Mangrove Managementin Tamil Nadu

M. S. Swami nathan Research FoundationChennai

Supported by

India-Canada Environment FacilityNew Delhi

- ..

M.S.SWAMINATHAN RESEARCH FOUNDATIONThird Cross RoadTaramani Institutional AreaTaramani, Chennai - 600 113, IndiaPhone +91-44-2254 1229, 2698, 1698, 2699Fax +91-44- 2254 1319E-mail msswami@mssrf.res.in

exec utived irecto r@mssrf.res.inWebsite: www.mssrf.org

Project Team:

Dr. V. SelvamDr.V.M. KarunagaranMr. K.K.RavichandranMs. G. Evanjalin Jessie Beula

Contents

1.0 Ma n9 roves 31.1 What are mangroves? 31.2 What are the factors that determine area, diversity and growth of mangroves? 31.3 What is the status of plant and animal diversity in mangrove wetlands? 41.4 What are the unique features of mangrove plants? 41.5 What is the global distribution of mangroves? 5

1.6 What are the uses of mangrove wetlands? 6

2.0 Ma ng roves Wetla nds of Ind ia ...............................•.............................................................. 72.1 Geomorphic settings 72.2 East coast mangroves 72.3 West coast mangroves 92.4 Andaman and Nicobar island mangroves 92.5 Changes in mangrove floristic 9

3.0 Mangrove Wetlands of Tamil Nadu 103.1 Pichavaram mangrove wetland ; 103.2 Muthupet mangrove wetland 12

4.0 MSSRF's contribution to restoration, conservation andmanagement of mangrove wetlands 144.1 Contribution to international mangroves 144.2 Contribution to national mangroves 154.3 Biotechnolog icaI resea rch 19

1.0 Mangroves

1.1 What are mangroves?

Mangroves are defined as woody trees and shrubs that grow in places where river water mixes withseawater. These places are otherwise called estuarine or brackish water environment. An assemblage ofsuch woody trees and shrubs is called a mangrove forest. Since mangrove forests are located in theestuarine environment, they are intersected by a number of small creeks and channels and in manycases large open water bodies are also found associated with them. Mangrove forests and associatedtidal creeks, channels, canals and water bodies together constitute mangrove wetlands. Mangrovewetlands are dominant features of the coastal areas of tropical countries.

1.2 What are the factors that determine area, diversity and growth of mangroves?

The health of the mangrove wetlands with reference to hydrological and soil conditions, and the wealthof the mangrove wetlands in terms of area, species diversity, biomass and productivity are determined by

.:. Degree of protection against high-waves

.:. Quantity and duration of freshwater flow and sediment supply

.:. Larger tidal amplitude and

.:. Gently sloping coastal topography.

Young mangrove plants of settle and grow only in coastal areas where wave energy is low or in placeswhere the mangrove wetlands are protected by a sand barrier against high-waves. The coastline of theMuthupet region of the then combined Thanjavur District and that of Sunderbans in West Bengal arethe best examples of low wave energy coasts where mangroves grow luxuriantly. In the Pichavarammangrove wetland of Cuddalore District, wave energy along the coast is high but a sandy beach,located between the mangroves and the sea, protects the mangroves.

Most of the mangrove plants require low salinity condition for their growth and reproduction. Hence,luxuriant mangrove forests can be seen only in the estuarine regions where a large amount of freshwater is discharged for long periods of time in a year. For example, the Sunderbans mangrove forest ofWest Bengal, which receives fresh water from the rivers Ganga and Brahmaputra throughout the year,harbours the highest number of mangrove plant species. The forest is also very thick and the height ofthe trees is very high. In the Pichavaram and Muthupet mangroves, which receive only low amounts of

4 Joint. Mangrove Management in Tamil Nadu

fresh water, that too only for a few months in ayear, the number of plant species present is verylow and the height of the trees is also very low.

The area of the mangrove wetland is determinedby tidal amplitude (difference between high tideand low tide) and the slope of the coastline. Forexample, tidal amplitude in the Sunderbansmangroves is about 4.8 m and the slope of thecoast is also very gentle. As a result, seawaterreaches up to 90 km inland from the sea and themangrove wetland is present all along the river,up to the point where seawater reaches. The totalarea of the Sunderbans mangrove wetland ofIndia is about 4, 26,000 ha (actual forest coveris about 2,12,500 ha). On the other hand, thearea of the Pichavaram mangrove wetland,where the tidal amplitude is only 0.65 m, is only1,300 ha (actual forest cover is only 900 ha).

1.3 What is the status of plant and animaldiversity in mangrove wetlands?

PlantsThe plant community in the mangroveenvironment is classified into two types namely,true mangrove species and associate mangrovespecies. True mangrove species are found only inthe mangrove wetlands, whereas associatedspecies are found both in the mangroveenvironment and in the nearby areas.Throughout the world, a total number of 68plant species are considered as true mangroveplants. All these species are able to grow in salinewater, but only a few of them tolerate highsalinity while most of them tolerate onlymoderate salinity. For example, a species calledAvicennia marina (it is present in Tamil Nadu

and it is called Kandal in the Pichavaram areaand Alayathi in the Muthupet region) cantolerate salinity as high as 90 grams/litre(seawater contains 35 gil of salt).

