Methods
Study Area
Each location was manually located in Google Maps (as there was little to no information in the paper about actual sampling locations used) and latitude and longitude coordinates were derived based on the area given by Google Maps. Each coordinate was an approximation of the location that was sampled by the researchers. We were unable to find point coordinates for all locations and therefore, some were omitted for our purposes.
There were also ten Pacific Fisheries Management Areas (PFMA’s) that were sampled (Figures 5 and 6). These locations were in accordance with the Fisheries and Oceans Canada locations that can be found through the Government of Canada open source database (Fisheries and Oceans Canada, 2021). While the Fisheries and Oceans map shows over 100 PFMA’s, the researchers only sampled from areas 1, and 3 to 10. Further, some salmon that were caught were from overlapping PFMA’s, like 6 and 7, or PFMA 5 through 10. For each single and aggregated PFMA, a mean center was found from each polygon or aggregated polygon using ArcGIS Pro. From the mean centers, latitude and longitude coordinates were able to be determined.
These coordinates were used solely for the collection of historic climate data which was generated with the ClimateNA v6.40b software package, available at http://tinyurl.com/ClimateNA, based on methodology described by Wang et al. (2016). This software gave us the minimum, maximum, and average temperatures for each month for the years between 1950 and 2013 for each location that we specified. We were also able to derive monthly precipitation in mm for each year and location as well.
The climate data was appended to our salmon data and all analyses were done in R software.
Figure 5: Map depicting Pacific Fisheries Management Areas (PFMAs) off the coast of British Columbia (Fisheries and Oceans Canada, 2021)
Figure 6: Map of Pacific Fisheries Management Areas 1 through 10 used in the Ogden et al. (2015) study with Mean Centers. These areas are off the coast of British Columbia and surrounding the archipelago of Haida Gwaii. Created by Isabella Orellana using ArcGIS Pro and data from Government of British Columbia (2004).
Figure 7. Map of the areas that encompass all locations that had latitude and longitude coordinates derived. Grouped into four major areas as described by the Ogden et el. (2015) study as North and Central Coast, Fraser, Inner South Coast, and Outer South Coast.
The locations above that had latitude and longitude coordinates derived are all encompassed by four major regions outlined by the researchers in the Ogden et al. (2015) study. The locations above include the PFMAs and all the Conservation Units (CUs) sampled by the researchers. The areas that encompass them are the North and Central Coast (blue), Fraser (green), Inner South Coast (red), and Outer South Coast (yellow) (Figure 7). These major areas were used in some of the subsequent analyses, as there were close to 100 specific locations sampled in the study.
Sampling Design
To visualize our data and check the assumptions of homogeneity and normality, a residual plot was created for our response variables (see figures under the 'Data' page). Line plots were created to visualize temperature and precipitation trends over the study period, which were coloured by the area shown in Figure 7.
Next, a correlation and regression test was performed for each Response Variable in response to the MAT and MAP Predictor Variables, and a linear model was performed to further analyze these results.