Navigation Links
Study assesses impact of fish stocking on aquatic insects
Date:3/26/2009

The impact fish stocking has on aquatic insects in mountain lakes can be rapidly reversed by removing non-native trout, according to a study completed by U.S. Forest Service and University of California, Davis, scientists.

Their findings appear in a current online issue of the journal Freshwater Biology where they describe experiments that examined some effects of fisheries management practices now in use in California mountain lakes where fish do not naturally occur.

The research has value because the vast majority of mountain lakes in the western United States have been stocked with trout for several decades. Studies following lake restoration to fishless conditions will help scientists and wildlife managers understand the impact of past actions and future decisions.

Since 2000, the California Department of Fish and Game has reduced the number of wilderness lakes it stocks by about half because non-native fish feed on declining species like the Sierra Nevada yellow-legged frog. Federal and state agencies have also begun removing introduced trout in some lakes because fish can survive for years and continue feeding on sensitive species, after stocking has ceased.

Until now, scientists seldom studied the response of aquatic insect populations to the removal of non-native trout.

"These highly-mobile predators don't naturally occur in small alpine lakes so they have significant top-down effects on ecosystems," said Karen Pope, a Forest Service scientist at the Pacific Southwest Research Station and one of the study's authors. "They prey upon aquatic insects that are also food for other insects, amphibians, birds and bats."

In 2003, Pope and her colleagues began testing the effects introduced fish had on lake ecosystems in 16 lakes in Northern California's Trinity Alps Wilderness.

The National Science Foundation, U.S. Forest Service, California Department of Fish and Game, and University of California funded the study, which matched current California fisheries management practices by including lakes with continued stocking of trout, suspension of stocking and removal of all fish. It also included fish-free lakes as reference sites for the study.

The researchers used floating nets on each lake's surface to quantify aquatic insect populations. They also used gill nets to sample trout density at lakes where there was continued stocking or suspension of stocking.

Their results showed the presence of introduced trout was the most important factor affecting the emergence of insects from the lakes.

Aquatic insect populations quickly increased when trout were removed from lakes. However, the scientists found suspension of stocking was not effective for restoring insect abundance in most lakes. This was not surprising because suspension of stocking alone had little effect on trout density, according to the researchers.


'/>"/>

Contact: Roland Giller
rgiller@fs.fed.us
510-559-6327
US Forest Service, Pacific Southwest Research Station
Source:Eurekalert

Related biology news :

1. Study unravels why certain fishes went extinct 65 million years ago
2. CellThera and WPI advance in regeneration study
3. Innerscope Research(R) Uses Same-Day Results From Biometric Study to Identify Key Themes, Styles Behind Effective, Engaging Speaker Presentations
4. Lancet study supports new, highly effective treatment for blood disorder
5. Scots and Irish at greater risk of drink-related death, study shows
6. Pilot study shows effectiveness of new, low-cost method for monitoring hand hygiene compliance
7. DOE awards UGA $3.1 million to support complex carbohydrate study nationwide
8. AJCN study shows moderate alcohol consumption related to stronger bones
9. The genetics of fear: Study suggests specific genetic variations contribute to anxiety disorders
10. Study suggests salt might be natures antidepressant
11. Study of protein structures reveals key events in evolutionary history
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/30/2017)... The research team of The Hong Kong Polytechnic University ... adopting ground breaking 3D fingerprint minutiae recovery and matching technology, pushing ... for use in identification, crime investigation, immigration control, security of access ... ... A research team led by Dr Ajay ...
(Date:3/29/2017)... 29, 2017  higi, the health IT company that ... North America , today announced a Series B ... of EveryMove. The new investment and acquisition accelerates higi,s ... to transform population health activities through the collection and ... higi collects and secures data today on behalf ...
(Date:3/27/2017)... March 27, 2017  Catholic Health Services (CHS) ... Systems Society (HIMSS) Analytics for achieving Stage 6 ... sm . In addition, CHS previously earned a ... using an electronic medical record (EMR). ... level of EMR usage in an outpatient setting.  ...
Breaking Biology News(10 mins):
(Date:5/24/2017)... (PRWEB) , ... May 23, ... ... Northeast's premier provider of high quality relocatable and permanent modular buildings, announced ... visual management tools and modern office design characteristics to help support on-site ...
(Date:5/23/2017)... Canada (PRWEB) , ... May 23, 2017 , ... ... Firmex FileSend, a cloud-based file transfer solution that makes it easy for organizations ... without having to worry about cumbersome FTP software or email file size limitations. ...
(Date:5/23/2017)... ... May 22, 2017 , ... NetDimensions ... in the Aragon Research Globe™ for Corporate Learning, 2017. , Aragon Research defines ... market demand, and effectively perform against those strategies. NetDimensions’ ranking as a Leader ...
(Date:5/23/2017)... ... 23, 2017 , ... Kathy Goin is joining myClin ... brings years of expertise in establishing and leading clinical operations at Sponsors including ... occupational therapist, through a variety of leadership roles in Clinical Operations, to her ...
Breaking Biology Technology: