Conclusions
Given potential reductions in favourable habitat due to accelerating
global warming, there is an urgent need to better understand the ocean
environment experienced by salmon and how this impacts their health and
condition. Up to now, little information has been available on
stock-specific salmon distribution which hampers our ability to resolve
stock-specific dynamics and develop appropriate management plans. The
marine environment is heterogeneous, and populations foraging in
different areas may be affected in different ways as environmental
conditions change. In this study, we showed that salmon stocks with
geographically close rearing grounds can have different at-sea
distributions, potentially driven by the difference in ocean entry
timing and size. Expanding this approach with data from other major
sockeye stocks and other salmon species would improve understanding of
the mechanisms explaining salmon spatial distribution in the high seas,
and how this distribution interacts with environmental conditions to
affect salmon survival and fitness.