This cruise was a part of the “Verbundprojekt BIOACID” (Biological Impacts of Ocean ACIDification) Phase II (consortium 4 of 5), funded by the German Ministry for Education and Research (BMBF). It was also connected to the Norwegian programme on ecophysiology and ecotoxicology of Polar cod (Boreogadus saida) under global change, “POLARISATION”. Together, the team investigates how the combined effects of ocean acidification and warming (OAW) affect different life stages of the interacting fish species Atlantic cod (G. morhua) and Polar cod (B. saida) and their prey. The main objectives of this cruise were to elucidate whether OAW affects interacting species differently due to divergent physiological optima and ranges, expressed in thermal tolerance windows and associated performance capacities and phenologies of specific life stages. Further, we intended to obtain specimens of both Polar cod (B. saida) and Atlantic cod (G. morhua) as well as planktonic organisms in the Atlantic and polar waters around Svalbard, which were used in experiments on board and back at the Alfred Wegener Institute and the University of Tromsø/Havbruksstasjonen i Tromsø. We left Bremerhaven on the morning of August 16th, and arrived in Tromsø on Aug 21st, where we met with our Norwegian colleagues and took some samples and the fish-lift (Holst&McDonald, 2000) on board. We left for Northern Svalbard the same afternoon and sampled the Northern range of sites before calling at Ny-Ålesund on August 30th, where samples and material from the 2013 summer campaign was taken on board. On August 31st, we called at Longyearbyen to exchange personnel and leave the fish-lift for our Norwegian colleagues. Over the next four days, we sampled the southern stations before leaving Svalbard for the last sampling site at Bear Island on Sept 4th. After this last sampling site, we left for Tromsø where we unloaded samples and live fish (B. saida) for the Havbruksstasjon in Kårvik on September 7th and 9th. In the late morning hours of Sept 9th, we left Tromsø towards Bremerhaven.