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Photo of two salmon swimming next to a log in a small stream
Different CSI teams go out each day during the fall salmon migration to count fish in the stream. These two adult coho migrated up Miller Creek October 23, 2009.

How many adult salmon return to Miller and Walker Creeks in Burien, Normandy Park, and SeaTac each year? How many coho salmon are dying from polluted water before they have a chance to spawn? We are finding out, thanks to many dedicated volunteers. As we learn how many of these fish are stricken by pre-spawn mortality each year, we find out how many survive long enough to lay the eggs of the next generation. Coho pre-spawn mortality has been linked to polluted road runoff - and the good news is, filtering polluted stormwater through soils made of sand and compost makes it non-toxic to fish! 

A better understanding of the numbers of fish returning to the streams in the Highline community and the extent of pre-spawn mortality is one of the top recommendations the community identified as part of coordinated monitoring of the streams (see the 2009 monitoring coordination recommendations). Adult salmon in our streams are the Pacific Northwest equivalent of the “canary in the coal mine” – they reflect the health of our lands and water. This important data is helping us make priorities for the watershed and track our progress.

The Community Salmon Investigation volunteers gathered data in 2010, 2011, 2012, 201320142015, and 2016 to help us learn more about this community resource.

2016 Miller-Walker Salmon CSI Findings

The 2016 CSI survey season ran from October 8 through December 19. Here is what our 34 volunteers saw in the streams:

Coho (live): 104
Chum (live): 139
Escapement estimates:  101 coho and 87 chum
Dead fish: 67 coho and 40 chum
Pre-spawn mortality female coho: 9

For more details, see the FINAL 2016 Miller-Walker CSI Results Presentation, or

click here for a summary of the 2016 CSI Results for Miller and Walker Creeks

Sign up to Volunteer for CSI in 2017! 

Adventurous volunteers are needed for salmon surveys starting in October 2017. To find out more and be eligible to conduct surveys, attend our 2-hour training workshop!

CSI 2017 Orientation Workshop 
October 5, 5:30-7:30 p.m.
Normandy Park City Hall, Council Chambers
801 SW 174th Street, Normandy Park 98166

Click this Survey Monkey link to sign up!

As a volunteer, here is what to expect:

  • Teams (two people minimum) are responsible for data collection on one day each week (e.g., every Tuesday). Teams may be as large as you like, and alternate weeks, or the same people may survey each week.
  • Volunteers should expect to spend at least three hours on their survey day.
  • Volunteers work only during daylight hours that become more limited as the season progresses. People who work five weekdays will want to volunteer for weekend surveys. Those with flexible schedules will be encouraged to do weekdays.
  • Volunteers need to be able to walk up stream channels/banks that are rocky, wet and slippery. You need to climb over and under downed trees and push through or go under brush. Overall distance walked on each daily survey is about one mile (only a portion will be in the stream).
  • Volunteers need to go out rain or shine but will not monitor when the stream is running high to keep you safe (plus it’s hard to see fish in deep, murky water).
  • Short drives will be needed for you to reach all the survey sites.
  • Volunteers work in pairs for safety and to maximize data quality.
  • Volunteers need to follow the access requirements of the private and public landowners who graciously provide access to the streams.
  • Volunteers count and record information on living fish.
  • Volunteers take measurements of each dead fish. This involves handling and cutting open carcasses. Gloves are provided. Volunteers record information on adipose fin presence (indicating whether the fish came from a hatchery), sex, percent egg retention, and spawning status.
  • Volunteers need to provide their own rain gear and footwear. You will need hip waders. Rubber hip waders can be purchased for around $45. Chest waders are also a good choice.
  • Volunteer teams are given sampling collection kits and recording documents.
  • New volunteers will be paired up with a trained volunteer.
  • The program coordinator or an experienced volunteer will survey with each team at least once during the season for additional training.
  • Click here to see the Volunteer Position Description for CSI

See the bottom of this page for the training slides, survey plan, data form, and participation form.

2015 Miller-Walker Salmon CSI Findings

Final 2015 Miller-Walker CSI Results Presentation (Adobe, large file)

Summary of 2015 Miller-Walker CSI Findings (2-page, Adobe)

Some highlights from 2015: 

35 volunteers took turns surveying the creek every day to count fish from October 8 through December 24. They saw 146 live fish! Here they are by type:

37 live coho, 64 live chum, and 45 live adult salmon that couldn't be identified - they were moving too fast. Coho pre-spawn mortality was 75%, and coho carcasses were only found in Miller Creek in 2015.

Salmon Monitoring Results in 2014

Final 2014 Salmon Survey Presentation for CSI: Highline (Adobe PDF, 16 MB)

In fall 2014, 37 volunteers took turns conducting daily surveys starting on October 8 and ending January 9, 2015. Volunteer teams in 2014 reported seeing the following live adult salmon:

Coho (live): 78
Chum (live): 48
Unidentified adult salmon (live): 20
Estimated escapement (population of spawning fish): 80 coho and 29 chum
Carcasses: 70 coho, 26 chum

Coho pre-spawn mortality rate: 83% - this is the percent of returning adult coho females who died before spawning, and did not show evidence of having been attacked by a predator. Pre-spawn mortality in coho has been shown to be caused by untreated road runoff.

