I noticed this year that fish prices in stores really have gone up - when I was buying trout or pink salmon last year, it was more budget-friendly. The reasons are standard for this kind of situation: demand increased, supply dropped, logistics got more expensive. Plus a lot of producers probably built in a safety margin for potential future cost increases, and that usually sticks around in the prices for a long time. The FAS got involved because the jump was too sharp and noticeable to regular shoppers - it's a politically sensitive product, people eat fish often.
As for whether prices will drop - realistically you shouldn't expect any significant fall in the next month or two. The FAS can inspect suppliers, look for monopolistic behavior, issue fines if needed, but that's not a magic wand. Price is set based on production costs, and if costs for production, transport, and storage really did go up, then the price will stick around. What's more likely is stabilization - prices will stop climbing as fast and start dropping more slowly, but we won't get back to the old levels anytime soon.
My advice - switch to cheaper fish (pollock, hake, herring), try frozen fillets from Asian traders if there's one nearby, or at least don't go hunting through stores looking for what's on sale. I wouldn't read into the panic based on news about the FAS - it's just the regulator doing its job, not a signal that prices are about to crash.