Here is some food for thought. In the 1970's the peregrine falcon was on the endangered species list and was disappearing from many areas. It was actually falconers, who had once taken chicks out of the wild, that brought the species back. Initially people blamed the falconers for the decline of the species but it was later discovered to be due to DDT ( a pesticide). In that hobby, like ours, the method of taking chicks from the wild was very controversial. However, had these captive individuals not been available to rejuvenate the population there is a decent possibility that no individuals would remain today. I see taking coral out of the wild much the same way. In a decently healthy coral reef system, a diver taking as much as they can will have a small immediate effect but very very little long term effect. The fact that the species then has a chance to end up being preserved in the aquarium hobby and potentially then restocking depleted areas is a benefit that far outweighs the cost. This hobby will likely play a key role in the future of coral reefs. Thus, I believe that even though harvesting techniques can be questionable, the small amount of damage done is an acceptable cost to the potential benefit
