Record Details

Environmental impact assessment of suspended oyster, Crassostrea madrasensis (Preston) culture

CMFRI Repository

View Archive Info
 
 
Field Value
 
Relation http://eprints.cmfri.org.in/7608/
 
Title Environmental impact assessment
of suspended oyster, Crassostrea
madrasensis (Preston) culture
 
Creator Ramalinga,
 
Subject Edible oyster
Theses
 
Description The environmental impact due to farming of the Indian backwater oyster
Crassostrea madrasensis (Preston) for five consecutive years was studied. The
changes during crop holiday periods of three; six and nine months were also
assessed. The water column and sediment characteristics and benthic macrofaunal
community changes of farm sites of different farming and crop holiday periods were
compared with those of reference sites. The study indicated that there were no
significant variations in the hydrographic parameters due to continuous farming.
Howeve ~ the sediment characteristics and the benthic macrofaunal composition at
the farm sites were found to change with continuous farming. The percentage of
coarse and fine sand was found to decrease while that of silt, clay and organic
carbon found to increase with the year of farming. The impact on sediment
characteristics due to farming for two years could be rectified with a crop holiday of
six months period but the impact due to continuous farming for five years could not
be rectified even with a long-term crop holiday of nine months. The benthic
macrofaunal communities of the farm and reference sites were found to vary with the
year of farming. The number of species recorded at the farm and reference site of
first year of farming was almost similar (30 for farm site, 28 for reference site). The
number of species recorded for the second year farming period was 24 for farm site
and 33 for reference site, but the difference was not significant. On the contrary,
Significant differences were found in the number of species at the farm and reference
sites of three, four and five years of farming. The number of individuals was always
higher at the reference sites than that of farm sites. Maximum number of individuals
(1278 m·2
) was recorded at the first year farm site and the minimum (279 m·2) at the
fourth year farm site. Improvements in number of species, number of individuals were
noticed at farm sites when crop holiday was given and a crop holiday of six months
proved to be useful in rectifying the impact of oyster farming of two years. Based on
findings of the present study it is recommended that oyster farming can be done
continuously for a maximum period of two years and if the culture needs to be carried
for more than two years at the same site, a crop holiday of at least six months is to be
given. Altemately, the location of farming has to be shifted to an adjacent site after 2
years.
 
Date 2006
 
Type Thesis
NonPeerReviewed
 
Format application/pdf
 
Language en
 
Identifier http://eprints.cmfri.org.in/7608/1/TH-150.pdf
Ramalinga, (2006) Environmental impact assessment of suspended oyster, Crassostrea madrasensis (Preston) culture. ["eprint_fieldopt_thesis_type_phd" not defined] thesis, Central Institute of Fisheries Education, Mumbai.