What are they doing there ?!
We’ve known for quite some time that there are many wonderful animals on Earth. But the fact that there was life even nearly a kilometer below the Antarctic Ice Shelf was a complete surprise to scientists. “This finding shows that life in Antarctica is incredibly special and has adapted to a frozen world in an amazing way,” said researcher Hu Griffiths.
Floating ice shelves are currently the largest unexplored habitat in the Southern Ocean. It covers more than 1.5 million square kilometers, but only one surface that can be compared to a tennis court has been explored so far. In a new study, researchers traveled to the Filchner-Ronne Ice Shelf, located in the southeast of the Weddell Sea. The purpose was to collect new sediment samples. But the researchers’ great surprise was that they suddenly ran into very strange animals.
“It was a strange way to do science,” Griffiths said in an interview. Scientias. Pictures of the animals were taken when some fellows dug into 900-meter-thick ice. They plan to collect sediment samples from the sea floor at a depth of another 500 meters. But instead of the target clay, the excavator hit a large stone. This was bad news for geologists. But the video images collected were wonderful for the biologists in attendance when it turned out that some animals were living on the rock. “
This means there is more life than expected, down the ice shelves in Antarctica. So life can thrive in complete darkness, in extreme cold and in extreme conditions. “Many of the animals look like sponges and they appear to be about 9 inches long,” says Griffiths. “Other animals have legs that reach into the water, but we can’t tell what exactly they are from the video.”
Filtrate feed organisms
On closer inspection, it also appears to be filter-fed organisms. This conflicts with prevailing theories about which species can survive at extreme depths. Current theories suggest that life gets smaller as you move away from open water and sunlight. Previous studies found only few scavengers and mobile predators in these deep spots. Think fish, worms, jellyfish, or krill. However, it was not expected to find filter-feeding creatures that depend on food from above deep under the ice. “These are the first filter-fed animals that we have detected on a rock so far below the ice shelf and far from daylight,” says Griffiths. These animals are unable to move and therefore depend on the food that comes to them. It was previously thought that these types of animals could not even live under the ice shelf due to lack of food. “
“These are the first animals to feed on a filter that we discover on a rock below the ice shelf and far from daylight.”
In this study, researchers discovered for the first time the existence of sedentary animals attached to a rock on the sea floor. And there may be many copies. “We have no idea how far they are exactly, but we do estimate that these large rocks fall nearly every mile,” says Griffiths. Because ice shelves cover about 1.5 million square kilometers of the entire Antarctic continental shelf, the critters may be very common. We found 38 samples on the rock in question, but unfortunately we couldn’t see the entire rock on the video images. Therefore, the total number could be several times greater. “
More questions than answers
The mysterious creatures discovered represent the first example of filter-fed organisms located beneath an ice shelf. Much remains unknown. “We don’t know exactly what role they are playing,” says Griffiths. So our discovery raises more questions than it answers. How did these animals end up here, for example? what do they eat? How long was it there? Exactly how often do these types of rocks covered with life occur? Are they familiar animals or are they a new species? And what happens to these creatures when ice shelves collapse? They may be new species that are unique in this hostile environment. This can make them extremely vulnerable to avalanche and climate change. “
In order to craft answers to these pressing questions, researchers need to find a way to get close to the animals and their environment. But how do you do that, at this extreme depth? “As scientists, we need to devise creative and innovative ways to properly study these creatures,” says Griffiths when asked. Water and sediment sample collection and environmental DNA testing can help. New technologies such as small underwater robots that fit wells to sample can also help. But also think of larger robots that can swim further under the ice to photograph the sea floor, map it out and collect samples. ”Overall, it’s not an easy task.“ Whatever we do, it won’t be easy, ”Griffiths said.
The results show conclusively that there is still a lot to learn about one of the least studied environments on Earth. “Antarctica has thousands of amazing seabed species that can withstand extreme conditions,” says Griffiths. “But this new discovery really enhances our understanding of how special and resilient Southern Ocean animals are.” But it is not all good news. “These animals are threatened by climate change and the potential collapse of the ice shelf,” Griffiths continues. So time is running out to study and protect these ecosystems.
However, Griffiths ends on a positive note. “I was very surprised to discover life so deep under an ice shelf for the first time,” said Griffiths. “Seeing spongy creatures fed by a filter seemed impossible. It confirms once again that nature does not like to abide by the rules laid down by biologists!”
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