I consider myself a conservationist and Goliath Groupers are one of my favorite fish when diving in Florida.
However, after living and diving for many years in the lower Keys, the "big picture" would have to include a study on the impact of continuing to protect an apex predator combined with added pressures on other species.
Years ago the GG's declined severely and their protection did an excellent job of bringing them back. I don't think a limited collection would be the end of the world for a couple of reasons.
First, their numbers have increased significantly.
Second, they do have a dramatic impact on the reefs where they live.
There is a definite decline in the number of fish on a reef when you have multiple resident GG's move in. This is not a hypothesis, I have seen it first hand on a couple of favorite dive spots.
Years ago fishermen were not harvesting GG's and the reefs did just fine, but there was also not a massive harvesting of other game fish at the same time.
A continued complete protection of such an apex predator might have a negative impact on other game fish species because of the added pressure from fishermen.
Having witnessed the rise in GG population for years and the related impact on the rest of the reef, I would never sign a petition against harvesting 400 fish. If it was a complete lifting of protection, count me in because GG's are just too voracious, inquisitive and friendly to survive on their own against fishermen.
So, I like analogies, let's assume the decline in small fish is because of the GG's protection (again stressing, like Walt did, that there is no scientific support for that). Now let's make an analogy, just follow my line of thought:
1. Lions are critically endangered.
2. People protect lions.
3. People start competing with lions for prey (impalas, zebras, etc).
4. Prey populations decline.
5. Hunt lions?
I think #5 is wrong. To me, the way to fix #4 in the above chain of events is to protect the prey, not hunt the predator.