Tag Archives: Stock Enhancement

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.

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.


Recovery Enhancement of Kilbella-Chuckwalla Chinook

Rivers Inlet Chinook are harvested in recreational fisheries, commercial and subsistence fisheries in BC and Alaska, and some of the largest Chinook salmon caught in marine waters originate from Rivers Inlet streams. This project is consistent with the 3rd goal of the Northern Fund, specifically, to enhance wild stock production through low technology techniques using capacity in existing facilities. This Kilbella-Chuckwalla  Chinook enhancement project that will promote production for a wild stock that is currently well below its production potential without creating any long-term operational obligations.