Floral diversity in Chilka Lake

Floral diversity in Chilka Lake, Orissa.

Out of several wetlands in India, Chilka lake in the state of Orissa was designated as Ramsar site in 1991 as an internationally important of waterfowl habitat. Chilka Lake is the largest one and unique of its kind for its magnificent biological diversity, ecological complexity and sustainability. This vast water body spreading over an area of 1100 sq. km harbours innumerable number of both floral and faunal components. It is a haven for migratory birds, having 159 species/subspecies (Dev, 1997). More than 800 species of animals are reported from this lake and its vicinity by Zoological Survey of India (Ghosh, 1995). About 225 species of fish have been reported from this lake (Dean & Saaltink, 1991). On the banks of the lake there are 8 fairly large towns and 122 villages. About 70% of this population depend upon fishing as the only means of livelihood. A population of about 1,27,000 souls are directly dependent on fisheries in the lake and 50,000 cattles may get their fodder need from the margin and bank of the lake (Trisal and Chauhan, 1998). A revenue of over 70 million rupees, is collected from 24 revenue villages on its banks (Bandyopadhay & Gopal, 1991). Besides these, the lake attracts several national and international tourists for its pristine beauty and charming environment. On an average 2.5 lakh tourists visit this lake annually.

Though much information regarding the common ecological and environmental status of the lake exist, still there is a gap in the baseline data on the total plant resources. Little is known of their taxonomy, quantitative ecological status and the mechanism by which they differ in their distributional patterns, their importance in the food chain of different fishes and birds as well as their effective role in protecting soil erosion and purifying the water quality. Not only information on ecological amplitude of algae/phytoplankton and seagrasses, or of aquatic macrophytes but also of the terrestrial plant communities living in the stressed environment of the islands and the shores and their role in this ecosystem are wanting. The detailed survey and studies on the plant resources of the islands and the lake surrounding, it is hoped, will give very important informations on the present status and monitoring the changes, if any, over time. These informations are required for proper planning of management towards sustainability of the ecosystem as a whole. Bandhyapadhya & Gopal (1991) suggested, “The biological and ecological diversity of this unique lagoon ecosystem need an in-depth study.

Vegetation & flora:

The vegetation of the lake ecosystem is broadly classified into aquatic and terrestrial Island vegetation. The aquatic vegetation is of algal vegetation and macrophytic vegetation. Phytoplankton and seaweed community is under the algal vegetation. Phytoplankton is abundant in all over the lake showing their seasonal fluctuation of species component. Seaweed community is distributed only in brackish and marine water zones. Aquatic macrophytes are of the Pleustophyte, Epihydate, Vittate, Rosette and Helophytic types. The terrestrial island vegetation is the formation of typical coastal scrubs.

12 seaweeds species are reported from this lake. 72 wetland plants including seagrass species are also collected/reported. Among the terrestrial vascular plants 305 species are collected/reported. Pteridophyte, Dicot and Monocot species are respectively 9, 288 and 80 that are reported from this lake.

A total number of 72 genera of phytoplankton and 8 genera of seaweeds have been collected from different sectors of the lake at different seasons. This large-scale diversity has a key role in the food chain of this lake ecosystem. Among the phytoplankton the number of genera under Myxophyceae, Chlorophyceae, Xanthophyceae, Bacillariophyceae and Dinophyceae are 12, 20, 1, 35, 3 respectively. The abundance of phytoplankton genera in the polluted water of the lake has also been studied.

A total number of 12 species of seaweeds under Chlorophyceae and Rhodophyceae are only distributed in marine and brackish water zone.

Table – 1: Seasonal and sectorial variation of the number of different phytoplankton groups.

NUMBER OF GENERA
SEASON	SECTOR
	NORTHERN					CENTRAL					SOUTHERN					OUTER CHANNEL
	MY	CH	XA	BA	DI	MY	CH	XA	BA	DI	MY	CH	XA	BA	DI	MY	CH	XA	BA	DI
SUMMER	5	3	-	4	-	6	1	-	3	-	5	4	-	21	-	4	9	-	18	2
MONSOON	3	4	-	3	-	9	4	-	15	2	3	3	-	13	2	1	2	-	13	3
POST MONSOON	6	8	-	12	-	7	11	1	13	-	4	3	-	11	-	4	6	-	24	1
WINTER	4	1	-	3	-	2	2	-	3	-	3	1	-	6	-	2	-	-	9	-

MY-MYXOPHYCEAE; CH-CHLOROPHYCEAE; XA-XANTHOPHYCEAE; BA-BACILLARIOPHYCEAE; DI-DINOPHYCEAE.