1.4 What are the unique features ofmangrove plants?

Unlike other plants, mangrove plants grow onlyin saline water. On the basis of physiologicalmechanism for salt tolerance mangrove plantsare classified into 3 types:

i) Salt excreting type: This type of mangroveplants take saline water as such throughroots and only water molecules and essentialsalts are retained in the tissues and excesssalts are excreted through salt glands.

ii) Salt excluding type: The roots of thesemangrove plants possess an ultra-filtrationmechanism called reverse osmosis by whichwater and salts in the seawater are separatedin the root zone itself and only water is takeninside and salts are rejected (reverse osmosismechanism is widely used in manufacturingbottled drinking water!).

iii) Salt accumulating type: This type ofmangrove plants possess neither salt glandsnor ultra-filtration system but these specieshave the capacity to accumulate a largeamount of salts in their leaves.

Breathing roots: The root system and other partsof the plants which are below the ground, alsorequire oxygen for respiration. Mangrove soil ischaracterized by low or nil oxygen and mangroveplants have adapted to survive in such anunpromising environment. The most striking

Mangroves 5

Table 1: Area of the mangrovewetlands of Asian countries

1.5 What is the global distribution ofmangroves?

The total area of the mangrove wetlands of theworld is about 181,077 sq.km or 18107700 ha.The area of the mangrove wetlands of some ofthe Asian, countries is given below:

Fish is another important animal component ofthe mangrove environment. Many of theestuarine species are found in mangroves andconstitute the fishery resources of the mangrovewetlands along with prawns and crabs.

Some of the mangrove wetlands harbour largeranimals like salt-water crocodiles, sea otters etc.and the Sunderbans mangroves is famous for theBengal Tiger. Many of the mangrove wetlandsalso act as feeding and breeding grounds for avariety of resident and migrant birds.

adaptations are aerial roots, which are otherwisecalled breathing roots. For example, in thespecies of Avicennia marina small finger-likeroots branch out from the main rootunderground and protrude out into theatmosphere. These roots have small poresthrough which oxygen enters into the root.

Viviparous plants: Another distinctive feature ofmost of the mangrove plants is vivipary, Le.seedlings grow when the seed is attached in themother tree itself (in other trees, seeds fall fromthe mother tree and grow into seedlings [in thesoil]). These seedlings are otherwise calledpropagules. Since the mangrove environment isharsh (salinity and low or nil oxygen in soils)most of the seeds falling from a tree might notsurvive and this would affect propagation of thespecies. To avoid this, mangrove plants produepropagules, which fall from the tree and fixthemselves in the mud or float in the water and fixthemselves in suitable areas and grow into trees.

AnimalsAlmost all groups of animals are present in themangrove environment but the most striking arecrabs, snails, bivalves and oysters. Interestingspecies among crabs are leaf eating crabs, tree-climbing crabs, fiddler crabs, hermit crabs, mudcrabs, mud lobsters, etc. Among them the mostcolourful are fiddler crabs. The male fiddler crabshave one greatly enlarged claw, coloured incrimson, orange and intense blue, used in socialdisplays and in jousting with rival males. Crabs ofthe mangrove environment are called ecosystemengineers since they modify the topography andair circulation in the soil and thereby influence thegrowth and productivity of the mangrove trees.

Country

BangladeshChina

India

IndonesiaMalaysia

MyanmarPakistan

Sri Lanka

ThailandThe Philippines

Toatal

Area (ha.)

5,76,70036,600

4,87,10045,42,1006,42,4003,44,4001,68,3008,900

2,64,1001,60,700

72,31,300

6 Joint Mangrove Management in Tamil Nadu

1.6 What are the uses of mangrove wetlands?

Mangrovewetlands comprise both mangrove forests and associatedwater bodies and hence, itstheir uses are multiple. The economic value of the mangrovewetlands stems from:

1. Availability of wood products ranging from timber, poles and posts and firewood

2. Availability of non-wood produce such as fodder, honey, wax, tannin, dye and plantmaterials for thatching

3. Availability of aquatic fo?d such as fish, prawn, crabs, mussel, clam and oysters.

Apart from these, mangrove wetlands provide a variety of amenities to coastalcommunities:

1. Mangroves mitigate the adverse impact of storms and cyclones in coastal areas.

2. They reduce coastal erosion.

3. They act as nursery grounds for many commercially important prawns, fish, crabsand molluscs.

4. They enhance the fishery productivity in adjacent coastal waters by providing themwith large quantities of organic and inorganic nutrients.

5. The root zone of the mangrove trees provide safe havens for young fish and prawns.

6. They provide habitats for diverse marine, estuarine and terrestrial wildlife, includingmigratory birds.

2.0 Mangrove Wetlands of India

State I Coast Mangrove Total area of Actual forestwetland the wetland (ha)* cover (ha)

East CoastWest Bengal Sunderbans 4,26,000 2,12,500Orissa Mahanadi 67,000 21,500Andhra Pradesh Godavari 33,250 . 24,100

Krishna 25,000 15600Tamil Nadu Pichavaram 1,300 900

Muthupet 13,000 1,855West CoastGujarat Gulf of Kutchh 58,200 85,400

Gulf of Combay 53,123 17,700Other mangroves - - 11,600Andaman and Andaman islands - 92,900Nicobar islands Nicobar islands - 3700

Total 4,87,755

Map showing distribution of mangroves in India

Table 2: Mangrove wetlands of India

,.

