(ORDO NEWS) — Unexpectedly for themselves, oceanologists discovered that quite a lot of large cod and octopuses are found in the subpolar waters of the Arctic Ocean. They presumably serve as food for the northernmost populations of polar bears and seals.
“The presence of large and small fish explains why walruses, seals and polar bears are found even in the vicinity of the North Pole.
Their numbers may not be as high as in other areas of the oceans, but both fish and mammals still somehow survive in this part of the Arctic,” said one of the authors of the study, a researcher at the Alfred Wegener Institute (Germany) Hauke Flores.
The area of polar ice is decreasing every year, so scientists are investigating how this affects the inhabitants of the polar oceans.
For example, a year ago, scientists discovered sea sponges off the coast of Franz Josef Land that can move along the bottom of the Arctic Ocean, and also discovered several dozen species of worms and other invertebrates that live on the bottom of the Antarctic, which was previously considered lifeless.
During the MOSAiC oceanographic expedition, which took place in 2019-2020 aboard the German icebreaker Polarstern, Flores and his colleagues found that in the deep layers of the subpolar waters of the Arctic there is a small but clearly visible population of octopuses, Atlantic cod and other large fish and shellfish.
Members of this expedition traveled for eight months towards the North Pole, periodically collecting water samples from different depths and tracking the inhabitants of the Arctic Ocean using sonars and robotic underwater cameras. Thanks to this, biologists have traced how the species composition and diversity of the circumpolar marine fauna has changed.
Flores and his colleagues unexpectedly managed to catch three dozen large octopuses, as well as several individuals of Atlantic cod, anchovies and other small and large fish. Previously, it was believed that they should not have been found in the polar region due to low water temperatures and the poverty of local food resources.
Therefore, scientists tried to understand how these mollusks and fish could get there. They found that the supposed source of cod and octopuses was the waters of the warm Atlantic currents that wash the coast of Norway, plunge there to great depths and then move towards the north pole.
According to scientists, the total number and mass of these fish and octopuses is relatively small, which makes their fishing useless and unprofitable.
However, oceanologists suggest that these “migrants” from the Atlantic play an important role in the functioning of the Arctic ecosystems. That is, their populations need to be studied and protected from poachers, summed up Flores and his colleagues.
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