caa a22 4500 467904073 CHVBK 20180406152828.0 cr unu---uuuuu 170328e20061001xx s 000 0 eng 10.1007/s10661-005-9146-9 doi (NATIONALLICENCE)springer-10.1007/s10661-005-9146-9 Isotopic Composition as a Tool for Assessment of Origin and Dynamic of Organic Matter in Tropical Freshwater [Elektronische Daten] [M. Cunha, M. Yabe, I. Lobo, R. Aravena] The isotopic composition (13C and 15N) and C:N ratio of sediment and particulate were investigated to assess the origin and dynamic of the organic matter in two river basins located in the Parana State, Brazil. The main sources of organic matter, plants, litter and soil, were analyzed in the study. This study was carried out during the dry and wet seasons. Although organic matter contribution for the particulate material has been mixed, the main contribution in the two seasons for both rivers was autochthonous characterized by δ13C and C:N ratio values ranging from −31.0 to −21.8‰ and from 5.1 to 11.4, respectively. The soil with δ13C values ranging from −25.9 to −20.6‰, and C:N ratio from 10.2 to 15.8, was the main carbon source for the river sediment for the two tributaries in the wet and dry seasons. The sediment δ15N values for both the rivers in the wet season showed an 15N enrichment trend in most of studied sites when compared to the dry season values, suggesting major input of nutrients as dissolved organic nitrogen and sewage nitrate. In the dry season, 14N enriched compounds, could have been used by phytoplankton, causing 15N enrichment. The isotope and C:N ratio data clearly showed that the agricultural activity has been influencing the origin and dynamic of organic matter in the two rivers, with potential biochemical consequences for the lower basin of the major Tibagi river. Springer Science+Business Media, Inc., 2006 isotopic composition nationallicence 13C nationallicence 15N nationallicence C:N ratio nationallicence organic matter nationallicence tropical freshwater nationallicence Cunha M. Depto de Química, Universidade Estadual de Londrina, CP-6001, 86051-970, Londrina-Paraná, Brazil aut Yabe M. Depto de Química, Universidade Estadual de Londrina, CP-6001, 86051-970, Londrina-Paraná, Brazil aut Lobo I. Depto de Química, Universidade Estadual de Londrina, CP-6001, 86051-970, Londrina-Paraná, Brazil aut Aravena R. Department of Earth Sciences, University of Waterloo, N2L3G1, Waterloo, Ontario, Canada aut Environmental Monitoring and Assessment Springer Netherlands 121/1-3(2006-10-01), 461-478 0167-6369 121:1-3<461 2006 121 10661 https://doi.org/10.1007/s10661-005-9146-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10661-005-9146-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Cunha M. Depto de Química, Universidade Estadual de Londrina, CP-6001, 86051-970, Londrina-Paraná, Brazil aut NATIONALLICENCE 700 1- Yabe M. Depto de Química, Universidade Estadual de Londrina, CP-6001, 86051-970, Londrina-Paraná, Brazil aut NATIONALLICENCE 700 1- Lobo I. Depto de Química, Universidade Estadual de Londrina, CP-6001, 86051-970, Londrina-Paraná, Brazil aut NATIONALLICENCE 700 1- Aravena R. Department of Earth Sciences, University of Waterloo, N2L3G1, Waterloo, Ontario, Canada aut NATIONALLICENCE 773 0- Environmental Monitoring and Assessment Springer Netherlands 121/1-3(2006-10-01), 461-478 0167-6369 121:1-3<461 2006 121 10661 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer