Mangroves: in Need of Estuary-based Estuary-based

Management Plans

M. D. Subash Chandran& 

TV R h dT.V. Ramachandra(CES, Indian Institute of Science)

MANGROVES: HABIT & HABITATS

Woody plants of intertidal habitats of estuaries and creeks – in tropics & sub‐

iMANGROVES: HABIT & HABITATStropics•Prefers muddy sediments•Salinity & water‐logging tolerant•34 genera & 79 species – 22 familiesg p•(about 40 spp. In India)•Substratum & water regime controlSubstratum & water regime control mangrove zonation

•Each species has its own range with•Each species has its own range withref to salinity

•Sea level rise: shift towards land

No. of Species: GlobalNo. of Species: Global

Sn Global region Natural species

Introduced species

Hybridsspecies species

1 West America 10 1 1

2 East America 9 1 1

3 West Africa 6 1 13 West Africa 6 1 1

4 East Africa 10 - -

5 Indo-Malesia 52 - 5

6 Australasia 43 - 5

Indian distribution No. of speciesS d b 32Sundarbans 32Orissa 30Godavari‐Krishna 17Cauvery delta 15Cauvery delta 15Kerala 18K t k 16Karnataka 16Goa 20Maharashtra 14Gujarat 10jAndaman & Nicobar 29

PRODUCTIVE ECOSYSTEMPRODUCTIVE ECOSYSTEM

• Spawning & nursery p g ygrounds of fish, crustaceans etc.

d f h ll f h• Producers of shell fish, oysters

• Habitat for birds• Habitat for birds• Timber, fuel, tannin, honey, medicine, foddery, ,

• Erosion control• Defense against gcyclones & tsunami

MANGROVE DECLINE: REASONSMANGROVE DECLINE: REASONS

Reclamation AquacultureReclamation Aquaculture 

Death due to dyke constructionDeath due to dyke construction

Other reasons: Pollution, hypersalinity, Rising sea level

Conservation & ManagementConservation & Management

• Working plans for Sundarbans from 1769Working plans for Sundarbans from 1769

• Matang (Malaysia) from 1902

C i i i i i• Community participation in management: MSR Foundation, Chennai (from 1993).  M i WMangrove manageent programme in W. Bengal, Orissa, A.P & T. Nadu

Flaws in ManagementFlaws in Management

• Most afforestation not fine‐tuned to intrinsicMost afforestation not fine tuned to intrinsic features  of estuaries – in the absence of comprehensive studiescomprehensive studies

• Restoration mostly monocultural – that could lead into imbalances in the ecosystemslead into imbalances in the ecosystems

• Mangroves degrade & disappear @1.5% /yr

• More of trial and error methods due to inadequate knowledge of ecological processes

Estuary‐based management plansEstuary based management plans

Ecological Restoration • Role of mangroves in co og ca esto at oProcess of assisting recovery of  an 

gecosystem functioning

• Estuarine historyyecosystem that has been degraded, d d

• Tidal dynamics, hydrology, soil & salinitydamaged or 

destroyed – complex estuarine features to

salinity

estuarine features to be related to mangroves

Objectives of management: Prioritisation

• Overall ecosystem functioning

• Enhancing fisheries

• Meeting needs of local community• Meeting needs of local community

• Pollution control & containment

• Preventing erosion

• Landscape beautification

• Nature education/recreation

• Bio‐shieding• Bio‐shieding

Identification of suitable areasIdentification of suitable areas

Use of Geo‐informatics for mapping

• Mapping areas for lnatural regeneration & 

enrichment planting• Afforestation using• Afforestation using multiple species based on physico‐chemical features, including pollution, erosion, siltationsiltation