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

Vembanad Lake
agrochemicals, sewage and industrial effluents &
excessive fishing pressure resulted in growth over
fishing followed by recruitment overfishing.
a) The Thanneermukkam salt barrier shouid be
kept open for longer periods so that the nursery
grounds of fishes and prawns can be doubled.
This would also remove the restriction imposed
on migration of many finfishes.
b) By construction of a dike along the
southeastern boundary, the problem of salt
incursion into the paddy field can be resolved.
c) The growth overfishing followed by recruitment
overfishing can be regulated by increasing the
mesh size of the gears to about 20-25 mm.
d) The number of stake nets should be reduced as
it exerts lot of pressure on the juveniles of
penaeid prawns. Illicit operation of stake net
during high tide should be stopped.
e) The seaward migratory species for spawning
purpose shall be protected by minimizing the
fishing activities at the bar mouth and adjacent
regions, especially during the monsoon months.
f) Ranching in the down stream region with seeds
of penaeid prawns, mullets, milk fish (Chanos
chanos) and sea bass (Lates calcarifer) and in
the upstream region with Indian major carps,
selected indigenous carps, exotic carps, pearl
spot and giant fresh water prawn should be
done.
g) Creation of artificial spawning areas or
sanctuaries for brackishwater fishes and clam.
h) The shallow water areas along the fringes of
Acknowledgements
the lake can be utilized for aquaculture
practices. The Padasekharams of the lower
Kuttanad region can be utilized for raising
freshwater prawns and fish as a follow-up crop
after the paddy harvest.
i) The downstream migrating berried females of
M. rosenbergii should be given the status of
endangered species. Ranching by hatcheryproduced
seeds could be tried. A similar
endangered status can be accorded to Labeo
dussumieri also.
j) Exploitation of black clams below 20 mm should
be banned.
k) The present practice of allowing clay-water
slurry to spread in the lake from dredgers
should be stopped.
I) Use of poisons, explosive devices etc. should be
strictly prohibited for catching fish.
m) The mangrove vegetation covering about 44 ha
and bird sanctuary now fenced have a total of
8 ha. This is one of the main tourist attractions.
This should be further developed to attract
more people. However, the rubber and coconut
plantations have resulted in damage to the
mangroves. Attempts should be made not only
to preserve the sanctuary and the vegetation
but also to improve the rehabilitation of
appropriate mangrove species within & outside
the sanctuary.
Trespassing the sanctuary should be strictly
prohibited. Only those with bonafide historical,
ornithological, ecological interest should be
allowed inside the campus.
The authors are grateful to M.S. Swaminathan Research Fbundation for
providing the opportunity to present this report.
The authors record their thanks to Dr. E. Vivekanandan, G. Gopakumar and C. Muthiah
for providing many of the reprints on the subject.
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