Investigating Freshwater and Ocean Effects on Pacific Lamprey and Pacific Eulachon of the Columbia River Basin: Projections Within the Context of Climate Change
In this report we utilized statistical models and G.I.S-based approaches to analyze available life cycle, abundance and distribution data from the last 80 years on Pacific Lamprey (Entosphenus tridentatus) and Pacific Eulachon (Thaleichthys pacificus), and determine how climate change may potentially impact these species in the Columbia River basin. Both species have experienced substantial declines in this basin, and are in urgent need of protection and restoration. While data on these species have incomplete spatial and temporal coverage in this region, some inferences can be derived on possible adverse effects of climate change and subsequent impacts on persistence and resilience of populations. The quantified impacts indicate that the predicted higher late fall and winter stream flows are likely to have a negative impact on Pacific lamprey and possibly a positive impact on Pacific Eulachon, though this could be negative for eulachon if the increased flow does not coincide with the spring oceanic upwelling transition. Higher ocean temperatures and reduced upwelling are likely to have negative impacts on the oceanic life cycle phases of both species. The current status and distribution of Pacific Lamprey during its freshwater lifecycle is likely to be negatively impacted by climate change effects (e.g. changes to seasonal stream flow and higher summer water temperature) to a greater degree in interior snow dominant parts of the basin, areas where lamprey are already severely imperilled.
Sharma, R., D. Graves, A. Farrell, and N. Mantua. 2016. Investigating freshwater and ocean effects on Pacific Lamprey and Pacific Eulachon of the Columbia River Basin: projections within the context of climate change. Columbia River Inter-Tribal Fish Commission, Technical Report 16-05. Portland, OR. 139p.