title: Mistaken identity? Visual similarities of marine debris to natural prey items of sea turtles.
abstract: BACKGROUND
  There are two predominant hypotheses as to why animals ingest plastic: 1) they are opportunistic feeders, eating plastic when they encounter it, and 2) they eat plastic because it resembles prey items. To assess which hypothesis is most likely, we created a model sea turtle visual system and used it to analyse debris samples from beach surveys and from necropsied turtles. We investigated colour, contrast, and luminance of the debris items as they would appear to the turtle. We also incorporated measures of texture and translucency to determine which of the two hypotheses is more plausible as a driver of selectivity in green sea turtles.
  
  
  RESULTS
  Turtles preferred more flexible and translucent items to what was available in the environment, lending support to the hypothesis that they prefer debris that resembles prey, particularly jellyfish. They also ate fewer blue items, suggesting that such items may be less conspicuous against the background of open water where they forage.
  
  
  CONCLUSIONS
  Using visual modelling we determined the characteristics that drive ingestion of marine debris by sea turtles, from the point of view of the turtles themselves. This technique can be utilized to determine debris preferences of other visual predators, and help to more effectively focus management or remediation actions.
authors.affiliation: School of Biological Sciences, University of Queensland, St, Lucia, Australia. Q.Schuyler@uq.edu.au.
authors.forename: Qamar A
authors.initials: QA
authors.lastname: Schuyler
authors.forename: Chris
authors.initials: C
authors.lastname: Wilcox
authors.forename: Kathy
authors.initials: K
authors.lastname: Townsend
authors.forename: B Denise
authors.initials: BD
authors.lastname: Hardesty
authors.forename: N Justin
authors.initials: NJ
authors.lastname: Marshall
mesh_terms: D000818:Animals; D003116:Color; D004435:Eating; D005735:Garbage; D005766:Gastrointestinal Contents; D008954:Models, Biological; D010969:Plastics; D011235:Predatory Behavior; D014426:Turtles; D014796:Visual Perception
chemical_list: D010969:Plastics