Featured Research

from universities, journals, and other organizations

Plunging fish numbers linked to dam releases

Date:
June 11, 2013
Source:
Griffith University
Summary:
An Australian study has thrown cold water on the notion that large dam releases compensate for the effects of interrupting natural water flows.

A significant decline in the numbers of native fish in the Murray-Darling Basin may be linked to released dam water being too cold for breeding.

This is just one of the findings from a Griffith University led study which found current water releases back into the Murray-Darling system limit fish reproduction and therefore impact freshwater biodiversity.

Griffith University Research Fellow Dr Rob Rolls said the results, published in Freshwater Biology, throw cold water on the notion that large dam releases compensate for the effects of interrupting natural water flows. And it's not just seasonal flooding which is important; the natural low flow periods matter too.

"Golden perch an iconic species that significant value for recreational fishing and it is often assumed that large floods are necessary to initiate spawning and recruitment of golden perch and many other fish," Dr Rolls said.

"But we found that more than 90% of golden perch juveniles occurred in unregulated lowland rivers in the northern Murray-Darling Basin, which naturally stop flowing for weeks or months, while regulated reaches now flow constantly.

"Restoring these natural low flow periods is critical because it is these shallow, warm reaches of waterways which produce the food fish depend upon."

The team also found that releases from the Pindari Dam on the Severn River did not encourage fish spawning because the water is much colder compared with nearby unregulated rivers.

"Stream temperature has a significant effect on spawning opportunities for fish, and cold water released from the bottom of dams may limit the benefits of environment flows," Dr Rolls said.

"The negative impact of this could be minimised by modifying dams so the warmer water from the surface of reservoirs is released rather than from the bottom."

This research was undertaken in conjunction with the New South Wales Office of Water, the Queensland Government and the University of New England.


Story Source:

The above story is based on materials provided by Griffith University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Robert J. Rolls, Ivor O. Growns, Tariq A. Khan, G. Glenn Wilson, Tanya L. Ellison, Andrea Prior, Caroline C. Waring. Fish recruitment in rivers with modified discharge depends on the interacting effects of flow and thermal regimes. Freshwater Biology, 2013; DOI: 10.1111/fwb.12169

Cite This Page:

Griffith University. "Plunging fish numbers linked to dam releases." ScienceDaily. ScienceDaily, 11 June 2013. <www.sciencedaily.com/releases/2013/06/130611102318.htm>.
Griffith University. (2013, June 11). Plunging fish numbers linked to dam releases. ScienceDaily. Retrieved August 29, 2014 from www.sciencedaily.com/releases/2013/06/130611102318.htm
Griffith University. "Plunging fish numbers linked to dam releases." ScienceDaily. www.sciencedaily.com/releases/2013/06/130611102318.htm (accessed August 29, 2014).

Share This




More Earth & Climate News

Friday, August 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Scientists Have Figured Out Why Rocks Move In Death Valley

Scientists Have Figured Out Why Rocks Move In Death Valley

Newsy (Aug. 28, 2014) The mystery of the moving rocks in Death Valley, California, has finally been solved. Scientists are pointing to a combo of water, ice and wind. Video provided by Newsy
Powered by NewsLook.com
Big Waves, Minor Flooding from Hurricane

Big Waves, Minor Flooding from Hurricane

AP (Aug. 27, 2014) Thundering surf spawned by Hurricane Marie pounded the Southern California coast Wednesday, causing minor flooding in a low-lying beach town. High surf warnings were posted for Los Angeles County south through Orange County. (Aug. 27) Video provided by AP
Powered by NewsLook.com
Calif. Quake Underscores Need for Early Warning

Calif. Quake Underscores Need for Early Warning

AP (Aug. 26, 2014) Researchers at UC Berkeley are testing a prototype of an earthquake early warning system that California is pursuing years after places like Mexico and Japan already have them up and running. (August 26) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins