Cruise title: Defying Dissolution: Unraveling the Enigma of North Pacific Deep-Sea Scleractinian Reefs in Undersaturated Water
Partners: Florida State University
Lead PIs: Amy Baco-Taylor, Brendan Roark, and Katie Shamberger
Location: North Pacific
Dates: Sept 2022
Despite expectations that deep-sea scleractinian reefs could not exist under the harsh carbonate chemistry conditions of the N Pacific, reefs were recently discovered in the Northwestern Hawaiian Islands (NWHI) and the Emperor Seamount Chain (ESC), with 4 of 7 sites in waters undersaturated with respect to aragonite (aragonite saturation state (Ωar) range 0.71–1.33; Ωar<1 indicates undersaturation). Building on this discovery, the overarching question we will test with this work is: How is it that deep-sea scleractinian coral reefs can occur in undersaturated water, well below the hypothesized reef development limit of Ωar = 0.9? To address this question on this NSF-funded research cruise on the RV Kilo Moana with the ROV Jason II, we will characterize the reefs and environmental parameters of 9 seamounts across an Ωar gradient where reefs exist above and below the aragonite saturation horizon.