On the basis of its size alone, we think that the key importance of the North Atlantic with regard to climate change is through its sensitivity to atmospheric CO2 exchange. Questions regarding the magnitude of this exchange, and the fate of CO2 drawdown are key to EUR-OCEANS.

The physics of the North Atlantic drives one of the most productive marine pelagic food webs in the world. The large fish stocks of the North Atlantic rim (e.g. cod, herring, and mackerel) depend on this food web. The biological components of the food web and the general physical conditions of the North Atlantic are fairly well described in general terms. However, the mechanisms responsible for the observed inter-annual variability in fish populations are still poorly understood.

We usually call “North Atlantic” both the North Atlantic Ocean itself and its shelf seas, which are the seas located on the continental shelf, closer to the coasts (North Sea, Irish Sea, and Bay of Biscay). Despite of their small areas, the shelf seas play a key role in the global ocean carbon cycle and buffer a major part of human impacts on marine systems. Through the “continental shelf pump” (CSP), shelf seas may act as a sink for atmospheric carbon. Moreover, intense biological production occurs in shelf seas, around 80% of world fish production being taken from waters <100 m. Intensive commercial fishing, oil/gas extraction, and shipping have significantly changed habitat structure, species distribution and relations between species in shelf ecosystems. Lastly, European shelf seas support significant populations of large predators (seals, cetaceans, sea-birds), to be considered in any ecosystem-based approach to managing marine resources.