Collecting data on salmon fork length to find out the best habitat for summer chum salmon survival, and to aim for rebuilding salmon population in the Pacific North West

1. Endangered “Summer Chum”: Finding Optimum Habitat
@hualianxu1995
y = 0.7227x + 37.982
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ForkLength
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Barrier beach
y = 0.2x + 41.118
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ForkLength
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Pocket estuary
y = 0.8864x + 35.864
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ForkLength
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Pocket estuary
y = 0.1955x + 38.464
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ForkLength
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Delta
y = 0.3773x + 37.1
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ForkLength
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Delta
y = 0.7045x + 36.909
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Bluff backed beach
y = 0.9318x + 35
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ForkLength
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Bluff backed beach
y = 1.0045x + 38.109
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Barrier beach
Hualian Xu *
Program on the Environment
University of Washington
Faculty Advisor:
Professor John Horne
School of Aquatic and Fisheries Sciences at
University of Washington
Site Supervisor:
Aaron Jorgenson
Wild Fish Conservancy
Background
Hood Canal summer chum salmon was listed as threatened under the
Endangered Species Act in 1999. Recovery planning and implementation were
underway prior to the listing, with harvest reductions and hatchery programs
enacted in the early 1990’s. Population abundance reductions were linked to
habitat loss due to climate change. We need to know what habitat is best for
growth and survival.
Research Question
Figure 1. We
are netting
salmon at a
bluff backed
beach (in the
snow and cold)
for salmon data
collection in
February 2018
Ⓒ Wild Fish
Conservancy
METHODS
 Supplement data collections to extend the 2 year database.
 Sampled 56 sites and categorized sites into 4 habitats: Pocket estuary,
Delta, Bluff backed beach, Barrier beach.
 Internship responsibilities included field work at Hood Canal, data
processing and analysis, and produce research products.
 During 2018, use beach seine to catch and release summer chum salmon
(see Fig. 1), record fork length of the first 40 fish, measure water
temperature, tide height, salinity, sample time, and catch composition.
 Analyze length data from 2016-17 (2018 data have not been entered into
the database). Filtered winter chum salmon (by date), created boxplots of
length samples, regressed fork length (mm) with day of year to estimate
growth rates (mm week-1)
Figure 2.
Sample of
identified
Summer Chum
salmon from
beach seine
catch ready for
length
measurements.
2018 Ⓒ Wild
Fish
Conservancy
Results
 Delta (0.25 mm week-1) and pocket estuary (0.5 mm week-1) habitats
have the lowest average growth rate within 2016 and 2017.
Growth rate of summer chums at four different habitat
2016 2017
Figure 3. Average fork lengths of summer chum salmon at four habitat types from
the Wild Fish Conservancy project from early January to mid-March 2016 - 2017.
Red lines represent average weekly growth rate of the fish at each habitat.
Significance
 This internship addresses the environmental problem of climate
change that is intensifying habitat loss and species extinction due to
loss of habitat and reduction in species numbers, which potentially
increases the risk of extinction.
 Added value of this data is that they can be used for many other salmon
research projects because the data includes environmental variables
(e.g. temperature, salinity, tide height).
Figure 4. This is a
picture of me
holding a 60+ mm
Coho to take
pictures for
recording data at
one of the estuary
sites on
February 2018 Ⓒ
Wild Fish
Conservancy
Acknowledgements
I like to thank John Horne for being an incredible Faculty Advisor and
Aaron Jorgenson for helping throughout the project and being my site
supervisor, my family supporting my work and understanding me, and P.
Sean McDonald to give me ideas and check in with my work.
Figure 5.
Examples of
the four
habitat types
used to
classify
beaches.
2018 Ⓒ Wild
Fish
Conservancy
Are there differences in juvenile summer chum salmon growth rates among
different habitats?
 Based on highest growth rate, barrier beach habitat should have the
highest priority for restoration
 Bluff backed beach (0.8 mm week-1) and barrier beach (0.85 mm week-1)
habitats have a highest growth rate average within 2016 and 2017.
 A future step for this research might be to inventory barrier beach
habitat in Puget Sound and potentially create additional barrier beach
habitat at other locations without disturbing other resident species.
Additional monitoring efforts are needed to ensure summer chum
salmon use and increased growth.
Pocket Estuary
Barrier Beach
Delta
Bluff Backed Beach