For the first time researchers will measure the fertilisation compatibility between farmed and wild salmon, and therefore the risk of farmed genes entering wild populations, which are in severe decline.
Wild Atlantic salmon stocks have fallen by more than 50pc, mainly through poorly-managed fisheries and deterioration of feeding and spawning habitats. But there are also serious ecological and genetic threats to wild populations from salmon farming, through the escape of farmed fish into wild salmon ecosystems.
The three-year study, which starts this month, has received funding of just over £330,000 from the Natural Environment Research Council. Much of the field work will be carried out at the Norwegian Institute of Nature Research and at hatcheries in Scotland.Leading the team is Dr Matthew Gage, from UEA’s School of Biological Sciences.
“Ecologically, escaped fish can reduce the fitness of wild fish by competing for resources such as food, space and mates, or by disturbing spawning sites or passing on pathogens that can cause disease. Such repeated releases of new genetic strains into an already stressed wild population could lead to ‘genetic swamping’ and the complete dilution of wild genes.”
Currently, more than 95 per cent of Atlantic salmon in existence are of farmed origin. An estimated two million farmed salmon escape and enter the North Atlantic each year, equalling the number of wild fish. Farmed fish enter spawning populations, with an average of 11-35 per cent of salmon in Norwegian rivers of farmed origin.
Farmed fish present a major problem for wild Atlantic salmon because they compete for resources, but potentially more important is the introgression of domestically-selected farmed genes into wild populations, leading to loss of local adaptation.
Farmed salmon have undergone decades of intense selective breeding, including selection for faster growth and efficient feed conversion and increased aggression, giving them a reduced fitness compared with wild strains under selection from the wild.
Dr Gage said: “Our project will try and actually quantify the degree of fertilization compatibility at that all-important sperm and egg level. Farmed fish have been selected under very different regimes to wild fish so their relative fertility might have gone up or down. We hope to provide the objective information on fertilization compatibility between farmed and wild fish, and that could allow policy makers to make more informed decisions for both aquaculture and salmon conservation.
“Evidence shows that escaped farmed salmon tend to be less behaviourally successful at spawning in the natural environment than their wild counterparts, but we will be looking in detail at fertilization compatibilities between sperm and egg, and under competition between males of farmed and wild origins.
“The other exciting aspect of this project is that we will be able to address questions on the evolution of reproductive isolation, which is likely to evolve initially via reductions in sperm-egg compatibility.”
Press Office | alfa
Energy crop production on conservation lands may not boost greenhouse gases
13.03.2017 | Penn State
How nature creates forest diversity
07.03.2017 | International Institute for Applied Systems Analysis (IIASA)
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
27.03.2017 | Earth Sciences
27.03.2017 | Life Sciences
27.03.2017 | Life Sciences