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
How much drought can a forest take?
20.01.2017 | University of California - Davis
Plasma-zapping process could yield trans fat-free soybean oil product
02.12.2016 | Purdue University
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences