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Figure 1. The red coloured arrays in the figure above were those
arrays implemented by Kintama Research and are additional
to the arrays managed by the Ocean Tracking Network (OTN)-
coloured yellow. The red-coloured arrays in the Discovery Islands
are 69 and 180KHz and can detect the new small and high
frequency V4 tags in addition to larger tags. Figure provided by
Kintama Research.
TELEMETRY STUDIES: FOLLOWING SALMON ON THEIR
JOURNEY IN RIVERS AND OCEANS
HOW?
This research was undertaken to assess how individual
physiological states relate to migration rates, behaviour
and survival of juvenile salmon travelling through the Strait
of Georgia and Discovery Passage areas of the Salish Sea.
Using small acoustic transmitters, the behaviour and fate
of Chilko Sockeye (2016 and 2017) and Seymour steelhead
(2015) smolts was tracked from release through the Salish
Sea. The condition of these smolts was assessed prior to
transmitter implantation and release through the use of
biomarkers for pathogen presence and load, presence of
immune- or stress-related responses and growth potential
to better understand the links between body condition
during initial outmigration may influence survival and
behaviour in the early marine environment.
Until 2015, the existing acoustic receiver arrays allowed
for fish detections in the lower Fraser River, in Juan de
Fuca Strait, in north-central Strait of Georgia (NSoG) and
in northern Queen Charlotte Strait only. PSF, working with
Kintama Research (Nanaimo, BC), established new acoustic
receiver arrays in Discovery Islands and Johnstone Strait in
2015, and also evaluated the detection efficiency of V9, V7
and the much smaller V4 Vemco acoustic tags. The addition
of the new arrays and the high efficiency of V4 tags opens
up the possibility of carrying out tagging studies on much
smaller fish than has been previously possible (Figure 1).
QUESTIONS ADDRESSED DATA CONCLUSIONS
What is migration survival of Pacific
Salmon through freshwater and
segments of the Strait of Georgia?
What are travel speeds and routes
taken out of the Strait?
What are causes of mortality?
Since 2010, ~2,500 out-migrating
Chilko Sockeye smolts and ~300
Seymour steelhead have been
acoustically tagged and tracked
from freshwater through coastal
regions.
Gill biopsies of 200 wild Chilko
Sockeye and 160 Seymour Steelhead
to examine links between health
and survival.
Predation studies of bull trout in
Chilko Lake.
Survival rates vary geographically
and are segment- and route-specific.
Cumulative mortality of Chilko
Sockeye was ~ 50% over the ~ 700
km freshwater migration, and reached
~ 90% over the subsequent 300 km
marine migration.
Travel speeds vary among species.
Pathogens and immune function
were important to migration success,
with higher predation on smolts
infected with pathogens.
Photo
by
Jeremy
Koreski
