With Torians in the game now, there's often lots of Aquatic planets to conquer. I've taken several from the Torians, and culture flipped the one they colonized deep in my territory.
I've had the Aquatic World Mastery tech for a few turns now, but all these planets are still suffering from -50% raw production. Perhaps this is just a bug for captured Torian planets?
I find it hard to believe this is intended.
.. neilkaz ..