Navigation Links
Climate threatens trout and salmon
Date:5/17/2010

Trout and salmon are among the world's most familiar freshwater fishes, but numbers have fallen over recent decades in some areas, dramatically.

Pollution, habitat loss and over-fishing have all been blamed in the past, but new evidence from Cardiff University shows that climate change could be a major factor, putting both species at risk.

The scientists studied populations of young salmon and trout in the River Wye in Wales, traditionally one of the UK's best angling rivers. Professor Steve Ormerod and colleagues from the Cardiff School of Biosciences found salmon numbers fell by 50% and trout numbers by 67% between 1985 and 2004 - even though the river itself became cleaner.

The fish were hit hardest following hot, dry summers such as 1990, 2000 and 2003. The results suggest that warmer water and lower river levels combine to affect both species. As both trout and salmon favour cool water, they face potentially major problems if climate warming continues as expected in the next two to three decades.

"Huge efforts have been put into bringing salmon back into Europe's formerly polluted rivers such as the Taff, Thames, Clyde, Seine and Rhine, so these results are a major worry," said Professor Ormerod.

"Salmon and trout fishing also generate many jobs and large economic benefits. In Wales alone, salmon fishing contributes around 90 million annually. Any risk of eventually losing these species to climate warming is therefore one we must consider very seriously. We suggest measures to ensure that river levels are maintained in hotter conditions alongside the use of riverside trees to create shade and protect against the highest temperatures. This week's Wales Sustainability Week is an ideal opportunity for us to consider action for Welsh rivers, particularly because trout and salmon are such important sustainability indicators."

The Cardiff team used data on fish population collected each year by the Environment Agency at more than 50 locations spread throughout the Wye. Stream temperatures increased over the study period by 0.5 0.7C in summer and 0.7 - 1.0C in winter, with the latter effects apparently affecting the fish at low flow. Water temperature is known to affect growth and susceptibility to disease in these fish, while lower water levels restrict their access to cooler habitats.

Peter Gough, fisheries scientist with Environment Agency Wales, added: "We recognise that climate warming is probably already affecting many elements of our natural environment, including salmon, trout and sea trout, and this detailed analysis of our long-term data is extremely interesting and, if proven correct, would be of great concern. We are currently examining these and other data further. There is a suggestion that earlier migration to sea of salmon smolts might account for at least part of the apparent decline, but this doesn't explain the reduction in trout numbers. More work is needed to clarify some important issues."

The comparison between trout and salmon is important because, unlike salmon, trout from the Wye never migrate to the sea. Only factors affecting the river can therefore explain their decline.

A paper on the findings has been published in one of the world's leading environmental journals, Global Change Biology.


'/>"/>

Contact: Professor Steve Ormerod
Ormerod@cardiff.ac.uk
44-292-087-5871
Cardiff University
Source:Eurekalert

Related biology news :

1. Climate change goes underground
2. Opportunity for students displaced by Katrina to assess climate vulnerability of Southeast US
3. Climate -- no smoking gun for Neanderthals
4. NASA celebrates a decade observing climate impacts on health of worlds oceans
5. NASA celebrates a decade observing climate impacts on health of worlds oceans
6. University and state agencies to forecast local health effects of climate change
7. A greenhouse in order to study the impact of climate change on plants
8. European lead in reading past climates from ice cores
9. International team of scientists warns of climate changes impact on global river flow
10. Heaps of climate gas
11. Nobel Peace Prize 2007 to intergovernmental panel on climate change
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/28/2016)... , April 28, 2016 First quarter 2016: ... up 966% compared with the first quarter of 2015 ... SEK 589.1 M (loss: 18.8) and the operating margin was 40% ... 0.32) Cash flow from operations was SEK 249.9 M ... revenue guidance is unchanged, SEK 7,000-8,500 M. The operating ...
(Date:4/26/2016)... , April 27, 2016 ... the  "Global Multi-modal Biometrics Market 2016-2020"  report to ... ) , The analysts forecast the ... CAGR of 15.49% during the period 2016-2020.  ... number of sectors such as the healthcare, BFSI, ...
(Date:4/15/2016)... , April 15, 2016  A new ... make more accurate underwriting decisions in a fraction ... timely, competitively priced and high-value life insurance policies ... screenings. With Force Diagnostics, rapid testing ... lifestyle data readings (blood pressure, weight, pulse, BMI, ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... ... 23, 2016 , ... ClinCapture, the only free validated electronic ... showcase its product’s latest features from June 26 to June 30, 2016 for ... Disrupting Clinical Trials in The Cloud during the conference. DIA (Drug Information ...
(Date:6/23/2016)... ... June 23, 2016 , ... Velocity Products, a division ... tuned and optimized exclusively for Okuma CNC machining centers at The International Manufacturing ... collaboration among several companies with expertise in toolholding, cutting tools, machining dynamics and ...
(Date:6/23/2016)... , June 23, 2016 ... research report to its pharmaceuticals section with historic ... details and much more. Complete report ... 151 pages, profiling 15 companies and supported with ... http://www.reportsnreports.com/reports/601420-global-cell-culture-media-industry-2016-market-research-report.html . The Global ...
(Date:6/22/2016)... , June 22, 2016 Research and ... Global Markets" report to their offering. ... billion in 2014 from $29.3 billion in 2013. The market is ... of 13.8% from 2015 to 2020, increasing from $50.6 billion in ... projected product forecasts during the forecast period (2015 to 2020) are ...
Breaking Biology Technology: