Tag Archives: sockeye

Babine River Sockeye Migration and Predation Assessment

Lake Babine Nation Fisheries (LBNF) plans to work with Fisheries and Oceans Canada (DFO) to continue the investigation of the behaviour and ecology of Babine River sockeye fry. The proposed project is composed of four relatively discrete components which include:

  1. early life history behaviour and migration;
  2. extent and rate of predation on juvenile sockeye;
  3. egg-to-fry and fry-to-smolt survival, frequency of occurrence of disease and parasites and condition as a function of length and weight; and
  4. presence and behaviour of sockeye fry rearing in downstream slow water habitats to obtain evidence of a riverine juvenile sockeye ecotype.

Other observed adverse effects that may affect sockeye fry survival and overall sockeye production will be documented. These studies are intended to address the diminished abundance of Late Run Upper and Lower Babine River sockeye in their juvenile freshwater environment.



Tatsamenie Lake Sockeye Fry Extended Rearing and Smolt Enumeration

A sockeye enhancement program has been ongoing at Tatsamenie Lake since 1990. A review of the program was funded by the Northern Fund in 2005, and in 2008, the Northern Fund began supporting the Extended Sockeye Fry Rearing Project.
The fry were originally reared in lake pens, but because of a devastating disease outbreak, the project shifted to onshore rearing systems beginning in 2009. The egg to smolt survivals of the fed fry have been variable but have ranged from 10% to 70%, or 5 to 15 times compared to wild fry, depending on fry behaviour after outplanting. Assessment of adult production from this project is ongoing. Smolt to adult survivals of the reared fry will be definitively determined with the return of the corresponding adults in the coming years, but to date, the adult production from reared fry has been lower than expected. This project continues to test a technique that has the potential of increasing production for other small scale sockeye salmon enhancement projects as well as rebuilding the Tatsamenie Lake sockeye stock in low brood year cycles.
Also at Tatsamenie Lake, the Canadian Department of Fisheries and Oceans began a smolt enumeration program in 1996, and this ran continuously from 1998 through to 2011. The Northern Fund began supporting this program in 2012, and the two programs were combined in 2015. The combination allowed the Tatsamenie Lake sockeye smolt mark-recapture project to extend beyond its previous end date of June 30, through to the second week of September. This provides a more accurate smolt population estimate as well as increased precision of the estimated enhanced sockeye survival and production. This also allows for monitoring of potential early out-migration of the reared fry.

Analysis of existing CPUE data from Canadian Commercial ITQ fisheries for the possible integration into run-size models for Fraser River sockeye and pink salmon

This project proposes to analyse the relationship between sockeye and pink salmon abundance and existing CPUE data from Canadian purse seine ITQ fisheries, years 2010-2014. This will entail: 1) obtaining catch data by set and location from individual purse seiners in Area 12 and comparing with indices of abundance by area. 2) Examining the special case situation in Area 29 where ITQ seiners have fished on delaying Fraser River sockeye (2010, 2014) and pink salmon (2013). 3) Exploring evidence for density dependence catchability in the ITQ fishery dynamics. 4) In consultation with PSC Staff, incorporate the above (if useful) within a Bayesian hierarchical methodology. 5) Review compliance with the requirements identified in the Kowal Letter to the Fraser River Panel (2002) and also with the Run-size estimation workshop (2003). And finally, 6) Develop a plan for additional sampling opportunities for the Panel’s consideration for implementation in future years.


Babine Lake Sockeye Salmon Nursery Ecosystem Structure, Functioning and Productive Capacity

Babine Lake sockeye salmon comprise the bulk (90%) of Skeena River sockeye captured in Canadian and U.S. waters, and were historically a major bi-lateral economic driver on the North Coast. Any reductions in returns significantly affect fisheries and subsistence in both countries.

