I took a trip to the Big Island in 2006. I did a lot of snorkelling on the Kona side, beach 69 to be exact. I could walk in the surf and see schools of aquarium sized convict tangs, various other large tangs, assorted butterflys, triggers.@EMeyer, there's a lot more to it than that. The areas you speak of that you can spear anything have very limited life in comparison to the protected areas on each of the islands. Those people spearing everything absolutely have a factor in the ecosystem there as well, see below article. I cant tell you how many times I have been disgusted when I get out of the water and find discarded fish at the showers, because the fish they gathered were too small...
7 divers cited after illegal spearfishing, trying to elude DOCARE officers in Waikiki
Officers seized their catch, which included about 130 illegally caught fish.www.hawaiinewsnow.com
You have to go to Hanauma or any of the reserves like that to see large adult fish. It's articles like the guy collecting hundreds of fish for the fish trade on one swoop that are going to make the legal changes not happen. The thing is that guy got caught, how many times has he done this before? How many other people are doing this and not caught?
A lot of the locals would tell me about certain bays where you could stand at the waters edge and see huge pools of yellow as schools of yellow tang swam across the rocks. I have seen this once and it is absolutely an awe inspiring sight, that is a rare instance now.
Unless you live in Hawaii, or understand how that land was taken you wont understand why the people of Hawaii fight so much for their natural resources. Then add that anyone in a government role wont want anything to happen to their main source of income, like I mentioned above, tourism. Those fish being in the water are a major factor in what drive people to come to the islands.
The only way I can see the fish trade becoming something in Hawaii, is if they somehow manage to get a fishery started. The above factors will make it hard to pass, as a lot of the people who end up moving their are more aligned with animal rights views. Outside of that, I agree with what @tautog83 mentioned. There are company's that are actively breeding species for the fish trade that are a more viable option.
I didn't see one yellow tang or moorish idol and I checked out both sides of that beach. I assumed it was from collecting.
We went south past Kona to the Historical Park near Two Step, you could see yellow tangs and moorish idols from the parking lot. Too bad I was coming down with a stomach virus, I never got to swim with them.