Table – 2: Number of genera/genus belonging to different Class associated with different

Vittate Macrophytes/ Seagrass/ Seaweeds of the lake.

No. of Phytoplankton Genera
Macrophytes	Myxophyceae	Chlorophyceae	Bacillariophyceae	Dinophyceae	Total
Potamogeton pectinatus	5	6	8	1	20
Najas indica	7	4	6	-	17
Halophila sp.	2	1	5	-	8
Hydrilla verticillata	4	4	11	-	19
Ceratophyllum demersum	4	4	5	-	13
Ruppia maritima	-	1	8	-	8
Enteromorpha intestinalis	3	3	7	-	14

Distribution of seaweeds varies depending on several factors like season, tidal amplitude, salinity, availability or quality of substrate, etc.

Table – 3: Distribution of the Seaweeds in the Lake.

CLASS	SEAWEEDS	DISTRIBUTION
CHLOROPHYCEAE	Chaetomorpha media	Ramb, P.C., SO, Nal..
	Cladophora glomerata	Sat, SO, B.F, P.C..
	Enteromorpha intestinalis	Balu, Nal, G.P., Satp, Ramb., P.C., SO, BF., HO., Bird..
PHAEOPHYCEAE	Rosenvingea intricate	Ari., Sat..
RHODOPHYCEAE	Ceramium elegans	Balu, Jat., G.P., Satp, Ramb., SO, BF., HO., Bird.
	Gracillaria lichenoides	Balu, Jat., G.P., Satp, Ramb., N.P., SO, BF., HO., Bird..
	Gracillaria verucosa	Balu, Jat., G.P., Satp, Ramb., N.P., SO, BF., HO. Bird..
	Gracillaria confervoides	Nal., Ram., G.P., Sat..
	Grateloupia filicina	Balu, Jat., G.P., Satp, Ramb., N.P., SO, BF., HO., Bird..
	Polysiphonia subtilissima	Balu, Jat., G.P., Satp, Ramb., SO, BF., HO., Bird..
	Polysiphonia sertularioides	Balu, Jat., G.P., Satp, Ramb.,S O, BF., HO., Bird..
CHAROPHYCEAE	Chara brachipus	Near Gopekuda Is.

[Balu = BALUGAON; Nal = NALBAN; Ramb = RAMBHA; So = SOMOLO ISLAND; Bird = BIRD'S ISLAND; Satp = SATPARA; Ari = ARIKUDA; P.C.: PALUR CANAL; B.F.: BREAKFAST ISLAND; G.P.: GARH KRISHNA PRASAD; HO.: HONEYMOON ISLAND; Jat.: JATIA ISLAND; N.P.: NUAPARA]

Table – 4: Distribution and association of seagrasses with seaweeds and other angiosperms.

Site	Seagrass	Associates
		Sea weeds	Other angiosperms
Nalban	Halophila ovalis ssp. Ovalis Halophila ovalis ssp. Ramamurtiana Halophila beccarii Ruppia maritima	Enteromorpha intestinalis Polysiphonia sertullarioides Gracillaria lichenoides	Potamogeton pectinatus
Rambha	Halophila ovalis ssp. Ovalis Halophila ovalis ssp. Ramamurtiana Halophila minor Halophila beccarii	Enteromorpha intestinalis Ceramium elegans Polysiphonia subtilissima Gracillaria lichenoides	Najas indica Najas graminea Potamogeton pectinatus
Somolo	Halophila ovalis ssp. Ramamurtiana Halophila beccarii Halophila minor Ruppia maritima	Enteromorpha intestinalis Ceramium elegans Gracillaria verucosa Gracillaria lichenoides	Potamogeton pectinatus
Palur Canal	Halophila ovalis ssp. Ovalis Halophila ovalis ssp. Ramamurtiana Halophila beccarii Halophila minor Ruppia maritima	Enteromorpha intestinalis Ceramium elegans Gracillaria lichenoides Polysiphonia subtilissima
Khola Muha	Halophila ovalis ssp. Ovalis Halophila ovalis ssp. Ramamurtiana Halophila beccarii Halophila minor Ruppia maritima	Enteromorpha intestinalis Ceramium elegans Gracillaria lichenoides Cladophora glomerata Chetomorpha media Polysiphonia subtilissima	Potamogeton pectinatus
Satpara	Halophila ovalis ssp. Ovalis Halophila ovalis ssp. Ramamurtiana Halophila beccarii Ruppia maritima	Enteromorpha intestinalis Ceramium elegans Gracillaria lichenoides	Najas indica Najas graminea Potamogeton pectinatus

