Unexpected fish and squids found in the Central Arctic Ocean

The research team discovered Atlantic cod in the Arctic Ocean.Credits: UFA Show & Factual, Germany

A single Atlantic cod and squid occurs far north than previously expected. Scientists who participated in the international MOSAiC expedition with the research icebreaker Polarstern discovered fish and squids in the deep waters of the middle of the Arctic Ocean. The results of colleagues at Stockholm University, the Alfred Wegener Institute, and the European Fisheries Catalog (EFICA) Consortium in the Central Arctic have been published in a scientific journal today. Science Advances..

Very in the 200-600 m deep Atlantic waters of the Amundsen Basin, as shown by a unique underwater acoustic dataset showing a “deep sea scattering layer” (DSL) consisting of animal plantations and fish collected by the EFICA Consortium. Small fish occur in small amounts. A 3170km long truck on the MOSAiC expedition.

Therefore, it was surprising that four large fish were caught at a depth of 350 to 400 meters. An even bigger surprise to the research team is that three of the fish are Atlantic cod, which are not supposed to live far north, are coastal fish, and live in the 4km-deep basin more than 500km away. I didn’t do it. From any coastline. By deploying deep-sea cameras under sea ice, scientists also discovered that Atlantic armhook squids and Atlantic lanternfish occur far norther than previously known. ..

Laboratory analysis shows that Atlantic cod originated from the Norwegian spawning ground and lived in Arctic water temperatures (-1 to 2 degrees Celsius) for up to 6 years. Fish preferred the Atlantic waters, slightly warmer water masses (0-2 degrees Celsius) extending far into the surface Arctic Basin, and deeper waters below 0 degrees Celsius.

“Therefore, even if the Atlantic cod does not have its own Central Arctic resources, this study shows that it can survive. A small number of individuals have enough food to stay healthy for a longer period of time. Seems to be finding, “said a professor of marine ecology at the EFICA Consortium and Stockholm University.

New insights into the functioning of pelagic food webs

Thus, this study adds a new trophic stage to the pelagic food webs of the central Arctic ecosystem, the food webs of large predatory fish and squids. Since seals and walruses can sneak into the Atlantic waters, continued migration of large Atlantic fish, along with small fish in the DSL, contributes to the potential food of mammals.

“The presence of small and large fish in the Atlantic waters causes seals, walruses, Polar bear You can also find it in the Arctic. There are very few fish and mammals, but they are there, “says Dr. Hauke ​​Flores, a biologist at the Alfred Wegener Institute.

In a new study, DSL diel vertical migration is not seen in polar night half-year continuous darkness (DSL 100-250 m) and polar night half-year continuous light (DSL 300-250 m). I also understood that. 500 meters). This means that the carbon flux from shallow to deep water due to the daily vertical movement of the DSL is hampered in the Central Arctic compared to all other oceans.

“During the short production period of polar days, DSLs stay 24 hours a day in the deeper parts of the Atlantic waters, even if sea ice disappears. This is due to the availability of light in this process. It’s because it’s regulated, “says Pauline Snoeijs. Leijon malm.

Unexpected fish and squids found in the Central Arctic Ocean

An arm hook squid in the Arctic Ocean discovered by an expedition fish cam.Credit: EFICA Consortium

No stock of harvestable fish

Based on them Scientific resultsThe author of a new paper Science Advances We conclude that there is no stock of fish that can be harvested now or in the near future, at least in the Eurasian Basin.

“This is because the Central Arctic has very low nutrient concentrations and very low biological productivity, assuming that the influx of water from the Atlantic has introduced more Atlantic fish and their prey. But the resources of fish that are larger than the capacity of the Central Arctic ecosystem is undoubtedly quite limited, “says Pauline Snoeijs Ray John Malm.

Pauline Snoeijs Leijonmalm emphasizes that it is very important that this fragile but fully functional ecosystem receive as strong international protection as Antarctica.

International agreement hinders commercial fishing

Global warming hits the Arctic Ocean more violently than any other Earth, and climate models predict that opening the Central Arctic Ocean for non-icebreakers will be a matter of only decades. Since most of the region consists of the high seas (the high seas outside the jurisdiction of the country), the potential for future human activity here is being discussed at the national and international political levels.

“Usually, the development of newly available natural resources tends to precede scientific research and control measures, and fish stocks shared internationally on the high seas are particularly prone to overfishing,” Pauline Snouis said. Ray John Malm says.

Taking a precautionary approach, Canada, China, Greenland (Denmark), Iceland, Japan, Norway, Russia, South Korea, the United States, and the European Union to prevent unregulated open sea fishing in the Central Arctic. The Agreement negotiated (CAO) came into effect on June 25, 2021. The 10 partners of the agreement will soon launch a large-scale collaborative scientific research and surveillance program to collect data on new fish and ecosystems in the Central Arctic Ocean. The EU has already begun this work by funding the EFICA Consortium’s Ecosystem Research on the MOSAiC Expedition (2019-2020) and the Synoptic Arctic Expedition by the Swedish icebreaker Oden (2021).New newspaper Science Advances This is the first scientific paper to present new field data in the context of the agreement.

“This agreement will stop commercial fishing for at least 16 years, make science a top priority, and guarantee a scientific assessment of the state and distribution of fish stocks in the Central Arctic Ocean and its supporting ecosystems. It’s a good start for wise political decisions and full protection, “says Pauline Snoace Rayjonmalm.

Tintinnids of Pacific origin invaded the Arctic Basin

For more information:
Pauline Snoeijs-Leijonmalm, Unexpected fish and squid in the Central Arctic Deep Sea Scattering Layer, Science Advances (2022). DOI: 10.1126 / sciadv.abj7536..

Quote: Unexpected fish and squids found in the Central Arctic (February 18, 2022) from https: // 2022 Obtained on February 18th

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Unexpected fish and squids found in the Central Arctic Ocean

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