Over the past decades, the occurrence of suboxic and anoxic zones has significantly increased worldwide with major implications for the affected ecosystems (Conley et al., 2011; Diaz & Rosenberg, 2008, and others). The generation of anoxic water masses in stratified marine systems is related to unbalanced rates of oxygen consumption, production, and transport. Especially in shallow marine and limnic systems, organic matter degradation and in turn oxygen depletion is largely determined by benthic processes and resuspension in the turbulent bottom boundary layer (Glud, 2008). In such systems, turbulent vertical transport of oxygen toward the sediment becomes a key factor in regulating deep-water oxygen dynamics. Lack of sufficient transport mechanisms may lead to permanent anoxia with well-known examples including the Black Sea, the Baltic Sea, and the Cariaco Basin (Astor et al., 2003;Konovalov et al., 2005;Reissmann et al., 2009). For understanding the oxygen dynamics in stratified marine systems, it is thus mandatory to identify and understand the physical transport mechanisms.Recent research has made considerable progress in identifying and quantifying both oxygen transport processes and oxygen consumption rates. For example, benthic consumption processes, especially relevant in shallow marine systems and lakes, have been studied in various settings using chamber landers, oxygen microprofilers, eddy-covariance techniques, and other approaches (

<div>The Weddell Sea is the largest contributor to deep water formation in the Southern Hemisphere. Dense and cold waters form during sea ice production on the continental shelves of the southern and western Weddell Sea, and are subsequently exported into the deep ocean via a dense near-bottom gravity current.  The current then propagates along the continental slope for several hundred kilometers. The gravity current is important for the global ocean circulation, although not all details are understood, as observations are sparse in this heavily ice-covered region. Furthermore, the current is likely modified by small-scale processes, which are generally unresolved by global ocean models. In this work, we use multi-year velocity measurements from 2017 to 2019 from moorings on the southern and northwestern Weddell Sea continental shelf and slope to quantify the relevant energy sources within the gravity current. Specifically, we investigate barotropic and baroclinic tidal energy, internal wave background and their dependence on location and time. Stronger internal waves up-slope coincide with the position of the gravity current main cores, which suggests that the bulk amount of mixing of the dense water with the ambient water occurs in shallower areas. Although the energy contained in waves with periods of several days varies throughout the year, the internal wave background on hourly time-scales seems to be largely unaffected. Our work is mainly aimed at the understanding of local energy levels within the dense gravity current, which may ultimately benefit a more accurate representation of dense water formation in global models.</div>