Table – 5: Number of species in different growth forms of Aquatic Macrophytes

Number of Species

Vittate

Pleustophyte

Epihydate

Hyperhydate

Rosulate

Helophyte

Table – 6: Macrophytic concentration in the different sectors of the lake:

Growth form	Northern Sector	Central Sector	Southern Sector	Outer Channel Sector
Vittate	Hydrilla verticillata, Ceratophyllum demersum, Najas graminea, Najas indica	Potamogeton pectinatus, Najas graminea, Najas indica,	Potamogeton pectinatus, Najas graminea, Najas indica.	Potamogeton pectinatus, Potamegeton crispus, Najas indica.
Pleustophyte	Eichornia crassipes, Azolla pinnata sub sp. asiatica, Salvinia nataus, Salvinia cuculata, Pistia stratiotes, Lemna perpusila Spirodella polyrhiza, Ludwigia adscendens, Ipomoea aquatica, Hygrorhiza aristata, Neptunia olerasia, Utricularia aurea	Nil.	Nymphoides hydrophylla.	Nymphoiedes hydrophylla, Potamogeton nodosus, Potamogeton perfoliatus, Potamgeton lucens.
Ephydate	Potamogeton nodosus, Nymphaea pubescens, Nymphaea rubra, Nymphaea nauchali, Nymphoides indica, Nymphoides hydrophylla, Pasplum vaginatum
Hyperhydate	Arundo donax, Pragmites karka, Typha angustifolia, Monochoria vaginalis, Schoenoplectus maritimus, Elaeocharis urticularis	Phragmites karka, Arundo donax, Schoenoplectus maritimus	Arundo donax, Phragmites karka, Schoenoplectus maritimus.	Schoenoplectus maritimus
Rosulate	Valisnaria spiralis
Helophyte	Bacopa monniera, Alternanthera philexeroides, Alternanthera paranychoides, Commelina suffruticosa, Commelina diffusa, Hygrophylla auriculata, Eragrostis nutans, Paspalum distichum, Paspalidium punctatum, Dentella repens, Mecardonia procumbens, Phylla nodiflora, Marsilea minuta, Persicaria orientale, Persicaria barbata	Salichornia brachiata, Suaeda maritima, Sesuvium portulacustrum, Heliotropium curassivicum (salt marsh), Alloteropsis cimicina, Chenopodium album, Cynodon dactylon, Paspalum vaginatum, Panicum psilopodium, Saccharum spontaneum.	Sesuvium portulacustrum (salt marsh) Commelina suffruticosa, Murdania spirata, Cyperus rotundus, Ludwigia perennis, Hemathria compressa, Bocopa monniera, Lindernia ciliata, Lindernia crustacea, Lipia javanica, Phyla nodiflora	Panicum palludosum, Panicum repens, Bocopa monnieri.

Table – 7: Seasonal variation of Aquatic Macrophytes/Seagrasses in Nalban Island.

Seasons	Aquatic macrophytes/ seagrass
Summer	Potamogeton pectinatus, Halophila ovalis sub sp. ovalis, Halophila ovalis sub sp. ramamurtiana, Halophila minor, Halophila beccarii, Panicum psilopodium, Cyperus rotundus, Schoenoplectus maritimus, Arundo donax, Cressa cretica, Haliotropium curassivicum, Salichonia brachiata, Sesuvium portulacustrum, Sporobolus tremulus, Cynodon dactylon, Fimbristylis cymosa.
Monsoon	Potamogeton pectinatus, Najas graminea, Najas indica, Schoenoplectus maritimus, Arundo donax, Paspalum vaginatum.
Post Monsoon	Potamogeton pectinatus, Najas indica, Najas graminea, Schoenoplectus maritimus, Cyperus rotundus, Paspalum vaginatum, Chenopodium album, Arundo donax.
Winter	Potamogeton pectinatus, Paspalum vaginatum, Schoenoplectus maritimus, Arundo donax, Cyperus rotundus, Salichornia brachiata, Sesuvium portulacustrum, Suaeda maritima, Heliotropium curassivicum.

Table – 8: Vegetation type, its nature and distribution in Chilka Lake.

Vegetation type

Nature of the type

Sector

Halophila pure strand

Halophila –Ruppia mixed strand

Najas-Potamogeton pectinatus mixed strand

Potamogeton pectinatus pure strand

Vallisneria – Hydrilla mixed strand

Ceratophyllum pure strand

Nymphaea – Nymphoides pure strand

Nymphoides pure strand

Azolla pure strand

Pistia – Eichornia mixed strand

Schoenoplectus-Phragmites mixed strand

Schoenoplectus pure strand

Phragmitis pure strand

Vallisneria-Hydrilla-Nymphaea-Nymphoides mixed strand

Ipomoea – Nymphoides mixed strand

Submerged

Floating

Emergent

Submerged-Floating

S.S., C.S.

