David Karl, Daniela Böttjer, Tara Clemente, Steve Poulos, Sam Wilson, Karin Bjorkman, and Sarah Searson
C-MORE, University of Hawaii at Manoa, United States
Keywords: OTEC, SWAC, nutrients, microbes, planktonThe development of seawater air conditioning (SWAC) and ocean thermal energy conversion (OTEC) industries in coastal marine habitats may have several unintended environmental consequences, including but not limited to the introduction of deep-sea nutrients (e.g., nitrate, phosphate, silicate), dissolved gases (e.g., carbon dioxide, nitrous oxide), and microbial genomes (especially Thaumarchaea) into the surface ocean. We have recently conducted several experiments on multiple scales (20-60,000 liters) to investigate potential impacts of enhanced ocean upwelling on microbial processes. Our results indicate that the removal of phosphate prior to the effluent discharge may be an effective means to minimize environmental impacts, especially the elimination of nutrient-induced phytoplankton blooms. We present a model for deep-sea phosphate capture that could lead to a coupled, derivative industry for fertilizer manufacturing and other purposes.