In cooler waters, researchers have found cod and squid, which appear to be thriving further north than previously thought.
Polarstern is a German research vessel and icebreaker, which conducts important research in the coldest regions of the world. Among other things, the icebreaker froze in the Arctic Ocean, which allowed the scientists on board to subject their immediate environment to a thorough examination. It leads to a surprising discovery. Because they unexpectedly found fish and squid in the deep waters of the heart of the Arctic Ocean.
First of all, scientists aboard the Polarstern discovered that some small fish swim at a depth of about 200 to 600 meters in the so-called Amundsen Basin. But they were even more surprised when they suddenly caught four larger fish at a depth of 350 to 400 meters. In addition, three of the four fish turned out to be cod; Of the predatory species, it is not found, as it was believed, even to the north. In addition, cod is considered a typical coastal fish. So the researchers did not expect to find this fish in an ocean basin four kilometers deep, more than 500 kilometers from shore.
Laboratory analyzes show that the cod fish has been living in the harsh Arctic waters for six years. This is while it was believed that cod is most comfortable at water temperature between 0 and 20 degrees Celsius. However, the research shows that fish can also thrive in cooler temperatures and seems to have found a nice habitat in the Arctic Ocean. “It appears that a small number of samples are able to find enough food to stay healthy for a long time,” researcher Pauline Snoijs Legonmalm said.
In addition to cod, researchers have found another fascinating species using a deep-sea camera scattered under the sea ice. For example, in the deep waters of the heart of the Arctic Ocean, there are also squid from the family Gonatidae to swim around. This also means that this species occurs much more northward than previously thought.
According to the researchers, these surprising discoveries have pulled some pieces of the puzzle together. “The presence of small and even larger fish could explain why seals, walruses, and polar bears are found in the Arctic,” says biologist Hook Flores. “Although small numbers of fish and mammals exist, they do exist.” Thus, the migration of large Atlantic fish contributes to the surface food web of the central Arctic ecosystem, and may represent an important food source for far north mammals.
Snoeijs Leijonmalm stresses that it is critical that this fragile, but fully functional ecosystem receives strong international protection. Global warming is hitting the Arctic more than the rest of the world. And this means that in just a few decades, not only icebreakers, but also ordinary ships will be able to navigate the Arctic Ocean. However, based on the new findings, the researchers concluded that at present and in the future, there are too few fish swimming in the waters to be able to catch. “This was to be expected,” says Snoeijs Leijonmalm. “The Arctic Ocean is known to be low in nutrients and very low biological productivity. Even with more Atlantic fish swimming in the waters, the ability of the Arctic Ocean ecosystem to support larger stocks of fish is undoubtedly very limited.”
As a precaution, Canada, China, Greenland, Iceland, Japan, Norway, Russia, South Korea, the United States and the European Union have already negotiated an agreement to prevent unregulated fishing on the high seas in the central Arctic Ocean. “This agreement bans commercial fishing for at least 16 years and puts ‘science first,’” said Snoeijs Leijonmalm. “A wise political decision and a good start for full protection.”