N

A150 0 150 Km~

.-\.J;'7_.'l- c•-; ..

T I IS E T

C " I N A

* Records of the State Forest Department

2.1 Geomorphic settingsOn the macro scale, geomorphic settings of themangrove wetlands of the east coast of India aredifferent from that of the west coast. The coastalzone of the west coast is narrow and steep inslope due to the presence of the Western Ghats.Secondly, there is no major west-flowing river. Asa result, mangrove wetlands of the west coast ofIndia are small in size, low in diversity and lesscomplicated in terms of tidal creek networks. Onthe other hand, mangrove wetlands of the eastcoast are larger, high in diversity and waterbodies associated with mangroves arecharacterized by the presence of larger brackishwater bodies and complex networks of tidalcreeks and canals. This is mainly due to thelarger deltas created by east-flowing rivers andthe gentle slope of the coast. According to ForestSurvey of India, out of 4,87,755 ha of themangrove wetlands of India, nearly 56.7%(2,75,800 ha) is present along the east coast and23.5% (1,14,700ha) along the west coast andthe remaining 19.8% (96,600ha) is found in theAndaman and Nicobar islands (Table 2).

2.2 East coast mangrovesSunderbansSunderbans is the largestmangrove wetland of theworld. The total area of theIndian part of the Sunderbansmangrove wetland is about4,10,000ha, of which2,12,500 ha is occupied bymangrove forest and1,78,100ha is water body.Large influx of fresh water intothe mangrove throughout theyear from the Ganga andBrahmaputra creates a highlyfavorable condition formangrove plants; nearly 27true mangrove species arepresent in this mangrove. Thepresence of flora and faunasuch as the Sundari, a beautifulmangrove plant, the Bengal

The east and west coasts of the mainland of Indiaand Andaman and Nicobar Island arecharacterized by the presence of mangrovewetlands.

8 Joint Mangrove Management in Tamil Nadu

tiger, saltwater crocodiles, spotted deer anddolphins, is one of the important features of theSunderbans mangroves. The Sunderbans containabout 300-500 tigers, the largest single survivingpopulation of tigers in the world. It has beenreported that about 25,000 tons of fish andprawn are harvested from the Sunderbansannually. In recent years the amount of freshwater reaching the Indian part of the Sunderbanshas reduced greatly due to the tilting of the landtowards east. The reduction in fresh water flow isone of the serious factors affecting thismangrove.Mahanadi mangrovesThe Mahanadi mangroves are present in the mid-region of the Orissa coast, about 250 km south ofthe Sunderbans mangrove. They are located in thecombined delta of the River Mahanadi, theBrahmini and the Baitarani rivers. TheBhitarkanika mangrove wetland, a part of theMahanadi mangroves is an important mangrovegenetic resources centre of the world. Since themangrove forest of the Mahanadi delta receivesfresh water from three rivers, the salinity of thewater and soil is comparatively less and hence,they are rich in species diversity and dense and talllike the Sunderbans. The diversity of animals isalso very high in Bhitarkanika mangroves. Thereare several species of mammals, birds,amphibians, reptiles, fishes, molluscs, crustaceansand other invertebrates. Hence, Bhitarkanikamangroves have been declared as a WildlifeSanctuary. It is also a habitat for a number of rareand endangered reptilians such as saltwatercrocodiles, water monitor, king cobra etc.Bhitarkanika holds the largest population ofendangered estuarine crocodiles in India. A larger

Remote sensing imagery of Mahanadhi mangroves

number of villagers, located within and aroundthese mangroves, utilise the fishery resources ofthe mangrove wetlands. In addition, a largeamount of honey is also collected. Conversion ofmangrove wetlands for agriculture andaquaculture is one of the serious problemsaffecting this mangrove wetland.

Godavari mangrovesThe Godavari mangrove wetland is located inAndhra Pradesh, in the delta created by the riverGodavari. The Coringa mangrove wetland, thelargest mangrove in Andhra Pradesh, has beendeclared a Wildlife Sanctuary. Fresh water flowsinto the mangrove wetlands of the Godavari deltafor a period of six months; the peak flownormally occurs during July to September,coinciding with the southwest monsoon season.During this period, the entire delta, including themangrove wetland, is submerged under freshwater. A large bay called Kakinada Bay isassociated with the northern part of the Godavariestuary. It has a long sand spit on the easternside, which separates Kakinada Bay from the Bayof Bengal. This bay is very shallow, about 2m indepth and during low tide, many areas of this bayare exposed. Comparing the growth of the sandspit with a map prepared in 1, 789, it isestimated that previously the mangrove wasabout 6 km inside the present shoreline. This isan indication of the expansion of the mangroveinto the sea. The presence of large populations ofsea otter is one of the important features of theCoringa Wildlife Sanctuary.

Krishna mangrovesThe Krishna delta is the seaward-extended landmass created by sediment deposits of the RiverKrishna. As in the case of the Godavarimangroves, the mangrove wetland of the Krishnadelta also receives fresh water for about sixmonths in a year. However the salinity level inthe Krishna mangroves is always high, asevaporation in the Krishna River is 15% morethan in the Godavari; also, there is a greatreduction in fresh water flow in recent years.Hence, the number of species present in theKrishna mangroves is less.

