Habitat simplification increases the impact of a freshwater invasive fish

M. E. Alexander, H. Kaiser, O. L. F. Weyl, J. T. A. Dick

Research output: Contribution to journalArticle

29 Citations (Scopus)
335 Downloads (Pure)

Abstract

Biodiversity continues to decline at a range of spatial scales and there is an urgent requirement to understand how multiple drivers interact in causing such declines. Further, we require methodologies that can facilitate predictions of the effects of such drivers in the future. Habitat degradation and biological invasions are two of the most important threats to biodiversity and here we investigate their combined effects, both in terms of understanding and predicting impacts on native species. The predatory largemouth bass Micropterus salmoides is one of the World’s Worst Invaders, causing declines in native prey species, and its introduction often coincides with habitat simplification. We investigated the predatory functional response, as a measure of ecological impact, of juvenile largemouth bass in artificial vegetation over a range of habitat complexities (high, intermediate, low and zero). Prey, the female guppy Poecilia reticulata, were representative of native fish. As habitats became less complex, significantly more prey were consumed, since, even although attack rates declined, reduced handling times resulted in higher maximum feeding rates by bass. At all levels of habitat complexity, bass exhibited potentially population destabilising Type II functional responses, with no emergence of more stabilising Type III functional responses as often occurs in predator-prey relationships in complex habitats. Thus, habitat degradation and simplification potentially exacerbate the impact of this invasive species, but even highly complex habitats may ultimately not protect native species. The utilisation of functional responses under varying environmental contexts provides a method for the understanding and prediction of invasive species impacts.
Original languageEnglish
Pages (from-to)477-486
JournalEnvironmental Biology of Fishes
Volume98
Issue number2
Early online date11 May 2014
DOIs
Publication statusPublished - Feb 2015

Fingerprint Dive into the research topics of 'Habitat simplification increases the impact of a freshwater invasive fish'. Together they form a unique fingerprint.

  • Cite this