I was reading a interesting article,Malin Pinsky of Stanford Uni did a study of 37 overfished species and 51 lesser fished species,thinking that the badly overfished species would remain genetically diversified,but he found that there was 18% fewer genetic variants,bottom line is if the gene for large size is gone ,its gone,little fish cant become big fish,this seems to be the problem with the overfished cod off Canada