Using stable isotopes to analyse extinction risks and reintroduction opportunities of native species in invaded ecosystems

Abstract

Invasive non-native species have pervasive impacts on native biodiversity, including population extirpations and species extinctions. Identifying reasons why a population of a native species is extirpated following an invasion often relies on literature-based results of anecdotal observations. The well-established schemes of existing risk assessments for invasive species assume that a species’ information (e.g. impacts or behavioural and biological traits) can be projected from one area to another to estimate the potential impact of a species in another environment. We used stable isotope data (δ13C, δ15N) from both invaded and uninvaded communities to predict such invasion impacts by reconstructing trophic relationships. This approach was tested on a community within a protected lake in Northern Spain where, following the introductions of non-native species, the last resident native species (the common tench Tinca tinca, the European eel Anguilla anguilla, and the whirligig beetle Gyrinus sp.) had been extirpated. Through the application of this novel approach, we found evidence that native species’ declines were related to direct predation by and resource overlap with non-native species, which occurred in conjunction with habitat modification. Using this approach, we outlined the mechanisms involved in the extirpation of native species in the post-invasion period. To compensate for losses of native species induced by invasions of non-native species, native species reintroductions might be an appropriate tool. For this, we further suggested and discussed a novel approach that predicts the outcome of arising interactions by superimposing stable isotope data from alternative sources to better estimate the success of native species´ reintroductions.

Expanding the invasion toolbox: including stable isotope analysis in risk assessment

“…Recently, SIA and associated mixing models have been proposed as a new and versatile approach in assessing potential risks arising from feeding pressure by invasive species, thus enabling to forecast the possible outcomes of the reintroduction of once native species (Haubrock et al 2019b) and unravelling the role of species introductions on native species extinction (Haubrock et al 2020b).…”

Shedding light on the decline of Iberian freshwater fish species over the period 1980–2020

“…In the European Union, the implementation of the 2000 Water Framework Directive (WFD) led to the creation of consistent physical, chemical and biological datasets (Hering et al, 2010). This explains why most studies aimed at identifying stressor-ecosystem relationships in European Union rivers rely on data collected after 2000, although longer term studies could provide more insights into community dynamics (Haubrock et al, 2020). So far in Spain, these relationships have been analysed mainly on a river basin district scale (e.g.…”

Food-web modification in the eastern Gulf of Finland after invasion of Marenzelleria arctia (Spionidae, Polychaeta)

“…SIA can detect potential diet overlap and feeding competition between species and estimating the proportion of different preys and carbon sources in the diet (e.g. Zwerschke et al 2018;Golubkov et al 2019;Verstijnen et al 2019;Golubkov et al 2020a;Haubrock et al 2020). Accordingly, it can be used to investigate and predict the impact of invasive species on native ones and on the whole local communities (Haubrock et al 2020).…”

“…Zwerschke et al 2018;Golubkov et al 2019;Verstijnen et al 2019;Golubkov et al 2020a;Haubrock et al 2020). Accordingly, it can be used to investigate and predict the impact of invasive species on native ones and on the whole local communities (Haubrock et al 2020).…”