Navigation Links
The same number of fishermen, but less salmon in Spanish rivers

"It's not that the salmon are biting less, there are less of them," explained Eva Garca Vzquez, lead author and Functional Biology researcher at the University of Oviedo (Spain).

The study, published in Transactions of the American Fisheries Society, shows a "very marked" decline in Atlantic salmon (Salmo salar) populations in the Narcea, Sella and Cares rivers (Asturias, northern Spain), especially during the last decade, almost simultaneously with the reduction in the amount caught by recreational fishermen.

"Given that fishing effort has almost been constant until this year, and that populations have reduced, exploitation of the populations has increased. There's the same amount of fishermen, but less fish," Garca Vzquez stressed.

To reach these conclusions, researchers obtained DNA samples from fish scales and estimated the actual population size (number of salmon that reproduce and contribute to population survival) in Asturian rivers from the 1980s, using different statistical methods, all of which were consistent with one another.

According to the research team, to which the University of Exeter and Westcountry Rivers Trust, Cornwall (both in the UK) collaborated, the increased fishing effort and higher temperatures have affected salmon in northern Spain, southern France and the south of the British Isles. These populations are suffering cyclic fluctuations, and "as a whole" are in recession.

For scientists, the decline in salmon could be due to an increase in recreational fishing licences, which has increased catches. However, the number of fish has decreased because populations have reached their maximum exploitation levels.

Will the salmon return?

The study highlights that the decline in salmon went unnoticed because there are no official estimations to calculate population size in Asturias. Therefore, the experts stress that protection measures should be gradually implemented for these Spanish populations.

"Solutions have been proposed to reduce fishing effort for these populations, which were implemented during the 2011 season in Asturias," notes Garca Vzquez. He added that monitoring and controlling natural populations would allow protective and restorative measures to be adapted according to the state of the populations.


Contact: SINC
FECYT - Spanish Foundation for Science and Technology

Related biology news :

1. High numbers of right whales seen in Gulf of Maine
2. First ever worldwide census analysis of caribou/reindeer numbers reveals dramatic decline
3. New biomarker method could increase the number of diagnostic tests for cancer
4. New stem cell research could reduce number of animal experiments
5. Annual survey shows high numbers of seed scallops on Georges Bank, low numbers in Mid-Atlantic
6. Study of huge numbers of genetic mutations point to oxidative stress as underlying cause
7. River flow and temperature limit trout numbers
8. U of C alumnus finds high numbers of heat-loving bacteria in cold Arctic Ocean
9. UNC study pinpoints gene controlling number of brain cells
10. Europes number 1 scientific network signs off with launch of new report
11. Healthy babies by the numbers
Post Your Comments:
Related Image:
The same number of fishermen, but less salmon in Spanish rivers
(Date:11/18/2015)... PHILADELPHIA , Nov. 18, 2015  As new ... in children, doctors and other healthcare providers face challenges ... counsel families and patients. In addition, as more children ... into a patient,s adulthood and old age. ... The Children,s Hospital of Philadelphia (CHOP) . ...
(Date:11/17/2015)... EASTON, Mass. , Nov. 17, 2015 ... a leader in the development and sale of broadly ... the worldwide life sciences industry, today announced it has ... of its $5 million Private Placement (the "Offering"), increasing ... to $4,025,000.  One or more additional closings are expected ...
(Date:11/11/2015)... Nov. 11, 2015   MedNet Solutions , an innovative ... clinical research, is pleased to announce that it will be ... (PCT) event, to be held November 17-19 in ... view live demonstrations of iMedNet , MedNet,s ... iMedNet has been able to deliver time and ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... Md. , Nov. 25, 2015  PharmAthene, Inc. ... Directors has adopted a stockholder rights plan (Rights Plan) ... net operating loss carryforwards (NOLs) under Section 382 of ... --> PharmAthene,s use of its NOLs ... "ownership change" as defined in Section 382 of the ...
(Date:11/25/2015)... 2015 /PRNewswire/ - Aeterna Zentaris Inc. (NASDAQ:  AEZS; TSX: ... prospects remain fundamentally strong and highlights the following ... received DSMB recommendation to continue the ZoptEC Phase ... the final interim efficacy and safety data ... men with heavily pretreated castration- and Taxane-resistant prostate ...
(Date:11/24/2015)... 24, 2015  Asia-Pacific (APAC) holds the third-largest ... market. The trend of outsourcing to low-cost locations ... higher volume share for the region in the ... margins in the CRO industry will improve. ... ( ), finds that the market earned ...
(Date:11/24/2015)... , ... November 24, 2015 , ... ... healthy metabolism. But unless it is bound to proteins, copper is also toxic ... (NIH), researchers at Worcester Polytechnic Institute (WPI) will conduct a systematic study of ...
Breaking Biology Technology: