I'm not sure what it means to be 'swept' into a river.. they would need to purposefully swim upstream. They might do that or they might not. Salmon live out in

I'm not sure what it means to be 'swept' into a river.. they would need to purposefully swim upstream. They might do that or they might not. Salmon live out in the sea and when they are ready (I think) follow the scents of the river of their birth to spawn. I presume that these don't actually have an impression of the scent so won't be heading anywhere. In fact, the article says they are having trouble feeding in the wild, so those that have swum 250 miles have mostly done so on empty stomachs.. because of all this I think the chance of them establishing a life is slim (but of course, there were a lot of them)