375
Table 11.1 Identification of factors and sub-factors of the nature of mangrove degradations in the
Sundarban coastal tract
Sl.
No.
Island area surveyed in
Southwest Sundarban
Identification of factors for
each island
Identification of sub-factors
(in number)
1
Patibania Island
Sediment deposition
8
2
Fredrick Island
Fishery development
8
3
Henry’s Island
Human uses
8
4
Bakkhali
Hyper salinity
8
5
Jambu Island
Storm effects
8
6
Mousuni Island
Land erosion
8
7
Susnir char
Mangrove regeneration
problems
8
Table 11.2 Preparation of mangrove degradation checklist by weighted values of factors and
sub-factors
Sl. No. Human uses:(parameters)
Patibania
Island
Fredrick
Island
Henry’s
Island
1
Fuel use and fodder use
1.0
2.0
2.0
2
Wood cut
0.5
1.0
0.5
3
Reclamation for agriculture and housing
0.5
4.0
3.0
4
Fixing nets by mangrove wood
0.5
1.0
1.0
5
Thatching roofs of mangrove leaves
0.5
0.5
0.5
6
Recreational uses for mangrove ecotourism
1.0
1.0
3.0
7
Coastal tourism expansion and industrialization
0.5
4.0
2.0
8
Waste disposal and pollution
1.0
1.0
0.5
Total scores
5.5
14.5
12.5
Sl. No. Fishery development:(parameters)
1
Construction of fish pond
0.5
2.0
4.0
2
Wetland for fish culture
1.0
2.0
3.0
3
Mari culture ponds
1.0
1.0
2.0
4
Dry fish processing platform
0.5
1.0
2.0
5
Construction of mud built bank wall and clay
mining
0.3
0.5
1.0
6
Fisher man’s colony development (temporary
structures)
0.2
0.5
0.5
7
Release of untreated water from the fish farms
0.1
0.5
1.5
8
Construction of fishing harbors and jetties; sluice
gates, bridges etc.
0.2
0.10
0.20
Total scores
3.8
7.6
14.2
Sl. No. Hypersalinity:(parameters)
1
Formation of saline blank
4.0
2.0
2.0
2
Sub-aerial exposure of mangrove swamps and
rapid evaporation
3.0
2.0
2.0
3
Salt spray on the sea front mangroves
2.0
1.0
2.0
(continued)
11 Mangrove Degradation in the Sundarbans