wildmanyeah
Crew Member
They have since updated this page, Its been posted a few times over the years but there is some more new interesting stuff.
https://marinesurvivalproject.com/research_activity/list/juvenile-salmon-studies-ca/
2017 Summary
Figure 1. Map of marine sampling locations in 2016. Trawl surveys include sampling in Puget Sound that is not shown on attached figure. Sampling is similar to 2015. Chinook and coho salmon were frozen (muscle or whole body) at -80°C for subsequent fatty acid, cesium, and stable isotope analyses based on the stock ID results. Diet analysis is being conducted on samples from all surveys. Otoliths have been retained from all samples for analysis based on stock ID results. Associated freshwater samples were collected from Cowichan, BQR, Puntledge, Quinsam and the Fraser River (at source and from Mission RST).
DNA for stock analysis has been submitted for all marine captured Chinook salmon over the two-year period. Based on DNA results, several stocks of Chinook salmon have been identified to conduct more detailed fatty acid, stable isotope and cesium analyses. For 2015 these stocks include Cowichan, Big Qualicum River, Puntledge and the group of stocks originating from the South Thompson. Initial results from these analyses are now being received and it is anticipated that analysis of these first results will be completed in the early spring of 2017. Additional 2015 samples and samples from 2016 sampling will be processed between January and March of 2017.
Figure 2. Results of DNA analysis on 2015 trawl captured Chinook salmon. The areas follow the regions outlined in Figure 1 (red lines). Results are summarized by key geographical regions. However, the proportion of Cowichan Chinook salmon captured in the Gulf Islands is shown in both surveys as they represent the majority of Chinook salmon captured in this region. In addition, in the September survey the proportion of Puntledge origin fish are shown for the northern Strait of Georgia region as they represent a large proportion of the ECVI group in this region. The DNA analyses demonstrate that ECVI Chinook salmon and South Thompson Chinook salmon represent a large proportion of the fish captured in both regions. Other key stocks from the Fraser River are present, particularly in the July survey, and are available for comparison of initial results. The presence of relatively large numbers of UPFR Chinook in July 2015 and 2016 is unexpected. These fish in particular will be added to the analysis.
https://marinesurvivalproject.com/research_activity/list/juvenile-salmon-studies-ca/
2017 Summary
- The salmon ecology and physiology in the Strait of Georgia study has completed 3 years of sampling from juveniles in freshwater through their early months in the ocean and into their first fall at sea. This included freshwater downstream sampling at multiple locations on Vancouver Island and Fraser River, beach and purse seining in Cowichan Bay, purse seining off BQR and charter trawl surveys in SOG in June and September and Puget Sound in July.
- The field objectives for 2015 to 2017 were completely met with samples collected over time. In 2018 auxiliary sampling using standard surveys was completed in June 2018 and will be conducted in September 2018 to support the research program. In addition to fishing, bongo (plankton) and CTD casts were conducted on all surveys.
- Stock analysis using DNA and CWT recoveries have been conducted for coho and chinook salmon from the three year study. Based on DNA results, several stocks of Chinook salmon have been identified to conduct more detailed analyses including Cowichan, Big Qualicum River, Puntledge, Chilliwack/Harrison and the group of stocks originating from the South Thompson.
- Prior to this study they had identified the distribution of Cowichan River Chinook salmon as being predominantly around the Gulf Islands region through the summer months with very few juveniles captured outside of the Gulf Islands (Beamish et al. 2010). Further analysis of distribution patterns in this study is showing that other stocks also have relatively distinct distributions through September. Big Qualicum/Puntledge juveniles were predominantly captured along the east coast of Vancouver Island. South Thompson juvenile Chinook salmon were seen in low numbers in the early summer survey but small numbers appeared around Howe Sound. By September they were predominantly captured along the mainland coast from the Fraser River through Malaspina Strait. Cowichan Chinook salmon were predominantly captured within the Gulf Islands. For each of these stocks, about 80-90% of the catch of each stock were within these regions. Harrison/Chilliwack chinook salmon were captured in the southern SOG. However, the numbers captured were low (about 5% of all chinook salmon) and did not represent the 30-40% that would be expended based on adult escapements. These fish are captured in both the San Juan and Puget Sound (purse seine and trawl survey) indicating a southerly Salish Sea distribution for these fish. Detailed analysis on stock distribution is ongoing.