The worrisome trends observed in freshwater survival, and routinely depressed escapements over the past ~20 years, highlight the critical importance of understanding the modern freshwater ecology of Babine Lake sockeye salmon and their nursery habitat. The fundamental ecological changes observed in Babine Lake in 2013 (changes in nutrient availability likely due to climate change, and resultant shifts in the food web) indicate a heightened need for long-term data to assess specific mechanisms of lake change and stock decline, such that informed decisions can be made to guide fisheries resource management, salmon enhancement, and habitat stewardship. As such, the current project consists of lake-wide limnological assessments, surveys of juvenile sockeye abundance, size, feeding ecology, physiological condition and freshwater survival, and an implementation of a spatially-resolved multiple trophic level paleolimnological food web assessment over the last 200 years (or more).


Genetic changes associated with in-basin supplementation of a population of Sockeye salmon

This joint project by NOAA and the University of Alaska Fairbanks evaluates the long term fitness of hatchery and wild sockeye salmon within a small watershed in Southeast Alaska. Concern over preserving wild stock fitness in enhancement project watersheds has been expressed in the case of both the Pacific Salmon Commission (PSC) Transboundary River Plans on the Taku and Stikine Rivers, and the PSC Northern Boundary Treaty Area of Southern Southeast Alaska (Hugh Smith and MacDonald Lakes). Measurement of the fitness effects and potential impact of such enhancement projects is needed to avoid long term undesirable effects on wild stocks. Initial genetic sampling and trial fish culture work in 2008, 2009, and 2010 showed potential for utilizing microsatellite and single nucleotide polymorphism (SNP) markers to assess the parentage of Auke Lake sockeye and to identify the progeny of wild and enhanced fish, and this allows the evaluation of the survival and introgression, if any, of the enhanced fish into the wild population. Furthermore, we have demonstrated the ability to sample very close to 100% of the adult sockeye entering the system and provided a low impact design for sampling, capturing, maturing and spawning small numbers for use as brood stock in this study. During the summers of 2011, 2012 and 2013, we captured and held adult sockeye in the Auke Creek Research hatchery, and conducted experimental matings in all three years. We have incubated, cultured and released approximately 50,000 juvenile sockeye into Auke Lake in the springs of 2012, 2013, and 2014. Complete sampling of upstream migrating adult sockeye has occurred from 2008 thru 2015 and smolt sub-sampling has occurred in May and June of those years as well.

Beginning in 2016, additional objectives were added to cover the sampling, marking and recovery of coho salmon at Auke Creek. Because of the operational efficiencies and base support this was accomplished with a small budget increment. Auke Creek is the longest and most complete coho salmon time series in Southeast Alaska, and is used as an indicator of marine survival, harvest and productivity for coho in the region.


Continuing the evaluation of abundance and stock composition of downstream migrating juvenile Sockeye Salmon in the lower Fraser River

While Fraser River sockeye salmon survival has declined over the past decade, it has also exhibited high interannual variability. The processes responsible for this trend and the variability are not understood and require investigation. This project builds on the previous work by adding a fifth year of sampling juvenile migrants immediately prior to their entry into the Strait of Georgia (SoG). The sampling platform will be identical to that employed successfully in 2013-2015, and GSI analysis will help to provide estimates of relative abundance and migration timing past Mission by stock. It is anticipated that sampling intensity in 2016, a juvenile Pink Salmon outmigration year, will be similar to that in 2014. In 2016, we propose to repeat the 2014 & 2015 study design and parameters assessed, including the assessment of the nocturnal migration patterns of Sockeye juveniles for a third year.
As in previous years, samples collected under this project will be compared to samples collected in other ongoing and proposed assessments, such as DFO’s annual SoG trawl survey occurring June-July and a similar trawl survey in Johnstone Strait. In combination, these three studies will add a third year to a comprehensive multi-stock assessment of Fraser River juvenile sockeye salmon relative abundance and condition, from nursery lake exit through early marine near-shore residency.
Sub-yearling ocean-migrant sockeye salmon (e.g. Harrison River stock) can be important contributors to Fraser River Sockeye production. The 2016 survey will continue to incorporate the bio-sampling of captured sub-yearling juveniles to identify their contribution, and migration timing at Mission by Conservation Unit (CU).
Lastly, the 2016 project will explore the feasibility of deploying an acoustic Doppler current profiler in an attempt to measure water current velocities over a depth range. This information may be important in determining absolute juvenile sockeye abundance at Mission.

