CHILIKA LAKE: ECOLOGY,BIODIVERSITY & CONSERVATION

PREPARED & PRESENTED BY:

RAJAN KUMAR:FRM MA2-01

Chilika on globe

Location-19028'N-19054'N & 85005'E-85038'E Boundries:

East-BOB North-alluvial plain of Mahanadi West & South-hills of eastern ghat

Coverage: Distt of puri Distt. Of kuurda Distt. Of ganjam

Origin

Quite recent Holocene period:6000-7000 yrs. Ago Fundamental process involved: coastal

submergence followed by coastal emergence Litttoral drift :imp. Process in spit barrier

formation Evidences of free oceanic connection of chilka

in past:sedimentological and minerological studies

Geometry Shape:pear Max. length:64.30 kms Max. width:18.00 Kms & Min. width:05.00 Kms Spit length:60 kms & width:150m-2000m Depth:0.38-6.20 mts WSA:(Annandale-1915-1924)

1165 sq. km(max.) 906 sq. km (min)

Av. lagoon area-760 sq. km(satellite studies late 1990s)

Ecological divisions

Northern sector Central sector Southern sector Outer channel Catchment area:3987 sq. km

Hydrological system

3 major system Mahanadi-Daya & Bhargavi Rivers from western catchment BOB

No. of rivulets: 52 N-E drainage basin- alluvial(<30m msl) N & N-W- laterite(30-50 msl) S & S-W-hills of eastern ghats(upto 600mts)

FW inlets of chilika lake

Physico-chemical character

• Imp. Parameters:– Temperature– pH– Dissolved oxygen– Salinity– Ammonia– phosphate

Temperature [03/08-02/09]• Higher temp.recorded during pre-monsoon period• Lowest recorded during monsoon

SEASON MAX.(DEGREE CELCIUS) MIN.(DEGREE CELCIUS)

PREMONSOON 34.2±0.25(OUTER CHANNEL)

30.6±0.31(SOUTHERN SECTION)

MONSOON 28.5 28.5

POST MONSOON 30.2±0.12(OUTER CHANNEL)

25.7±0.75(CENTRAL SECTION)

pH[03/08-02/09]

• PH of different parts of chilka varies differently in different season

• During premonsoon higher pH is recorded in Madarchua (near confluence of palur canal)and Bazarkote

• During monsoon drop in pH occurs in northern region but not translated in to lower region due to by passing of FW through muggermukh

• During post monsoon drop in pH is obseved in many places due to increased FW volume

SEASON MAX. MIN.

PREMONSOON 8.41±0.62(CENTRAL SECTION)

7.13±0.25(SOUTHERN SECTION)

MONSOON 8.4±0.35(SOUTHERN SECTION)

7.6±0.53(OUTER CHANNEL)

POST MONSOON 8.67±0.18CENTRAL SECTION)

7.62±0.22(CENTRAL SECTION)

DO(03/08-02/09)• Pre monsoon & monsoon do not have much variation in DO at

many zone

• Post monsoon have relatively higher DO @ several places

SEASON MAX.(mg/l) MIN.(mg/l)

PREMONSOON 10.17±0.23(SOUTHERN SECTION)

1.626±0.21(OUTER CHANNEL)

MONSOON 8.7±0.64(OUTER CHANNEL) 2.84±0.35(SOUTHERN SECTION)

POST MONSOON 10.32±0.31(SOUTHERN CHANNEL)

2.91±0.15(OUTER CHANNEL)

Salinity(03/08-02/09)• Pre monsoon the the area close to BOB like

Muggermukh & Arkhakudda have salinity of 30+ ppt

• During monsoon & post monsoon relatively lower salinity is observed

• Zonation based on salinity:– Outer channel-Mixohaline– South & central-Mesohaline– Northern -Oligohaline

SEASON MAX.(ppt) MIN.(ppt)

PREMONSOON 36.82±0.26(seamouth of outer channel)

5.27±0.21(Arakhakuda of outer channel)

MONSOON 14.08±0.31(SOUTHERN SECTION)

4.1±0.91(OUTER CHANNEL)

POST MONSOON 298.28±0.32(sea mouth of outer channel)

7.49±0.41(CENTRAL SECTION)

PO4 (03/08-02/09)

• Dissolved PO4 is most critical in maintenance of aquatic fertility.

