Not sure anyone cares but for interest sake...
Earlier this year I helped my 11 year old son train a goldfish to swim through a hoop as a project for the science fair at school.
Here's two things we learned that have bearing on the news story above;
Number one, we started with two goldfish, a fancy shubokin and more natural shaped comet. The fancy shaped one, contrary to my prediction, was far and away the better learner. Actually, the comet seemed almost untrainable and his influence was impeding the other. When we seperated them, the fancy learned much quicker and we gave up on the comet. Interestingly, as they matured, it became obvious the smart fancy one was a female. Once she became visably ripe, the obviously male stupid one was pretty much preoccupied with chasing tail and not too interested in swimming through hoops.
I would assume this would be a factor in trying to train a mixed sex school of sea bass as well.
Second, and probably more significant, we found without constant reenforcment, the conditioning wore off very quickly. The goldfish remained at the school for several days after the science fair before I could get back and break down the tank and bring it home. During that time, numerous different kids were feeding ["rewarding"] the goldfish without making it swim through the hoop. By the time I got it home, it wanted nothing to do with the hoop.
Assuming food would be the reward used to condition the seabass, I doubt the conditioning would last very long once they got in the wild and foraged for themselves.
As a post script, when the goldfish tank became needed for a native fish project [mudminnow breeding], the poor goldfish were moved to a bucket which was subsequently "accidently" left outside on a night when temps dipped to single digits. When I informed my son, instead of being sad, he made a flip comment about not having to feed them anymore.
I guess that lack of emotional connection bodes well for the researchers that like to eat seabass.