PWS - Prince William Sound, a large bay in Alaska. Bonkers - crazy, so a large amount. Fry - juvenile fish Seine - a type of net that hangs vertically in the water used to corral fish. Only allowed at certain times of year?
So fish farms feed whales, which also eat everything else, greatly reducing wild fish populations.
The decision to open or close is made based on "escapement" numbers, i.e. the estimated number of fish who have made it back up their origin river to spawn. In the case of hatcheries, that's easy to determine, but they've been using a sonar system named Bendix since the 70s or so to figure out the rivers.
I'd never seen so many otters, seals, and orcas as I had in my return trip. With a lot more predators, it's a stretch to think that could be contributing.
So while environmental contamination is never a bad bet, I'd be surprised if that's all it was.
The people who say stuff like "overfishing" in regard to Alaskan fisheries (some of the best managed in the world) have no idea what they're talking about.
Fucken English enough for ya?