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dc.contributor.authorNaqvi, S.W.A.
dc.contributor.authorNaik, H.
dc.contributor.authorJayakumar, A.
dc.contributor.authorPratihary, A.K.
dc.contributor.authorShirodkar, G.
dc.contributor.authorKurian, S.
dc.contributor.authorAgnihotri, R.
dc.contributor.authorShailaja, M.S.
dc.contributor.authorNarvekar, P.V.
dc.date.accessioned2009-12-22T10:00:19Z
dc.date.available2009-12-22T10:00:19Z
dc.date.issued2009
dc.identifier.citationIn "Indian Ocean biogeochemical processes and ecological variability. eds. by: Wiggert, J.D.; Hood, R.R.; Naqvi, S.W.A.; Brink, K.H.; Smith, S.L.", 333-345p.
dc.identifier.otherno
dc.identifier.urihttp://drs.nio.org/drs/handle/2264/3516
dc.description.abstractThe eastern Arabian Sea contains the only eastern-boundary-type upwelling environment in the entire Indian Ocean, albeit on a seasonal basis. During the southwest monsoon, when the surface current flows equatorward, upwelling brings oxygen-poor, nutrient-rich subsurface waters to the Indian continental shelf that turn anoxic (sulfate-reducing) by late summer due to exhaustion of oxygen and nitrate by heterotrophic microorganisms. This natural oxygen-deficient system, by far the world’s largest in the coastal ocean, is apparently more intense now than it was three decades ago. This is consistent with the sedimentary record, which indicates that productivity over the past few decades has been the highest ever in the last seven centuries. However, a trend of ongoing intensification is not seen in the data collected during the last 10 years at a coastal time series station off Goa. These data, nevertheless, show considerable interannual variability with the most severe anoxia having occurred in 2001, adversely impacting local fisheries (especially demersal fish catch). While increased nutrient loading to the coastal zone largely through atmospheric deposition of nitrogen most likely occurred in the last few decades, contributing to a shift to fully anoxic conditions, the observed interannual variability suggests that subtle changes in local hydrography/circulation could also modulate coastal anoxia in the region
dc.language.isoen
dc.publisherAmerican Geophysical Union
dc.rightsCopyright [2009] AGU. All efforts have been made to respect the copyright to the best of our knowledge. Inadvertent omissions, if brought to our notice, stand for correction and withdrawal of document from this repository.
dc.subjectSeasonal anoxia
dc.subjectIndian Ocean
dc.subjectheterotrophic microorganisms
dc.subjectnutrient loading
dc.titleSeasonal anoxia over the western Indian continental shelf
dc.typeBook Chapter


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