Walleye Sander vitreus and smallmouth bass Micropterus dolomieu interactions: an historic stable‐isotope analysis approach

Abstract

The carbon (δ(13) C) and nitrogen (δ(15) N) values of Sander vitreus scales differed pre and post-introduction in treatment lakes among years following the introduction of Micropterus dolomieu. No difference of δ(13) C and δ(15) N in S. vitreus scales was found in control lakes where M. dolomieu were not introduced. In treatment lakes, S. vitreus δ(15) N increased and δ(13) C decreased. No relationship was found between S. vitreus and M. dolomieu abundance in the two treatment lakes. Size structure of S. vitreus and M. dolomieu was negatively correlated and condition of the two species was positively correlated. Although S. vitreus feeding habits may have changed in the treatment lakes after M. dolomieu introductions, evidence suggests that fitness-related factors (i.e. abundance and condition) of S. vitreus remained unchanged, indicating S. vitreus and M. dolomieu may coexist where M. dolomieu have been introduced.

Projected impacts of climate change on three freshwater fishes and potential novel competitive interactions

“…Smallmouth bass are voracious predators that have been found to out‐compete cold‐water predators, such as lake trout, for energetically rewarding littoral prey fish (Vander Zanden et al ., ). The effect of smallmouth bass expansion on coolwater fish is less clear because there are large geographic regions of habitat overlap, and evidence that suggests co‐existence is possible when prey availability is high (Johnson & Hale, ; Frey et al ., ; Galster et al ., ). Individual lake studies have often yielded mixed results: Johnson & Hale () found that smallmouth bass invasions reduced walleye populations in three of four Minnesota lakes, while Kempinger & Carline () found that walleye introductions in smallmouth bass lakes caused bass to decline.…”

“…A more recent study by Galster et al . () analysed stable carbon and nitrogen isotope changes in walleye before and after smallmouth bass colonization in four lakes and found that walleye tissue became more nitrogen‐rich and carbon‐negative after colonization, indicating a shift in consumption of benthic to pelagic prey. It is possible that this shift occurs because smallmouth bass display competitive territorial behaviour in the presence of other predators, which could exclude walleye from near‐shore prey resources (Wuellner et al ., ; Galster et al ., ).…”

Utility of fish scales from stock assessment surveys in stable isotope analysis for initial assessments of trophic relationships in riverine fish communities

“…These standard ellipse areas are a bivariate measure of the distribution of individuals in trophic space; each ellipse encloses~40% of the data and, therefore, represents the core dietary niche of that species in that river (Jackson et al, 2011(Jackson et al, , 2012. The second method was to use the stable isotope data within generalized linear models (GLMs) in which fish length was a covariate, as per Galster et al (2012). The full methodology for calculating these metrics is available in Jackson et al (2011Jackson et al ( , 2012.…”

Trends and potential cautions in food web research from a bibliometric analysis

“…Biological invasion, as a pervasive and costly environmental problem, has changed the interspecies relationships, trophic levels of organisms, and habits of native species; it poses a serious threat to biodiversity and native food webs and ecosystems (Qiu and Chen 2009;Vander Zanden et al 1999;Wesner and Belk 2015). For example, after the invasion of smallmouth bass (Micropterus dolomieu) in glacial lakes, the feeding habitats of native species Walleye (Sander vitreus) was displaced from a littoral to a pelagic area (Galster et al 2012).…”