In search of the Polar cod
A similar sight awaits the team the following day, as the RV Heincke sails into the Hinlopenstretet: plenty of Atlantic cod, yet no sight of its Arctic conspecific. They move on, heading southeast, where the cold waters of the Barents Sea push into the strait. Here the water temperature drops to 1,1 degree Celsius. However, the echo sounding does not detect any activities in the surrounding water.
Defeat is not tolerated and so they steam off to other fishing grounds. They advance towards the ice edge within the range of vision, no further, as the ship does not have any ice class. Here the echo sounding finally sends a signal. At a level below 140 metres they can identify fish swarms. And yet, as they haul the fish lift on deck, it barely holds any fish, let alone Polar cod.
Hitting the jackpot
Dismal prospects for the Polar cod, that once dominated the waters of Svalbard. While the scientists put more and more Atlantic cod into the aquariums, the two Polar cods from the first haul still are waiting for company. Not till the final days of the expedition, as they reach the Hornsund at the western side of Spitsbergen’s southernmost tip, they finally succeed. Jackpot! The buckets on deck are filled with juvenile Polar cod in all sizes and the scientists begin to select the biggest ones. The smaller fish they put pack into the sea, once they have recovered from the haul.
Felix Mark is satisfied: RV Heincke returns with fish tanks filled with Atlantic and Polar cod. A crucial success, because once back at the Alfred Wegener Institute in Bremerhaven he and his colleagues will need these fish for their experiments on how the two species react to ocean acidification. Experiments that will span over the following year.