Pichavaram and Mlltl111pet mang1'OvesPichavaram and Muthupet mangrove wetlandsare located in the northernmost andsouthernmost ends respectively of the Cauverydelta and the distance between the two mangrovewetlands is about 140 km. Unlike the othermangrove wetlands of the east coast, both the

Pichavaram and Muthupet mangroves receivefresh water mostly during the northeastmonsoon season, from October to November.Thus, in these two mangrove areas, the dryseason is long, extending from February toSeptember and corresponding to it, the averagesalinity of the mangrove water is very high.Hence, species diversity is very less and the heightof the trees is also less. Reduction in fresh waterflow and closure of the mouth of the mangroveestuary during most part of the year are theserious threats to these two mangroves.

2.3 West coast mangrovesIn the west coast of India, a major wetland ispresent in the State of Gujarat. The climate is hotwith a rather cold season (subdesertic) and withvery strong average annual thermal amplitude.The average rainfall in the Gulf of Kutchch isonly about 470 mm and the dry seasoncontinues from October to June. No permanentriver discharges fresh water into this mangrovewetland. As a result of the above harshenvironmental conditions, the status of the

Gujarat mangroves iscomparatively poor. Thetotal area of the mangrovewetlands of Gujarat is about1,05,100 ha of which densemangrove vegetation ispresent only in about21,500 ha (20% of the totalarea) while the remainingarea is degraded. A largepopulation of camel grazesin this mangroves throughout the year.

2.4 Andaman and Nicobar island mangrovesThe total area of the mangrove wetland in thisgroup of islands is about 1,15,000 ha. Theclimate is humid and annual rainfall in theAndaman and Nicobar group of islands is veryhigh, about 2,750 mm and 3,080 mmrespectively. Hence, the Andaman and Nicobar

Mangrove Wetlands of India 9

island mangroves are also rich in plant andanimal diversity.

2.5 Changes in mangrove floristicIn most of the Indian mangrove wetlands floristichas changed dramatically. In the Sunderbans,Heriteria fomes was the most abundant speciesand attained more than 30 m in height in thepast. Now it has disappeared completely from theIndian part of the Sunderbans and only a limitedpopulation is present in the BangladeshSunderbans. Similarly, in the Pichavarammangrove wetlands Xylocarpus granatum,Sonneratia apetala, Kandelia candel and Bruguieragymnorhiza were present till recently but now noindividual of these species is present. Thepalynological studies carried out in Muthupetmangrove wetland indicate that true mangrovespecies belonging to Rhizophoraceae were thedominant species about 150 years ago but nowthey are locally extinct. Dense and tall trees ofAvicennia officina lis, Excoecaria agallocha andLuminitzera reacemosa constituted nearly 90% ofthe population of the Godavari mangrovewetlands in the 1950s, but now they constituteonly 37% of the population and are replaced bybushes of Suaeda maritima and S. monica. Thesetwo species are not true mangrove species andcan tolerate salinity as high as 100 gil. Ingeneral, the current status indicates that exceptin Andaman and Nicobar islands, in all themangrove wetlands of India, low-saline tolerantspecies are gradually disappearing and specieslike Avicennia marina which can tolerate a high

and broad range ofsalinity are

.~becomingdominant. Themain reason forsuch changes is thereduction in theperiodicity andquantity of freshwater reaching themangroveenvironment.

3.0 Mangrove Wetlands of Tamil Nadu

-- ----

~--;.---- -~~-,2::,:,.- -

Tamil Nadu has a coastline of about 950 km.Along the coastline major mangrove wetlands arepresent in two areas: one at Pichavaram inCuddalore District and the other in theMuthupet region in Thiruvarur-ThanjavurDistricts. Small patches of mangroves are alsopresent along the Palk Bay, particularly in theDevipattinam region and also in some of theislands of the Gulf of Mannar inRamanathapuram District.

3.1 Pichavaram mangrove wetland

The Pichavaram mangrove wetland is locatedabout 200 km south of Chennai in thenorthernmost part of the Cauvery delta. It issituated between the River Vellar in the northand River Kollidam (Coleroon) in the south andconnected to the estuaries of these two rivers bylarge brackish water canals,' called backwaters.The backwater canal which joins the mangroveswith River Kollidam is large and very deep. ThePichavaram mangrove wetland consists of 3Reserve Forests (RF), namely Killai RF,Pichavaram RF and Pichavaram Extension area.According to the remote sensing data of 1986the total area of these RFswas about 1474 ha(area in 1897 when this mangrove wetland wasdeclared a Reserve Forest was about 13 58 ha).Of this, thick mangrove forest occupied an areaof 325 ha (22%) and degraded mangrove forestwas found in about 375 ha (25%). The area ofthe water bodies associated with the Pichavarammangrove wetland was about 380 ha (25.7%).In addition, .sandy area, which is not suitable for

mangroves due to higher elevation, occupiedabout 394 ha (26.7%). The above data indicatesthat nearly 53% of the mangrove forest area (notthe wetland area) was in degraded state in 1986.

