Bijoy, Nandan S(The University of Waikato, Private Bag 3105, Hamilton, New Zealand, November 4, 2008)
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Abstract:
The South West (S.W.) coast of India is blessed with a series of wetland systems popularly
referred to as backwaters covering a total area of 46128.94 ha. These backwaters are
internationally renowned for their aesthetic and scientific values including being a repository
for several species fish and shell fishes. This is more significant in that three wetlands
(Vembanad, Sasthamcotta and Ashtamudi) have recently been designated as Ramsar sites of
international importance. Thirty major backwaters forming the crux of the coastal wetlands
form an abode for over 200 resident or migratory fish and shellfish species. The fishing
activities in these water bodies provide the livelihood to about 200,000 fishers and also provide
full-time employment to over 50,000 fishermen. This paper describes the changes on the
environmental and biodiversity status of selected wetlands, during 1994-2005 period. The pH
was generally near neutral to alkaline in range. The salinity values indicated mixohaline
condition ranging from 5.20-32.38 ppt. in the 12 wetlands. The productivity values were
generally low in most of the wetlands during the study, where the gross production varied
from 0.22 gC/m3/day in Kadinamkulam to 1.10 gC/m3/day in the Kayamkulam. The diversity
of plankton and benthos was more during the pre-monsoon compared to the monsoon and
post-monsoon periods in most of the wetlands. The diversity of plankton and benthos was
more during the pre-monsoon compared to the monsoon and post-monsoon periods in most of
the wetlands. The average fish yield per ha. varied from 246 kg. in Valapattanam to 2747.3 kg.
in Azhikode wetland. Retting of coconut husk in most of the wetlands led to acidic pH
conditions with anoxia resulting in the production of high amounts of sulphide, coupled with
high carbon dioxide values leading to drastic reduction in the incidence and abundance of
plankton, benthic fauna and the fishery resources. The major fish species recorded from the
investigation were Etroplus suratensis, E. maculatus, Channa marulius, Labeo dussumieri, Puntius
sp. Lutianus argentimaculatus, Mystus sp., Tachysurus sp. and Hemiramphus sp. The majority of
these backwaters are highly stressed, especially during the pre monsoon period when the
retting activity is at its peak. The study has clearly reflected that a more restrained and cautious
approach is needed to manage and preserve the unique backwater ecosystems of South-west
India
Description:
Proceedings of the Conserv-Vision Conference, University of Waikato, 2-4 July 2007
Ashokakumaran, Unnithan K; Dr.Menon,N R; Dr.Kuttyamma, V J(Cochin University Of Science And Technology, August , 1997)
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Abstract:
The present research programme envisages a comparative study of the effects of
two piscicides of plant origin, viz., mahua oil cake, a derivative from the plant fig
Iatifolia and croton seed, a product from the plant Croton tiglium. Although some reports
on the effects of mahua oil cake and croton seed on fresh water pond culture systems are
available, information on their effect on brackishwater culture systems are rather scanty
This was the guiding principle for launching the present study It is hoped that the findings
will enable aquaculturists to make use of the piscicides in a more rational and efficient
way, and will go a long way towards realising the maximum return liom culture systems
without hampering the environment.
The thesis is presented in seven chapters such as Introduction, Review of
literature, Materials and Methods, Results, Discussion, Summary and Bibliography
Description:
School of Marine Sciences. Cochin University of Science and
Technology
Rashiba, A P; Dr.Saramma, Panampunnayil U(Cochin University of Science And Technology, April 9, 2010)
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Abstract:
The main objectives of the study are: To study the seasonal distribution of copepods with special reference to their qualitative and quantitative distribution, with notes on biodiversity in the Andaman Sea and the Bay of Bengal.
To study the spatial and temporal distribution of copepods in the Andaman Sea
and the Bay of Bengal.To understand the hydrography and the environmental characteristics of the Andaman Sea and the Bay of Bengal and their role in the distribution and biomass of copepods.To study the vertical migration/diurnal migration of the copepods.
To study the difference between the coastal and oceanic composition of copepods
in the study area and the factors responsible for it.
Description:
National Institute of Oceanography, Regional Centre, Kochi