Hourigan, Thomas F., Etnoyer, Peter J., and Cairns, Stephen D. 2017. "Introduction to the State of Deep-Sea Coral and Sponge Ecosystems of the United States." In The State of Deep-Sea Coral and Sponge Ecosystems of the United States. Hourigan, Thomas F., Etnoyer, Peter J., and Cairns, Stephen D., editors. 1–38. Silver Spring: NOAA. In NOAA Technical Memorandum NFS-OHC-4.