“Trout Scout’ finds water, critical habitat conditions, in Arroyo Seco

By John Goraj
Guest Contributor

Hello all:

I wanted to give you a quick update on the initial “trout scout” that Arroyo Seco Foundation and volunteers did last week at Switzer’s Falls on Feb. 11. Please keep in mind that this first trip was not meant to be a technical, scientific survey, but rather to get a general idea of the habitat conditions for native trout and stream ecology/hydrology at the moment. But, the next few trips will become more technical as time goes on, employing GIS, DNA extraction and using snorkeling and wetsuit gear to look for trout.

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One of several 3-4 foot deep pools we saw as we made our way through the canyon. (Courtesy John Goraj)

We walked about two miles down the trail, stopping several times along the way to survey conditions and look for evidence of life. One thing is for certain — the Arroyo Seco has not flowed this turbulently in several years! I would guess that the streamflow was close to 50-75 cubic feet per second. It was so wonderful to see. We had to jump over the stream on rocks and downed logs several times along the way. There were several three-to-four-foot-deep pools as we made our way through the canyon. Many of these pools possessed some critical habitat features needed for rainbow trout: clean gravel beds; in-stream woody debris and boulders that create additional pools, turbulent, cool water and overhanging vegetation creating cover. Additionally, the strong root systems of white alder and cottonwood trees that line the stream have established solid banks, which is another key component of healthy mountain streams needed to sustain trout species.

Although we did not see any fish this time, the most salient observation I can make right now is that I do believe some trout are living up there. All or most of the necessary habitat conditions are present and I think it’s only a matter of time before we see some fish.

The next survey will focus on going deeper into the Bear Canyon area. I have heard from several anglers that they have seen trout up here prior to the 2009 Station Fire. The combined effects of the fire and the recent five-year drought had made seeing trout in this area improbable. But I don’t think this is case anymore. The Switzer Falls/Bear Canyon area is recovering quickly and now with all the rain and snowmelt, conditions have changed for the better.

Thank you for your interest as always and feel free to email me with any questions or comments at: john@arroyoseco.org.

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River Health Update: Biologists and volunteers return to work on the upper river fish study

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STAYING FOCUSED on the fish study at hand, volunteers get some company in the background. (Credit RCDSMM Stream Team)

By Rosi Dagit
Guest Contributor

On our return to Sepulveda Basin, to continue the upper river fish survey, we captured 203 fish, a far cry from the more than 3,600 tilapia fry caught this time last year.

There had been the first major rain of the season the day before, on Monday, Nov. 21, with between 0.75-1.25 inches over the LA River basin. Sediment and the remains of several homeless encampments were in our car park site. Muck was unconsolidated and varied from 1-6 inches deep. We couldn’t walk far upstream, starting 30 yards to the underpass at Burbank Blvd. because the water was too deep but flow in the main stem concrete area where the sample sites are located was shallow. Most of the vegetation along the banks was gone with just a few patches of water primrose (Ludwigia hexapetala), a few cattails and some willows closer to the bridge were all that remained.

The majority of fish were non-native juvenile Tilapia sp. and Gambusia affinis. Both of these species are common and abundant throughout the LA River, where they were initially released to control mosquito larvae. Samples of both species, as well as fathead minnow, juvenile red swamp crayfish and Asiatic clams were also collected and frozen for toxicology testing.

A single adult Plecostomus (Hypostomus plecostomus), which is a common aquarium fish, was also found washed up on the concrete bank at site 2. It recovered when placed into cool water, but was collected for toxicology testing.

An Army Corps ‘dozer and dump truck moved sediment and debris out of the concrete channel, according to their management permit. The site supervisor kindly allowed us to complete our site 1 and 2 sampling before they moved heavy equipment into that area. The rest of our six sites were upstream of their work area.

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YOU NEVER KNOW when an aquarium dweller will show up in the LA River, in this case the gnarly Plecostomus. (Credit RCDSMM Stream Team)

Following collection of what looked like an arroyo chub (but was later confirmed to be a fathead minnow) at site 1, just downstream of the disturbance in the channel, we contacted the California Department of Fish and Game about this potential threat to any other arroyo chub that might have washed down.

Dagit is the Senior Conservation Biologist, Resource Conservation District of the Santa Monica Mountains.

Volunteer opportunity: Tuesday, Nov. 22, Sepulveda Dam

friday-nov-22-parking

Friends of the Los Angeles River (FoLAR)

Sepulveda Basin Fish Survey
Tuesday, Nov. 22

CALL FOR VOLUNTEERS

8 a.m., arrive at meeting site – The park gate on Burbank Boulevard, just west of Woodley Avenue. This is the kayak loading site and it’s roughly a quarter-mile upstream from Sepulveda Dam.

8:30 a.m., William Preston Bowling will greet everyone with liability waivers. Volunteers signed in, put on waders/sunscreen, and took the fishing gear and buckets down to the river at site 1 and Anglers bring their own gear and valid fishing license.

We are collecting fish to observe and throw back, showing all your catch to biologists once caught, they will decide what species to keep for toxicity study.

This will be the second outing of the third “Los Angeles River Fish Studies” created by FoLAR. This study is in Partnership with Stillwater Sciences and the Resource Conservation District of the Santa Monica Mountains.

