Recently there has been a push to farm "dry-land" salmon. In other words, the salmon live in large tanks on land, rather than in pens in the sea.

At the moment a company is trying to start one of these close to me. Some local people are opposed, some are supportive, but most just want more objective study and information (i.e. not performed/paid for by the company itself).

The devil may be in the implementation, but it certainly has some big advantages over the coastal pens.