Which species, how many, and from where: Integrating habitat suitability, population genomics, and abundance estimates into species reintroduction planning

Abstract

Extirpated organisms are reintroduced into their former ranges worldwide to combat species declines and biodiversity losses. The growing field of reintroduction biology provides guiding principles for reestablishing populations, though criticisms remain regarding limited integration of initial planning, modeling frameworks, interdisciplinary collaborations, and multispecies approaches. We used an interdisciplinary, multispecies, quantitative framework to plan reintroductions of three fish species into Abrams Creek, Great Smoky Mountains National Park, USA. We first assessed the appropriateness of habitat at reintroduction sites for banded sculpin (Cottus carolinae), greenside darter (Etheostoma blennioides), and mottled sculpin (Cottus bairdii) using species distribution modeling. Next, we evaluated the relative suitability of nine potential source stock sites using population genomics, abundance estimates, and multiple-criteria decision analysis (MCDA) based on known correlates of reintroduction success. Species distribution modeling identified mottled sculpin as a poor candidate, but banded sculpin and greenside darter as suitable candidates for reintroduction based on species-habitat relationships and habitats available in Abrams Creek. Genotyping by sequencing revealed acceptable levels of genetic diversity at all candidate source stock sites, identified population clusters, and allowed for estimating the number of fish that should be included in translocations. Finally, MCDA highlighted priorities among candidate source stock sites that were most likely to yield successful reintroductions based on differential weightings of habitat assessment, population genomics, and the number of fish available for translocation. Our integrative approach represents a unification of multiple recent advancements in the field of reintroduction biology and highlights the benefit of shifting away from simply choosing nearby populations for translocation to an information-based science with strong a priori planning coupled with several suggested posteriori monitoring objectives. Our framework can be applied to optimize reintroduction successes for a multitude of organisms and advances in the science of reintroduction biology by simultaneously addressing a variety of past criticisms of the field.

Riverscape correlates for distribution of threatened spotfin chub Erimonax monachus in the Tennessee River Basin, USA

“…comm.). Thus, we suggest that ENM is only one aspect of reintroduction planning that should take place, a point recently made by Malone et al (2018). Local conditions and in-stream characteristics are known to influence the occurrence of E. monachus but have only been extensively studied in 2 of the 5 extant populations (Kanno et al 2012b).…”

“…In our ENM, the probability of occurrence for E. monachus in lower Abrams Creek was 0.30 to 0.49, suggesting a low probability of successful reintroduction. Therefore, factors other than coarse-scale habitat alone influence the success of reintroductions, as recently discussed by Malone et al (2018). Additionally, historical records from smaller catchments (< 300 km 2 ), such as Abrams, Citico, and Little Bear creeks, may represent temporary use by the species or individuals uncharacteristically present when sampling occurred (e.g.…”

Designing a fence that enables free passage of wildlife while containing reintroduced bison: a multispecies evaluation

“…Metrics of reintroduction success often focus on both population viability and the long term adoption of the reintroduction zone. Success rates are increased by building on the achievements and failures of previous reintroductions (Malone et al 2018, Abáigar et al 2019. This in part has evolved into the applied science of reintroduction biology, which works to provide knowledge to facilitate decisions about the appropriate management strategies used for reintroductions (Taylor et al 2017).…”

If you build it, they will go: A case study of stream fish diversity loss in an urbanizing riverscape

“…These approaches collectively promote efficiency because proactive conservation implemented before species extirpation avoids the extensive planning and resource investment necessary for successful species reintroduction (e.g. Malone et al, ). Similar multi‐scale analyses can be applied to other systems, regardless of their location, size, or the complexity of their fish assemblages, to advance the conservation of stream fishes in altered riverscapes on a global scale (Hermoso, Pantus, et al, ).…”