Central Sierra
University of California
Central Sierra

Green Blog

The flood-controlled LA River supports fish life

Long before European settlers arrived in America, the Los Angeles River was an important source of food and water for native peoples. Europeans settled the Los Angeles area in part because of the river and the fertile alluvial soils it provided. The river and its tributaries frequently flooded and changed course, forming wide alluvial floodplains that extended across southern Los Angeles from modern day Santa Monica to Long Beach. When Los Angeles began its transition to teeming metropolis and settled these flat floodplains, the river's natural characteristics led to disastrous flooding.

In the interest of saving lives and property, civil engineers sloped the banks and encased them in more than 30 miles of concrete, a move that completely altered the fishery. Recently completed UC Cooperative Extension research indicates that, despite the concrete and influx of pollutants from LA storm drains and sewage treatment plants, the Los Angeles River is still capable of sustaining life.

Working with Friends of the Los Angeles River, an organization interested in restoring the LA River to a more natural state, UCCE natural resources advisor Sabrina Drill surveyed the fish population in the river's eight-mile Glendale Narrows area, a section that, because of its underlying geology, was left with a natural bottom. The researchers discovered a diverse and bountiful fish population in this stretch of the river.

"To our surprise and delight, toxicity reports show the small number of fish we tested to be free of mercury and have extremely low levels of PCBs," Drill said. "This may not be true for the rest of the river. Glendale Narrows is one of the cleanest sections, probably because the natural river bottom cleans itself and because of the high quality effluent coming out of upstream water reclamation plants."

The survey identified eight species of fishes, none of them native, plus tadpoles and red swamp crayfish in the river. The eight fish species are: fathead minnow, carp, black bullhead, Amazon sailfin catfish, mosquito fish, green sunfish, largemouth bass and tilapia. They hail from Africa, South America, Eastern North America and Asia.

Whether reestablishment of native species to the river is possible remains to be seen, and may not be the most important factor in river restoration.

"Difficult though it may be, you can't make the LA River what it used to be simply by digging up the concrete," Drill said. "Because of all the development, the water we import, and changes in hydrology, temperature, and water quality, it’s not the same system it was before people settled here."

But restoration can still take place, and Drill believes that in the next 10 to 20 years, large-scale habitat restoration and restoration of some historical floodplains will dramatically enhance the ecological function and natural beauty of the Los Angeles River.


LA River Fishing
USC film maker Megan McCarty created a seven-minute documentary on fishing the Los Angeles River, which includes an interview with UCCE's Sabrina Drill. See the video here:

L.A. River Fishing from Meghan Mccarty on Vimeo.

Click the link below for the complete 21-page report on the Los Angeles River fish survey.

Los Angeles River Fish Study (pdf)
Los Angeles River Fish Study (pdf)

Posted on Tuesday, October 19, 2010 at 11:35 AM

Pacific fisher kits returned to the wild

Four baby Pacific fishers were released in the forest this week, with the aid of UC Berkeley scientists who are studying the Sierra Nevada population of the rare weasel-like carnivore.

Pacific fishers were once an abundant species, but the population has been in decline for more than 20 years. As part of the Sierra Nevada Adaptive Management Project (SNAMP), an ongoing study aims to determine what factors are influencing the fishers' fate, such as habitat loss, timber harvest, disease, development and climate change.

"We are extremely excited that the four fisher kits have been repatriated back out in the forest, where we hope they will survive and become part of the fisher population in this area," said Rick Sweitzer, UC Berkeley Research Wildlife Biologist and Adjunct Associate Professor.

Last May, two fishers being monitored as part of the SNAMP study were killed – one by a bobcat, the other hit by a car on Highway 41. It just so happened they were both nursing mothers.

“We knew that the female fishers had kits, and that these animals are rare in California,” Sweitzer said. “We couldn’t in good conscience let the baby animals perish in their den cavities knowing we might be able to intervene.”

The scientists staged two daring rescues and spirited the babies to the Fresno Chaffee Zoo for care. In time, the young animals were moved to a large pen and taught to hunt live prey by a regional wildlife rehabilitation organization.  The young fisher kits have been under the care of the Fresno Chaffee Zoo, by agreement with the California Department of Fish and Game.  Last week, the Department of Fish and Game gave approval for the "juvenile" fishers to be released back out into the forest.

"We aided this process by finding the most appropriate release areas where the animals will be most likely to find food in good quality fisher habitat," said Sweitzer.

Two of the fisher kits were released in the west Kaiser area. Two others were returned to the Beasore Road/Chilkoot Lake area of the Sierra National Forest, close to where their mother was killed in the SNAMP study area.

