Category Archives: Climate Change

Global climate change is predicted to have a large impact for aquatic ecosystems. Global air temperatures are predicted to increase between 1.4 and 5.8°C by the year 2100, with variability among estimates being due to difference expectations about economic development. In regions closer to the poles, temperatures are predicted to increase at even faster rates (4-7°C). Therefore, fish species which typically rely on warm-water habitats may have access to additional favourable thermal habitat, shifting the northern limit of the distribution of species further north and potentially negatively impacting native fish communities. The spread of non-native species into novel habitats can cause serious ecological impacts, including: homogenization of native fauna, genetic hybridization, and reductions in ecosystem services (Poesch et al. 2016). In the PoeschLab, we use climate change models to assess impacts to vulnerable species (e.g. Pandit et al. 2017) and help develop appropriate management actions (Poesch et al. 2016).

Pandit, S.N.*, Koriala, L., Maitland, B.M*, Poesch, M.S., and E. Enders. (2017) Climate change risks, extinction debt, and conservation implications for an endangered freshwater fish Carmine Shiner (Notropis percobromus). Science of the Total Environment 598: 1-11.

Citation: Pandit, S.N.*, Koriala, L., Maitland, B.M*, Poesch, M.S., and E. Enders. (2017) Climate change risks, extinction debt, and conservation implications for an endangered freshwater fish Carmine Shiner (Notropis percobromus). Science of the Total Environment 598: 1-11.

Abstract

Climate change is affecting many freshwater species, particularly fishes. Predictions of future climate change suggest large and deleterious effects on species with narrow dispersal abilities due to limited hydrological connectivity. In turn, this creates the potential for population isolation in thermally unsuitable habitats, leading to physiological stress, species declines or possible extirpation. The current extent of many freshwater fish species’ spatio-temporal distribution patterns and their sensitivity to thermal impacts from climate change − critical information for conservation planning − are often unknown. Carmine shiner (Notropis percobromus) is an ecologically important species listed as threatened or imperilled nationally (Canada) and regionally (South Dakota, United States) due to its restricted range and sensitivity to water quality and temperature. This research aimed to determine the current distribution and spatio-temporal variability in projected suitable habitat for Carmine shiner using niche-based modeling approaches (MaxEnt, BIOCLIM, and DOMAIN models). Statistically downscaled, bias-corrected Global Circulation Models (GCMs) data was used to model the distribution of Carmine shiner in central North America for the period of 2041–2060 (2050s). Maximum mean July temperature and temperature variability were the main factors in determining Carmine shiner distribution. Patterns of projected habitat change by the 2050s suggest the spatial extent of the current distribution of Carmine shiner would shift north, with > 50% of the current distribution changing with future projections based on two Representative Concentrations Pathways for CO2 emissions. Whereas the southern extent of the distribution would become unsuitable for Carmine shiner, suitable habitats are predicted to become available further north, if accessible. Importantly, the majority of habitat gains for Carmine shiner would be in areas currently inaccessible due to dispersal limitations, suggesting current populations may face an extinction debt within the next half century. These results provide evidence that Carmine shiner may be highly vulnerable to a warming climate and suggest that management actions – such as assisted migration – may be needed to mitigate impacts from climate change and ensure the long-term persistence of the species.

*Lab members: Shubha Pandit, Bryan Maitland, Mark Poesch. Check out opportunities in the lab!

Predicted Change in Carmine Shiner Distribution given Climate Change Scenarios (RCP 2.6 top; RCP8.5 bottom) across various thresholds

Poesch, M.S., Chavarie, L., Chu, C., Pandit, S.N.*, and W. Tonn. (2016) Climate change impacts on freshwater fishes: A Canadian perspective. Fisheries 41(7): 385-391.

Citation: Poesch, M.S., Chavarie, L., Chu, C., Pandit, S.N.*, and W. Tonn. (2016) Climate change impacts on freshwater fishes: A Canadian perspective. Fisheries 41(7): 385-391.

Abstract

Current and projected patterns of global climate change are a major concern to freshwater fisheries in Canada. The magnitude of the impacts of climate change vary among species and ecoregions. The latest climate change scenario projections for Canada suggest that by 2050 temperatures will increase between about 4.9°C ± 1.7°C (average mean ± standard deviation) and 6.6°C ± 2.3°C under the Representative Concentration Pathways (RCPs) 2.6 and 8.5 emission scenarios, respectively. These changes will have an important influence on the physiology, distribution, and survival of freshwater fishes, as well as other ecological processes in direct, indirect, and complex ways. Here we provide a perspective from the Canadian Aquatic Resources Section on the impacts of climate change to freshwater fishes. Given the geographic size and diversity of landscapes within Canada, we have divided our perspective into three regions: eastern, western, and northern Canada. We outline the impacts of climate change to these regions and outline challenges for fisheries managers. Because climate change does not operate in isolation of other environmental threats, nor does it impact species in isolation, we suggest improved inter jurisdictional integration and the use of an adaptive and ecosystem-based approach to management of these threats.

*Lab members: Shubha Pandit, Mark Poesch. Check out opportunities in the lab!

List of species that have potential to extend their range and/or abundance northward into the Arctic, with some biological characteristics related to expansion of their existing ranges.