Salmon Monitoring Results for 2013

Final 2013 Salmon Survey Presentation (Adobe PDF, 16 MB)

In 2013, surveys started on October 4, and continued through January 5, 2014. Volunteers walked each day to look for salmon in sections of Miller and Walker Creeks where eleven property owners gave written permission. The survey reaches are approximately 2/3 of a mile long in each stream, and are not continuous.

Volunteer monitoring teams in 2013 reported seeing the following adult salmon (last updated 4/8/2014):
Coho (live): 119
Chum (live): 28
Unidentified adult salmon (live): 45

Salmon Monitoring Results for 2012

Final 2012 Salmon Survey presentation (PDF, 16.3 MB)

In 2012, surveys started on October 10, and ended on December 24, since no live salmon had been seen for a week. Volunteers walked each day to look for salmon in sections of Miller and Walker Creeks where eleven property owners gave written permission. The survey reaches were approximately 2/3 of a mile long in each stream, and were not continuous.

Volunteer monitoring teams in 2012 reported seeing the following adult salmon (last updated 3/15/2013):

  • Coho (live): 432 (of these, 216 were in Miller Creek, and 216 were in Walker Creek)
  • Chum (live): 113 (of these, 56 were in Miller Creek, and 57 were in Walker Creek)
  • Unidentified adult salmon (live): 69
  • Coho carcasses (dead): 240 (150 females, 90 males)
  • Coho Pre-spawn Mortality (died before they spawned, females only): 88%, or 100 of 115 females of known spawning condition
  • Spawned Coho Females: 14% (21 of 150)
  • Predated Coho (marks indicating they had been eaten by a predator or scavenger): 27% (56 of 274 coho, chum and unidentified carcasses recovered)
Video of coho salmon female showing symptoms of pre-spawn mortality (swimming near the water's surface, disoriented, lethargic)

Final Salmon Monitoring Results for 2011

 Fall 2011 Salmon Survey Results Presentation (Adobe PDF - large file)

In 2011, surveys started on October 10, and continued until December 23. Volunteers looked for salmon in sections of Miller and Walker Creeks where nine property owners gave written permission. The survey reaches were approximately 2/3 of a mile long in each stream, and were not continuous.

Volunteer monitoring teams in 2011 reported seeing the following adult salmon:
  • Coho (live): 419 (of these, 262 were in Miller Creek, and 157 were in Walker Creek)
  • Chum (live): 508 (of these, 158 were in Miller Creek, and 350 were in Walker Creek)
  • Unidentified adult salmon (live): 66

 The first coho of the 2011 fall spawning season was seen on October 12 in Miller Creek, and the last live coho was reported on December 11. The first chum was seen on November 13 in Walker Creek. Chum were still making their way upstream to spawn on the day of the last survey, and are expected to spawn in these streams until sometime in January.

 Carcass and spawning status information reported for coho:

  • Out of 89 coho carcasses (found dead):
  • 38 had successfully spawned!
  • 16 females died before spawning (pre-spawn mortality)
  • 14 were predated (eaten by a predator, not able to tell spawning status)
  • 21 had an undetermined spawning status
  • Rate of pre-spawn mortality (percent of females that died before spawning, not due to predation): 39%
  • Percent female: 46%
  • Hatchery origin (no adipose fin): 62%

 Pre-spawn mortality data 2011 (11/9/11 version) (Adobe PDF)

2011 Photos/Video

Youtube video of live coho in Walker Creek on November 20, 2011. Courtesy of D. Bobanick.

Two high school seniors from Highline participated in the 2011 surveys as their Culminating Senior Project. Courtesy of D. Bobanick

Program Materials

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Stewardship of the Miller/Walker Creeks basin is jointly funded by the City of Burien, City of Normandy Park, City of SeaTac, King County, and the Port of Seattle. On behalf of the partners, this page is proudly hosted by King County Department of Natural Resources and Parks - Water and Land Resources Division.

Related information

King County Salmon Watcher Program

Salmon SEEson - Where to view fall salmon

Sign up for Miller-Walker emails

Community Salmon Investigation (CSI) for Highline results are in!!  

Bring your family and friends for a fun-filled evening and learn about the status of salmon in your watershed.

Wednesday, March 7th, 2018
6:00 - 7:00 pm
Burien Community Center
Lakewood Room 
14700 6th Avenue SW

- and - 

Wednesday, March 14th, 2018
6:00 - 7:00 pm 
Normandy Park Community Club
1500 SW Shorebrook Drive
For more information, email Matt Goehring or call 206-263-6826.