As a reminder, the Arroyo Seco Foundation will be hosting a free trout habitat survey workshopthis Sunday.
The workshop will feature Ken Jarrett, a fisheries biologist with Stillwater Sciences, and cover key methods for professional stream assessment. This is a great opportunity for anyone interested in river restoration and native fish!
There are still spots left. Please RSVP to me (firstname.lastname@example.org) if you can make it.
Date & Time Sunday, May 20, 9AM – 2PM (includes a lunch break)
Location Hahamongna Native Plant Nursery in Hahamongna Watershed Park (The nursery can be hard to find. Click here for directions.)
Parking and restrooms are available at the nursery. From there we will take a short walk over to the stream channel and learn stream surveying methods for the assessment of native trout habitat. Be prepared for insects and uneven/slippery terrain. Some activities (such are measuring the stream gradient) will be done in the water, and closed toe shoes are required.
What to Bring
• Sun protection
• Sack lunch
• Note-taking materials
• Closed toe shoes (ideally water shoes or rubber boots if you have them)
By Tim Brick
Arroyo Seco Foundation
It’s time to head to the upper watershed in search of native trout. It has been another disappointingly dry year, but there is water in the stream, and some chance of spotting native fish. The flow in the upper Arroyo stream is now about 2 cubic feet per second, compared to the historic average of 5-6 cfs for this time of year, but 2 cfs is better than it’s been for a while.
WHERE TO LOOK: The most likely place to find native trout would be in the pools up around Switzer’s Falls and in nearby Bear Canyon, but trout sometimes go as far as the mouth of the Arroyo near Jet Propulsion Laboratory. (Btw, the Mount Wilson Bicycling Association has been doing monthly trail restoration work in the stretch of the Gabrielino Trail between Oakwilde and Switzer’s Camp.)
No one that I know of has claimed to see any native trout since the Station Fire nine years ago. I recently went with Wendy Katagi of Stillwater Sciences to visit the Riverside Corona Resource Conservation District, which has an excellent native fish program. They are willing to help us restore native fish in the Arroyo Seco, but first we need to document their current status, so we need your help now.
Take a hike! It’s always enjoyable in the upper Arroyo, particularly this time of year. Let me know what you find, and thanks for caring!
Tim Brick, the foundation’s managing director, adds:
“We’re still look for trout, but the stream is below 1 cubic feet per second again. We need to identify the pools and resting spots where the trout are hiding. Probably Bear Canyon is the most likely spot. Anyone care to go on a trout scout adventure?”
Did the trout survive the drought?
What is the history of fish in the Arroyo?
What is the potential for native fish restoration?
What is the current restoration program?
Fish or Concrete — What’s the Future?
Wednesday, July 12, 7 p.m.
Donald Wright Auditorium
Pasadena Central Library, 285 E. Walnut St., Pasadena
Myself, along with three other volunteers, began the scout at the Altadena Crest Trailhead in Altadena. We hiked for about two and a half miles on the Gabrieleno Trail along the Arroyo Seco to Gould Mesa Trail Camp, eventually turning around somewhere between Gould Mesa and Paul Little Picnic Area. The Arroyo is beautiful right now and as always, a very thriving ecosystem. We saw several California newts, who are mating right now and mountain yellow-legged frogs.
We stopped several times along the way making several notes about trout habitat and riverine conditions. We saw several things that made me confident of the existence of rainbow trout in the Arroyo. Here are some of the major habitat features that we discovered in several key habitat categories.
This central section of the stream currently possesses all of the necessary habitat requirements needed for native southern California trout to thrive; cool and clear water, stable undercut banks, clean gravel beds with little to no silt, overhanging vegetation, structural/habitat diversity and the food that trout eat.
The stream is flowing well about 5-10 cfs and the water temperature is cool. The banks along this section of the stream are undercut creating sufficient pool depth for trout to live in during the drier summer months.
Additionally, the roots of white alder trees which grow abundantly along the stream provide strong support along the banks. The gravel beds are clean and soft creating high quality habitat for trout to possibly spawn in the future. Canopy cover above the stream (overhanging vegetation) was almost always 50-to-75 percent, which keeps dissolved oxygen adequately high for native trout to thrive.
Lastly, many of the key components of trout dietary needs were present as well. These include terrestrial insects, spiders, midges, dragonflies and water boatman bugs.
Perhaps the most promising feature was the discovery of several two-to-four-foot-deep pools created by in-stream structural diversity, such as boulders and large woody debris. These pools are essential for trout survival and illustrate the important function that downed logs and boulders play in providing high quality for trout.
I will keep you all updated on the next “Trout Scout” and any possible trout sightings!
John Goraj is the Native Trout Program Manager at the Arroyo Seco Foundation.