• Depends upon soil-water system

• In recent times PO4 content is increasing due to fertilizer ap[plication in upland area

SEASON MAX.(micromol/l) MIN.(micromol/l)

PREMONSOON 1.035±0.06(CENTRAL SECTION)

0.17±0.13(OUTER CHANNEL)

MONSOON 5.4±0.24(OUTER CHANNEL) 0.855±0.25(SOUTHERN SECTION)

POST MONSOON 3.54±0.15(central section) 0.19±0.25(southern section)

NO3 (03/08-02/09)

• High content of NO3 through out year

• In highly weed infested zone NO3 is high

• High NO3 with higher pH becomes topic

SEASON MAX.(micromol/l) MIN.(micromol/l)

PREMONSOON 117.4±0.37(CENTRAL SECTION)

1.55±0.15(southern section)

MONSOON 96.21±0.54 (southern section) 19.48±0.61 (SOUTHERN SECTION)

POST MONSOON 94.65±0.25(central section) 10.46±0.29(southern section)

Variation in physico-chemical parameters in chilka lake

PARAMETERS BEFORE OPENING OF MOUTH

AFTER OPENING OF NEW MOUTH

pH 6.4--9.5 7.13-8.67

DO(mg/l) 3.9-12.4 1.63-10.32

NITRATE 0.02-13.1(microgram/L) 1,55-117.4(micromole/L)

PHOSPHATE 0.12-0.40(microgram/L) 0.17-5.4(micromole/L)

SALINITY(PPT) 3.8-32 4.1-36.8

Meteorological Aspects

SW monsoon: june-sep(major rainfall) NE monsoon:nov-dec(minor rainfall) Av. annual rainfall:1200mm Wind system:trade winds, south easterlies,

north westerlies & cyclonic depression Direction of wind:

feb-sep:from S & SW-clockwise circulation oct-jan:from N & NW-anticlockwise circulation

Wind major source of circulation & tide minor

Impotance of chilika lake

Livelihood and nutritional security :0.2 million fishermen and 64000 fisher families

Employment through artisnal support services 71% economic value generated from chilka

fisheries Av. prod:10,000mt Value of prod:Rs.587 million

High diversity: Fish-268 sps. Shrimp & prawns-29 sps. Lobsters-2 Crabs -35

Home of Irrawaddy dolphins In Orissa seafood export:

7.56% by volume 6.72% by value

tourism

CHILIKA & RAMSAR

2002 ramsar wetland award Removed from montreux record

Biodiversity

Fish-268 sps. Prawns & shrimps-29 lobsters-2 Crabs-35 Phytoplankton-399 sps. Zooplankton-170 sps. Molluscs-136 sps.

Algae -22 sps. Plants-720 sps.(8 rare & 11 endemic) Amphibians-7 sps. Reptiles-30 sps. Birds-225 sps. mammals-18sps. Annelids-31 sps. Nematodes-37 sps.

Important fish species

• Mugil cephalus• Liza macrolepis• Sparus sarba• Lates calcarifer• Tenualosa ilisha

• Nematalosa nasus• Eleutheronema

tetradactylum• Mystus gulio• Etroplus suretensis• Gerres setifer

Commercial important prawn species– Penaeus indicus– Penaeus monodon– Metapenaeus monoceros– Metapenaeus dobsoni

Commercial inportant crabs– Scylla serrata– Portunus sp.

Problem faced by chilika lake

↓ salinity ↑ siltation Chocking of inlet and outer channel ↓ WSA ↑ Weed infestation ↓ fish landings Faunal changes

salinity Most dominant in lake ecology

Reasons: Shift of inlet towards north Sediment build at mouth of chilika

Overall Av. salinity

YEAR SALINITY(PPT)

1957-58 22.3

1961-64 9.4-11.8

1995 1.4-6.3

Siltation Approx. 1.5 million tonnes/yr enters in North 0.3 million tonnes/yr from western catchment Nets, prawn traps etc. free sediment movement Blocking of outlet-restricts outflow of sediments

source:Orissa remote sensing agency

DEPTH

YEAR MAX(CM) MIN(CM)

1992-93 340 74

1994-95 332 58

1996-97 142 42

Chocking of inlet & outer channel

Magarmukh-summer depth alarmingly low(0.3m)

Cross section of outer channel reduced -poor flushing action.

