Hatchery-Wild Salmon Stock Interactions:
Southeast Alaska Chinook Salmon
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John Joyce
Auke Bay Laboratories
Alaska Fisheries Science Center, NOAA Fisheries
Ted Stevens Marine Research Institute
17109 Pt Lena Loop Rd
Juneau AK 99801
(907) 789-6618
John.Joyce@noaa.gov
Southeast Alaska has many large and successful salmon stock
enhancement programs. The fish produced from these programs interact
with wild fish in both freshwater and marine ecosystems. Fishery
scientists are concerned about possible deleterious effects from
hatchery-produced salmon on wild salmon runs. Therefore, MSI scientists
are investigating domestication selection in hatchery brood stocks
of Chinook salmon in Southeast Alaska.
Research on brood stock development of Chinook salmon has been
conducted at the Little Port Walter (LPW) research station since 1976.
Presently there are two continuous Chinook salmon brood lines, which span
more than six generations. Chinook salmon from the Unuk and Chickamin rivers,
located on the Southeast Alaska mainland near Ketchikan, provided gametes
for the LPW experimental hatchery brood stock. These lines have been
ocean-ranched at LPW since 1976 (Unuk) and 1978 (Chickamin). Group-specific coded-wire tagging and spawning have allowed maintenance of distinct brood lines. For more information on 2003 LPW
Chinook salmon releases and recoveries, see Data
Sets, Monitoring: Little Port Walter (LPW)
The LPW research station provides a unique opportunity to compare fitness
characteristics of hatchery stocks with the undisturbed natural
populations that they were derived from. The MSI researchers returned
to the Chickamin and Unuk Rivers in 1996 and 1998, respectively, with the
cooperation of the
Alaska Department of Fish and Game,
in order to collect gametes from chinook salmon of the same natal
systems that the original LPW donor stocks were from. These gametes were
brought to LPW to create experimental groups of hatchery, wild,
and hybrid brood lines. These experimental groups are being studied for
differences in behavior and life history characteristics. Predation avoidance, growth and freshwater survival, and predation
ability experiments are being conducted. Marine survival has been evaluated
beginning with the first major adult return in 2001. Final adult returns
were expected in 2004. Data collection from the returning adults as well
as culture and behavioral trials on the second generation experimental
fish will continue in cooperation with the University
of Alaska Fairbanks School of Fisheries and Ocean Sciences.
For more information, see
Domestication
Issues in Alaska Chinook Salmon
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