Dr. N Chandramohanakumarhttps://dyuthi.cusat.ac.in:443/xmlui/handle/purl/46062024-02-07T19:35:06Z2024-02-07T19:35:06ZSeasonal Variability Of Dissolved Nutrients In Mangrove Ecosystems Along South West Coast Of Kerala, IndiaChandramohanakumar, NGeetha, RLizen, Mathewshttps://dyuthi.cusat.ac.in:443/xmlui/handle/purl/46042014-08-14T20:30:32Z2009-12-13T00:00:00ZSeasonal Variability Of Dissolved Nutrients In Mangrove Ecosystems Along South West Coast Of Kerala, India
Chandramohanakumar, N; Geetha, R; Lizen, Mathews
The mangroves of Kerala are fast disappearing due to developmental activities.There are very few
studies conducted in the chemical aspects of these ecosystems.The main objective of this study is to
assess the spatial and seasonal variation of hydrographical as well as nutrients in mangrove
ecosystems along Kerala coast. Five sampling sites least intervened by industries were selected for
the study. Sampling was done for a period of six months in monthly intervals. A monsoonal hike of
dissolved nutrients was observed in all ecosystems except in the constructed mangrove wetland. The
constructed wetland exhibited a different hydrography and nutrient level in all seasons. The mangrove
forest in this area consists of the species Bruguiera gymnorrhiza which has been planted since forty
years.
Journal of Wetlands Ecology, (2009) Vol. 3, pp 32-42
2009-12-13T00:00:00ZToxicMetals Enrichment in the Surficial Sediments of a Eutrophic Tropical Estuary (Cochin Backwaters, Southwest Coast of India)Chandramohanakumar, NMartin, G DRejomon, GeorgeShaiju, PMuraleedharan, K RNair, S Mhttps://dyuthi.cusat.ac.in:443/xmlui/handle/purl/46032014-08-14T20:30:31Z2011-12-29T00:00:00ZToxicMetals Enrichment in the Surficial Sediments of a Eutrophic Tropical Estuary (Cochin Backwaters, Southwest Coast of India)
Chandramohanakumar, N; Martin, G D; Rejomon, George; Shaiju, P; Muraleedharan, K R; Nair, S M
Concentrations and distributions of trace metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in surficial sediments of the Cochin
backwaters were studied during both monsoon and pre-monsoon periods. Spatial variations were in accordance with textural
charaterstics and organic matter content. A principal component analysis distinguished three zones with different metal accumulation
capacity: (i) highest levels in north estuary, (ii) moderate levels in central zone, and (iii) lowest levels in southern part.
Trace metal enrichments are mainly due to anthropogenic contribution of industrial, domestic, and agricultural effluents, whose
effect is enhanced by settling of metals due to organic flocculation and inorganic precipitation associated with salinity changes.
Enrichments factors using Fe as a normalizer showed that metal contamination was the product of anthropogenic activities. An
assessment of degree of pollution-categorized sediments as moderately polluted with Cu and Pb, moderately-to-heavily polluted
with Zn, and heavily-to-extremely polluted with Cd. Concentrations at many sites largely exceed NOAA ERL (e.g., Cu, Cr, and Pb)
or ERM (e.g., Cd, Ni, and Zn). This means that adverse effects for benthic organisms are possible or even highly probable.
The ScientificWorld Journal
Volume 2012, Article ID 972839, 17 pages
2011-12-29T00:00:00ZGeochemical characteristics of surficial sediments in a tropical estuary, southwest IndiaChandramohanakumar, NRenjith, K Rhttps://dyuthi.cusat.ac.in:443/xmlui/handle/purl/46022014-08-14T20:30:13Z2007-08-09T00:00:00ZGeochemical characteristics of surficial sediments in a tropical estuary, southwest India
Chandramohanakumar, N; Renjith, K R
Geochemical characteristics of surficial sediments in the Panangad region of Cochin estuary, the largest
brackish-water humid ecosystem in the south-west coast of India, were analysed. Temporal variations
in nutrient stoichiometry, seasonal characteristics of redox elements Fe and S, and the phosphorus geochemistry
were employed for the purpose. The stoichiometric analysis pointed towards autochthonous
origin of organic matter, possibility of nitrogen limitation, and allochthonous modification of redox
conditions. Seasonal variations were not statistically significant for all the geochemical parameters,
whereas significant spatial variations were observed with lower values at sandy stations, suggesting
that the texture of the sediments is the main factor influencing the sediment geochemistry. Significant
inter-relations between the geochemical parameters also suggest a common control mechanism. Based
on these geochemical characteristics, the study region can be effectively categorized into two distinct
zones, viz. (1) erosion and transportation and (2) deposition zones
Chemistry and Ecology
Vol. 23, No. 4, August 2007, 337–345
2007-08-09T00:00:00ZFractionation and bioavailability of phosphorus in a tropical estuary, Southwest IndiaChandramohanakumar, NRenjith, K RManju, Mary Josephhttps://dyuthi.cusat.ac.in:443/xmlui/handle/purl/46012014-08-14T20:30:32Z2010-05-07T00:00:00ZFractionation and bioavailability of phosphorus in a tropical estuary, Southwest India
Chandramohanakumar, N; Renjith, K R; Manju, Mary Joseph
Phosphorus fractionation was employed
to find the bioavailability of phosphorus and its
seasonal variations in the Panangad region of
Cochin estuary, the largest estuarine system in
the southwest coast of India. Sequential extraction
of the surficial sediments using chelating agents
was taken as a tool for this. Phosphate in the
water column showed seasonal variations, with
high values during the monsoon months, suggesting
external runoff. Sediment texture was found to
be the main factor influencing the spatial distribution
of the geochemical parameters in the study
region. Similarly, total phosphorus also showed
granulometric dependence and it ranged between
319.54 and 2,938.83 μg/g. Calcium-bound fraction
was the main phosphorus pool in the estuary.
Significant spatial variations were observed for
all bioavailable fractions; iron-bound inorganic
phosphorus (5.04–474.24 μg/g), calcium-bound inorganic
phosphorus (11.16–826.09 μg/g), and acidsoluble
organic phosphorus (22.22–365.86 μg/g).
Among the non-bioavailable phosphorus, alkalisoluble
organic fraction was the major one (51.92–
1,002.45 μg/g). Residual organic phosphorus was
K. R. Renjith (B) · N. Chandramohanakumar · M. M. Joseph
Department of Chemical Oceanography, School
of Marine Sciences, Cochin University of Science
and Technology, Kochi 682016, Kerala, India
e-mail: renjithaqua@gmail.com
comparatively smaller fraction (3.25–14.64% of
total). The sandy and muddy stations showed
distinct fractional composition and the speciation
study could endorse the overall geochemical character.
There could be buffering of phosphorus,
suggested by the increase in the percentage
of bioavailable fractions during the lean premonsoon
period, counteracting the decreases in
the external loads. Principal component analysis
was employed to find the possible processes
influencing the speciation of phosphorus in the
study region
Environ Monit Assess (2011) 174:299–312
2010-05-07T00:00:00Z