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Development of a Life-Cycle
Model of Sockeye Salmon in the Okanagan Basin
Okanagan Nation Alliance
ESSA is developing a life-cycle model of sockeye
salmon in the Okanagan Basin. Historical records indicate that sockeye
salmon were once found in most of the lakes in the Okanagan Basin.
Currently, the only sockeye population within the Okanagan Basin
is found in Osoyoos Lake. A 1997 workshop to discuss strategies
for restoring Okanagan sockeye recommended that sockeye be re-introduced
to Skaha Lake as an experimental management strategy to resolve
some of these uncertainties. In preparation for such an experiment,
the Okanagan Nations Fisheries Commission, the Colville Confederated
Tribes, and other fisheries agencies have undertaken a research
project to identify and assess the risks and benefits of an experimental
re-introduction of sockeye salmon into Skaha Lake. This project
includes targeted field work on such topics as disease, exotic species,
and habitat inventories, as well as development of the life-cycle
model.
The overall role of the life-cycle model within
the overall Skaha Lake project is to explore the relative benefits
and risks of possible reintroduction strategies and alternative
monitoring approaches to assess the impacts of reintroduction. Consequently,
the key function of the model is to provide a framework for capturing
key hypotheses about sockeye and kokanee and the stressors that
act on them throughout their entire life-cycles (including interactions
among sockeye/kokanee/Mysis in Skaha Lake), and produce a
range of possible relative outcomes from various management and
environmental scenarios. The model operates on an annual time step
and provides annual relative abundance estimates of sockeye salmon
in Osoyoos and Skaha Lakes, Skaha Lake kokanee, and Skaha and Osoyoos
Lake Mysis populations.
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