Transboundary Sockeye Thermal Mark Recovery (ADFG Mark, Tag & Age Lab Support)

The Thermal Mark Laboratory at the ADF&G Mark, Tag and Age (MTA) Laboratory is responsible for examining sockeye salmon otoliths recovered from commercial fisheries in southeast Alaska for thermal marks indicating hatchery origin, and for making the associated data available to biologists for management of sockeye from the transboundary Taku and Stikine Rivers.



Mixed Stock Analysis of U.S. Districts 101, 102, and 103 Sockeye Seine Fisheries

Annual stock-specific run reconstructions (catch plus escapements) are required to accurately estimate relative contribution of each stock caught in Northern Boundary Area fisheries. Estimates of national origin of contributing stocks provides the most reliable information currently available to complete these run reconstructions, and are used to evaluate stock-specific productivity and revise pre-season forecasts. While the catch of Nass and Skeena sockeye salmon is only subject to treaty harvest-sharing annexes in the Alaska District 101 gillnet and Alaska District 104 purse seine fisheries, the harvest of these stocks in all fisheries, and their escapements, needs to be estimated in order to calculate the total run and the percentage caught in the annexed fisheries.
This project will complete genetic stock identification (GSI) analysis on sockeye salmon tissue samples collected from the 2016 commercial purse seine fisheries in Districts 101, 102, and 103 in Southeast Alaska. This project is a complement to the ongoing project at the Auke Bay Laboratory for Northern Boundary Area sockeye salmon GSI in Districts 101 and 104, and continuing work by DFO in Areas 3, 4, and 5; and will allow for complete assessment of the catches of Nass and Skeena sockeye salmon in all major Northern Boundary Area fisheries for run reconstructions. Estimates will be provided for up to 3 time strata in District 101, up to 3 time strata in District 102, and over the entire season in District 103, for a total of 1,500 samples analyzed.

Northern Boundary Area Sockeye Salmon Genetic Stock Identification

Provisions of the Pacific Salmon Treaty specify harvest sharing arrangements of Nass and Skeena River sockeye salmon returns for the U.S. and Canada. The United States is allowed to harvest a fixed percentage of the Annual Allowable Harvest of Nass and Skeena sockeye stocks in Alaska’s District 101 gillnet and District 104 purse seine fisheries. Accurate estimates of the stock-specific catch in commercial fisheries of each nation are required to estimate the total return of these stocks and the percentage of each stock caught in treaty-limited fisheries. Annual catches over or under the agreed percentage are made up for in subsequent years.

Until recently, the Alaska Department of Fish and Game (ADF&G) used scale pattern analysis successfully to estimate contributions of Nass, Skeena and Southeast Alaska sockeye stocks to fisheries in southern Southeast Alaska. Since  2006, the Auke Bay Laboratories has used genetic analysis for the Northern Boundary sockeye fisheries. Results from comparisons between stock composition using scales and genetic analysis show both methods provide accurate estimates of stock composition, although DNA analysis is able to discriminate stocks at a finer resolution than scales. An additional advantage of the DNA technique is that it does not require annual sampling to re-establish the escapement baseline.

The purpose of this project is to continue the genetic stock identification of the commercial sockeye catch in ADF&G District 101 gillnet fishery and District 104 seine fishery using the baselines developed by the ADF&G.

Assessing Effects of Supplementation on Fitness of Sockeye Salmon in Auke Creek, Alaska

The overarching goal of this joint project by the University of Alaska and the Alaska Department of Fish & Game is to use parentage-based tagging over three generations of experimental hatchery supplementation to quantify differences in fitness between wild and hatchery-origin sockeye salmon in Auke Creek, Alaska. Secondary goals of this research are to test for second-generation differences in fitness between wild and hatchery-origin individuals that spawn naturally, and to quantify changes in genetic diversity and population structure in the wild sockeye salmon population as a result of three generations of hatchery supplementation. Results of this study will provide information critical for assessing the relative costs and benefits of hatchery supplementation in managing sockeye salmon populations subject to the Pacific Salmon Treaty.