Turned out they could. In short order they became the top predator and pushed out over to Norwegian waters.
The Norwegians consider them an invasive species so they allow them to be trapped in unlimited quantities 24/7. The Russians view them as a valuable resource ~ particularly for export.
The result is the Russians feed them and the Norwegians give'em away.
The Pachenga River estuary is pretty close to the Norwegian border. Until about 1820 no one knew there was a border there.

To this outside Nikel, Russia, just across the border:

Fascinating contrast. The pollution of the nickel mine is astounding.
http://www.trentobike.org/Countries/Russia/Tour_Reports/Crossing_into_Russia/