In this article, Dupuis-Desormeaux et al. (2022) discuss the manner in which introduced species are frequently labeled as “bad,” without first considering their potential to promote the ecological functions of degraded ecosystems. This paper is extremely significant in the world of conservation work, as it asks its audience to completely reevaluate what an invasive species means for an ecosystem, and for most conservation biologists, that would mean considering an invasive species as beneficial. The species that Dupuis-Desormeaux et al. (2022) ask their audience to reconsider is the red-eared slider (Trachemys scripta elegans), but the idea presented by this paper goes much further than just the red-eared slider. The paper suggests that under certain circumstances, some invasive species may be beneficial to an ecosystem, or at least contribute to some ecosystem function. This idea is relatively foreign to most, as we are taught on a large scale that invasive species are damaging to ecosystems. This paper introduces that invasive species may not just be bad for ecosystems, and that they could even be used methodologically to repair damaged ecosystems. 

Dupuis-Desormeaux et al. (2022) ask audiences to completely reevaluate how they view the red-eared slider, considering beyond the many threats that they pose, and instead assessing how they may perform as “contributors to ecosystem functions in degraded” habitat. Turtle species globally provide paramount ecosystem functions. This article classifies these functions into six categories: biomass contributions, energy flow and scavenging value, mineral cycling and bioaccumulation, trophic status, seed dispersal and germination enhancement, and bioturbation in soil dynamics. Like most turtle species, red-eared sliders perform all six of these ecosystem services; however, as Dupuis-Desormeaux et al. (2022) highlight, this species is deemed extremely undesirable, even in habitats where native turtles have been eradicated and are no longer able to perform such services. It is important to note that this article does not advocate for the further release of red-eared sliders into wild and natural spaces; however, it offers that in the current ecosystem of turtle populations declining precipitously as a result of increased anthropogenic pressures, especially overutilization and habitat destruction, red bearded slides, being the prolific species that it is, may be able to provide ecosystem restoration services in habitats that have become to degraded for native species to occupy. 

While reading this paper, I began to question whether red-eared sliders have been studied sufficiently to warrant their classification as an invasive species. In several sections discussing the ecological effects of red-eared sliders in non-native habitats, the author notes that many of the proposed impacts remain inconclusive due to a lack of comprehensive research. This raises an important question: what criteria must be met for a species to be officially designated as “invasive”? If, as the author hints, the red-eared slider has never been proven to have all of the suggested negative impacts on ecosystems, what is distinguishing the turtle as an invasive species rather than an introduced species? However, this species has been proven and is largely known as a prolific invasive species. Given the red-eared slider’s listing as one of the top 100 worst invasive species by the IUCN due to its significant global ecological impacts, allowing populations to remain unchecked poses a legitimate risk of rapid and uncontrolled population growth.

The author suggests that in some cases, it may be beneficial to allow red-eared sliders to remain in their non-native environments, as they may be filling vacant ecological niches. While this idea may seem reasonable in the short term, the paper also highlights that more habitats are becoming suitable for these turtles, potentially allowing their populations to expand further. If their numbers continue to increase, it is plausible that they may enter ecosystems where they could have detrimental effects. Additionally, if red-eared sliders are allowed to persist in non-native areas, there is the possibility of hybridization with native turtle species, such as the yellow-bellied slider. This poses further issues concerning the significance of said hybridization, and its potential to be used to increase genetic diversity rather than eradicate local existing species. This case is also quite interesting as although hybridization is a natural phenomenon, the global span of this species could have broader implications, contributing to the creation of several hybrid species.

Reference: Dupuis-Desormeaux, M., Lovich, J.E. & Whitfield Gibbons, J. Re-evaluating invasive species in degraded ecosystems: a case study of red-eared slider turtles as partial ecological analogs. Discov Sustain 3, 15 (2022). https://doi.org/10.1007/s43621-022-00083-w