{"title":"Isotopic niches of Silver Carp and two native planktivores in a large reservoir","authors":"D. Lebeda, Allison M. Lebeda, M. Flinn","doi":"10.1086/722054","DOIUrl":null,"url":null,"abstract":"Human-mediated biological invasions can greatly reduce native species diversity. More than 138 nonnative fishes have been introduced to the United States. Many of these nonnative species can alter ecosystem dynamics and compete with native species. The planktivorous Silver Carp (Hypophthalmichthys molitrix Valenciennes in Cuvier and Valenciennes, 1844) is a nonnative species of concern that is currently expanding its range across the Greater Mississippi River Basin in the Midwestern United States. The objective of our study was to determine the degree of potential competition among invasive Silver Carp and the native planktivores, Gizzard Shad (Dorosoma cepedianum Lesueur, 1818) and Threadfin Shad (Dorosoma petenense Günther, 1867), in Kentucky Lake, a large reservoir located in western Kentucky and Tennessee. We used data derived from N and C isotopes to model isotopic niches, calculate quantitative metrics to describe variability within and among isotopic niches and trophic positions, and qualitatively assess seasonal shifts in trophic positions. Our results suggest that in the spring, older (≥1 y old) Silver Carp share resources with older and young-of-year (YOY; <1 y old) Gizzard Shad, whereas YOY Silver Carp only share resources with YOY Gizzard Shad. Additionally, our analyses showed that older Silver Carp and older Gizzard Shad share resources in the summer. In contrast, we found no overlap in resource use between YOY Threadfin Shad and YOY or older Silver Carp. Furthermore, we provide evidence of intraspecific ontogenetic shifts in isotopic niche area and overlap between invasive and native fishes (measured by sample-size corrected standard ellipse area). If resources become limiting, invasive Silver Carp may compete with multiple life stages of Gizzard Shad in Kentucky Lake and alter foodweb dynamics.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"626 - 636"},"PeriodicalIF":1.7000,"publicationDate":"2022-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Freshwater Science","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1086/722054","RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ECOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Human-mediated biological invasions can greatly reduce native species diversity. More than 138 nonnative fishes have been introduced to the United States. Many of these nonnative species can alter ecosystem dynamics and compete with native species. The planktivorous Silver Carp (Hypophthalmichthys molitrix Valenciennes in Cuvier and Valenciennes, 1844) is a nonnative species of concern that is currently expanding its range across the Greater Mississippi River Basin in the Midwestern United States. The objective of our study was to determine the degree of potential competition among invasive Silver Carp and the native planktivores, Gizzard Shad (Dorosoma cepedianum Lesueur, 1818) and Threadfin Shad (Dorosoma petenense Günther, 1867), in Kentucky Lake, a large reservoir located in western Kentucky and Tennessee. We used data derived from N and C isotopes to model isotopic niches, calculate quantitative metrics to describe variability within and among isotopic niches and trophic positions, and qualitatively assess seasonal shifts in trophic positions. Our results suggest that in the spring, older (≥1 y old) Silver Carp share resources with older and young-of-year (YOY; <1 y old) Gizzard Shad, whereas YOY Silver Carp only share resources with YOY Gizzard Shad. Additionally, our analyses showed that older Silver Carp and older Gizzard Shad share resources in the summer. In contrast, we found no overlap in resource use between YOY Threadfin Shad and YOY or older Silver Carp. Furthermore, we provide evidence of intraspecific ontogenetic shifts in isotopic niche area and overlap between invasive and native fishes (measured by sample-size corrected standard ellipse area). If resources become limiting, invasive Silver Carp may compete with multiple life stages of Gizzard Shad in Kentucky Lake and alter foodweb dynamics.
期刊介绍:
Freshwater Science (FWS) publishes articles that advance understanding and environmental stewardship of all types of inland aquatic ecosystems (lakes, rivers, streams, reservoirs, subterranean, and estuaries) and ecosystems at the interface between aquatic and terrestrial habitats (wetlands, riparian areas, and floodplains). The journal regularly features papers on a wide range of topics, including physical, chemical, and biological properties of lentic and lotic habitats; ecosystem processes; structure and dynamics of populations, communities, and ecosystems; ecology, systematics, and genetics of freshwater organisms, from bacteria to vertebrates; linkages between freshwater and other ecosystems and between freshwater ecology and other aquatic sciences; bioassessment, conservation, and restoration; environmental management; and new or novel methods for basic or applied research.