Tasty or Toxic? Biogeochemistry of marine sediments in a warming ocean

沉积物过程在推动生物地球化学循环中的重要性，从蓝碳储存到营养物质（二氧化硅、铁）和污染物（铅、砷），正越来越多地从地方到全球尺度得到认识。然而，准确测量海洋沉积物的通量是一项重大挑战，因为经典方法（孵养、孔隙水梯度）侧重于小尺度扩散过程，而沉积物通量还取决于大尺度和非均质非生物过程（如温度、潮汐、海流）和大型动物活动，如沉积物改造（生物扰动）和洞穴通风（生物灌溉）。本研究的目的是采用一种尖端的放射性同位素不平衡方法[2]来量化未来一系列环境设置（如气候变暖和海洋酸化）中海洋沉积物的营养物和污染物通量。这将通过量化英国各地不同沉积物类型、相关大型动物群落和不同人为影响水平的底栖生物通量来实现。一个关键的焦点将是比较决定英国温带水域和南极半岛西部之间微量营养素通量的因素，那里不断变化的环流正在给大陆架底部的水域带来越来越多的热量。

The importance of sediment processes in driving biogeochemical cycles, from blue carbon storage, to nutrients (silica, iron) and pollutants (lead, arsenic), are becoming increasingly recognized, from local to global scale [1]. However, accurately measuring fluxes from marine sediments presents a significant challenge as classical approaches (incubations, pore water gradients) focus on small scale diffusive processes, whereas sediment fluxes also depend on large scale and heterogeneous abiotic processes (e.g. temperature, tides, currents) and macrofaunal activities such as sediment reworking (bioturbation) and burrow ventilation (bioirrigation).The aim of this study is to employ a cutting-edge radioisotopic disequilibrium approach [2] to quantify nutrient and pollutant fluxes from marine sediments across a range of future environmental settings such as climate warming and ocean acidification. This will be achieved by quantifying benthic fluxes around the UK across varying sediment types, associated macrofaunal communities, and differing levels of anthropogenic influence [3]. A key focus will be the comparison of the factors determining micronutrient flux between temperate UK waters and the western Antarctic Peninsula, where changing circulation is bringing increasing heat to the bottom waters of the shelf.