The vertical movement of krills may have a smaller impact on carbon exports than before.

The seabed and submarine landing ships developed by the Australian Antarctic Bureau, that is, Kombi (krills for bottom surveys), are equipped with a variety of devices to measure krills and the nature of water. After this equipment was collected, the octopus was safely returned to water. Credit: Neil Brown
According to the research results published in a science magazine, Nankyokuokii, who swims between the surface layer of the Antarctic Ocean and the deep seabed, has a “surprisingly small” contribution to carbon exports to the “highway” of carbon exports than rapidly sinking feces. “
The discovery brought a challenging theory of krills in the carbon cycle of the marine carbon circulation, and influenced models that provide information on climate policy and climate easing strategies.
Deep -sea spy
Dr. Abigail Smith, the lead author of the Australian Antarctic Bureau and the Australian Antarctic Partnership, said that the research team used a new “Umizu Land Ship”, which was anchored for one year anchored at a depth of 387 meters off the Prizes Bay off the Davis Research Base off. 。
The landing ship monitored the daily migration pattern of the Antarctica krill using a video camera and a krill that moves between the seabed and the sea surface using sound.
By combining these outdoor observations with a numerical model, the research team moves only for less than 10 % (from a plant plankton) to the deep sea of ​​200 meters or less due to the vertical movement of the krill. I was surprised to discover that I was not.
“It is estimated that there are about 300 million tons of Nankyokioki in the Antarctic Ocean, which is the world’s largest creature as a single wildlife,” said Smith.
“They eat carbon plankton, which is rich in carbon in surface water, and generate a rapidly sinking dung pellet that exports up to 40 million tons of carbon a year to the deep sea, plays an important role in the carbon cycle of the earth. , You can stay in the deep sea. “
“These fecal pellets are broken down when sinking or consumed by other organisms or bacteria, so not all carbon are exported to the deep sea.
“It has been considered an efficient way to inject carbon directly into this deep water storage for a large amount of krills to eat food on the surface and dung in a deep layer.
“However, the number of krills migrating a year is only 25 %, and it turns out that the number fluctuates depending on the season.”
Seasonal swimming
In the research team, most of the krills that actually move up and down are small plant plankton, and thus in winter, which can be exported, most of them swim full of the full distance between the surface and the seabed. I found.
In the summer, krills only perform shallow migration between the surface and the depth of about 100 meters, which means that it takes a long time for the sinking poo to decompose and return the carbon to the surface layer.
So what does this mean for carbon models and climate models?
In the past, the observation of krills vertical migration has been performed from the surface of the water using a ship -based acoustic deeper. However, these acoustic observations are limited to a depth of about 250 meters, and cannot be observed in winter due to sea ice.
As a result, the biological globe chemical model, which maps the flow of carbon passing through the marine system, has insufficient observation data, and Dr. Smith said that the expression of carbon cycle by mobile creatures is excessively simplified.
“Because of the lack of observation data, the carbon export model is based on the assumption that average 50 % of animal plankton individuals such as krills moves to the deep sea every day,” she said.
“If you combine the huge amount of organisms of krills to this, it will eventually become a large amount of carbon.
“Our data is not all krills travel all year round, and most of the migration to the sea floor is very low in the productivity of plant plankton, so much carbon exported. It indicates that it is small.
“This means that the contribution of vertical movement to the efficiency of carbon exports may be overrated by up to 215%, which will lead to an imbalanced climate model.”
Carbon flag spower
Dr. Smith said that not only ecological and biological globe -chemical studies throughout the year, but also the seasonal movement patterns of krills and other animal plankton across the Antarctica and other animal plankton needed.
“This research is only part of the puzzle because the migrating krills have contributed to the outflow of carbon through death, molting, excretion, and breathing,” said Dr. Smith.
“To deal with krill contributions to all mechanisms of carbon exports, further observation and research are required. In that case, the model provides accurate carbon flux estimation and information on climate policy and climate easing strategy. Can be provided.
Detailed information: AJR Smith et al, vertical movement of Nankyokuokii is the SCIENCE (2025), which regulates seasonal carbon exports. Doi: 10.1126/Science.adq5564
Provided by the Australian Antarctic Bureau
Quoted: The vertical movement of krills may have a smaller impact on carbon exports than before (January 24, 2025) (https://phys.org/news/2025-01-) KRILL-VERTICAL-MIGRATION-SMALLER-I got it from January 24, 2025). html
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