Introduction

Figure 4: Illustration of salmon lifecycle (Five Countries Salmonid Conservation Program, 2022)

Background

Salmon runs are a large source of food in Canada and are significant for many cultures and fisheries off the coast of British Columbia (Janetski et al., 2009). Any changes to the abundance of salmon in these areas can affect the freshwater ecosystems as well as the Pacific ocean ecosystems where salmon spend most of their adult life.

Beamish et al. (1999) found that climatic variations correlate with shifts in the abundance of Salmon in the pacific ocean. SST (sea surface temperatures) can be powerful predictors of salmon survival (Mueter, Peterman, & Pyper, 2002), and as a result, can be an effective tool to illustrate the impacts that many of our native fish species face within our warming world.

According to Whitney (2012), temperature variations in spawning streams of Pacific salmon (Oncorhynchus spp.) can increase the energy consumption of the fish, altering gametogenesis and negatively impacting egg development. Even temperature increases of just a few degrees in natal streams can potentially have negative impacts on fish survival. With global temperatures continuing to vary widely, it is possible that rising temperatures in the natal streams from our study could become a detriment to future recruitment and survival of the 3 species included in this study (Whitney, 2012). Understanding how the fish respond to changes in temperature could inform management practices and possibly improve the overall health of stocked species and native fish populations.

Research objectives

In this study, we will analyze how climatic changes over the period of 1950 to 2009 may have affected salmon productivity off the coast of British Columbia, which may have broader implications for ocean ecosystems (Janetski et al., 2009). We aim to answer the following questions:


  1. How has the climate off the coast of British Columbia changed from 1950-2009?

  2. How have climatic changes affected salmon productivity over this time period?

  3. How do salmon species differ in their responses to climatic changes?