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Zooxanthellae, endosymbiotic algae of reef-building corals, substantially contribute to the high gross primary production of coral reefs, but corals exude up to half of the carbon assimilated by their zooxanthellae as mucus. Here we show that released coral mucus efficiently traps organic matter from the water column and rapidly carries energy and nutrients(More)
Oxygen flux measurements at the seafloor are fundamental for the understanding of respiration and oxidation processes and the global cycling of matter (Jahnke and Craven 1995; Jahnke 1996). Where anaerobic mineralization products are fully oxidized within the sea bed, benthic oxygen consumption reflects the mineralization of organic carbon (Canfield et al.(More)
Based on noninvasive eddy correlation measurements at a marine and a freshwater site, this study documents the control that current flow and light have on sediment–water oxygen fluxes in permeable sediments. The marine sediment was exposed to tidal-driven current and light, and the oxygen flux varied from night to day between 229 and 78 mmol m 22 d 21. A(More)
Oxygen distribution and benthic mineralization rates were investigated in a permeable intertidal sand flat (permeability: 3.9 3 10 211 m 2) in a transect from the low toward the high waterline. At all stations, oxygen penetrated several millimeters to centimeters into the sediments during inundation because of pore-water advection. The wave-and(More)
The effects of surface gravity waves on pore-water release from permeable sediment (k ϭ 1.3–1.8 ϫ 10 Ϫ11 m 2) in shallow water were studied in a wave tank. Our tracer experiments demonstrated that shallow-water waves can increase fluid exchange between sandy sediment and overlying water 50-fold, relative to the exchange by molecular diffusion. The main(More)
After the explosion of the Deepwater Horizon oil rig, large volumes of crude oil were washed onto and embedded in the sandy beaches and sublittoral sands of the Northern Gulf of Mexico. Some of this oil was mechanically or chemically dispersed before reaching the shore. With a set of laboratory-column experiments we show that the addition of chemical(More)
The fragility of thin Clark-type glass microelectrodes used in aquatic eddy covariance measurements of benthic oxygen fluxes is a challenge when using this powerful technique. This study presents a new fast-responding dual oxygen-temperature sensor for eddy covariance measurements that is far more robust. Response time tests in the lab, where the sensor was(More)
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