I keep hearing that blackmouth stink. Does anyone have a theory on this?

My theory is this....for those blackmouth caught in the Puget Sound I think for one reason or another take on the smell of their environment (i.e., the Puget Sound). I don't know if this is correct, but I've noticed shrimp from the Puget Sound taste more briney than those from the Hood Canal with a similar smell as blackmouth. Just a theory, but I wondered if anyone else had any thoughts.