0.04

24.44

 

Kurla

23.64

2.42

18.01

0.96

45.03

Sub-Total

 

40.21

8.44

27.44

1.00

77.09

 

 

 

 

 

 

 

Raigad

Alibag

15.19

9.40

24.79

0.31

49.69

 

Mahad

0.18

0.51

1.55

0.00

2.24

 

Mahsala

2.07

6.04

11.26

0.00

19.36

 

Murud

1.89

2.47

6.42

0.86

11.64

 

Panvel

2.78

8.19

20.16

0.85

31.98

 

Pen

6.77

4.39

10.69

5.21

27.06

 

Roha

1.05

5.77

7.47

0.41

14.71

 

Shrivardhan

1.17

3.82

5.92

1.46

12.37

 

Tala

0.00

2.06

4.00

0.46

6.52

 

Uran

6.19

7.60

28.18

4.66

46.64

Sub-Total

 

37.30

50.25

120.43

14.23

222.21

 

 

 

 

 

 

 

Ratnagiri

Chiplun

1.60

1.17

0.22

0.00

2.99

 

Dapoli

1.61

2.07

1.94

0.16

5.79

 

Guhaghar

2.14

1.42

1.51

0.00

5.07

 

Khed

1.60

1.60

0.23

0.00

3.48

 

Mandangad

2.57

1.41

1.43

0.00

5.41

 

Rajapur

3.07

2.01

3.60

0.02

8.71

 

Ratnagiri

2.35

5.93

9.40

0.08

17.76

 

Sangmeshwar

0.04

0.00

0.13

0.00

0.17

Sub-Total

 

14.98

15.62

18.52

0.26

49.37

 

 

 

 

 

 

 

Sindhudurg

Devgad

2.17

1.55

5.77

0.11

9.59

 

Malwan

2.69

3.30

2.76

0.72

9.47

 

Sawantwadi

0.13

0.42

0.63

0.00

1.19

 

Vengurla

0.04

0.62

1.97

1.25

3.87

Sub-Total

 

5.03

5.89

11.14

2.07

24.13

 

 

 

 

 

 

 

Grand Total

 

137.90

119.81

285.43

56.90

600.04

Page updated on 29th April 2009.

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