| 1 | Human's impacts on the Pichavaram mangrove ecosystem a case study from Southern India Various type of human settlement and activities along the mangrove ecosystem in Pichavaram, Tamil Nadu (India) are described. This mangrove ecosystem is influenced by mixing of neritic water, brackish water and fresh water. Coastal human communities are highly dependent on mangrove ecosystem. Activities like grazing, bund construction for fishing, aquaculture and reclamation of land have caused erosion of the banks, species extinction, and ecological imbalance of the mangrove ecosystem Source: Krishnamurthy, K.; Jeyaseelan, M.J.P. Proceedings of the Asian Symposium on Mangrove Environment Research and Management. Soepadmo, E. ; Rao, A.N. Eds. 1984; 624-632. 0237. | ||
| 2 | Ecology and faunal association of intertidal mangrove habitats in the Hooghly-Matlah Estuarine System The mangroves at the Sundarbans, West Bengal were studied for establishing the flora and faunal associations. The core areas are dominated by the trees, shrubs and herbs; the semicore areas by trees with twiners; and the mudflats in medium saline zones with shrubs and herbs. Tree-crabs hasten the process of compositing by chewing the falling leaves. The burrowing Thalassina spp. enrich the soil by mixing soil layers. Nutrient-rich zones like that of Sudhannyakhali is dominated by Thalassina sp. and Acetes sp. The floral and faunal concentrations at different formative zones have also been worked out Source: Ghosh, A.; Chakrabarti, P.K.; Naskar, K.R.; Chattopadhyay, G.N.; Nath, D.; Bhowmik, M.L. J. Inland Fish. Soc. India. 22(1-2); 1990; 31-37. 0533. | ||
| 3 | Ecology of mangrove infested saline sewage-fed wetland in relation to fish culture Investigations conducted in a mangrove infested sewage-fed wetland having no mangrove vegetation. The plankton density was found to be low, ranging between 0.3 and 2.5 ml/50 l and represented principally by Amphora sp., Navicula sp., Oscillatoria sp., Spirulina sp., Lyngbya sp., Closterium sp., Cyclops sp., Branchionus sp., Diatoma sp. and Mysids. Benthos was found to be of higher density and represented principally by filamentous algae. The wetland was found to have lower microbial activity. Mangrove plants e.g., Excoecaria agallocha, Acanchus ilicifolius, etc. are existing in the wetland. The ecological conditions and productivity of the wetland demonstrated almost same situation as that of another wetland in the same area. It is assumed that due to sewage influence no effect of the presence of mangrove plants is detectable Source: Ghosh, A.; Chakrabarti, P.K.; Ghosh, A.; Das, R.K.; Naskar, K.R. National Seminar on Conservation & Management of Mangrove Ecosystem with Special Reference to Sunderbans, December 6-8, 1991. 1991; p.41. 0695. | ||
| 4 | Some aspects of the nitrogen cycle in mangrove and estuarine waters The seasonal changes of nitrogen nutrients, regeneration rates and uptake rates of nitrogen nutrients were investigated in a mangrove ecosystem on the west coast of India during 1997-1998. The changes of nutrient concentrations followed clear seasonal cycles. In case of NOd3u-@@ and NO@d2@@ @u-@@, advection with freshwater in monsoon and in situ biological processes during the rest of the year controlled concentration changes. In case of reduced forms, they were regulated by biological in situ production rates. The gradual increase in concentrations of the reduced forms in the dry months was mainly due to intense microbial decomposition of organic matter. Particulate organic nitrogen (PON) concentrations showed clear seasonal variations and ranged from 12.1 to 207.9 mu g. Litterfall appeared to be the major source of PON to the water column. Unlike that the PON, chlorophyll @ia@@ followed a different seasonal trend and concentration ranged from 0.1 to 21.6 mu g. The seasonal patterns of uptake rates were distinct, with a dominance of NO@d3@@ @u-@@ and NO@d2@@ @u-@@ uptake in the post-monsoon, followed by dominance of NH@d4@@ @u+@@ and urea uptake in pre-monsoon. Ammonium and nitrite production rates were among the highest known for nearshore waters and showed clear seasonal patterns Source: Heredia, A.M. 2000; 201; pp. 1136. | ||
| 5 | Studies on benthic nitrogen flux in a mangrove ecosystem The benthic nitrogen fluxes in the mangrove ecosystem of Achra Estuary, Ratnagiri, Maharashtra, India has been studied. The work was carried out at three stations along the estuary representing vegetated, partially vegetated and non-vegetated areas. It examined the sources of nutrients, their relationships and the influence of physical and biological processes on their abundance and distribution. The spatial heterogeneity in the nutrient pool was characterised by variations in the sediment structure, organic load and microbial mineralization rates. Ammonium was the dominant form of nitrogen at the mangrove zone whereas nitrate, at the non-mangrove zone. The autochthonous and allochthonous sources activity influenced the nutrient pool in different seasons. The benthic microalgal population showed significant succession in the taxonomic species composition and cell size structure with the season. The microbial processes were active in the non-monsoon months and showed well-marked spatial variations. The benthic microalgae utilized nitrogen nutrients from the overlying waters, besides from the pore waters. The spatial variations in the uptake rates were mainly due to the variations in the phytobenthos biomass at each locality Source: Dham, V.V. 2000; 165; pp. 1137.
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