Rapid climate and environmental changes challenge the health of the Baltic Sea ecosystem and our capacity to predict ecosystem responses. Eutrophication and its wideranging ecosystem effects is a key problem in the Baltic Sea that is driven by overavailability of nitrogen (N), as well as phosphorus. While N-research has gotten fair attention in the Baltic Sea community, we still lack a holistic approach bringing together data, experience, and knowledge across national borders.
The Baltic Sea Nitrogen Cycle Network (BSNCN) project aims to fill this gap by pooling the expertise on N-cycling from around the Baltic Sea to improve understanding and predictive power in the face of ongoing changes. The project is funded by the Swedish Institute (https://si.se/en).
The aquatic N-cycle includes processes that add bioavailable N to the system, such as riverine and submarine groundwater discharge, atmospheric deposition, and N2-fixation, as well as processes that remove bioavailable N permanently from the system, such as denitrification and anaerobic ammonium oxidation. Furthermore, net production and atmospheric release of the potent climate gas nitrous oxide links the aquatic N-cycle to global climate change.
N-research is well established in the Baltic Sea, covering both the open sea and the coastal areas. The key processes in water column and sediments are understood and the ecosystem impact of processes such as riverine and atmospheric input of bioavailable N are well acknowledged. Nevertheless, many of the underlying processes, organisms, and abiotic parameters driving or affecting the N-cycle are still not well known and/or knowledge is scattered across the different marine institutes and countries bordering the Baltic Sea. A holistic understanding of these processes and their major players, such as bacteria and phytoplankton, is however essential to enable predictions on how a changing climate will affect Baltic Sea N-cycling and subsequently ecosystem health.
We identified the following challenges regarding N-cycling in the Baltic Sea:
● Communication and collaboration across national borders
● Synthesis of existing data and knowledge
● Climate change effects on the involved processes
● Knowledge on major (microbial and planktonic) players
● Communication with policy makers and stakeholder
● Increasing the accuracy of biogeochemical models, esp. for the northern Baltic Sea.
To advance these issues we discuss monthly and prepare joint publications.
BSNCN 