Evaluating the use of live rock in closed-system aquaria with mesophotic corals Coral Propagation Technique Development Project

The use of "live rock," defined as hard substrate consisting of microbial communities capable of breaking down harmful waste by-products, is valued in the aquarium trade and among aquarists. These bacterial communities can improve the health of aquarium inhabitants and the water in which they live. Careful scientific evaluations of the risks and benefits of adding live rocks to experimental aquarium systems are few. This study was conducted to determine the effect of live rock on the health of three octocoral species kept in aquaria: Muricea pendula, Swiftia exserta, and Thesea nivea. The corals were used to assess whether benefits gained by the presence of live rock are also dependent upon the source of the rock. This study documented water quality, coral health and growth, and microbial communities of corals and rocks over six months in experimental aquaria. The results of this investigation will aid husbandry practices for these coral species and others, which are among those injured by the Deepwater Horizon disaster and targeted for restoration.