OK - I feel somewhat qualified to post because my summer research mentor from Georgia Tech just did a presentation on coral reef research in Fiji for the Atlanta Reef Club. One of the research projects he's collaborating on (and a minor one, as he's a biologist and not an aquaculturist) is a study of the effects of live rock collection and production. Mainly, he introduced the idea, and explained how Walt Smith's work in LR aquaculture; they'd met and discussed such research several times in Fiji. Walt Smith makes (concrete?) "donuts" and strings them on heavy line on the Fiji reef flats. In under a year, the planted live rock is harvested. This system does not affect the net growth of the reef; foreign rock is merely added and removed, and the reef flat provides the living growing habitat necessary for the colonization.
What I remember most about this presentation was not my mentor's work, for he is only slightly augmenting the more impressive research he showed us that came directly from Walt Smith. Walt has done social research on the Fiji islanders' communities too, producing numbers for impacts of live rock production and harvesting and their importance to the Fijian economy, also demonstrating that without LR, Fijians would shift their commercial operations to fishing - which, though I shouldn't have to say it, is an already stressed industry.
Anyways, I regret not going to the site and pulling out the data for you, but I'm sure you can find it all on
www.waltsmith.com. Check it out; it feels good to read about responsible aquarium products and aquaculture.