Sunday, March 1, 2015
YOLO COUNTY NEWS
99 CENTS

River water diversions threaten sturgeon, study shows

Green SturgeonW

Sturgeon are one of the largest and oldest families of bony fish in the world, with 15 of the remaining 25 species listed as critically endangered due to over-fishing, habitat changes and habitat loss. UC Davis/Courtesy photo

By
From page A9 | January 19, 2014 |

UC Davis researchers have used laboratory studies to estimate the risk to young green sturgeon, which may be killed by unscreened pipes that divert water from the Sacramento River into adjacent farm fields.

The study confirms that this ancient protected fish species may be jeopardized by the current system of water diversion pipes. The findings also suggest that the threat could be lessened by diverting river water more slowly and over longer periods of time, meeting agricultural needs while conserving the green sturgeon populations.

The researchers report the study results this week in the online journal PLOS ONE.

“Our work highlights the potential danger that unscreened water diversions pose to migrating juvenile green sturgeon — a risk that is poorly understood for this species,” said Jamilynn Poletto, a doctoral student in the laboratory of the study’s lead researcher Nann Fangue, an assistant professor in the department of wildlife, fish and conservation biology.

Sturgeon are one of the largest and oldest families of bony fish in the world, with 15 of the remaining 25 species listed as critically endangered due to over-fishing, habitat changes and habitat loss.

One of those endangered species is the green sturgeon, which lives in coastal waters of the Pacific Ocean, from Alaska to Mexico. A specific population of these green sturgeon spawn only in the Sacramento River and is listed as threatened under the U.S. Endangered Species Act.

Unscreened agricultural water-diversion pipes that line the Sacramento River banks and levees have long been considered a threat to native fishes, but there has been limited data assessing their impacts.

Water is diverted from the rivers for agricultural use at more than 3,300 locations throughout the Sacramento-San Joaquin Watershed, and 98 percent of the diversion pipes are unscreened, posing a significant threat to juvenile green sturgeon.

Fish drawn into the pipes are either killed directly by water pumps or die when they are stranded in seasonally irrigated canals, ditches and fields when the water supply is withdrawn.

In an effort to quantify that threat, Poletto, Fangue and their colleagues simulated river conditions with an experimental flume, complete with an unscreened diversion pipe, angled bank and flowing water. The study was conducted in collaboration with the J. Amorocho Hydraulics Laboratory, which is run by M. Levent Kavvas, a UCD professor of civil and environmental engineering.

The research team found that a surprisingly large percentage of the young sturgeon placed in the flume was drawn into the unscreened pipe. Data from the study estimate that up to 52 percent of green sturgeon that pass within 1.5 meters of a water diversion pipe just three times could become irreversibly drawn into the pipes.

Unlike young Chinook salmon previously tested in the flume, the young green sturgeon did not demonstrate behaviors that would cause them to recognize and avoid the intake pipes.

The green sturgeon also were trapped in the diversion pipes at a higher rate than the Chinook salmon observed in the flume.

The researchers suggest that this difference between the sturgeon and the salmon could be explained by the fact that the sturgeon have fewer sensory organs that detect changes in water velocity than do the salmon.

The study also demonstrated that a 50 percent reduction in the flow of water through the diversion pipe resulted in a 78 percent decrease in the number of fish drawn into the pipe.

The researchers note that extrapolation of their findings to in-river conditions must be done with caution, but they suggest that new water diversion strategies, such as slowing the rate of water diversion, might be successful in balancing agricultural needs in the Sacramento Valley with fish conservation priorities.

“To create effective management strategies for green sturgeon and other native fishes, we first must understand the factors like these water diversions that could be impacting population declines,” Fangue said.

In addition to Fangue, Poletto and Kavvas, the researchers on this study were Timothy Mussen, Dennis Cocherell, Jon Reardon, Zachary Hockett, Ali Ercan, Houssein Bandeh and Joseph Cech, Jr.

The study was funded by the California Department of Fish and Wildlife’s Ecosystem Restoration Program, the UC Agricultural Experiment Station, the U.S. Department of Interior’s Anadromous Fish Screen Program and the National Science Foundation.

