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Fernandes Dearlyn Wu Ying Shirodkar Prabhaker Vasant Pradhan Umesh Kumar Zhang Jing 《海洋学报(英文版)》2020,39(4):18-32
Transitional ecosystems,estuaries and the coastal seas,are distinctively affected by natural and anthropogenic factors.Organic matter(OM)originating from terrestrial sources is exported by rivers and forms a key component of the global biogeochemical cycles.Most previous studies focused on the bulk biochemical and anthropogenic aspects affecting these ecosystems.In the present study,we examined the sources and fate of OM entrained within suspended particulate matter(SPM)of the Zuari River and its estuary,west coast of India.Besides using amino acid(AA)enantiomers(L-and D-forms)as biomarkers,other bulk biochemical parameters viz.particulate organic carbon(POC),δ13C,particulate nitrogen(PN),δ15N and chlorophyll a were analyzed.Surprisingly no significant temporal variations were observed in the parameters analyzed;nonetheless,salinity,POC,δ13C,PN,δ15N,glutamic acid,serine,alanine,tyrosine,leucine and D-aspartic acid exhibited significant spatial variability suggesting source differentiation.The POC content displayed weak temporal variability with low values observed during the post-monsoon season attributed to inputs from mixed sources.Estuarine samples were less depleted than the riverine samples suggesting contributions from marine plankton in addition to contributions from river plankton and terrestrial C3 plants detritus.Labile OM was observed during the monsoon and post-monsoon seasons in the estuarine region.More degraded OM was noticed during the pre-monsoon season.Principal component analysis was used to ascertain the sources and factors influencing OM.Principally five factors were extracted explaining 84.52%of the total variance.The first component accounted for 27.10%of the variance suggesting the dominance of tidal influence whereas,the second component accounted for heterotrophic bacteria and their remnants associated with the particulate matter,contributing primarily to the AA pool.Based on this study we ascertained the role of the estuarine turbidity maximum(ETM)controlling the sources of POM and its implications to small tropical rivers.Thus,changes in temporal and regional settings are more likely to affect the natural biogeochemical cycles of small tropical rivers. 相似文献
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《Marine Policy》2002,26(4):231-241
This paper attempts to predict changes and trends in future UK marine resource development and management. It does this by asserting that our presumptions about marine resources and the way in which they should be used are changing. Some emerging presumptions may not only preclude the use of existing technologies in some cases (e.g. dumping at sea), but may also act as drivers to the development of new technologies, such as offshore wave and wind power generation devices. A variety of maritime industries exploiting both living and non-living resources are examined individually. Attention is paid to marine conservation and the technologies that are important to providing generally for the protection of the marine environment. The authors conclude that major drivers will be ones for cleaner seas, for the development of renewable marine energy sources, and for the innovative management of the consequences of sea-level rise. With regard to the exploitation of living resources the finite limits to fisheries are stressed, and the present importance of industrial fishmeal supplies for salmon farming are highlighted. One of the greatest potential technological advances is predicted to be in marine habitat mapping. Given the changes in presumptions about our use of the seas, one over-riding conclusion is that the sustainable development of marine resources, and the conservation of priority habitats and species (for both the local seas and global oceans), must involve sustainable mechanisms for conflict resolution and decision-making. 相似文献
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