We propose a workshop to review the current approaches to assessing and modelling salmon survival across freshwater/coastal and marine life history stages and to recommend options that will inform the host of management tools/processes that require consideration of the full life history. We will bring together experts possessing experience with these techniques to share their knowledge in a structured manner. Case studies drawn from Pacific Salmon Treaty stocks that have requisite information will be developed that can be used to test the modelling approach. A Workshop Technical Planning Team will be convened from North Pacific Anadromous Fish Commission -International Year of the Salmon partner government agencies, NGO’s and academia to ensure relevance of the work to management and to assist in identifying a complete complement of experts. Experts will include representatives from Pacific Salmon Commission Secretariat staff and Technical Committees (Chinook, Coho, Chum and Sockeye). We will support travel for experts from Asia, Canada, Europe and the U.S. to attend. It will be essential for us to incorporate approaches to understanding freshwater and marine ecosystem status with Indigenous Peoples. Additionally, we will assess the potential for the development of new and emerging technologies and citizen science to augment this work.
This project’s goal is to estimate the Coho escapement to the Lower Chilcotin River using resistivity methods which are highly reliable, efficient, and cost effective. The Lower Chilcotin system supports Interior Fraser Coho but is not currently enumerated and no other systems in the Chilcotin watershed are monitored using accurate and precise methods. Obtaining Coho spawner counts from the Lower Chilcotin will improve our ability to assess the stock status of Interior Fraser Coho against PST management reference points which include returns to sub-populations. This project will also provide information that will improve stock recruit modeling and could form an important component of a system wide estimate for IFC using high accuracy counts and PIT tags. As well, DFO is now monitoring Chinook escapement using a resistivity counter at the Lower Chilcotin system, which provides an opportunity to extend the field program to produce a high quality estimate of Coho escapement.
Due to the complicated life history of Pacific salmon, which environmental factor (s) has major influences on their growth and productivity remains unknown, particularly accounting for their entire life history. Most previous studies focus on the short time period when they first enter the ocean. We will fill the gap by investigating salmon growth in all their marine years. We plan to use Chum salmon in southern British Columbia as an example to address this question because Chum salmon migrate to the ocean right after hatching, providing the great candidate to compare marine growth in the multiple years and seasons.
We propose to process the historic scales, measuring the seasonal (summer and winter separately) growth and identifying stocks, to reconstruct stock-specific long-term time series of growth rates of Chum salmon in multiple ocean years. Fish scales provide a record of individual growth during their entire life history and have long been used to study age structure and growth. The scales of Chum salmon have been consistently collected with fish length measured during a test fishery in Johnstone Strait since 1980. In recent years, along with the scales, tissues for genetic stock identification have been collected and processed on a fairly consistent basis from that test fishery. The number of stock-specific adult returns (2008-2019) can be estimated using the Chum Genetic and Environmental Management Model (ChumGEM) based on recent catch, escapement, and the genetic data.
By linking growth rates of Chum salmon stocks with density dependence and ocean conditions (1980-2019), this project will attempt to define which environmental factor(s) would be the best indicator of returns for each stock; by linking growth rates of Chum salmon stocks with the stock-specific adult returns, this project will determine which season and year of growth rate would be the best indicator of adult returns for each stock.
There is a general consensus that increasing temperatures have negative impacts on many species of fish. Laboratory studies demonstrate fish growth exhibits a‘thermal window’, increasing with temperature to species-specific thermal optima, beyond which additional increases in temperature lead to decreases in fish growth (Portner et al.2017). Slower growth can result in lower survival, leading to reduced stock productivity.
In British Columbia, annual maximum air temperatures has increased by 0.031°C/year since the 1950s, resulting in increases in the average number of days per year that the Fraser River at Hope is above 19°C from just two days/year in the 1950’s to over 20 days/year in 2010’s (David Patterson. Personal Communication). This increase in water temperature is posing physiological challenges to salmon migration, in some cases inducing pre-spawning mortality (Eliason et al., 2011; Martins et al. 2011).
The influence of climate warming on the growth of juvenile Fraser River Sockeye Salmon rearing in nursery lakes, remains poorly understood, particularly in the context of the multiple factors that regulate growth in these environments. This represents a key area where climate change and other forcings may be influencing stock outcomes (i.e. productivity), unbeknownst to fisheries managers.