Currently, 12 true mangrove plant species arepresent in the mangrove wetland. The scientific(botanical) name and local name of thesespecies are given in Table 3. A mangrove treespecies, namely, Excoecaria agallocha, locallycalled Thillai has been worshiped as a temple tree(sthala viruksham) at the Lord Nataraja Templeat Chidambaram. The images of the Thillai areseen carved in rock sculptures and beingworshipped. These sculptures were made in theNataraja temple probably in the 2nd centuary AD.

Table 3: True mangrove plant species present in thePichavaram mangrove wetland

S.No Botanical name Local name1. Acanthus illicifolius Kazhuthaimulli2. Agiceras cornicu/atum Narikandal3. Avicennia marina Venkandal4. Avicennia officina/is Karungkandal5. Bruguiera cylindrica Pannukuththi6. Ceriops decandra Sirukandal7. Excoecaria agallocha Thillai8. Luminitzera racemosa Thipparathai9. Rhizophora mucronata Surrapunnai10. Rhizophora apicu/ata Surrapunnai11. Rhizophora natural hybrid sp Surrapunnai12. Xy/ocarpus mekongensis Somundhri

Among the 12 species found in Pichavaram,Avicennia marina (Venkandal) alone constitutes74% of the tree population.

Unique features of these mangroves.:. Trees of Rhizophora (Surrapunnai), which are

evergreen, are important from biodiversitypoint of view. The population of Rhizophorain the other mangrove wetlands of India,except in Andaman and Nicobar islands, isvery less.

.:. Another interesting point is the presence of anatural hybrid of Rhizophora species. Thishybrid species is born out of cross-pollinationbetween Rhizophora apiculata and Rhizophoramucronata. It is highly vigorous in growth andtall trees of this are found all along theborder of tidal creeks and canals.

.:. Harvestable forest resources are limited inthe Pichavaram mangroves. No timber and

Mangrove Wetlands of India Tamil Nadu 11

non-timber forest produce is available.Fodder and limited firewood are available butcollection is banned.

Uses of the mangrovesThe Pichavaram mangrove wetland is rich infishery resources. About 237 tons of fisheryproduce is harvested every year from thePichavaram mangrove wetlands, of whichprawns alone constitute 208 tons (82% of thetotal catch) whereas fish and crab constitute 19and 9 tons respectively. Both prawns and crabsare mainly exported. In addition to these, edibleoysters and green mussels are also available inlarge quantities; the green mussels are harvestedand exported to Kerala.

People belonging to 17 hamlets of 5 revenuevillages, namely, C.Manambadi, Killai,Pichavaram, T.S.Pettai and Thillaividangan,utilise the wood, non-wood and fishery resources.

Among the 17 hamlets, 9 arefishing and 8 are farming hamlets.The purpose and intensity of use ofmangrove resources differ fromone hamlet to the other; overall,only 8 hamlets are intensivelyusing the resources. One of theserious concerns in these hamletsis that nearly 41% of theemployable age group (15- 55years) has no stable occupation.Declining fish catch in therr..angrove waters, erosion oftraditional fishing rights anddegradation of the mangrovewetlands are some of the majorconcerns of the communities thatuse these mangrove resources.

Changes in the physical structureof the mangrove wetland due topast unscientific managementpractices and reduction infreshwater flow are the maincauses of degradation (elaboratedin Section 4). Grazing by cattle,particularly in the peripheral areasduring the monsoon season whennew seedlings establish is theimportant secondary factor fordegradation. Till the late 1980s, theForest Department permittedgrazing in the peripheral area of

12 Joint Mangrove Management in Tamil Nadu

the mangrove wetland through a permit systemsbut this has been stopped now to prevent theadverse effects of grazing.

3.2 Muthupet mangrove wetland

The Muthupet mangrove wetland is located inthe southernmost part of the Cauvery delta withPalk Strait in the south and extensive mudflats inthe north. Many of the drainage arteries of theCauvery River, namely, Pamini, Korayar,Marakakoryar, Pattuvanachi and Nasuvini,empty their water into the Muthupet mangrovewetland. The Muthupet mangrove wetlandcomprises healthy and degraded mangroves,large lagoon and canals, and creeks and man-made fishing canals.

According to the 1996 remote sensing data, thetotal area of the Muthupet mangrove wetland isabout 12,000 ha and for administrative purposesit is divided into 6 Reserve Forests. The differentcategories of wetlands found in these RFs aregiven in Table 4. The presence of two large

lagoons of about 1,700 ha, which arecontiguous, is one of the characteristic featuresof the Muthupet mangrove wetlands. The dataalso shows that the area of the healthy mangroveforest is only about 1855 ha whereas nearly7,178 ha of mangrove forest is in degradedcondition.

Only 5 mangrove species namely, Acanthusillicifolius, Agiceras corniculatum, Avicenniamarina, Excoecaria agallocha and Luminitzeraracemosa are present in the Muthupet mangrovewetland. Among them, Avicennia marina, whichis locally called Alaiyathi (alai = waves; athi =mitigate) is dominant, constituting more than95% of the tree population. But unlikePichavaram, trees of Avicennia marina are verytall in Muthupet and form a beautiful line alongthe banks of the tidal creeks, lagoons and canals.Hyper salinity in soil and water is the mainreason for the presence of low number ofmangrove species.

