Navigation Links
River damming leads to dramatic decline in native fish numbers
Date:7/9/2008

Damming of the Colorado River over the last century, alongside introduction of game fish species, has led to an extensive decline in numbers of native fish whilst introduced species have flourished. Scientists have found that physical changes which occur to a river when it is dammed have had an adverse effect only on native fish, due to differences in their life histories. Armed with this knowledge, they have made proposals to management agencies, which, if implemented, could reverse the loss of native species not only in the Colorado but on a country or even world-wide scale. Dr Alice Gibb from Northern Arizona University will be presenting her research on Thursday 10th July at the Society for Experimental Biology's Annual Meeting in Marseille [Session A4].

Dr Gibb and her colleagues believe that differences in the early life of native and introduced species can account for the recent changes in population dynamics. They measured 'escape responses' of both native and introduced species to predators under laboratory conditions. "Our studies have shown that the larvae of native fish, which are usually less developed when they hatch, have a poorer escape response, due to their lack of adult swimming appendages. In contrast, many introduced species can prey upon the native species, and produce larvae that are more morphologically mature at hatching and thus may themselves be better equipped to escape predation," she explains.

Changes that damming has imposed on the Colorado River environment have amplified the disadvantage that native species face, according to Dr Gibb. "Historically, the less-developed native larvae had a natural refuge from predators due to sediment suspended in the water, and water turbulence increased the ability of larvae to encounter the plankton that they feed on. Fish also rapidly outgrew their period of high-vulnerability to predation due to higher water temperatures," she declares. "Damming the Colorado River has brought about the replacement of streams and rivers with large, still lakes, which has led to a decrease in sediment, turbulence and temperature, leaving the native larvae at a grave disadvantage."

Using all of the data they have gathered, the scientists have put forward proposals for how to reverse the decline in native fish numbers. "We suggest to management agencies that, in addition to removing introduced predators of native fishes from key river reaches, efforts must be undertaken to recreate the high-flow, sediment-rich, warm waters that gave the Colorado its name," Dr Gibb reports. "What is more, this advice is also relevant on a much wider scale: recent work in both Texas and the Pacific Northwest suggests that increased suspended sediment favours native fish larvae in these areas. Thus, dam removal may be critical for rehabilitating fish populations across the US, and almost certainly in other, less studied, areas of the world as well," she concludes.


'/>"/>

Contact: Holly Astley
hma25@cam.ac.uk
44-779-285-5259
Society for Experimental Biology
Source:Eurekalert  

Related biology news :

1. Baiji Dolphin previously thought extinct spotted in the Yangtze River
2. UC Riverside biologist receives prestigious MacArthur Fellowship
3. International team of scientists warns of climate changes impact on global river flow
4. Stronger EPA leadership needed to improve water quality in Mississippi River
5. UC-Riverside partners with Chinese university to address Chinas environmental problems
6. X-effect: female chromosome confirmed a prime driver of speciation
7. Tiny fish can yield big clues to Delaware River health
8. Scientists from the UGR prove that rivers do not act as barriers for groundwater flow
9. More comprehensive analysis of Klamath River basin needed to aid decision makers
10. Chemicals used as fire retardants could be harmful, UC-Riverside researchers say
11. LSU, Yale team study agricultural impact on Mississippi River
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
River damming leads to dramatic decline in native fish numbers
(Date:5/3/2016)... VILNIUS, Lithuania , May 3, 2016 /PRNewswire/ ... today released the MegaMatcher Automated Biometric Identification ... deployment of large-scale multi-biometric projects. MegaMatcher ABIS can ... and accuracy using any combination of fingerprint, face ... of MegaMatcher SDK and MegaMatcher ...
(Date:4/26/2016)... -- Research and Markets has announced the ...  report to their offering.  , ,     (Logo: ... forecast the global multimodal biometrics market to grow ... 2016-2020.  Multimodal biometrics is being implemented ... healthcare, BFSI, transportation, automotive, and government for controlling ...
(Date:4/14/2016)... April 14, 2016 BioCatch ... Detection, today announced the appointment of Eyal Goldwerger ... role. Goldwerger,s leadership appointment comes at a ... of the deployment of its platform at several of ... technology, which discerns unique cognitive and physiological factors, is ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... , ... June 23, 2016 , ... ... pleased to announce the launch of their brand, UP4™ Probiotics, into Target stores ... 35 years, is proud to add Target to its list of well-respected retailers. ...
(Date:6/23/2016)... - FACIT has announced the creation of a ... Propellon Therapeutics Inc. ("Propellon" or "the Company"), to ... of first-in-class WDR5 inhibitors for the treatment of ... an exciting class of therapies, possessing the potential ... patients. Substantial advances have been achieved with the ...
(Date:6/23/2016)... , June 23, 2016 Houston Methodist ... the Cy-Fair Sports Association to serve as their ... agreement, Houston Methodist Willowbrook will provide sponsorship support, ... connectivity with association coaches, volunteers, athletes and families. ... the Cy-Fair Sports Association and to bring Houston ...
(Date:6/23/2016)... Prostate Cancer Foundation (PCF) is pleased to announce 24 new Young ... cancer. Members of the Class of 2016 were selected from a pool of ... More About the Class of 2016 PCF Young Investigators ... ... ...
Breaking Biology Technology: