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Trace metal accumulation as complementary dietary information for the isotopic analysis of complex food webs

Food web structure is a fundamental feature of ecosystems. Stable isotopes (δ15N and δ13C) are used to estimate the relative contribution of food sources to consumer’s diets (e.g. mixing models). In complex food webs, the use of δ15N and δ13C measurements cannot always solve trophic interactions and distinguish among aquatic organisms with different feeding habits if little intra- and interspecific isotopic differentiation occurs. We have developed a method to characterize trophic relationships using Bayesian stable isotope mixing models in combination with trace metal data as prior information. Trace metal information is useful because of the high correspondence between trace metal profiles in consumers and their food sources, as we show here in an example of concentrations of fish and their expected dietary items. Trace metal concentration allows a more accurate estimation of relative contributions of food sources to consumer species compared to estimates based only on stable isotope values. We show the improvement of the procedure using four freshwater fish species with well-known feeding habits. The method provides a better estimation of the inter- and intraspecific dietary variability and correspondence with the feeding habits of these species. The approach described shows a considerable potential as a tool to assess trophic links in situations in which stable isotope methods are not conclusive. The method can be applied using other compounds that bioaccumulate in consumers (e.g. persistent organic pollutants)

Funding was provided by the Spanish Ministry and the Catalan Water Agency (MOBITROF), theGRACCIE project (CSD2007-00067), a Spanish Ministry of Education FPU fellowship (to DXS), the Spanish Ministry of Economy and Competitiveness (projects CGL2009-12877-C02-01 and CGL2013-43822-R) and the Generalitat of Catalonia (ref. 2014 SGR 484, 2014 SGR 1249)

© Methods in Ecology and Evolution, 2016, vol. 7, núm. 8, p. 910-918

Wiley

Author: Soto, David X.
Benito, Josep
Gacia, Esperança
García-Berthou, Emili
Catalán Aguilà, Jordi
Date: 2016 August
Abstract: Food web structure is a fundamental feature of ecosystems. Stable isotopes (δ15N and δ13C) are used to estimate the relative contribution of food sources to consumer’s diets (e.g. mixing models). In complex food webs, the use of δ15N and δ13C measurements cannot always solve trophic interactions and distinguish among aquatic organisms with different feeding habits if little intra- and interspecific isotopic differentiation occurs. We have developed a method to characterize trophic relationships using Bayesian stable isotope mixing models in combination with trace metal data as prior information. Trace metal information is useful because of the high correspondence between trace metal profiles in consumers and their food sources, as we show here in an example of concentrations of fish and their expected dietary items. Trace metal concentration allows a more accurate estimation of relative contributions of food sources to consumer species compared to estimates based only on stable isotope values. We show the improvement of the procedure using four freshwater fish species with well-known feeding habits. The method provides a better estimation of the inter- and intraspecific dietary variability and correspondence with the feeding habits of these species. The approach described shows a considerable potential as a tool to assess trophic links in situations in which stable isotope methods are not conclusive. The method can be applied using other compounds that bioaccumulate in consumers (e.g. persistent organic pollutants)
Funding was provided by the Spanish Ministry and the Catalan Water Agency (MOBITROF), theGRACCIE project (CSD2007-00067), a Spanish Ministry of Education FPU fellowship (to DXS), the Spanish Ministry of Economy and Competitiveness (projects CGL2009-12877-C02-01 and CGL2013-43822-R) and the Generalitat of Catalonia (ref. 2014 SGR 484, 2014 SGR 1249)
Format: application/pdf
ISSN: 2041-210X
Document access: http://hdl.handle.net/10256/13036
Language: eng
Publisher: Wiley
Collection: MICINN/PN 2010-2012/CGL2009-12877-C02-01
MINECO/PE 2014-2016/CGL2013-43822-R
AGAUR/2014-2016/2014 SGR-484
Reproducció digital del document publicat a: http://dx.doi.org/10.1111/2041-210X.12546
Articles publicats (D-CCAA)
Is part of: © Methods in Ecology and Evolution, 2016, vol. 7, núm. 8, p. 910-918
Rights: Tots els drets reservats
Subject: Peixos d’aigua dolça -- Alimentació
Freshwater fishes -- Feeding and feeds
Ecologia d’aigua dolça
Freshwater ecology
Title: Trace metal accumulation as complementary dietary information for the isotopic analysis of complex food webs
Type: info:eu-repo/semantics/article
Repository: DUGiDocs

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