Table 4: Categories of wetlands in Muthupet mangrove wetland (area in hal

Category I Healthy Degraded Water body OtherReserve Forest mangroves mangroves (lagoon etc) vegetation Salt pan Total

Muthupet RF 950 4,553 1,100 200 0 6,803Thuraikadu RF 350 1,687 600 a 0 2,637T.Vadakadu RF 60 312 0 a 2 372Maravakkadu RF 75 525 0 a 890 1,490Thamarankottai RF 350 27 0 150 0 530Palanjur RF 70 74 0 25 20 189

Total 1,855 7,178 1,700 375 912 12,021

Like the Pichavaram mangroves, the harvestableforest resources such as timber and non-timberproduce are very limited in the Muthupetmangroves. Though fodder is available in thewetland, no regular grazing is practised sincemangrove forest is located far away from thevillages and access is very difficult due to muddysoil. Use of mangroves for firewood for householdconsumption is also very less but about 75families, mostly headed by destitute women andwidows, collect dead wood and dry twigs of themangroves and sell them at the local market fortheir livelihood.

People belonging to 26 hamlets of 16 revenuevillages live around the Muthupet mangrovewetlands. Out of these, 22 are fishing hamlets.The total population of these hamlets is about37,255 but average use of the mangrove wetlandfor fishing is only limited. Only during themonsoon season (October to December) fishersof all these fishing hamlets are engaged in fishingin the mangrove lagoon and trough-shapeddegraded area (locally called thottam); in otherseasons, the number of people fishing in themangrove waters is limited. During the non-monsoon period, most of the fisherfolks fish inthe nearby coastal water. The main concerns ofthe fishing families of the Muthupet region are

1) declining fish and prawn catch in themangroves

2) shrinking mouth of the mangrove lagoon dueto silt deposition

3) reducing depth of the mangrove lagoon,again due to silt deposition

Mangrove Wetlands of India Tamil Nadu 13

4) over-exploitation of fishery resources in thecoastal waters by trawlers and

5) Reduction in the mangrove forest cover.

One of the interesting aspects of the Muthupetmangrove wetland is the practice of thetraditional fishing method called canal fishing(vaaikkal meenpidippu), which integratesmangrove and fishery development. In thismethod, long canals about 1.5 to 2 km are dugacross degraded areas of the mangrove wetlandsthrough which tidal water flows freely in and out.The young fish and prawns that migrate into themangrove wetlands from the sea through thesecanals are trapped and allowed to grow for about3 to 4 months, after which well-grown fish andprawn are periodically harvested using a uniquetrap. This traditional method is being followed formore than 200 years by some of the fishingfamilies, particularly of Maravakkadu andnearby fishing hamlets. These man-made canalsprevent stagnation of tidal water in the mangrovewetlands but allow tidal water to flow freely in .and out during the high tide and low tide. As aresult, soil salinity becomes low and soil moisturebecomes high, which help the mangrove plants toestablish and grow. In fact, in the Muthupetmangrove wetland, a large area of healthymangrove forest is present only in the placeswhere the canal fishing method is being followed.

As in the case of the Pichavaram mangrovewetland, changes in the physical structure of themangrove wetland due to past unscientificmanagement practices and reduction in freshwater flow are the main causes of degradation.

4.0 MSSRF's contribution to restoration, conservationand management of mangrove wetlands

From 1990, the work of the M.S.SwaminathanResearch Foundation has led to an upsurge ofnational and international interests inrestoration, conservation and sustainablemanagement of mangrove wetlands.

It all began in September 1989, at aninternational conference in Tokyo on globalenvironment and sustainable development. Atthe conference, Dr.M.S.Swaminathan warnedthat global warming in future years would lead toa rise in sea levels, flooding coastal areas with seawater. He said that mangroves could help avertsuch a calamity because of their salt tolerant andsoil-binding characteristics. He called foranticipatory research so that scientists couldtransfer the salt-tolerant properties of mangroveplants to crop varieties, so that they can be grownin saline affected areas. He also urged integratedeffort towards the conservation, evaluation,classification and sustainable utilisation ofmangroves to protect the ecological security ofcoastal regions and the livelihood security ofcoastal communities.

4.1 Contribution to international mangroves

Establishment of Global Network ofMangrove Genetic Resource CentresDr.Swaminathan's remarks and suggestionsaroused much interest. They led the InternationalTropical Timber Organization (lITO) to supportMSSRFto conduct a project design workshop forestablishing a global grid of mangrove geneticresource centres. They also led to the setting up ofthe International Society for MangroveEcosystems (lSME) at Okinawa, Japan, in 1990.Dr.Swaminathan was elected its first President.

On the basis of the recommendations of theproject design workshop, two teams of scientistsvisited 23 mangrove sites in South and SoutheastAsia, Oceania and West and Central Africa.These two teams conducted intensive surveys in1992 and evaluated the sites using 10 criteria.On the basis of the recommendations of theteams, four sites, Bhitarkanika (Orissa, India),Sandakan (Malaysia), Baimuru (Papua NewGuinea) and Mouanko (Cameroon) wereselected for establishing mangrove geneticresources centres.

MSSRF's contribution 15

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resource centre of this area is being protectedwith the help of local communities.

