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06-bioresourcesstatu.. - M. S. Swaminathan Research Foundation

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Vembanad Lake<br />

b. Kumarakom (9°37' N; 76°26' E)<br />

It is located by the side of Vembanad estuary the<br />

largest of its kind in Kerala as a continuous chain<br />

of about a kilometer in length. Tidal action in Fort<br />

Cochin is nearly 90 cm as recorded in the year<br />

1974. But a study in 1984 shows at present the<br />

tidal range is 20-60 cm. Major discharges into the<br />

estuary are the rivers such as Meenachal,<br />

Achancoil, Pamba, Manimala, and Moovattupuzha.<br />

The Kavanar, a tributary of the Meenachal River<br />

empties very near to the mangrove location.<br />

Construction of Thanneermukkam barrage and<br />

Thottapally spillway have changed the physicochemical<br />

properties of the water body in this part<br />

of the estuary with a host of other still unknown<br />

characteristics totally different from natural<br />

Vembanad estuary that existed two decades ago.<br />

c. Kannamali (9° 52' Nand 76° 16'E) :<br />

This mangrove is also in the Vembanad estuary<br />

near the bar mouth and hence the marine<br />

influence is very prominent. Area of the Cochin<br />

Corporation is a typical mangrove location. Thus<br />

mangroves are seen in Kumbalam, Trippunithura,<br />

Edappalli and Vypin besides the Mangalavanam of<br />

Cochin near the FCI godown and the surrounding<br />

artificial islands. Rivers Periyar and Varapuzha<br />

join the lake north of this part of the Vembanad<br />

Lake.<br />

d. Kumarakom :<br />

There is a mixed population of Rhizophora<br />

apiculata and Bruguiera gymnorrhiza running<br />

north to south bordering the Vembanad estuary.<br />

Pure stands of Sonneratia caseolaris is observed<br />

inside the sanctuary proper with a dense under<br />

growth of Phragmites karka (tall grass) suitable<br />

for perching birds. The Sonneratia trees are 10m<br />

high with a dense under growth of young saplings<br />

and seedlings of the mother tree. However,<br />

whenever openings are made, species such as<br />

Ardisia elliptica, Cerbera odollam, Hibiscus<br />

tiliaceus, Thespesia populnea, Terminalia<br />

catappa, Excoecaria agallocha, Heritiera<br />

littoralis do occur. Since the margins of the<br />

estuary is well protected by laterite walls, the<br />

characteristic natural zonation is unfortunately<br />

regulated (Ramachandran and Mohanan, 1987).<br />

The estuarine margins are pinged by Kandelia<br />

candel and Bruguiera gymnorrhiza, Rhizophora<br />

apiculata, Sonneratia caseolaris and Avicennia<br />

officinalis are observed up to the Barringtonia<br />

86<br />

racemosa zone where Heritiera littoralis,<br />

Calophyllum inophyllum, Hibiscus tiliaceus are<br />

also seen. Derris trifoliata, Caesalpinia crista,<br />

Salacia chinensis, Mucuna pruiriens, Argyeria<br />

sp and Anamirta coeculus are the climbers.<br />

Presence of Flagellaria indica is unique and it is<br />

the common climber masking the canopy. Littoral<br />

species such as Pongamia pinnata, Morinda<br />

citrifolia, Premna serratifolia, Lagerstroemia<br />

speciosa, Dolichandrone spathacea, Pandalus<br />

fascicularies etc. are present further inside along<br />

the bunds. Few cultivated taxa such as Cocos<br />

nucifera, Hevea braziliensis, Gliricidia sepium<br />

are also thriving well. Semiparasitics<br />

Loranthaceae like Dendrophthoe falcata and<br />

Viscum sp. are often found hanging on Kandelia,<br />

Rhizophora and Bruguiera sp. Acampe<br />

praemorsa an epiphytic orchid is rarely seen in<br />

the area. The inside canals support water plants<br />

such as Nymphoides indica, Salvinia molesta,<br />

Crinum defixum, Eichhorinia crassipes, Pistia<br />

stratiotes and Ludwigia adscendens.<br />

e. Kannamali (Edapalli, Cochin) :<br />

The areas adjoining Cochin and nearby islands at<br />

the mouth of Vembanad estuary used to be the<br />

single largest mangrove habitat in Kerala. The<br />

high population density of the area has<br />

deteriorated the mangrove. However, still in some<br />

pockets mangroves remain. Rhizophora<br />

mucronata attains its maximum development<br />

towards Kannamali. Avicennia officinalis has<br />

invaded most of the disturbed and reclaimed<br />

areas. Rhizophora mucronata fringes the<br />

margins of canals followed by R apiculata,<br />

Bruguiera gymnorrhiza & B cylindrica. On the<br />

tidal levels are Avicennia officinalis and<br />

Sonneratia caseolaris. Thick foliage of Acanthus<br />

ilicifolius, Acrostichum aureum is seen in areas<br />

with low salinity. Samadera indica and Hopea<br />

ponga are the species often found along with<br />

mangroves in Edappally region. Areas with more<br />

brackishwater influence support Typha<br />

angustata, Cyperus javanicus, Eichhorinia<br />

crassipes, SCirpus littorali, Cyperus pangorei<br />

etc.<br />

ii. Fauna<br />

The fauna is similar to any of the tropical rain<br />

forest. Among the endangered species of mammals<br />

Loris tardigradus, commonly known as slender

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