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

Chilika Lake
meanwhile has been removed from the Montreux
Record on 11 November 2002. Efforts, largely by
the Chilika Development Authority (CDA), were
rewarded by the Ramsar Wetland Conservation
Prize for 2002, which was conferred upon the CDA
at ceremonies in Spain on 18 November 2002.
To address the various problems concerning the
Chilika lagoon, the Government of Orissa has
established the Chilika Development Authority
(CDA), in the year 1992. CDA has been executing
and monitoring various multi-disciplinary and
multi-dimensional developmental activities either
by itself or through commissioning of out side
agencies, the overall objective being to protect the
ecosystem of the lagoon with all its genetic
diversity. Apart from several measures
undertaken, one of the major accomplishments
achieved by the CDA in this direction has been
artificial opening of a mouth on September 23,
2000 linking the sea, Bay of Bengal, near
Magarmukh. While efforts have been on to protect
and restore Chilika from further degradation, it is
imperative that the status of Chilika with its
ecosystem and people and their socio-economic
conditions need reassessment. This has become
more pertinent after September 23, 2000 when the
unprecedented interference into the ecology of
Chilika through the opening of the new mouth at
Sipakuda took place. The status report may help
in detection of the changes that have been taking
place transforming the lagoon system in the conrse
of time. This information is vital for predicting the
fate of the lagoon as most lagoons do not persist
for long periods in the geological time scale and
eventually become swamps, marshes and
ultimately mig~t vanish with plant-colonisation
and encroachment (Barnes, 1980).
Figure 1: Location and map of the Cb/llke lagoon snowing
the sectors with some of lis towns a.nd vl/Jages and road
links and wafer routes.
202
II. Description of the Site
i. Location
Chilika lagoon is located at 19° 28' - 19° 54' N and
85° 06' - 85° 35' E on the east- coast of the state of
Orissa, India. The lagoon is about 71km long and
3-32 km wide. The area ranges from and 89,100 ha
during dry season (December-June) to116, 500 ha
during rainy season (July-October). The lagoon is
separated from the sea by a sand bar of 60 km in
length. The total area of the sand bar has been
estimated to approximately 323.62 km' and it acts
as a barrier island between the lagoon and the
sea. The lagoon has a 24 km long channel,
designated as the outer channel, which runs
parallel to the coast to join the Bay of Bengal near
Arakhakuda, the only mouth of Chilika till
September 2000. Choking and silting of the mouth
at Arakhakuda was causing reduction of tidal
influx of sea water, which in turn resulted in
decease of salinity of water inside Chilika. lt i.s
reported that high rate of littoral drift at the
shore-front of the lake resulted in a shift of the
inlet mouth towards north (Chandramohan and
Nayak, 1994).
The outer channel, at Satapada peninsula divides
into two branches. One continues along the
original course and the other turns at right angle
and enters into the main part of the lake at a
point called Magarmukh near Satpada. At
Satpada opposite the village Sipakuda the second
mouth measuring 110 m width and 280 m length
was opened on the 23'" September 2000. Based on
depth and hydrographic parameters the lagoon
has been divided into 1. Northern, 2. Central, 3.
Southern sectors, and 4. Outer channel (Figure 1).
Rivers Daya, Bhargavi and tribu taries of river
Mahanadi enter into the Chilika on the north. Th.e
two rivers along with eight smaller rivulets like
Ratnachira, Kusumi, Kina, Salia, Khalajhare,
Malgoni, Dhanua, Salia and ten water channels,
discharge approximately 375,000 cusecs of
freshwater carrying about 13 million tonnes/year
of silt into the lagoon. Deposition of silt has been
rendering the lagoon shallower over the years. On
the south the lagoon is connected to Rushikulya
estuary by the Palur canal.
As of now, the said canal has been narrowed off
due to heavy siltation. Further, the water holdings
along the canal being used for prawn culture do
not allow much water to flow into Chilika.