Show simple item record

dc.contributor.authorCastro, Paula
dc.contributor.authorValiela, Ivan
dc.contributor.authorFreitas, Helena
dc.date.accessioned2011-04-26T13:05:47Z
dc.date.available2012-01-01T09:30:26Z
dc.date.issued2007-12-06
dc.identifier.citationMarine Ecology Progress Series 351 (2007): 43-51en_US
dc.identifier.urihttp://hdl.handle.net/1912/4515
dc.descriptionAuthor Posting. © Inter-Research, 2007. This article is posted here by permission of Inter-Research for personal use, not for redistribution. The definitive version was published in Marine Ecology Progress Series 351 (2007): 43-51, doi:10.3354/meps07173.en_US
dc.description.abstractTerrestrial inputs of nitrogen in estuaries are increasing and altering salt marsh primary production, plant communities and associated biota. We used N isotope ratios and %N in Spartina maritima, Halimione portulacoides, Zostera noltii and below-canopy sediments to study eutrophication caused by anthropogenic land-derived nitrogen in the Mondego and Mira estuaries, Portugal. In spite of different land use practice intensities between estuaries, there were no marked differences in nitrate concentrations in the water column, but ammonium, total dissolved nitrogen and dissolved organic nitrogen concentrations were greater in the Mondego estuary. Sediment and shoot N contents suggest a general pattern of high nitrogen regimes in Mondego and Mira, and point to a somewhat higher delivery of nitrogen into the Mondego. However, these parameters were not sensitive indicators of level of eutrophication. In contrast, δ15N ratios in plant shoots differed significantly and were higher in Mondego for all 3 plant species. Plant δ15N signatures were therefore more sensitive sentinels of land-derived nitrogen load. The parallel increase of δ15N in shoots and sediments indicated that both shoots and sediments followed and reflected the level of eutrophication and some larger whole estuary difference in N loads. Thus, nitrogen isotopic signatures in macrophytes and sediments were useful indicators of land-derived nitrogen in estuaries.en_US
dc.format.mimetypeapplication/pdf
dc.language.isoenen_US
dc.publisherInter-Researchen_US
dc.relation.urihttps://doi.org/10.3354/meps07173
dc.subjectLand-derived nitrogenen_US
dc.subjectN-15en_US
dc.subjectRooted macrophytesen_US
dc.subjectMondego estuaryen_US
dc.subjectMira estuaryen_US
dc.titleEutrophication in Portuguese estuaries evidenced by δ15N of macrophytesen_US
dc.typeArticleen_US
dc.identifier.doi10.3354/meps07173


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record