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

lake from the sea. The two openings, one
natural at Arakhaknda, and the second
artificial one at Sipakuda, provide the tidal
links for the lake with the sea. Tidal inlets
through the above openings are mainly
responsible maintaining the salinity gradient as
well as buffering action across the lake. The
inlets of the lagoon are reportedly closed due to
strong long shore drifts in the past. For better
protection of sand dunes and ridges
aforestation along the sand bar was suggested
(Orissa Government, 1974).
c. Nursery/Breeding grounds: The Chilka lagoon
has been a breeding ground for a number of
fishes. Information with respect to breeding and
spawning is available with respect to at least
44 species, of which Mugil cephalus, Liza
macrolepis, Hilsa ilisha, Nematolosa nasus,
Eleutheronema tetradactylum, Mystus gulio,
Pseudosciaena coiber, Lates calcarifera,
Gerres setifer and Etroplus suratensis are of
economic importance (Kowtal, 1969; Natrajan
and Pattnaik, 1971; Mohanty, 1975).
The lagoon provides vital protection and support
for many fishes during one or more stages of their
life cycle. The lake forms the nursery ground for
about 30 species in addition to the immigrants
from the sea. As of 1964-65,the outer channel was
the richest in species composition, besides serving
as a gate way for the fry of perches and mullets
(M. cephalus, L. macrolepis etc.). The northern
sector comes next in providing breeding and
nursery ground, followed by southern and central
sectors in that order. The lagoon serves as nursery
ground for large number of post larval and
juvenile immigrants such as clupeids, mullets and
perches (Kowtal, 1969)
d. Nesting grounds: Of 156 birds listed, there are
about 28 resident birds seen throughout the
year in Chilika (ZSI, 1995). Chilika has been
the breeding ground for the entire resident as
well as a few migrant birds. The site is an
important area for wintering and staging water
birds. Out of 159 bird species listed by Dev
(1997), 60 are indicated as resident and 99
winter migrants.
Inside the lagoon, a few islands in the central
sector, Bhasramunda and Chadyoga, for instance,
also serve as perching and nesting ground for
winter-birds. Yet another island, Nalabana, in
central sector off Balugaon, has a wide stretch of
swampy zone (ca 8 km') and has emerged as a bird
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Chilika Lake
sanctuary, playing host to the migratory birds from
Siberia and Kazakhstan. The island is covered
with aquatic plants, predominantly, Phragmites
karka that provide nesting ground for birds.
During the season of mansoon the island Nalabana
remains entirely under water. With the onset of
summer the island gradually emerges. Migratory
birds start flocking from October-November
onwards. At the time of our field tour undertaken
during the winter season in the months of October-
November 2001 we had observed that the
vegetation of P. karka at Nalabana island was no
more as luxuriant and prolific as it used to be in
the preceding years. It remains to be seen how the
disappearance of Phragmites will affect the
nesting and breeding population of the wetland
birds.
e. Refugium for endangered species: In addition
to supporting large to very large numbers of
waterfowl, Chilika lagoon also provides a
refugium for certain rare and endangered
species, such as the Spoon-billed Sandpiper
(Eurynohynchus pygmeus), Asian Dowitcher
(Limnodromus semipalmatus) and Goliath
Heron (Ardea goliath). Birds of prey seen at
Chilika include the Brahminy kite (Haliastur
indus), the Pariah Kite (Mitvus migrans),
Crested Honey-buzzard (Pernis ptilorhymus),
Black-shouldered Kite (Etanus caerulins),
Sparrow-hawk (Accipiter nisus), White-bellied
Sea-eagle (Haliaeetus leucogaster), Whitebacked
Vulture (Gyps bengalensis), Pale
Harrier (Circus macrourus). Pied Harrier
(Circus melanoleucos) and Marsh Harrier
(Circus aeroginosus), b'lt also rare species
such as Palla's Fish-eagle (Haliaeetus
leucoryphus) and Osprey (Padion haliaetus).
According to a recent survey conducted in
January 2001 by the Bihang Institute of
Ornithology and Mass Ecodevelopment (BlOME)
the population of migratory birds was 9.9 lakhs
comprising of 112 species, as compared to 15
lakhs of 125 species reported in 2000 (The
HIndustan Times, Orissa Edition, New Delhi
04/02/2001). The aforesaid source further
indicated that the birds which reappeared in
the lake after a gap of four to five years
included the Australian Stilt (Himaqutopus
leucocephalus), Asian Dowitcher
(f,imnodromus semipalmatus), Spoonbilled
Sandpiper (Eurynohynchus pygmeus), Curlew
Sandpiper (Calidris ferruginea) and
Broadbilled Sandpiper (Limicola falcinellus).