Hi All.
I'm new here, so let me say hello to all.
But I'm far from new to fishing, in fact I'm a bit of a greybeard. Perhaps I can enter a bit of information here that might serve to clarify what I think is being argued here? I'm a Scot, and fish for all sorts of things. And even (occasionally) succeed!
Loch Lomond is nowadays full of Ruffe. Or Pope, if you prefer the other name for this little perch-substitute.
Ruffe don't occur naturally in Scotland. At least they didn't until some guys from Southern parts decided to import some and use them for pike-livebait. And then when they were done, they emptied their bait kettles into the loch.
This probably happened a number of times, with unknown numbers of guys doing this.
Now there's an acknowledged plague of Ruffe in Lomond, and it's likely to cause all sorts of mayhem in terms of impacting other species (like Powan) that occur (almost) nowhere else. This was stupid, and it was selfish. And also now apparently irreversible.
This wouldn't have happened if people had sensibly followed guidelines about not moving fish around between waters, or in this case countries. Our waters plainly can't cope with invasive species like Ruffe.
Yet now we have to cope them regardless.
Think on...
Charrfisher.