Representative images of the biotic zones on the Tasmanian seamounts.

a. Blue grenadier (Macroronus novaezelandiae) swimming above the relatively barren rock substratum at 729 m on the peak of the Mongrel Seamount. A variety of gorgonian corals are visible on the bottom. Jason dive 386. b. The live S. variabilis reef, at about 1300 m on Seamount A1. Jason dive 382. c. Seascape of the dead Solenosmilia reef at 1480 m on Seamount A1. Jason dive 382. d. Solenosmilia rubble zone, at 1615 m on Seamount A1. Jason dive 383. e. Seamount A1, at 1530 m. The rock formation is pillow lava with fractured ends. f. Close-up of the side of a rock, showing a mix of epibenthic organisms attached to the rock, including solitary corals (Desmosphyllum dianthus), bivalves, and sponges, along with the motile ophiuroids and urchins. Jason dive 383. A large number of additional frame grabs taken during the Jason dives are available at http://4dgeo.whoi.edu/jason, under 2008 and tn228.