Integrating complementary methods to improve diet analysis in fishery‐targeted species. Issue 18 (29th August 2018)

• Record Type: Journal Article
• Authors: Matley, Jordan K.; Maes, Gregory E.; Devloo‐Delva, Floriaan; Huerlimann, Roger; Chua, Gladys; Tobin, Andrew J.; Fisk, Aaron T.; Simpfendorfer, Colin A.; Heupel, Michelle R.
• Is Part Of: Ecology and evolution. Volume 8:Issue 18(2018)
• Page Start: 9503
• Page End: 9515
• Publication Date: 2018-08-29
• Subjects: coral reef -- coral trout -- diet -- fisheries -- metabarcoding -- next‐generation sequencing -- Plectropomus -- stable isotopes -- stomach contents; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.4456
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Developing efficient, reliable, cost‐effective ways to identify diet is required to understand trophic ecology in complex ecosystems and improve food web models. A combination of techniques, each varying in their ability to provide robust, spatially and temporally explicit information can be applied to clarify diet data for ecological research. This study applied an integrative analysis of a fishery‐targeted species group— Plectropomus spp. in the central Great Barrier Reef, Australia, by comparing three diet‐identification approaches. Visual stomach content analysis provided poor identification with ~14% of stomachs sampled resulting in identification to family or lower. A molecular approach was successful with prey from ~80% of stomachs identified to genus or species, often with several unique prey in a stomach. Stable isotope mixing models utilizing experimentally derived assimilation data, identified similar prey as the molecular technique but at broader temporal scales, particularly when prior diet information was incorporated. Overall, Caesionidae and Pomacentridae were the most abundant prey families (>50% prey contribution) for all Plectropomus spp., highlighting the importance of planktivorous prey. Less abundant prey categories differed among species/color phases indicating possible niche segregation. This study is one of the first to demonstrate the extent of taxonomic resolution provided by molecular techniques, and, like other studies, illustrates that temporal investigations of dietary patterns are more accessible in combination with stable isotopes. The consumption of mainly planktivorous prey within this species group has important implications within coral reef food webs and provides cautionary information regarding the effects that changing resources could have in reef ecosystems. Abstract : This study applied an integrative analysis of a fishery‐targeted species group—Plectropomus spp. in the central Great Barrier Reef, Australia, by comparing three diet‐identification approaches. The results demonstrate the extent of taxonomic resolution provided by molecular techniques, and illustrate that in combination with stable isotopes, greater temporal resolution of diet is possible. The selection of planktivorous prey within a species group typically considered to be generalists has important implications and provides cautionary information regarding the effects that changing resources could have in reef ecosystems.