Revealing organic carbon sources fueling a coral reef food web in the Gulf of Mexico using stable isotopes and fatty acids

• DOI: 10.4319/lo.2013.58.2.0593
• Publication Date: 2016-08-08T21:12:10Z
• Authors: Laura Carreón-Palau; Christopher C. Pa...; Jorge A. del Ange...; Horacio Pérez-España; Sergio Aguiñiga-G...
• Keywords: Isotope Analysis; Primary producers

Carbon and nitrogen stable isotopes fatty acids (FAs) revealed primary producer organic carbon sources that fuel a coral reef food web with river influence. A isotope mixing model was used to assess the relative contribution of six different producers nine most ubiquitous invertebrate fish consumer's bulk carbon. Mangrove phytoplankton were difficult differentiate in some consumers; likely solutions involved one or other but not both at same time. FA concentration upper trophic levels corrected for producer's according model, retention evaluated using calculated factor (TRF). The C 18 FAs, 18:2 ω 6 18:3 3, plentiful mangrove, sea grass, green algae, decreased across TRF ≤ 1, probably due decomposition drifting leaves then consumer metabolism. In contrast, macroalgae 24:1 9, highly unsaturated (HUFAs), arachidonic acid (ARA) 20:4 6, docosapentanoic (DPA) 22:5 docosahexanoic (DHA) 22:6 showed accumulation (TRF > 1), while eicosapentanoic (EPA) 20:5 3 had similar concentrations = suggesting following degrees HUFA retention: DHA ARA EPA. This study indicates are major source essential dietary nutrients all fish, energy from mangroves is transferred juvenile Caranx hippos , grass nonessential FAs entire web. Moreover, among species studied, urchin Echinometra lucunter brown red algae also consumed by surgeon Acanthurus chirurgus.