C.S., S.S.

C.S. S.S.

N.S.

O.S.

N.S.

N.S.,C.S., S.S.

N.S.

N.S

C.S. - Central Sector; N.S. - Northern Sector; S.S. - Southern Sector; O.C.S. -Outer Channel Sector

Table - 9: Number of economically important plant resources.

Vegetable

Fodder

Paper, Pulp, Fibre and Thatching materials

Medicine

Fish Food

Bird’s Food & Nest

No. of Genera

No. of Sp.

No. of Genera

No. of Sp.

No. of Genera

No. of Sp.

No. of Genera

No. of Sp.

No. of Genera

No. of Sp.

No. of Genera

No. of Sp.

162

185

The landmass of this lake is classified into mainly three categories - viz. 1. Island 2. Shoreline or spit 3. Adjoining areas or bank sites.

Islands: According to different topographic pattern the islands can be divided into four major types on the basis of major edaphic conditions such as. i. Rocky islands, ii. Sand mixed rocky islands, iii. Sand-clay mixed rocky island and iv. Sandy islands.

Table - 10: Vascular plant diversity of the lake Chilka.

GROUPS	NUMBER
	Family	Genus	Species	Sub Species	Variety	Wetland Plants	Climber
DICOTYLEDONS	72	212	284	4	7	25	53
MONOCOTYLEDONS	16	56	81	2	-	42	4
PTERIDOPHYTES	8	8	9	1	-	5	1
SEAWEEDS	8	9	12	-	-	12	-
TOTAL	104	285	386	7	7	84	58

Table - 11: Threatened Flora of Lake Chilka:

NAME OF THE SPECIES	STATUS	CAUSE
Cassipourea ceylanica (Gardn.) Alston	Rare	The population of the species has been reduced to countable number
Gloriosa superba L.	Rare	Increasing demand for isolation colchisin.
Rauvolfia serpentina (L.) Benth. ex Kurz.	Rare	Overexploitation of roots
Capparis roxburghii DC.	Rare	The population of the species is very reduced.
Commiphora wightii (Arn.) Bhandari	Threatened	Overexploitation for fuel wood.
Cissus vitiginea L.	Threatened	Only restricted in one island and exploited vigorously for fuel.
Eulophia epidendrea (Retz.) Fischer	Threatened	Only single plant observed in the whole area
Sarcostema acidum (Roxb.) Voight	Threatened	It’s rapid destruction mainly during Commiphora wightii as it is closely associated to it.
Aegiceras corniculatum (L.) Blanco	Threatened	Only a few plants are noted on two islands mainly due to unsuitable condition for multiplication
Aristolochia indica L.	Threatened	Overexploitation for medicine
Halophila beccarii Asch.	Threatened	Habitat change mainly for extensive prawn culture and fish catch.
Halophila minor (Zoll. ex Miq.) Hartog	Threatened	Habitat change mainly for extensive prawn culture and fish catch.
Halophila ovalis (R. Br.) Hook. f.	Threatened	Habitat change mainly for extensive prawn culture and fish catch.
Halophila ovalis (R.Br.) Hook. f. sub sp. ramamurtiana Ravikumar & Ganesan	Threatened	Habitat change mainly for extensive prawn culture and fish catch.
Ruppia maritima L.	Threatened	Habitat change mainly for extensive prawn culture and fish catch.
Macrotyloma ciliatum (Klein ex Willd.) Verde.	Threatened	Only a few plants are growing on lake bank. Overgrazing caused its thin population.
Pisonea aculiata L.	Threatened	Population is very thin due to clean up of the scrub jungles.
Colubrina asiatica (L.) Brogn.	Threatened	Population is very thin due to clean up of the scrub jungles.
Chara brachipus Braun	Threatened	Restricted only in one region, can not spread for wave action.
Rosenvingea intricata (J. Ag.) Boergs	Threatened	Population of the species has been reduced to countable number.

TOP

BACK

SEASON

Myxophyceae

Bacillariophyceae

CLASS

SEAWEEDS

DISTRIBUTION

CHLOROPHYCEAE

Chaetomorpha media

Ramb, P.C., SO, Nal..

RHODOPHYCEAE

Ceramium elegans

Balu, Jat., G.P., Satp, Ramb., SO, BF., HO., Bird.

Medicine

GROUPS

NUMBER