That's very sad, but to be fair it's a very new industry. While people like Dr Suzuki have initially spoken out strongly against fish farming practices: [davidsuzuki.org] there may be improvements that can make these safer over time.
Then again in cattle farming things seem to be polarizing (organic/ free range, grass/ grain fed vs cheap, crowded, chemical pumped), so I guess it has a lot to do with consumers and their desire and ability to pay for the best farming practices.

As usual it's all about short term profit - not long term sustainability. ..... and profits purchase politics.

humanity as such will not acknowledge other animal species as equally sentient - ever! sad enough, but that's why we have to cease.

Its all about money, isnt it?