Yes I know where you got it. As I have done studies myself on this. Thus my Biology and Environmental background. There are good theories out there on this and some I agree with and others I dont. But definitively there isnt an exact 100% accurate proven theory on this as of yet. Unless it has been published in the last year and I have not seen it yet.
Personally based on our data that we collected over 2 years at various lakes in the south, we were not able to pin point the exact DNA profile differences in our studies. Mostly due to lack of adequate equipment to do so at the time. At any rate, they still taste good!