The role of iron in nitrogen fixation and photosynthesis in changing polar oceans

铁对海洋初级生产是必不可少的，因为它在光合作用、呼吸作用等关键代谢功能中需要酶，并需要获得固定氮等大量营养素[1]。海洋光合作用为海洋中的生命提供动力，是碳循环的基础，因此也是气候的基础。在海洋的许多部分，特别是南大洋，铁有效地限制了浮游植物的生长。随着北冰洋变暖并变得无冰，支撑整个北极生态系统的初级生产力已经增加，但由于关于北极微营养限制的持续辩论和北极氮收支的不平衡，未来的趋势尚不明朗[3]。固氮对铁的需求量很大，因此可能是维持当代和未来海洋生产力的关键氮源。我们的目标是进行船上的生物测试，以调查铁在北极固氮中的作用，并了解铁、营养物质和光如何照亮铁有限的南大洋。该项目将为在气候快速变化的时期铁在固氮和光合作用中的作用提供重要的新见解。

Iron is essential for marine primary production due to its enzymatic requirement in key metabolic functions such as photosynthesis, respiration and the acquisition of macronutrients such as nitrogen fixation [1]. Oceanic photosynthesis powers life in the oceans and is fundamental to the carbon-cycle and hence the climate [2]. In many parts of the ocean, particularly the Southern Ocean, iron availably limits the growth of phytoplankton. As the Arctic Ocean warms and becomes ice free, primary productivity, which underpins the entire Arctic ecosystem, has already increased, but the future trend is unclear due to the ongoing debate on Arctic micro-nutrient limitation and the imbalance in the Arctic nitrogen budget [3]. Nitrogen fixation, which has a large iron requirement may therefore be a critical source of nitrogen to sustain contemporary and future ocean productivity. We aim to carryout shipboard bioassays to investigate the role of iron for nitrogen fixation in the Arctic and to understand how iron, nutrients and light the iron-limited Southern Ocean. This project will provide important new insights into the role of iron in both nitrogen fixation and photosynthesis in a time when the climate is changing rapidly.