Acknowledgements
This research was part of the sponge aquaculture programme of AIMS@JCU, which received funding and in kind support from the Australian Institute of Marine Science, James Cook University Advancement Programme (Finfish and Emerging Aquaculture), Great Barrier Reef Research Foundation and the Coolgaree Aboriginal Corporation. We thank R. Hidlebaugh, M. Holme, A. Mills and S. Whalan for assistance in the field and N. Paul for statistical advice.