Trophic ecology of green sea turtles in a highly urbanized bay: Insights from stable isotopes and mixing models

article i nfo The green turtle, Chelonia mydas, is a circumglobal species that is susceptible to overexploitation as a food resource,incidentalmortality in fisheries, andcoastalforaginghabitatdegradation,all of whichhavecontributed to its listing as Endangered on the IUCN Red List. Efforts to recover regional green turtle populations have been hampered bya lackof information ontheir biology. In particular,temporalpatternsof diet intake and habitat use inneriticforagingareasarenotwellunderstood.Historicalparadigmssuggestthatadultgreenturtlesareobligate herbivores with diets consisting of seagrasses and/or marine algae. However, these insights are largely based on conventional diet analysis techniques that only yield snapshots of recently consumed foods. Stable isotope analysis has been used to determine contributions of various potential food resources to a consumer's diet, and this approach is commonly applied to identify diet composition and long-term trophic relationships of a species. In this study, we measured the stable carbon (δ 13 C) and nitrogen (δ 15 N) isotope values of 86 green turtles and