Free Newsletters - Space - Defense - Environment - Energy
. Farming News .

For fish and rice to thrive in Yolo Bypass, 'just add water'
by Staff Writers
Davis CA (SPX) Oct 30, 2013

UC Davis Center for Watershed Sciences and California Trout researchers study salmon growth in seasonally flooded rice fields in the Yolo Bypass near Woodland, Calif., on Feb. 19, 2013. Scientists are investigating whether the Central Valley's historical floodplains could be managed to help recover California's populations of Chinook salmon. Credit: Carson Jeffres/UC Davis.

From a fish-eye view, rice fields in California's Yolo Bypass provide an all-you-can-eat bug buffet for juvenile salmon seeking nourishment on their journey to the sea. That's according to a new report detailing the scientific findings of an experiment that planted fish in harvested rice fields earlier this year, resulting in the fattest, fastest-growing salmon on record in the state's rivers.

The report, provided to the U.S. Bureau of Reclamation, describes three concurrent studies from researchers at the University of California, Davis, nonprofit California Trout and the California Department of Water Resources. The scientists investigated whether rice fields on the floodplain of Yolo Bypass could be managed to help recover California's populations of Chinook salmon, and if so, the ideal habitats and management approaches that could allow both fish and farms to thrive.

"We're finding that land managers and regulatory agencies can use these agricultural fields to mimic natural processes," said co-author Carson Jeffres, field and laboratory director of the Center for Watershed Sciences at UC Davis. "We still have some things to learn, but this report is a big step in understanding that."

Researchers found that the fish did not have a preference among the three rice field types tested: stubble, plowed and fallow. The food supply was so plentiful that salmon had high growth rates across habitats and management methods.

"It's like a dehydrated food web," said Jeffres of the harvested rice fields. "Just add water. All of those habitats are very productive for fish."

The salmon did demonstrate a preference for habitats with better water flow. Jeffres compared it to choosing among three good restaurants: Each offers good food with hearty portions, but one has better ambience and so is chosen above the others. In this case, the better water flow was the ambience the fish preferred.

Among the key findings:
+ Experimental flooding of Yolo Bypass rice fields during the winter can create productive aquatic food webs for salmon.

+ Average growth rates during the study's 41 days were the highest recorded in freshwater in California. Growth of juvenile Chinook averaged 0.93mm per day, with growth of 1.5 mm per day observed during specific two-week intervals.

+ Mortality was greater than in the team's previous 2012 study at Knaggs Ranch. In the 2013 study, between 0 and 29 percent of free-swimming fish survived, while 35-98 percent of fish in enclosures survived.

+ Lower survival rates were attributed to bird predation. The winter of 2013, when the study was conducted, was one of the driest on record in the Sacramento Valley, which may have drawn more birds to the inundated rice fields, and to the fish. The study plots were also relatively shallow, providing little escape for fish. A follow-up study planned for 2014 will explore the role of depth as a refuge for fish against avian predators.

+ Fish reared in plowed rice fields grew faster than those reared over stubble or weedy vegetation. However, all habitat types were beneficial to the fish, suggesting farm managers may have more flexibility in land treatment after harvest.

"These results are good news for the effort to rebuild salmon populations in California," said lead author Jacob Katz, a biologist with California Trout. "We've always suspected that when we mimic natural flood processes in agricultural fields, we give these fish a food-rich habitat they recognize and thrive in. These findings support that theory and provide a strong path forward for California land use planners, conservationists and farmers alike. This is a win-win model that can be replicated around the state."

The Yolo Bypass is the Central Valley's largest contiguous floodplain and provides critical fish and wildlife habitat, the report said. It is covered by floodway easement held by the state of California, making other land uses subservient to flood control. Agriculture is a major land use in the bypass, with rice the primary crop.

More than 95 percent of Central Valley floodplain habitat that was historically used to rear juvenile Chinook salmon has been altered, primarily diked, and drained for agriculture conversion. Most former floodplain wetlands are now only inundated during major floods. The report said access to floodplain habitats and the high growth rates associated with them during even a limited time may be critical in improving return rates for Central Valley salmon populations.

The project was completed in collaboration with landowner partners Cal Marsh and Farm Ventures and Knaggs Ranch, with funding from California Trout, Knaggs Ranch LLC, Metropolitan Water District of Southern California, Resources Legacy Fund, State and Federal Contractors Water Agency, and the U.S. Bureau of Reclamation. Read the study.


Related Links
University of California - Davis
Farming Today - Suppliers and Technology

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

Argentine bread prices keep rising as grain scarcity kicks in
Buenos Aires (UPI) Oct 29, 2013
Argentina's wheat and corn distribution chaos, caused by erratic supplies and now widespread scarcity, has finally reached bakeries that are charging exorbitant prices for bread despite government warnings of a crackdown. Corn and wheat shortages began several months ago and weren't relieved despite what critics called the government's stopgap measures. The timing of the grain shortage ... read more

Astrium delivers microwave radiometer for the Sentinel-3A satellite

Time is ripe for fire detection satellite

Canadian Satellite SCISAT Celebrating 10 Years Of Scientific Measurements

Developing Next Generation K-12 Science Standards

Russia Retires Faulty Glonass-M Satellite

Raytheon demonstrates first Direct Geo-Positioning Metric Sensor

Britain considering car-tracking 'bullet' technology

Orbcomm Launches Solar-Powered Trailer Tracking Solution

Gold mining is ravaging Peruvian Amazon: study

Working wood locally in Congo basin poses challenge

Gum leaves rich in lil' gold nuggets

Risk of Amazon rainforest dieback is higher than IPCC projects

Plant used as biodiesel source found to hide poisonous problem

Maverick Biofuels Awarded Three US Patents for the Production of Mixed-alcohols from Methanol

The proteins in major biodiesel plant have been mapped - and it does not look good

The potential of straw for the energy mix has been underestimated

Breakthrough for solar cell efficiency

Trina Solar Anesco partnership goes from strength to strength - aiming for 150MW

Hanwha Q CELLS USA to offer one stop shop for commercial solar customers

Scientists' new approach improves efficiency of solar cells

Shifting winds in turbine arrays

Spain launches first offshore wind turbine

Key German lawmaker: End renewable energy subsidies by 2020

Installation of the first AREVA turbines at Trianel Windpark Borkum and Global Tech 1

US ends most financing of overseas coal projects

Two China miners saved 10 days after flood, 10 confirmed dead

Calculating the true cost of a ton of mountaintop coal

Ukraine designates 45 coal mines for sale in privatization push

Women driven to fury by Beijing police road tips

US, family urge China to free anti-censorship activist

Anti-corruption activists face trial in China

Beijing divorces soar over property tax

The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement