Cumulative Impacts of Environmentally Controlled Life History Events on Climate Induced, Production Variations of Wild and Hatchery-Origin Salmon Populations: End-to-End Assessment from North-to-South

Description

Coho salmon sac fry in a tank at a hatchery. Photo: DFO

Climate variation and change events have an impact on salmon at a wide range of life stages, in both freshwater and marine ecosystems. Useful review of trends exhibited by Pacific salmon requires an assessment of interactions among salmon growth, survival, and reproduction, and how each of those considerations is associated with environmental factors at different life stages. Because for most populations of Pacific salmon there is a deficiency of information, this project will create modelled scenarios of life history and events based on salmon populations for which extensive data exists, in order to understand the effect of climate variation on Canadian fisheries.

Results: Researchers recorded migration and environmental data for six Sockeye salmon populations and two Chinook salmon populations (representing eight out of the nine salmon-bearing zones in BC). The migration and environmental data were compared to determine whether there is any correlation between environmental changes and migration changes over periods of ranging from 24 to 54 years (depending on the data available for individual populations).

Analysis of BC central and north coast rivers indicated that the migrations of salmon populations are rarely disrupted by high temperatures or low water flow volume. However, migrations were affected by higher water flow volume, resulting in delays of several days or over a week. By contrast, in BC south coast rivers, high water flow volume rarely influenced migration, but high temperature and low water flow volume resulted in migration delays or acute mortality events and production losses. With these findings, researchers can use models and climate change projections to identify the future vulnerability of salmon migrations to climate-induced changes.

Ongoing work is focused on improving models for higher resolution in space and time scales so that accurate projections of climate-induced changes in BC rivers can be generated. The results of this study will be included in a scientific publication.

Program Name

Aquatic Climate Change Adaptation Services Program (ACCASP)

Ecoregion(s)

Pacific: Vancouver Island West Coast

Principal Investigator(s)

Kim Hyatt
Fisheries and Oceans Canada

Gayle Brown
Fisheries and Oceans Canada

James Irvine
Fisheries and Oceans Canada

Chuck Parken
Fisheries and Oceans Canada

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