Scientists had noted that many overfished cod, by the end of the 20th century, had developed what looked to be a survival advantage -- maturing earlier and growing less large, making them less likely to be singled out to be caught and more likely to reproduce before being caught. Searches for transformations in key genes, however, turned out to be unsuccessful.

 

The new research insights offer hope for the possible re-emergence of the codfish population which has been slowly rebounding since fishing pressure has been reduced, the scientists said."Since evolution in response to fishing happened through lots of small changes in many genes rather than large changes in one or two genes, and cod have maintained most of their genetic diversity, it will be easier for cod to evolve back towards their previous pattern of slower growth at large sizes," Reid said. "The fact that cod populations are rebounding and shifting back towards previous patterns of growth suggests, given proper management, this fishery can return to its previous state and provide a sustainable source of food for a large number of people and a source of income for coastal communities that heavily depend on fishing."