Potential export of unattached benthic macroalgae to the deep sea through wind-driven Langmuir circulation

Carbon export to the deep sea is conventionally attributed to the sinking of open ocean phytoplankton. Here, we report a Langmuir supercell event driven by high winds across the shallow Great Bahama Bank that organized benthic non-attached macroalgae, Colpomenia sp., into visible windrows on the seafloor. Ocean color satellite imagery obtained before and after the windrows revealed a 588 km 2 patch that rapidly shifted from highly productive macroalgae to bare sand. We assess a number of possible fates for this macroalgae and contend that this event potentially transported negatively buoyant macroalgae to the deep Tongue of the Ocean in a pulsed export of > 7 x 10 10 g of carbon. This is equivalent to the daily carbon flux of phytoplankton biomass in the pelagic tropical North Atlantic and 0.2-0.8% of daily carbon flux from the global ocean. Coastal banks and bays are highly productive ecosystems that may contribute substantially to carbon export to the deep sea. Citation: Dierssen, H. M., R. C. Zimmerman, L. A. Drake, and D. J. Burdige (2009), Potential export of unattached benthic macroalgae to the deep sea through wind-driven Langmuir circulation, Geophys. Res. Lett., 36, L04602, doi: 10.1029/2008GL036188.