The collapse of cod stocks here to less than 1% of their former abundance remains the exemplar of human over-consumption of resources and of nature's response to it. But this week there's a bit of good news - well, sort of - in the shape of a study in Nature journal suggesting the cod, as well as some of the other big predatory fish we love to eat, could be on their way back. The statistics revealed in the paper by Kenneth Frank and colleagues, from the Bedford Institute of Oceanography in Dartmouth, Nova Scotia, are fascinating.