clipped from: www.abc.net.au   
Karin Strohecker
Industrial-scale fisheries have changed fish evolution, exacerbating the effect of overfishing by producing smaller and less fertile fish,
fish on ice

Dr Ulf Dieckmann, from the International Institute for Applied Systems Analysis in Austria, and co-authors write a commentary on managing fish stocks today in the journal Science.

Dieckmann also says that overfishing and the practice of throwing lower quality fish back into the sea to raise the value of fishing quotas might explain the massive drop in population
"Human activity had a possibly irreversible evolutionary effect in just a few generations," he says
"We are running up a Darwinian debt that future generations will have to pay back."

Looking at fishery data from the past few decades, the scientists found that increased mortality due to overfishing has favoured fish that mature smaller and earlier, yet also carry far fewer eggs at their first reproduction.

"The question is not whether such evolution will occur, but how fast