Hatha, A A M; Abhirosh, Chandran; Sherin, Varghese; Ellen, Kandeler; Ambattu, Thomas; Asit, Mazumder(Elsevier, January 15, 2011)
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Abstract:
Microcosm studies were performed to evaluate the survival of Escherichia coli, Salmonella paratyphi and
Vibrio parahaemolyticus in water and sediment collected from the freshwater region of Vembanad Lake
(9 35◦N 76 25◦E) along the south west coast of India. All three test microorganisms showed significantly
(p < 0.01) higher survival in sediment compared to overlying water. The survival in different sediment
types with different particle size and organic carbon content revealed that sediment with small particle
size and high organic carbon content could enhance their extended survival (p < 0.05). The results indicate
that sediments of the Lake could act as a reservoir of pathogenic bacteria and exhibit a potential health
hazard from possible resuspension and subsequent ingestion during recreational activities. Therefore,
the assessment of bacterial concentration in freshwater Lake sediments used for contact and non contact
recreation has of considerable significance for the proper assessment of microbial pollution of the
overlying water, and for the management and protection of related health risk at specific recreational
sites. Besides, assessment of the bacterial concentration in sediments can be used as a relatively stable
indicator of long term mean bacterial concentration in the water column above
Description:
International Journal of Hygiene and Environmental Health 214 (2011) 258– 264
Sujatha, C H; Manju, Nair P(Academic Journals, September , 2013)
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Abstract:
This study gave the first report on the biennial metal divergence in the sediments of Cochin
Estuarine system (CES). Surface sediments from 6 prominent regions of CES were sampled
in 2009 and 2011 for the geochemical and environmental assessment of trace metals (Cd,
Co, Cr, Cu, Pb Fe, Mg, Mn, Ni and Zn).Besides texture, total organic carbon (TOC) and
CHNS were also done. The contamination and risk assessment were performed by
determining geochemical indices. Comparison with sediment quality guidelines were done
to assess the probability for ecotoxicological threat to the estuary. Results showed that the
measured heavy metals had varied spatial distribution patterns, indicating that they had
complex origins and controlling factors
Description:
International Journal of Recent Scientific Research
Vol. 4, Issue, 9, pp.1365- 1369, September, 2013
Sujatha, C H; Nify, Benny; Ranjitha, Raveendran; Fanimol, C L; Samantha, N K(December , 2009)
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Abstract:
Distribution and chemistry of major inorganic forms of nutrients along with physico-chemical parameters were
investigated. Surface sediments and overlying waters of the Ashtamudi and Vembanad Lakes were taken for the study,
which is situated in the southwest coast of India. High concentrations of dissolved nitrogen and phosphorus compounds
carried by the river leads to oxygen depletion in the water column. A concurrent increase in the bottom waters along with
decrease in dissolved oxygen was noticed. This support to nitrification process operating in the sediment-water interface of
the Ashtamudi and Vembanad Lake. Estuarine sediments are clayey sand to silty sand both in Ashtamudi and Vembanad in
January and May. Present study indicates that the sediment texture is the major controlling factor in the distribution of these
nutrient forms. For water samples nitrite, inorganic phosphate was high in Vembanad in January and May compared to
Ashtamudi. For sediments, enhanced level of inorganic phosphate and nitrite was found in Vembanad during January and
May. It had been observed that the level of N and P is more in sediments. A comparative assessment of the Ashtamudi and
Vembanad Lake reveals that the Vembanad wetland is more deteriorated compared to the Ashtamudi wetland system
Description:
Indian Journal of Marine Sciences
Vol. 38(4), December 2009, pp 451-456
Hatha, A A M; Abhirosh, C; Sherin, V; Thomas, A P; Abhilash, P C(Springer India, August 3, 2010)
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Abstract:
Prevalence of faecal coliform bacteria and the
survival of Escherichia coli, Vibrio parahaemolyticus and
Salmonella paratyphi were studied in the water and sediment
from Vembanadu Lake in the presence and absence
of protozoan predators. The density of faecal coliform bacteria
ranged between mean MPN value 5080–9000/100 ml
in water and 110,000–988,000/1 g in sediment (p <0.01),
which was 110 times greater than in overlying water. The
laboratory microcosm studies revealed that E. coli, V. parahaemolyticus
and S. paratyphi showed significantly higher
survival (p <0.05) potential in sediment than in overlying
water both in the presence and absence of protozoan predators.
The results indicate that Vembanadu Lake sediment
constitutes a reservoir of pathogenic bacteria and exhibits
potential health hazard from possible resuspension and subsequent
ingestion during recreational activities. Therefore,
assessment of bacterial concentration in freshwater lake sediments
used for contact and non-contact recreation is of considerable
significance for the proper assessment of microbial pollution of the overlying water and the management
and protection of related health risk at specific recreational
sites. In addition, assessment of the bacterial concentration
in sediments can be used as a relatively stable indicator of
long-term mean bacterial concentration in the water column
above.
This paper presents the first detailed investigation on the residual levels of organochlorine insecticide
(OCI) concentrations in the Cochin estuarine sediment. It aims in elucidate their distribution and ecological
impact on the aquatic system. Concentrations of persistent organochlorine compound (OC) were
determined for 17 surface sediment samples which were collected from specific sites of Cochin Estuarine
System (CES) over a period of November 2009 and November 2011. The contaminant levels in the CES
were compared with other worldwide ecosystems. The sites bearing high concentration of organochlorine
compounds are well associated with the complexities and low energy environment. Evaluation of
ecotoxicological factors suggests that adverse biological effects are expected in certain areas of CES