Trophic interactions and consequent impacts of the invasive fish Pseudorasbora parva in a native aquatic foodweb: a field investigation in the UK

Abstract

Introduction of the invasive Asian cyprinid fish Pseudorasbora parva into a 0.3 ha pond in England with a fish assemblage that included Cyprinus carpio, Rutilus rutilus and Scardinius erythrophthalmus resulted in their establishment of a numerically dominant population in only 2 years; density estimates exceeded 60 ind. m(-2) and they comprised > 99% of fish present. Stable isotope analysis (SIA) revealed significant trophic overlap between P. parva, R. rutilus and C. carpio, a shift associated with significantly depressed somatic growth in R. rutilus. Despite these changes, fish community composition remained similar between the ponds. Comparison with SIA values collected from an adjacent pond free of P. parva revealed a simplified food web in P. parva presence, but with an apparent trophic position shift for several fishes, including S. erythrophthalmus which appeared to assimilate energy at a higher trophic level, probably through P. parva consumption. The marked isotopic shifts shown in all taxa in the P. parva invaded pond (C-13-enriched, N-15 depleted) were indicative of a shift to a cyanobacteria-dominated phytoplankton community. These findings provide an increased understanding of the ecological consequences of the ongoing P. parva invasion of European freshwater ecosystems

Assessing the ecological impacts of invasive species based on their functional responses and abundances

“…and Daphnia magna. Despite overwhelming evidence that P. parva is a highly damaging invader (Britton et al 2010;Gozlan et al 2010), the FR of P. parva was significantly lower overall than that of R. amarus. Again, however, the RIP metric, by incorporating the abundances of the invader and native, clearly provides high explanatory and predictive power with respect to the ecological impact of this invader.…”

“…Alexander et al 2014a, b;Dick et al 2013Dick et al , 2017Paterson et al 2014;Laverty et al 2015;Xu et al 2016) have shown that the comparative FR methodology is rapid, efficient and effective at explaining and predicting the ecological damage caused by invasive species. However, in some cases the FR of invasive species is unremarkable when compared to those of native species, yet ecological damage is known to occur, as is the case with N. melanostomus and P. parva toward invaded communities (Barton et al 2005;Britton et al 2010;Gozlan et al 2010;Pagnucco and Ricciardi 2015). When the abundances as well as FRs of invasive and native species are included in the ''Relative Impact Potential'' assessment, the overall forecast of impact is better reconciled with known field impacts.…”

“…We supplement this with FR data from N. melanostomus and another native comparator, the mottled sculpin Cottus bairdi, towards Gammarus prey (see Dubs and Corkum 1996), again with available abundance data. Then, we repeat this exercise with the highly invasive and ecologically damaging topmouth gudgeon, Pseudorasbora parva, an Asian fish which has also invaded European waters (Britton et al 2010;Gozlan et al 2010), and its native analogue the European bitterling, Rhodeus amarus, towards two prey species, Daphnia magna and Chironomus spp.. We stress that this exercise is to compare and quantify the impacts of the invaders on the broader prey community and it is not intended to examine any interaction, such as competition, among the invader and native fishes (but see Dick et al 2014Dick et al , 2017. Amphipods and isopods were chosen as common prey items of these fish species (see Welton et al 1991;Dubs and Corkum 1996;Corkum et al 2004;Barton et al 2005).…”

Influences of environmental and chemical parameters on the spatial growth patterns of four riverine cyprinid fishes

“…(2015) 416, 12 minimal differences in the estimates of mean length from age using both models and so the use of the log-log quadratic function was personal preference of the authors. These values then enabled the standardized residual of the length at age of each fish to calculated (Britton et al, 2010;Beardsley and Britton, 2012), enabling calculation of mean standardized residuals per river that were used to subsequently test the effects of the abiotic factors on the growth rate of each species. The second growth metric was focused on the growth increment produced between age 1 and 2 years, the rationale being that: (i) using length at age 1 as the increment might be affected by the timing of adult spawning and multiple spawning events in S. cephalus (Bolland et al, 2007), resulting in variability in the duration of the growth season for 0+ fish that was unlikely to be related to abiotic variables alone; and (ii) between age 1 and 2, the focal species are, generally, still sexually immature at this latitude (e.g.…”

Impact of topmouth gudgeon (Pseudorasbora parva) on production of common carp (Cyprinus carpio) — question of natural food structure

“…Its negative impact as a result of the grazing pressure on zooplankton is known as the "top-down" effect which is manifested by increased development of phytoplankton and accelerated eutrophication processes characterized by higher organic and nutrient load. Britton et al (2010) revealed a significant trophic overlap between P. parva, Rutilus rutilus (L., 1758) and Cyprinus carpio (L., 1758) by stable isotope analysis (SIA) method. Oberle (2003) observed an influence of P. parva on common carp production and the results of his experiment show that a high incidence of P. parva is very dangerous for carp rearing in ponds.…”