Seasonal Variation in Resource Overlap Between Red Swamp Crayfish (Procambarus clarkii) and Native Species in Poyang Lake Wetland, China

Abstract

Biological invasions are a significant component of current global environmental change that affect biodiversity as well as ecosystem processes and services. The red swamp crayfish (Procambarus clarkii) is one of the most invasive species worldwide, with a documented ability to deplete basal food resources and alter the structure of aquatic food webs. The red swamp crayfish has extensively invaded the Poyang Lake wetland, located in the middle reach of the Yangtze River basin. Here, we use an isotopic mixing model (MixSIAR) with data from stable isotope ratios (δ13C, δ15N) to estimate relative contributions of potential resources to the biomass of red swamp crayfish and ten common native species, and we use hierarchical clustering analysis to assess basal resource breadth and interspecific similarity of invasive and native species. We hypothesized that red swamp crayfish and several native species have similar trophic niches and may compete for basal resources. Results from the mixing model demonstrated seasonal variation in the basal resource of all species, including the red swamp crayfish and native snails, prawns, and fishes. Submerged macrophytes and detritus were estimated to be the most important sources during the rising-water season; during the high-water season, emergent macrophytes and detritus were most important; and during the falling-water season, detritus, POM, and floating macrophytes were most important. Resource overlap was substantial between the invasive crayfish and dominant native species, particularly the freshwater snail (Bellamya aeruginosa), indicating the potential exists for negative impact from competition under conditions of resource limitation.

Isotopic Overlap of Invasive and Native Consumers in the Food Web of Lake Trasimeno (Central Italy)

“…Procambarus clarkii was shown to have the largest nichecluding among the invertebrate species included in this study, confirming the results of other isotopic investigations performed in both lentic and lotic environments [ 82 , 87 ]. Current information on the trophic ecology of this omnivorous species mostly pertains to food selection and dietary overlap with other crayfish species [ 88 , 89 , 90 , 91 ]; only recently, Wu and colleagues [ 92 ] verified in a Chinese reservoir a substantial resource overlap between P. clarkii and native crustaceans and gastropods, indicating the potential for the crayfish to exert negative impacts through competition. Here, P. clarkii overlapped with a number of native species, including the amphipod E. veneris and the gastropod P. acuta .…”

Will the experimental population control of an invasive crayfish influence the diet and trophic position of a native crayfish? An assessment using stable isotopes

“…These shifts are likely to be a consequence of environmental variation between the 2 years rather than competition. Seasonal shifts in the isotopic signatures of crayfish are well documented (Beatty 2006;Magoulick and Piercey 2016;Vesely et al 2020;Wu et al 2022), yet inter-annual shifts are not evident in the literature (Stenroth et al 2006). However, in other species inter-annual variation in isotope values has been attributed to environmental change across years (e.g.…”

Ecological impact of a generalist invader in the aquatic food web is mediated by environmental context

“…Moreover, ecological responses of native species to biological invasion may also depend on differences in environmental conditions, such that the level of trophic niche overlap between the native and non-native species is modified (Wang et al, 2021;Wu et al, 2022).…”

“…This despite the fact that differences in dietary resource specialisation among individuals can lead to important implications for community and population dynamics, as well as for evolutionary trajectories (Bolnick et al., 2003). Moreover, ecological responses of native species to biological invasion may also depend on differences in environmental conditions, such that the level of trophic niche overlap between the native and non‐native species is modified (Wang et al., 2021; Wu et al., 2022). Therefore, dietary resource specialisation of invasive species, and how it is modulated by environmental gradients in abiotic and biotic factors, is important to determine because it can potentially alter invasive species’ impacts on native ecological communities.…”