I don’t know about Chinese fish, but our U.S. fish & wildlife commission – as Miggs noted – raise the fish on farms and then stock them in the local rivers, etc.
They even post some of the dates and locations of where they stock.
And Purge is correct about the smell.
Ideally, when you open the package, you should not smell “fish.”
The fresher the fish, the lower the odor.
One other test I know people have used successfully is to look at the fish’s eyes (provided it has its head). Clear eyes is a sign of freshness.
If the eyes appear cloudy or hazy, not so fresh.
Everything above pertains to identifying freshness.
I’m not aware of any methods to determine where a fish is harvested – particularly in China.
However, if their “raising & stocking” practices are anything like America’s, it may not make as big a difference as you think.
