Exploring uncertainty in population viability analysis and its implications for the conservation of a freshwater fish

Abstract

1.A spatially explicit metapopulation viability model was created within RAMAS-GIS to address questions related to the conservation and management of a freshwater species at risk (Notropis anogenus). Population viability analysis was conducted to evaluate extinction risk and sensitivity analyses were undertaken to identify the most important spatial and non-spatial parameters influencing extinction and decline.2. As biodiversity offsets are increasingly used to compensate for habitat loss, the population model was also used to explore the effectiveness of four potential offsetting mechanisms. In particular, this study addressed whether the impact of habitat loss on a species at risk could be compensated by: (i) increasing habitat elsewhere; (ii) increasing vital rates; (iii) increasing abundance; and (iv) increasing connectivity.3. Results suggest that extinction risk is low for this metapopulation and that the risk of extinction was most sensitive to vital rates. 4. Compensating habitat loss with habitat gain, the most straightforward approach explored, was by far the most effective type of compensation. Increasing vital rates was the second most promising approach. Although increasing abundance and increasing connectivity could not be categorically ruled out, their effectiveness was much more limited.5. Overall, this study provided insight into the influence of spatial and non-spatial parameters on abundance, patch occupancy, and extinction risk of an aquatic species. This approach can be applied to a wide variety of species to evaluate the effect of ecosystem perturbations and inform management options.

Extinction risk to lake minnow (Eupallasella percnurus) due to habitat loss: Eastern Poland case study

“…Nevertheless, extinction risk prediction may be misleading to some extent or for some sites. In addition, other researchers underline the fact that prediction accuracy should be improved to obtain a more realistic view of fish habitat extinction risk (McCusker et al 2017). In reference to our study, the model occurred to be incorrect in relation to ten reservoirs, which already vanished that were not determined based on the prediction model.…”

“…For example, in population viability analysis (PVA), remote sensing can be used to assess different environmental indicators that affect the existence of a given population in a certain area (Leasure et al 2019; Loannidou and O’Hanley 2019; Roberts et al 2016). GIS techniques also allow for the identification of which habitat patches have the greatest effect on metapopulation viability and to run extinction simulations under various model conditions (McCusker et al 2017) of executed analysis based on historical data to identified parameters that may affect fish extinction in the present (Klippel et al 2016; Tedesco et al 2005). They are also used in species distribution models (SDMs) to obtain habitat suitability maps based on historical species occurrences and environmental variables (Klippel at el.…”

Integrating fishing and conservation in a risk framework: A stochastic population model to guide the proactive management of a threatened freshwater crayfish

“…The influence of climate change on flow could be assessed, along with impacts of altered thermal regimes on different life stages ( sensu Todd, Ryan, Nicol, & Bearlin, ), as well as other threats to life history such as pollution, sedimentation, and eutrophication. Importantly, given the documented declines across its range, the model can be used to assess trajectories of recovery (McCusker, Curtis, Lovejoy, & Mandrak, ; Whiterod et al, ), as well as to explore management strategies, including translocations, which may be needed to restore degraded populations.…”

Forgotten fishes: What is the future for small threatened freshwater fish? Population risk assessment for southern pygmy perch, Nannoperca australis

“…removals, density-dependence, trends in habitat change) about the population in question. The construction and use of such population models is also useful for ranking management options for rare or endangered species, predicting results of recovery actions (Koehn & Todd, 2012;Morrison, Wardle, & Castley, 2016;Todd & Lintermans, 2015), identifying emerging issues, testing hypotheses and evaluating management actions before implementation (McCusker, Curtis, Lovejoy, & Mandrak, 2017;Todd & Lintermans, 2015), and guiding future research (Morrison et al, 2016).…”

“…While complex models have been developed and used in commercial fisheries management (Sainsbury, Punt, & Smith, 2000) and for larger, recreationally important fishes (Koehn & Todd, 2012), this approach has been used rarely for small threatened freshwater fish species (McCusker et al, 2017). The model development process often uses inclusive expert workshops to allow the most up to date knowledge to be included and discussed within the management framework for the species (Koehn & Todd, 2012).…”