Aquaculture has been targeted as the "next big thing" for awhile, since it lets us produce a lot of protein without pillaging the oceans for wild fish. People need protein, and cheap sources like this are rare.
Of course, everything has its costs, and another one may be just becoming apparent. A virus that became common in Atlantic salmon aquaculture may have migrated to the Pacific. That would be bad.
I'm otherwise in favor of aquaculture, though: people need protein, and particularly if fish can fed on grains (see this previous post) then it could potentially be pretty important, particularly in places like southeast Asia which rely on fishing. As always, trying to recognize the costs and maximize the net benefits, and the costs just went up a bit.