Fish may be evolving to swim faster so they can avoid capture in trawler nets, according to research. Scientists at the University of Glasgow found that fitter fish are better at evading nets. They said that, over time, it could lead to physiological changes in fish. Study leader Dr Shaun Killen: “Intense fishing pressure may cause evolutionary changes to the remaining fish that are not captured.”
The university group used simulated trawling with schools of wild minnows to investigate whether some individual fish were consistently more susceptible to capture.
They measured the swimming ability, metabolic rate and indicators of aerobic and anaerobic physical fitness of 43 fish.
The minnows were then placed in a tank with a simulated trawling net to identify those most susceptible to capture.
‘Selective harvest’
Dr Killen, of the Institute of Biodiversity, Animal Health and Comparative Medicine, said: “Fish being trawled will try to swim at a steady pace ahead of the mouth of the net for as long as possible, but a proportion will eventually tire and fall back into the net. Continue reading – http://www.bbc.com/news/uk-scotland-33782321