Restoration of degraded mangrovesThe 1992 survey, conducted in various mangrovewetlands of India and other countries showed thatmost of these mangroves were in a highlydegraded condition. In order to restore these areas,MSSRFinitially started a project in Pichavaramand Muthupet mangrove wetlands in 1993 withthe support of the Canadian InternationalDevelopment Agency. The aims of this projectwere i) to identify causes of degradation ofPichavaram and Muthupet mangrove wetlandsand ii) to develop and demonstrate techniques torestore the degraded areas.

Identification of the causes of degradationGrazing by cattle and felling by local communitywere commonly sited as the major causes ofdegradation of the Pichavaram and Muthupetmangrove wetlands. But ecological studyconducted by the MSSRF team unearthed thereal reasons for the degradation. It was found outthat "coupe-felling" that was followed inPichavaram mangrove wetland from 1911 to thelate 1960s was the main cause of degradation.Coupe-felling is a system of managementfollowed by government agencies whereby treesare felled on a rotation basis every 20 to 30 yearsfor revenue generation. Studies indicated thatcoupe felling in Pichavaram exposed large areasof mangrove wetlands to sunlight, which in turncaused evaporation of soil water (mangrove soilcontains nearly 80% of water). As a result, soil inthe coupe-felled area shrank, changing the flattopography into a trough shape. Saline waterwhich entered the trough-shaped portions duringthe high tide became stagnant. Evaporation of

stagnant water increased soilsalinity to a level' lethal tomangroves. As a result, noregeneration of mangrove plantswas seen in the coupe-felled area.

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Following this, an international trainingprogramme on "Conservation of mangroveforest genetic resources" was organized inChennai with the aim of training the managersof the mangrove centres on all aspects ofmangrove conservation, evaluation,documentation and utilisation. Candidates from12 countries took part in the training andprepared a Charter of Mangroves for theirrespective countries.

Establishment of Mangrove EcosystemInformation ServicesUsing the information collected from 23mangrove sites in various countries as well asinformation collected from other mangroves, theMangrove Ecosystem Information Services wasestablished at MSSRF in 1993. It has fourdatabases: Mangrove Expert Database, MangroveBibliographic Database, Mangrove ResourcesDatabase and Mangrove Genetic VariabilityDatabase. This Information Service formed thebasis for the development of the GlobalMangrove Information Service (GLOMIS). TheInternational Tropical Timber Organisationsupported all the above activities.

4.2 Contribution to national mangroves

Establishment of a Mangrove GeneticResource Centre at PichavaramImmediately after the project design workshop, aMangrove Genetic Resource Centre wasestablished in about 50 ha of forestland providedby the Tamil Nadu Forest Department with thesupport of the Ministry of Environment andForests, Government of India. An area calledPeriaguda in the Pichavaram mangroves hasbeen selected for the Centre and now the genetic

16 Joint Mangrove Management in Tamil Nadu

East

Restoration techniqueOn the basis of the above findings, MSSRFdeveloped a simple technique to restorethe degraded areas and successfullydemonstrated it in the Pichavarammangrove wetland between 1993 and1996. A canal system, consisting of mainand feeder canals, was designed and dug inthe degraded area. The main canals were

connected to natural canalsnearby. This enabled tidalwater to flow freely in andout of the degraded area(instead of stagnating), thusdecreasing soil salinity andincreasing soil moisture.Planting mangrove saplingscompleted the task ofrestoration. This techniquewas demonstrated in adegraded area plot of about10 ha. The Tamil NaduForest Department as well asthe Ministry of Environmentand Forests, Government ofIndia, evaluated thistechnique through a sub-committee, which consideredthis technique as the bestavailable method to restoredegraded mangroves andincluded it in the NationalMangrove Action Plan.

Chatram Department and continued the samepractice of cutting and selling mangrove wood togenerate revenue to maintain numerous ehatrams.This practice was followed by the ForestDepartment even after independence, till the1970s. As explained in the case of the Pichavarammangrove wetland, suchlarge-scale felling of mangrove trees caused severalchanges in the biophysical condition of themangrove wetland, finally leading to thedevelopment of the hypersaline condition. Theproblem of hypersalinisation has been furtheraggravated in recent times due to the reduction infresh water flow into these mangrove wetlands.

Grazing by cattle, which is a problem in thePichavaram mangrove wetland and fellingby a few families in the Muthupetmangroves, could be considered only as asecondary causes of degradation.

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The same situation is responsible for large-scaledegradation in the Muthupet mangroves. Hereclear felling of trees started as early as the 1700s,when this mangrove was under the control of theKings Ekoji and Saraboji of Tanjore. These kingsconstructed a number of rest houses (ehatrams)for the convenience of pilgrims to south Indiafrom the north. Food and accommodation forovernight stay in the ehatrams were provided freeof cost. According to available records, the king ofTanjore decreed that these ehatrams should bemaintained by the revenue generated bymangrove wood, which was cut and sold astimber and firewood. After the British took overthe mangroves in 1799, they set up a separate

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MSSRF's contribution 17

Joint Mangrove ManagementAt the end of the demonstration described above,the following questions were raised: who wouldmaintain these artificial canals if they silted-up?Who would restore other degraded areas? Whowould protect plantations in the restoration area?This led to the genesis of community-basedmangrove restoration, conservation andmanagement, otherwise called as Joint MangroveManagement. This was started in the Pichavarammangrove wetland and later extended toMuthupet mangroves and further to Godavariand Krishna mangroves of Andhra Pradesh,Mahanadi and Bhitarkanika mangroves of Orissaand Sunderban mangroves of West Bengal. Theaim of this project was to build the capacities ofthe local communities, government agencies andgrass-root institutions such as Panchayats, torestore, conserve and utilise the mangrovewetlands in a sustainable manner throughparticipatory analysis and action.

