I pulled this info from the Hawaii coral reef network webring, current laws pertaining to both corals and liverock. The last one is what will interest you. I also posted a question to the board of Marine Biologists there and I am waiting on a reply.
Taking or damaging coral, live rocks and coral rubble
State law prohibits the intentional taking of, breaking or damaging, with crowbar, chisel or any other implement, any live stony coral from the waters of Hawaii, including any live reef or mushroom coral. HRS § 188-68
It is unlawful to intentionally take, break or damage, with crowbar , chisel or any other implement, any rock or coral to which marine life of any type is visibly attached or affixed. HRS § 188-68
nullThe taking of sand, coral rubble or other marine deposits is permitted in certain circumstances. The material may not exceed one gallon per person per day, and may be taken only for personal, noncommercial purposes. HRS § 171-58.5, § 205A-44