{"id":246,"date":"2010-10-27T17:31:18","date_gmt":"2010-10-27T08:31:18","guid":{"rendered":"http:\/\/www.oceanecol.com\/?p=246"},"modified":"2015-09-07T16:46:38","modified_gmt":"2015-09-07T07:46:38","slug":"reef-fish-discrimination-wyatt-et-al-plos-one","status":"publish","type":"post","link":"https:\/\/www.oceanecol.com\/?p=246","title":{"rendered":"Reef fish discrimination (Wyatt et al., PLoS One)"},"content":{"rendered":"<h2><a href=\"http:\/\/journals.plos.org\/plosone\/article?id=10.1371%2Fjournal.pone.0013682\" target=\"_blank\">Variability in Isotope Discrimination Factors in Coral Reef Fishes: Implications for Diet and Food Web Reconstruction<\/a><\/h2>\n<p>Alex S.J. Wyatt, Stuart Humphries, Anya M. Waite<\/p>\n<blockquote><p>Interpretation of stable isotope ratios of carbon and nitrogen (\u03b4<sup>13<\/sup>C and \u03b4<sup>15<\/sup>N) is generally based on the assumption that with each trophic level there is a constant enrichment in the heavier isotope, leading to diet-tissue discrimination factors of 3.4\u2030 for <sup>15<\/sup>N (\u0394N) and ~0.5\u2030 for<sup>13<\/sup>C (\u0394C). Diet-tissue discrimination factors determined from paired tissue and gut samples taken from 152 individuals from 26 fish species at Ningaloo Reef, Western Australia demonstrate a large amount of variability around constant values. While caution is necessary in using gut contents to represent diet due to the potential for high temporal variability, there were significant effects of trophic position and season that may also lead to variability in \u0394N under natural conditions. Nitrogen enrichment increased significantly at higher trophic levels (higher tissue \u03b4<sup>15<\/sup>N), with significantly higher \u0394N in carnivorous species. Changes in diet led to significant changes in \u0394N, but not tissue \u03b4<sup>15<\/sup>N, between seasons for several species:<em>Acanthurus triostegus<\/em>, <em>Chromis viridis<\/em>, <em>Parupeneus signatus<\/em> and <em>Pomacentrus moluccensis<\/em>. These results confirm that the use of meta-analysis averages for \u0394N is likely to be inappropriate for accurately determining diets and trophic relationships using tissue stable isotope ratios. Where feasible, discrimination factors should be directly quantified for each species and trophic link in question, acknowledging the potential for significant variation away from meta-analysis averages and, perhaps, controlled laboratory diets and conditions.<\/p><\/blockquote>\n<p>Keywords: diet, food web, gut contents, mixing models, Ningaloo Reef, tissue isotopes<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Variability in Isotope Discrimination Factors in Coral Reef Fishes: Implications for Diet and Food Web Reconstruction Alex S.J. Wyatt, Stuart Humphries, Anya M. Waite Interpretation of stable isotope ratios of carbon and nitrogen (\u03b413C and \u03b415N) is generally based on the assumption that with each <a class=\"more-link\" href=\"https:\/\/www.oceanecol.com\/?p=246\">| Click for More \u2192<\/a><\/p>\n","protected":false},"author":1,"featured_media":249,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[13],"tags":[24,59,32,63,31,39,38,65,45],"class_list":["post-246","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-papers","tag-coral-reef","tag-fish","tag-fractionation","tag-indian-ocean","tag-isotope","tag-ningaloo","tag-paper","tag-plos-one","tag-stable-isotope-analyses"],"_links":{"self":[{"href":"https:\/\/www.oceanecol.com\/index.php?rest_route=\/wp\/v2\/posts\/246","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.oceanecol.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.oceanecol.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.oceanecol.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.oceanecol.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=246"}],"version-history":[{"count":3,"href":"https:\/\/www.oceanecol.com\/index.php?rest_route=\/wp\/v2\/posts\/246\/revisions"}],"predecessor-version":[{"id":321,"href":"https:\/\/www.oceanecol.com\/index.php?rest_route=\/wp\/v2\/posts\/246\/revisions\/321"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.oceanecol.com\/index.php?rest_route=\/wp\/v2\/media\/249"}],"wp:attachment":[{"href":"https:\/\/www.oceanecol.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=246"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.oceanecol.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=246"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.oceanecol.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=246"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}