Check out FoLAR’s past studies here:

http://folar.org/wp-content/uploads/studies/fish-study-2008.pdf

http://folar.org/wp-content/uploads/2014/03/2016_FoLAR_LongBeach_FishStudy.compressed.pdf

William Preston Bowling
FOLAR  (310) 428-5085

More than 3,600 tilapia fry netted in upper river fish survey

BIOLOGISTS Sabrina Drill (left) and Rosi Dagit inspect part of the tilapia haul. (William Preston Bowling)

BIOLOGISTS Sabrina Drill (left) and Rosi Dagit inspect part of the tilapia haul. (William Preston Bowling)

By Rosi Dagit

Guest contributor
Looks like we captured 3,699 fish, the majority of which were juvenile tilapia under 1 inch. Based on the few larger (up to 3 inches) fish, most appeared to be redbreasted tilapia (Tilapia rendalli), but that is not yet verified with the voucher specimens.  These fish can breed year around in warm waters, and it was quite interesting to find such young fish at this time of year, but water temperatures were 24-27 degree C. (75-81 degrees F.), which is pretty warm. They can reach up to 18 inches and live for up to seven years.
They are native to Africa, and are primarily herbivores that spawn in the substrate and guard their nests.  They are considered to be competitors with native fish for food and spawning areas, and high densities of fish can negatively impact native aquatic vegetation.
In other areas, they have not survived strong flows or colder temperatures, so it will be really interesting to see if they make it through the winter El Nino.
SEINE NETS yield 3,000 tilapia fry in Haskell Creek above Sepulveda Dam on Friday. (William Preston Bowling)

SEINE NETS yield more than 3,600 tilapia fry in Haskell Creek above Sepulveda Dam on Friday. (William Preston Bowling)

First citizen science fishing event tomorrow at Sepulveda Basin

 

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Here’s an updated message from organizer Rosi Dagit:

Alex and I will meet Bill by 7:45 and see if we can figure out how to open the gate – pending hearing back from MRCA. We will offload all the gear from my truck and stage it there either way.
8 am Meet Bill at the corner of Burbank and Woodley, see attached map where it says PARK HERE
We can direct you back across Burbank to the kayak parking area. Parking here at the Reserve involves a lovely 15-20 minute hike along Haskall Creek, back downstream under Burbank Blvd, through the south reserve and across the river, to grandmother’s house, oops, across the river and back upstream to eventually get to the kayak boat launch area where all the nets will be staged.
We recommend that you bring your lunch, water, etc. in a daypack so that you can carry it over 1 mile and have hands available to help with rods, buckets, waders, etc. (Full details here)
If you get stuck in traffic or have problems please call me at 310.488.6381 so we can sort things out.
Thanks everyone for your patience while we got this all sorted out! Looking forward to a fun day in the river on Friday. Can’t wait to see what we catch!
Cheers, Rosi
You can also email FoLAR’s William Preston Bowling at web@folar.org for more information.
See you on the river, Jim Burns

Next up: Fish for science at Sepulveda Dam on Nov. 20

Yucking it up in 1938: Herald-Express photographer Coy Watson Jr. (left) and reporter Fred Eldridge (Courtesy KCET).

Yucking it up in 1938: Herald-Express photographer Coy Watson Jr. (left) and reporter Fred Eldridge (Courtesy KCET).

Update: because of permit issues, this event has been postponed until Friday, Nov. 20.

Hi Everyone,

Attached please find the info for the upcoming fishing day.
We caught more fish in dip nets on our exploratory mission last Friday than we have at all other events. They were juvenile tilapia, but still!

We still need 2-3 more volunteers at least but the more the merrier! Please spread the word!

If some of the anglers want to bring kayaks and or floatie chairs along with their rods, there is a cool place under Burbank to send them.

We will also have lots of seine nets available.

Thanks to Bill for setting this up! thanks to all of you for your help in making it happen! This should be really fun!


If you are interested, please email me at oaksrus@verizon.net and I’ll send you the rest of the info.

Rosi Dagit
RCD of the Santa Monica Mountains
540 S. Topanga Canyon Blvd
Topanga, CA 90290

oaksrus@verizon.net

SEPULVEDA DAM- LA RIVER SAMPLING

 

Friday, 30 October 2015

PURPOSE: To characterize the fish community near Sepulveda Dam prior to the onset of the rainy season.

7am RCD team meets at office to load truck and carpool

RCDSMM gear to bring:

waders                         8 buckets                                 dip nets

seine nets                    GPS                                         cameras

blocking nets               fish measuring board               fish id books

data sheets                  clipboard and pencils              cooler and ice

meter tapes                 ziplock baggies                        fish labels/scale envelopes

8am Meet Bill and other volunteers at the pull out off Burbank Blvd.

(Directions to follow!)

EVERYONE should come prepared to get wet to the waist.

Close toe shoes required. Lots of algae to slip on so please come prepared.

If you want to borrow some waders, contact Rosi with your shoe size!

Bring lunch, water, sunscreen, hat and change of clothes if you wish.

If you have a valid CA Fishing License, please bring it along.

8-12     FISHING! We will be working between the Sepulveda Dam upstream to the

bridge under Burbank Blvd. If there is time, we would also like to sample at a few locations in Haskell Creek.

12-12:30 lunch on site (Rosi will bring cookies!)

12:30 – 3 FISHING!

3- 3:30 Clean and pack gear and samples. Head home after a fun day in the river!