- Diet and condition are being examined by year and by stock group. In addition, analysis of fatty acid, stable isotopes and energy density is being conducted on the key stocks to examine differences in condition from ocean entry through the first fall, differences in condition between stocks and between years and differences between condition of fish that remain in natal rearing areas with fish that migrate out of these regions. In addition, differences between hatchery and wild fish are being examined for Cowichan Chinook salmon. To date, fatty acid and stable isotope analysis is completed for 2015 and 2016 and analysis of results is ongoing. Preliminary results from the fatty acid analysis indicate differences time in the ocean however for Cowichan and Big Qualicum Puntledge the levels were decreasing over time. Interpretation of these differences are ongoing and results will be available in the fall.
- Analysis of the diet of Chinook salmon is indicating that the majority of the diet is composed of 4-6 key diet items. However, there is variation in the proportion of these diet items by area within the Strait of Georgia and possibly by stock or size of fish. This analysis is currently in progress but results of the initial two years of study are anticipated to be complete by the end of June 2018. Sampling is designed to ensure we have a cross –section of results from all surveys by March 2018.
- Integration of diet and survival data with studies in Puget Sound continues to improve their understanding of variability between the basins.
- Otolith and scale analysis is ongoing with focus on fish that have been processed for energy density, fatty acid and stable isotope analysis. This cross analysis is expected to help in the interpretation of the resultsGIS mapping of fish catch, ocean conditions and food production across the Strait of Georgia to start informing on the interaction between these metrics. Over the coming year these map layers will be an important component as we move into spatial analysis of stock distribution, growth and condition.
- Initiation of work to incorporate their fish surveys with results from other programs has been undertaken. They are working with researchers from UBC, UVIC as well as other DFO staff to begin to examine the relationship of primary productivity through to the juvenile salmon growth and survival.
Figure 1. Map of marine sampling locations in 2016. Trawl surveys include sampling in Puget Sound that is not shown on attached figure. Sampling is similar to 2015. Chinook and coho salmon were frozen (muscle or whole body) at -80°C for subsequent fatty acid, cesium, and stable isotope analyses based on the stock ID results. Diet analysis is being conducted on samples from all surveys. Otoliths have been retained from all samples for analysis based on stock ID results. Associated freshwater samples were collected from Cowichan, BQR, Puntledge, Quinsam and the Fraser River (at source and from Mission RST).
DNA for stock analysis has been submitted for all marine captured Chinook salmon over the two-year period. Based on DNA results, several stocks of Chinook salmon have been identified to conduct more detailed fatty acid, stable isotope and cesium analyses. For 2015 these stocks include Cowichan, Big Qualicum River, Puntledge and the group of stocks originating from the South Thompson. Initial results from these analyses are now being received and it is anticipated that analysis of these first results will be completed in the early spring of 2017. Additional 2015 samples and samples from 2016 sampling will be processed between January and March of 2017.
Figure 2. Results of DNA analysis on 2015 trawl captured Chinook salmon. The areas follow the regions outlined in Figure 1 (red lines). Results are summarized by key geographical regions. However, the proportion of Cowichan Chinook salmon captured in the Gulf Islands is shown in both surveys as they represent the majority of Chinook salmon captured in this region. In addition, in the September survey the proportion of Puntledge origin fish are shown for the northern Strait of Georgia region as they represent a large proportion of the ECVI group in this region. The DNA analyses demonstrate that ECVI Chinook salmon and South Thompson Chinook salmon represent a large proportion of the fish captured in both regions. Other key stocks from the Fraser River are present, particularly in the July survey, and are available for comparison of initial results. The presence of relatively large numbers of UPFR Chinook in July 2015 and 2016 is unexpected. These fish in particular will be added to the analysis.