The project's integrated approach to mangroverestoration, conservation and management isvisible in a wide range of activities-technical,socio-economic and administrative. The approachencompasses many implementing agencies, andincludes all the stakeholders: the mangrove user

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These remote sensing imageries demonstrate the project's success - they show an increase in mangrove areaat Pichavaram between 1986 and 2002 (Red patches indicate mangroves).

18 Joint Mangrove Management in Tamil Nadu

communities, MSSRF, the FD of different states,other government departments, rural agenciessuch as Panchayats, local NGOs, schools andprivate companies. This project has so far achievedthe following results in the states of Tamil Nadu,Andhra Pradesh, Orissa and West Bengal.I@il Established 28 village mangrove councils for

Joint Mangrove Management (JMM)involving 5,240 families as members

I@il Restored about 1,500 ha of degradedmangroves and planted 6.8 millionmangrove saplings with 75-80% survival

~ About 12,000 ha of prime mangrove forestbrought under JMM

I@il Organized 194 Self-help Groups including104 women SHGs through which a numberof poverty alleviation programmes wereimplemented

I@il Empowered women and women groups,youth and men groups technically, sociallyand economically to participate in JMM.

After seeing the success of JMM, the Ministry ofEnvironment and Forests has increased itsfunding for community-based mangroverestoration programmes in many of the statesand now mangrove restoration and conservationhas become a people's movement.

Joint Mangrove Management in Tamil NaduJoint Mangrove Management programmes wereimplemented both in the Pichavaram andMuthupet mangrove wetlands with a tripartiteagreement between the Tamil Nadu ForestDepartment, MSSRF and local mangrove usercommunities. In Pichavaram region, JMM isimplemented through the Village MangroveCouncils (VMCs) of Vadakku Pichavaram,Thandavarayan Sozhan Pettai (T.S.Pettai) andKalaingar Nagar and MGR Nagar of Killai town

Panchayat. A total number of 480 families aremembers in the VMCs. These VMCs restoredabout 250 ha of degraded areas in Pichavarammangroves and the remaining areas are nowbeing restored by the Forest Department. Thus,the entire Pichavaram mangrove has beenrestored, which is considered as one of theoutstanding successes of MSSRF's initiatives inmangrove conservation and management. In the

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MSSRF's contribution 19

Transfer of salinity - tolerant genefrom mangrove tree to rice

through VMCs and SHGs with the participationof different government departments. Three ofthe VMCs of the Muthupet region have also beenadopted by the Forest Development Agency.

4.3 Biotechnological research

Since 1990, the Department of Biotechnologyhas been supporting the MSSRF's on-goingprogramme for genetic enhancement of thecoastal ecosystem using modern biotechnologicalinterventions. Despite the ecological andeconomic potential of mangroves, studies onmangrove genetics have received little attention.With the anticipation of rise in the sea level as aresult of global warming in the years to come,MSSRF has initiated work on molecular mappingof major mangrove plant communities with anaim of isolating novel genetic combinations frommangrove species that offer tolerance to coastalsalinity, and utilise such genes to developlocation-specific and stress-tolerant cultivars.

The major emphasis of this programme is to@jiI analyse genetic diversity and species

relationships among Indian mangrove speciesand other economicallyimportant crop species,using molecular markertechnology as a preludeto genetic conservationand

@jiI isolate and characterisestress-tolerant genes todevelop salt-tolerantcrop varieties for coastalagri -eco-systems.

The ultimate objective ofthis activity is to develop anumber of location-specificsalinity-tolerant cropvarieties - an approachimmensely important inview of the increasingsalinisation of coastalregions in the years to come.Currently, a saline-tolerantrice variety has beendeveloped using mangrovegenes, which is underlimited filed trials as per thenorms of the Department ofBiotechnology, Governmentof India.

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Pichavaram villages, 30 women SHGs and 22men SHGs have also been formed. These SHGshave implemented a number of incomegenerating activities and various socialdevelopmental and welfare programmes with thehelp of the project, Tamil Nadu ForestDepartment, District Rural DevelopmentAgencies, scheduled banks and variousgovernment agencies. The newly formed ForestDevelopment Agency has adopted three of theproject villages and is implementing itsprogrammes through the VMCs of these villages.

In the Muthupet region four villages namely,Veerankoil, Manganangkadu, Karisaikkadu andMudukkukadu are participating in JMMprogrammes. In all these villages, VillageMangrove Councils, with a total membership ofabout 400 families, are functioning efficientlyand have restored about 375 ha of degradedmangroves. A total number of 33 SHGs,including 20 women SHGs, with more than 350members, is functioning. As in the case of thePichavaram JMM villages, a number ofdevelopmental activities are implemented

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