I'm working under the assumption that these people are not dumb enough, to release them into the wild. This proposed stunt will outright kill the modded fish traction...
Sorry, I but I have to L O L at that one. Being super scientists doesn't mean they don't make foolish assumptions or face palming mistakes.
Also, it just doesn't make economic sense, why make it harder to catch the fish? Why let 'other' people catch and sell 'your' fish?
For one, almost every non-native species that gets brought to a country ends up in their ecosystem whether they like it or not. Snake Fish, a whole bunch of others here in America. THC has been doing tons of specials about these monster fish and their impact on the environment when they're introduced without controls.
And for two, you can only sell as much fish as you can breed. You can only breed as much as you can feed. You can only feed as much as you can afford.
So from their perspective, why NOT dump them in the ocean and let them eat off natural resources? It'd be cheaper for them than creating large spawning beds, seeding it with plants and other edibles and maintaining all that. They could even claim they're being philanthropic by refilling the ocean with fish. The issue isn't they want a super magical, never before tasted fish that they want to own the patent on. They want a fish, period, that can sustain the fishing industry.
If commercial fisherman start pulling up their fish, all it takes is one DNA typing test and they have as much negotiating power as they need to arrange whatever deals they want. There really is no economic downside for them if they own the patent. If the only fish commercial fishers can catch are fish YOU made, then they'll all owe you some form of royalties whether they like it or not. Large commercial fishers may not even know or care, since they just turn in their quota to the docks and get paid by weight. The owners of the patent would be making their agreements with harbors and shippers who buy the fisherman's catches.