The fertility of the coastal and estuarine waters is of great concern because of its influence on the
productivity of these waters. Seasonal variations in the distribution of organic carbon, total nitrogen and
total phosphorus in the sediments of Kuttanad Waters, a part of the tropical Cochin Estuary on the south
west coast of India, are examined to identify the contribution of sediments to the fertility of the
aquatic systems. The adjoining region has considerable agricultural activity. The fresh water zones had
higher quantities of silt and clay whereas the estuarine zone was more sandy. Organic carbon, total
phosphorus and total nitrogen were higher in the fresh water zones and lower in the estuarine zones.
Total phosphorus and organic carbon showed the lowest values during monsoon periods. No significant
trends were observed in the seasonal distributions of total nitrogen.
Ratios of C/N, C/P and N/P, and the phosphorus and nitrogen content indicate significant modification
in the character of the organic matter. Substantial amounts of the organic matter can contribute to
reducing conditions and modify diagenetic processes
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.
Description:
Journal of Wetlands Ecology, (2009) Vol. 3, pp 32-42
Chandramohanakumar, N; Ratheesh Kumar, C S; Joseph, M M; Gireesh Kumar, T R; Renjith, K R; Manju, M N(July 5, 2010)
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Abstract:
Heavy metals in the surface sediments of the two coastal ecosystems of Cochin, southwest
India were assessed. The study intends to evaluate the degree of anthropogenic influence on heavy metal
concentration in the sediments of the mangrove and adjacent estuarine stations using enrichment factor and
geoaccumulation index. The inverse relationship of Cd and Zn with texture in the mangrove sediments suggested
the anthropogenic enrichment of these metals in the mangrove systems. In the estuarine sediments, the absence
of any significant correlation of the heavy metals with other sedimentary parameters and their strong
interdependence revealed the possibility that the input is not through the natural weathering processes. The
analysis of enrichment factor indicated a minor enrichment for Pb and Zn in mangrove sediments. While,
extremely severe enrichment for Cd, moderate enrichment for Zn and minor enrichment of Pb were observed
in estuarine system. The geo accumulation index exhibited very low values for all metals except Zn, indicating
the sediments of the mangrove ecosystem are unpolluted to moderately polluted by anthropogenic activities.
However, very strongly polluted condition for Cd and a moderately polluted condition for Zn were evident in
estuarine sediments
Chandramohanakumar, N; Martin, G D; Rejomon, George; Shaiju, P; Muraleedharan, K R; Nair, S M(Hindawi Publishing Corporation, December 29, 2011)
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Abstract:
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.
Description:
The ScientificWorld Journal
Volume 2012, Article ID 972839, 17 pages