— UC Davis News

Comments

comments

.

News

Sheriff: Mother ‘sole person responsible’ for infant’s death

By Lauren Keene | From Page: A1 | Gallery

 
Rifle Team has a blast with competitive shooting

By Savannah Holmes | From Page: A1 | Gallery

Child abduction case in jury’s hands

By Anne Ternus-Bellamy | From Page: A1

 
Pipeline project will soften water in 2016

By Dave Ryan | From Page: A1

Pig out at Farmers Market’s Pig Day

By Enterprise staff | From Page: A1

 
Weekend storm drops snow, rain, hail in California

By The Associated Press | From Page: A2

Christie to Republicans: No rush to pick 2016 nominee

By The Associated Press | From Page: A2

 
Bob Dunning: Colon prep can be hard to swallow

By Bob Dunning | From Page: A2

Scouts help fill STEAC’s pantry

By Enterprise staff | From Page: A2

 
Explore Asia at Arboretum storytime

By Enterprise staff | From Page: A3

MU Games closing in late March

By Special to The Enterprise | From Page: A3

 
Still no parole in toddler case

By Enterprise staff | From Page: A3

City offers wetlands tour

By Special to The Enterprise | From Page: A3 | Gallery

 
Parole denied in 1987 killing spree

By Enterprise staff | From Page: A3

Young patients bond with special stuffies

By Special to The Enterprise | From Page: A4 | Gallery

 
Diversity theater group continues creativity workshops

By Special to The Enterprise | From Page: A4

Radio talk show moves to Mondays

By Enterprise staff | From Page: A4

 
Assault awareness campaign kicks off

By Anne Ternus-Bellamy | From Page: A4

UCD student with meningococcal disease is recovering

By Special to The Enterprise | From Page: A4

 
UCD student panel to cover anti-Semitism, Islamophobia

By Special to The Enterprise | From Page: A6

Yolo Food Bank hosts thank-you breakfast on Pig Day

By Enterprise staff | From Page: A9

 
.

Forum

Milt Priggee cartoon

By Debbie Davis | From Page: B4

 
Rowing: PE as well as life skills

By Letters to the Editor | From Page: B4

Police complaint procedures drafted

By Letters to the Editor | From Page: B4

 
Clarifying energy update letter

By Letters to the Editor | From Page: B4

Weekly claw pickup necessary

By Letters to the Editor | From Page: B4

 
Mars or ISIS? Similar outcome

By Letters to the Editor | From Page: B4

City may get charged up over energy choices

By Special to The Enterprise | From Page: B4

 
Design innovation centers for the 21st century

By Special to The Enterprise | From Page: B5

 
Speak out

By Enterprise staff | From Page: B5

 
A new perspective on life

By Creators Syndicate | From Page: A7

Distant water crisis has lessons for Davis

By Marion Franck | From Page: A7

 
Call for study to settle if anesthesia poses risk to babies

By The Associated Press | From Page: A7

.

Sports

Winning close games is the key for DHS softballers

By Spencer Ault | From Page: B1 | Gallery

 
Aggie men get a bounce-back win at Cal Poly

By Enterprise staff | From Page: B1

 
The mystery continues: lowly Gauchos upset UCD women

By Bruce Gallaudet | From Page: B1 | Gallery

Devils get a soccer win despite finishing woes

By Evan Ream | From Page: B1 | Gallery

 
Sports briefs: Razo throws well as Aggies get a baseball win

By Enterprise staff | From Page: B2 | Gallery

Defending champion Blue Devils have diamond holes to fill

By Thomas Oide | From Page: B3 | Gallery

 
Republic FC falls to storied New York Cosmos

By Evan Ream | From Page: B10

.

Features

.

Arts

.

Business

Yolo Federal Credit Union honored for supporting business education

By Special to The Enterprise | From Page: A10

 
Online store will celebrate, mock People’s Republic of Davis

By Wendy Weitzel | From Page: A10 | Gallery

.

Obituaries

.

Comics

Comics: Sunday, March 1, 2015

By Creator | From Page: B8