Evaluating the vulnerability of freshwater fish habitats to climate change and identifying regional adaptation strategies in the Cariboo-Chilcotin

Climate change effects have been  modeled for British Columbia with the largest increasing temperatures  predicted for the north of the province. In general during winter temperature will whereas changes in precipitation, especially in the summer have been predicted in the south of the province.

This province and region vulnerability to climate change is in line with other studies carried out at the global level. However, in order to better understand the impacts of these changes at the regional level, we need to link goods and services that are valued and relied on by human communities. Politician and regional managers do not have direct control on climate change motors, however they can control land and water use decisions and implement them as adaptation strategies. This could benefit the ecosystem in the future and reduce the effects of climate change.

The intention of this project was to develop a first approach to provide information in order to better inform short-term decision-making with an aim to then benefit the local populations and freshwater ecosystems in the long term.

This study built on previous works that identified potential fish adaptation strategies and also developed technics to assess fish habitat’s vulnerability.

Methods

The project’s main focus was to:

  • to use experts knowledge to guide the assessment of vulnerability and analysis of adaptation to ensure it could best be tailored for decision making. A survey was developed to get a first feedback on their approaches. Four main topics were approached, these being prioritize adaptation strategies; identify indicators of adaptation potential; identify metrics of freshwater vulnerability; and identify administrative units to summarize adaptation information.
  • to update information sources and methods for assessing vulnerability including modelling climate change, predicting stream flow conditions, predicting stream temperature conditions and assessing suitability of habitats.
  • to analyze existing data layers to identify adaptation opportunities. Utilising experts prioritization, two adaptation strategies were identified to be the basis of the study analysis; to restore riparian ecosystems, and to adjust water licensing and allocations.

Results

Vulnerability and adaptation

Three species (Bull trout, Chinook Salmon and Coho Salmon) habitat’s loss and gain was predicted using 6 GCM model scenarios .

For the Bull trout habitat suitability was predicted to reduce drastically while the two salmon species would see  a general habitat gain. However the potential of warming is predicted in the lower region of important

migration corridors

Their prediction for 2080 from a flow perspective calculates a reduction in the summer spawning and rearing access flows.

Adaptation opportunities have been identified in certain location, especially  in the Nazko, Quesnel, and Horsefly River watersheds.

Feedback from experts

As a whole, in general experts concurred the baseline predictions of stream temperature and flow conditions in the study area, with actual local knowledge. However, predictions of distributions of fish species,  showed more disagreement, mainly due to the analysis not including some major barriers.

Conclusion

Improvements to this study should included refining the model and analyses on according to expert comments, and relaying those findings to wider audiences. Further studies could overlap vulnerability and adaptation information in order to develop adaptation strategies

This study makes it clear that decision makers should base adaptation decisions on solid basis of informationn and researches. Although progress has been made in the modeling of climate change predictions, more will be needed in order for regional panellists to work towards developing strategies to adaptat to climate change.

  • Source Nelitz, M., K. Wieckowski, M. Porter, K. Bryan, F. Poulsen, and D. Carr. 2010. Evaluating the vulnerability of freshwater fish habitats to climate change and identifying regional adaptation strategies in the Cariboo-Chilcotin. Report prepared for Fraser Salmon and Watersheds Program by ESSA Technologies Ltd.