SCIENTISTS from a UK university are warning that overfishing of larger fish leads to diminishing size and numbers of species.
Researchers at Bangor University say they found that over-harvesting larger fish leads to a population of smaller, less fertile fish.
The research suggests that the change happens within a few generations and the scientists say the findings could have a massive impact for the future of global fishing policies.
“Our findings have major implications for the sustainability of harvested populations,” said Prof Gary Carvalho, of Bangor University’s School of Biological Sciences.
He said a “shift in the genetic make-up of harvested fish to smaller less fertile individuals” would be “serious global consequences for the environment and for global fishing industry”.
“We would urge the scientific community, policy makers and managers to consider the capacity of harvested stocks to adapt to, and recover from, harvesting and predation.”
The north Wales scientists collaborated with research teams at University of East Anglia, the University of the West Indies and the Max-Planck-Institute for Developmental Biology.
In lab tests, they studied a model tropical fish, the Trinidadian guppy, and managed to examine changes in the DNA of genes as the fish became fewer and smaller.
The loss of these genetic “types” may mean that populations may not be able to recover completely or at all”
The scientists stated that they had proved for the first time that changes in the body size and maturation of the fish is “an evolutionary response to over-fishing”.
The scientists stated that they had proved for the first time that changes in the body size and maturation of the fish is “an evolutionary response to over-fishing”.
“What was seen under laboratory conditions has probably already taken place in any number of commercial fishing grounds,” warned the researchers.
The teams also suggested that the time for fish stocks to recover from the changes to their DNA and return to larger fish specimens will take five to 10 times longer than anticipated – if the DNA change can be reversed at all.
Read the full story at: http://www.bbc.co.uk/news/uk-wales-21813736
