Assessing trophic position quantification methods for three piscivorous freshwater fish using stable isotopes and stomach contents
| Autor: | Aaron T. Fisk, Scott F. Colborne, Brent Nawrocki, Joshua Del Papa, Nigel E. Hussey, Anne M. McLeod |
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| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
Ecology biology Food chain 010604 marine biology & hydrobiology Micropterus Trophic position 010501 environmental sciences Aquatic Science biology.organism_classification 01 natural sciences Freshwater ecosystem Food web Diet-tissue discrimination factor Predatory fish Baseline Guild Freshwater fish Marine ecosystem 14. Life underwater Ecology Evolution Behavior and Systematics Stable isotopes 0105 earth and related environmental sciences Trophic level |
| Zdroj: | Great Lakes Institute for Environmental Research Publications |
| ISSN: | 0380-1330 |
| DOI: | 10.1016/j.jglr.2020.03.017 |
| Popis: | Accurate trophic position (TP) estimates are important for the development of ecosystem-based management plans. TPs can be quantified by carbon (δ13C) and nitrogen (δ15N) stable isotopes in tissues, but these can disagree with observed and perceived feeding ecology. A recent method that has used a scaled diet-tissue discrimination factor (DTDF), reflecting the inverse relationship between DTDF and δ15N, was found to better describe TPs of predatory fish species in marine ecosystems, but this has not been tested in freshwater ecosystems. Here, we compare methods of TP estimations in the Lake Huron-Erie corridor (HEC), a system where high diversity of prey items has contributed to the concern that foraging ecology of piscivorous fish species is poorly understood. Using δ15N and δ13C, we quantified TP of longnose gar (Lepisosteus osseus), largemouth bass (Micropterus salmoides), and northern pike (Esox lucius) to assess the efficacy of a scaled DTDF compared to traditional DTDF isotope methods and stomach content analysis (SCA). The scaled DTDF method produced TP estimates that were at times consistent with SCA and were generally higher and with a greater range among individuals than non-scaled DTDFs. The scaled method was not sensitive to baseline choice nor influenced by incorporating carbon source in the model. Greater variability of TP estimates using a scaled DTDF suggests more complex trophic structuring in the upper trophic level guild of the HEC. These results, particularly the lack of baseline sensitivity, provide support for using the scaled DTDF in freshwater food web characterization. |
| Databáze: | OpenAIRE |
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