Juvenile Monitoring

Summer 2019 salmon and steelhead snorkel counts

Sea Grant and Sonoma Water biologists conduct snorkel surveys each summer in order to document the presence, distribution and minimum count of salmon and steelhead. Wild coho young-of-the-year (yoy) were observed in 22 of the 43 streams surveyed, with an expanded count of approximately 4,200. Steelhead yoy were seen in all surveyed streams and the expanded count was nearly 80,000--the highest since standardized counts began in 2013 (note: number and length of streams surveyed varied by year). It's likely that the disparity between the high number of returning hatchery coho salmon adults over the winter of 2018/19 and the relatively low number of juveniles observed could likely be explained by the large, intense winter storm events scouring out or burying fragile eggs and/or emergent fry. The highest flows were after the primary coho spawning window, while steelhead spawning occurred over a longer period of time and into late spring. 

The table below lists the results by stream. Snorkel surveys were conducted in every second pool and expanded counts were generated by doubling the observed count. 

See our annual Summer Monitoring Report for more information on methods and outcomes. 

snorkeler underwater
Sea Grant Fish Biologist Nick Bauer is ready to head off in search of juvenile fish

snorkeler in a stream
Sea Grant Fish Biologist Nick Bauer snorkels through a pool on Green Valley Creek, counting juvenile salmon and steelhead
juvenile coho salmon
Wild juvenile coho salmon on Felta Creek

Observed and expanded counts of wild coho salmon and steelhead trout young-of-the-year in Russian River tributaries: Summer 2019

Tributary 

Number of pools snorkeled

Coho salmon yoy

Expanded count coho yoy1

Steelhead yoy

Expanded count steelhead yoy1

Willow Creek 110 146 292 820 1,640
Sheephouse Creek 71 100 200 372 744
Freezeout Creek 34 19 38 164 328
Austin Creek 149 3 6 2,216 4,432
- Kidd Creek 29 14 28 14 28
- East Austin Creek 94 21 42 1,107 2,214
 - - Black Rock Creek 32 3 6 532 1,064
 - - Gilliam Creek 34 0 0 20 40
 - - Thompson Creek 15 0 0 129 258
 - - Gray Creek 2 244 689 689 3,778 3,778
 - - Devil Creek 15 0 0 152 304
- Ward Creek 60 0 0 364 728
- Bearpen Creek 15 0 0 141 282
Dutch Bill Creek 105 32 64 1,258 2,516
- Perenne Creek 12 2 4 17 34
- Grub Creek 21 0 0 9 18
Hulbert Creek 113 9 18 3,768 7,536
- Mission Creek  3 0 0 134 268
Green Valley Creek 95 311 622 857 1,714
- Sexton Creek (Atascadero) 4 0 0 0 0
- Redwood Creek (Atascadero) 30 0 0 96 192
- Purrington Creek 70 101 202 662 1,324
- Little Green Valley Creek 18 0 0 63 126
- Nutty Valley Creek 13 20 40 10 20
- Harrison Creek 3 0 0 6 12
Santa Rosa Creek 73 0 0 2,402 4,804
Mark West Creek 3 229 714 1,428 4,468 8,936
- Porter Creek (Mark West) 62 24 48 1,118 2,236
Porter Creek 129 8 16 1,059 2,118
- Press Creek 9 0 0 8 16
Mill Creek 152 12 24 1,526 3,052
- Felta Creek 97 74 148 748 1,496
- Wallace Creek 31 0 0 301 602
- Palmer Creek 52 0 0 343 686
Crane Creek 36 0 0 287 574
Grape Creek 60 0 0 1,356 2,712
- Wine Creek 36 0 0 287 574
Pena Creek 114 34 68 8,803 17,606
- Woods Creek 81 106 212 700 1,400
 - - Dead Coyote Creek 10 3 6 33 66
Redwood Creek 51 0 0 703 1,406
- Yellowjacket Creek 69 0 0 253 506
Total   2,445 4,201 41,510 79,242

1 Expanded count is the observed count multiplied by a factor of 2. 

2 Snorkel counts include yoy released as part of an RSI trial. Every pool was snorkeled for RSI monitoring.

3 Snorkel surveys occurred after stocking so observed count likely consists primarily of stocked fish.