Causing : Flood in northern sector Nalabana bird sanctuary remain submerged

during Oct. Prevent tidal ingress

Shrinkage of WSA

WSA in 1972-73 was 824 sq.km(summer)

Land sat-5 data(1986)-790 sq.km

Siltation can be attributed

Weed infestation

Potomogeton pectinatus dominate central & southern sector

Phragmitis karka are emergent weed in northern sector

Area under weed

YEAR AREA(SQ.KM)

1973 20

1977 60

1993 398

1998 440

Fish landings

• Av. Fish landing during mid 1980s-6000t• Declined to 1641.5t in 1997-98• Factors:

– Over fishing– Obstruction of migratory route– Salinity changes

TypeAnnandale(1914-24)

Ghosh(1995) comments

Fish 217 69 24 sps. FW

Crustacean Brachyura

36 28 ---------------------------------------------------

Molluscs 74 87 50 sps recorded in 1916 not found

Reptalia 22 23 8 sps.recorded in 1916 not found

Mammals 18 18 5 new entrant in place of 5 earlier oneFAUNAL CHANGES

CDA and its measures

• Comes into picture in 1992• Opening of new mouth along the outer channel• Excavation of lead channel of 3.2 km @

Magarmukh• Renovation of palur canal

Note:EIA of the impact of this lead channel is carried out by NIO

Impacts of measures

• ↑ in Av. Salinity level• ↑in tidal flux by 45%• Improvement in sediment flux• Quick discharge of flood waters• Decrease in invasive sps.

• Auto recruitment of fish & shrimp• 8 folds ↑ in fish prod.• ↑ in Irrawaddy dolphin (Orcaella brevirostris)

habitat from 25.91 sq.km to 183 sq.km• ↑ in seaweed area from22.32 sq.km(may 2000)

to 86.84 sq.km(jun 2004)• Improved biodiversity & return of threatened

species

Change in salinity & tidal flux

Declining weed cover in chilika

Weed category Oct 2000(sq.km) May 2001(sq.km)

Emergent weeds 86.07 71.62

Free floating weeds 110.74 51.81

Submerged weeds 336.20 227.58

Weed free area 333.20 505.82

Total fish landings:11995 T in 2009-10

Biodiversity restoring

• Return of mullets & P.indicus (50% of shrimp landings)

• Crabs (20.51% of total during 2001)• Six one time considered threatened sps. Are

back: Hilsa ilisha; Chanos chanos; Megalops cyprinoids; Elops machnata; Rhabdosargus berda; Rhinomugil corsula

• Improved seagrass meadow & sps. Diversity• Irrawady dolphin in central & southern region

Remaining problems

• Waste water discharge-25 million gallons/day from capital city & from 141 villages

• Upstream land use pattern• Regulation of tourism• Lack of strong legislation and implementation• Threats with irrigation project (Naraj barrage)

On going works• Project water with ICEF• Microwater shed project ant catchment

improvement• Biodiversity conservation:

– Dolphin survey & research– Bird conservation

• Improvent of water exchange & salinity gradient• Fisheries resource management

– JICA-CDA project– Pilot crab fattening project

• Telemetric data collection centre

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References• Kohli,M.P.S.2007.Ecology & fisheries of wetlands in India.

• ICAR.2011.Handbook of fisheries & aquaculture

• Sakhare V.B.2007. Applied fisheries

• CDA.2011.Strengthening of wetland research & training centre & biodiversity conservation of chilika lake

• Ashish k.Ghosh.Chilika lagoon:exprience & lesson learned

• GOI.2008.Report on visit to chilka lake in Orissa under NWCMP of MoEF

• CDA.2005.Habitat evaluation of chilka lake with special reference to bird as bioindicators

• CICFRI.1998.Chilka lake present & past

• Patra A.P.2010.Seasonal variation in physicochemical parameters of chilika lake after opening of new mouth near Gabankund,Orissa India.World journal of fish & marine sciences 2,PP.109-117

THANKS!