We aim to address this knowledge gap by reconstructing stock-specific, long-term time series of annual freshwater growth rates of juvenile Sockeye Salmon in relation to their thermal environments and other key biological and environmental factors.
Scales have long been used to study fish age and growth. The scales of at least eight major Fraser River Sockeye Salmon stocks have been consistently collected by the Pacific Salmon Commission (PSC) since the 1950s, which can be paired with otolith samples since the 1970s.
We propose to non-destructively extract a time series of returning Fraser River Sockeye Salmon (1970 – 2019) freshwater growth from the existing PSC scale archive, and conduct a suite of statistical analyses on these data to define growth variability and change within Fraser River Sockeye Salmon.
On June 23, 2019, a significant rock slide was discovered in a narrow section of the Fraser River at Big Bar. The rock slide created a five-meter waterfall that many stocks of Chinook, Sockeye, Coho, Pink salmon, and steelhead need to overcome to reach their spawning grounds. This blockage impedes migration to most of the watershed and so far has stopped spawning migrations for the vast majority of Fraser Sockeye stocks.
While plans are in place to continue remediation efforts into the future, the slide and the migration challenge it created will impact the number of spawners reaching the spawning grounds for years to come. At this point, it is assumed that funding would be available for further work to restore or mitigate migration passage and this proposal therefore focuses on the management implications.
For effective management of the stocks located upstream of the rock slide, it is crucial to understand the current and long-term impacts of the slide on migration success and survival rates under different river conditions such as discharge, temperature, debris, etc. In order to efficiently explore the impact of the slide on populations of Fraser salmon we will take a two pronged approach to initiate some immediate analysis and preparatory work for the 2020 field season, while developing a robust framework to identify and target key data and analysis gaps.
The absence of reliable escapement estimates for Coho Salmon in the Lower Fraser River (LFC) MU and its three component Conservation Units (Lillooet, Lower Fraser A, and Lower Fraser B collectively discussed as LFC in this proposal) represents a critical information gap for Southern Boundary Coho Salmon Management.
This proposal addresses this concern by proposing an approach that eliminates the need to access hard-to-reach watersheds, reduces the need for visual escapement surveys from several to only the Nicomen Slough and Upper Lillooet River, and leverages existing infrastructure (hatcheries), processes (Coded Wire Tagging (CWT) and otolith tagging) and projects (monitoring of recreational and Food, Social and Ceremonial harvests, Lillooet sonar imaging (ARIS), and Nicomen Coho CWT, Chilliwack hatchery juvenile rearing and adult counts) with advanced technologies (PIT, radio tags, GSI) and a test fishery.
We propose to estimate total LFC escapement through the expansion of stock composition ratio data gathered at a test fishery. A new test fishery will sample the Fraser Coho migration, and a random, representative sample of Coho will have DNA, CWT and otolith samples taken to estimate stock composition ratios.
S19-SP46A Estimating Aggregate Coho Salmon Terminal Run and Escapement to the Lower Fraser Management Unit (DFO Portion) 2019 Report
S19-SP46C Feasibility of Estimating Aggregate Coho Salmon Escapement to the Lower Fraser Management (LFFA Portion) 2019 Report
A Salmonid Enhancement Program (SEP) hatchery may collect over 2,000 adult Chinook heads each year for dissection and recovery of coded-wire tags (CWTs). Each head is identified using an attached label (e-label in escapement samples), which in recent years includes a barcode as well as the numeric identifier (ID). Using the E-label ID, CWT data is linked to biological data, such as length, sex, thermal marks and genetic identification, for a given sampling stratum. The e-label IDs, and most of the biological data, are manually entered into the data management system at the hatchery. This is a process that requires substantial time and effort to ensure there are no errors associated with the manual data entry.
This project proposes to improve hatchery data management and reporting through the development of a hatchery protocol for automated sampling data collection with the purchase, testing and operationalization of barcode scanners in hatcheries where CWTs are recovered. Use of barcode scanners will enable hatchery staff to automate data capture and reduce errors from manual data entry.