Unusual circumstances precipitated the two fishers' release into an area where their population is being researched. Late last year, two fishers died during captures when they were given anesthetic agents from a particular production lot that, unbeknownst to the scientists, had been causing serious problems with domestic pets and other animals and were subsequently recalled, but not until after both fisher deaths had occurred.  With permission from the California Department of Fish and Game, two of the fisher kits replaced the two that died because of the research project.

Read more about the UC Pacific fisher study.

Posted on Friday, October 8, 2010 at 2:43 PM

4-H member named a 'Young Hero'

Mariposa County 4-H member Sydnie Edwards, who coordinated efforts to reforest land devastated by the 2008 Telegraph Fire, was named a distinguished finalist by the Gloria Barron Prize for Young Heroes. She will receive $500 for higher education or service work.

The Barron Prize honors outstanding young leaders who have made a significant positive difference to people and the planet. Sydnie is one of five students across the U.S. chosen for this honor from a pool of 400 applications.

For her "Emerald Tree Project," Sydnie, 15, secured donations of lodge pole pine trees from Cal Fire and private nurseries and arranged with landowners to plant the trees. Fellow 4-H members, Girl Scouts, school friends and community members joined Sydnie in planting 2,000 trees.

The project is part of the national 4-H Million Trees Project, which hopes to inspire 4-H youth to plant one million trees as a way to slow climate change.

Posted on Tuesday, October 5, 2010 at 10:05 AM
Tags: 4-H (3), reforestation (1)

Talking about water

At a recent public meeting held in Contra Costa County by UC Cooperative Extension, a female cattle rancher representing a family that has owned land in the Sacramento-San Joaquin Delta for generations dumped out a grocery bag with dozens of envelopes onto the table in front of her.

“This is the amount of mail I get in one week from agency people," she said, her voice trembling with anger. "They want to come onto my land and look at where they want to put big tubes to carry water down south. My family has been on this property for a long time. It’s my family’s land.”

For this woman and many others, UCCE directors in the five Delta counties opened the flood gates when they invited the public to share their feelings about water. Ten meetings were hosted to give ordinary citizens a chance to speak.

“There is a lot of frustration in the Delta region,” said Carole Paterson, director of UC Cooperative Extension in Solano County. “People felt their voices weren’t being heard.”

Paterson and county directors in Yolo, Sacramento, San Joaquin and Contra Costa counties held community conversations in local libraries and invited the public to have their say. The participants’ thoughts will be synthesized in a written report and some of their comments - videotaped during the sessions - will be part of an audio-visual presentation.

A few common themes emerged from a preliminary review of the 10 conversations, Paterson said.

Frustration. People believe the public policy process is flawed.

Education. People do not understand what is happening to their water. The issues are extremely complex and over the years, layer upon layer of legislation, lawsuits, court decisions and media reports have muddied the water.

Science. People are concerned that science is being manipulated by various stakeholders to support a particular point of view.

The reports on the water conversations will be shared with county boards of supervisors, farm bureaus, legislators, agencies and individuals involved in the state’s water policy.

The Delta faces a host of problems, including invasive species, water degradation due to urban and agricultural runoff, aging infrastructure and the threat of flooding should the sea level rise due to climate change.

“We weren’t looking for solutions,” Paterson said. “We just wanted to give citizens a chance to share their experiences."

Posted on Tuesday, September 7, 2010 at 1:32 PM

Earthworms signal success on innovative tomato farm

If the return of earthworms to farm fields is an indication of success, then Sano Farms is on the right track.

“I haven’t seen earthworms in these fields in years,” said Firebaugh farmer Alan Sano. Sano and his partner, Jesse Sanchez, combine subsurface drip irrigation, winter cover crops and strip tillage to consistently produce a high-yielding crop of processing tomatoes.

In addition to boosting yield, the system they developed for the 4,000-acre farm is cheaper, increases soil organic matter and improves the tilth of their silty clay soil.

The farmers took several trips to the Midwest and consulted with UC Davis Cooperative Extension specialist Jeff Mitchell to learn the improved management techniques they applied on the farm.

After switching from furrow irrigation to drip, Sano and Sanchez began experimenting with cover crops.

"It wasn’t always an easy transition into cover crops," Mitchell said. "It did take some time to learn the best way to manage them."

As the benefits of years of cover cropping accumulated, they saw that they didn’t need to till the entire field to get good soil-seed contact; they only needed to till a strip of soil a few inches wide.

Recently, they shared their innovative farming system with other growers at an open house event sponsored by California's Conservation Tillage and Cropping Systems Workgroup.

Farmers interested in adopting conservation tillage techniques may contact Mitchell for more information at mitchell@uckac.edu.

Posted on Monday, August 2, 2010 at 11:42 AM

First storyPrevious 5 stories  |  Next 5 stories | Last story

 
E-mail
 
Webmaster Email: cecentralsierra@ucdavis.edu