S19-I44 Using Bar Scanners and Tablets to Automate CWT Data Management 2019 Report
The Salmonid Enhancement Program (SEP) maintained a Chum and Pink database of mark (fin clips with or without CWTs) recapture information until 2009, at which point reduced capacity and changing priorities in the program resulted in chum sampling data not being compiled in the standardized database for regional analysis. The Chum and Pink database reports annual contribution to catch and escapement for fin clipped chum and pink stocks, allowing estimation of survival and exploitation rate metrics, used to adaptively manage annual hatchery and spawning channel chum production. Currently historical biostandards are used to estimate production levels needed to meet fishery objectives.
This project proposes to compile missing years (2010 to present) of chum fin clipped release data from historical data in the Enhancement and Planning database (EPAD), clip observations in fisheries (Fraser River, Johnstone Strait, Central Coast) from J.O. Thomas sampling, and clip observations in escapement from hatchery sampling programs, using the SEP Chum and Pink database, where analysis can provide assessment metrics, and allow QA and reporting for all years.
Specifically, this proposed work will improve chum escapement and exploitation rate assessments by publishing historical enhanced contribution estimates in fisheries and escapement, based on fin clip rates observed in sampling. This should aid chum run reconstruction analyses by providing estimates of exploitation for Vancouver Island and Fraser River marked enhanced stocks.
S19-SP32 Enhanced Chum Data from 1980 to 2018 Return Years 2019 Report
Coho escapement to the Lower Fraser River (LFC) management unit (MU) is an important requirement of the Fishery Regulation Assessment Model (FRAM) but is estimated with unknown and high uncertainty. Inch Creek Coho are used as the hatchery coded-wire tag (CWT) indicator stock for LFC, but estimates of survival and exploitation rates lack precision due to the low number of CWT recoveries from recreational fisheries and spawning ground escapement surveys in the Nicomen Slough. However, hatchery raised Coho from Norrish Creek (a tributary to Nicomen Slough) are adipose-fin-clipped (AFC) and released into Nicomen Slough, but CWT’s are not applied. We propose to reduce the uncertainty in survival and exploitation rate estimates by doubling the number of CWTs available to be sampled by applying CWTs to Norrish Creek Coho in addition to Inch Creek Coho. Additionally, expanding Creel survey coverage in Nicomen Slough will yield greater recovery of CWT’s, further reducing the uncertainty of our estimates of survival and exploitation for the LFC MU. This work would bring us closer to being able to generate an entire system estimate of LFC escapement for use in FRAM when combined with a Lillooet Coho CU SONAR project (proposed by LGL and in their second year of SEF Funding) and a potential future Lower Fraser test fishery. The improved estimates generated from this current work would better inform backward FRAM exploitation rate estimates, and increase the quality of the forecasts for use in forward FRAM to plan bilateral fisheries. Lastly, we propose to analytically produce a more accurate estimate of the escapement of natural-origin Coho in Nicomen Slough and measure the precision of that estimate from the additional information generated from this project.
The Cohen Inquiry into the Decline of Fraser Sockeye in 2009 identified many stressors that affect Fraser Sockeye survival, including predation, disease, contaminants, climate change, fisheries, hatchery competition, aquaculture, and freshwater stressors. The mechanisms through which these stressors negatively affect salmon have been well documented. However, as the Cohen Inquiry concluded, we continue to lack clear understanding of the population level impacts of these stressors on survival.
A better understanding of population-level consequences can be gained by isolating stressors to examine their effects. This is attained by identifying responses across populations whose distributions overlap in time and space, in alignment with those stressors. Currently, we do not have the ability to efficiently compare survival responses across Fraser Sockeye populations, since the data are not consolidated or organized at appropriate spatial and temporal scales to link salmon populations across their freshwater and marine life stages. Further, there are currently no user friendly tools to effectively isolate stressors through data exploration.
To address these significant gaps, we propose to build the Salmon Pattern Analysis Tool (SPAT). SPAT is a statistical tool that will enable users to investigate stressors affecting population-level survival through examining trends across salmon populations according to user-defined filters. Project funding will be used to design, build, evaluate, and refine SPAT for Fraser River Sockeye.