Australian scientists aboard the icebreaker ship RSV Nuyina uncovered a host of unique marine creatures during a 60-day expedition near the Denman Glacier in East Antarctica. The mission aimed to study the impact of rising sea temperatures on the glacier, which retreated by about 5 kilometers between 1996 and 2018, making it the fastest-melting glacier in the region.
Among the unusual organisms discovered are pink, puffed-up sea pigs, human-sized sea spiders, large plate-sized starfish, and delicate sea butterflies, some possibly unknown to science. "We have collected a very large marine biodiversity, and possibly some new species to science," said Professor Jan Strugnell, a marine biologist.
One of the notable findings was a sea butterfly, nicknamed Clio by the scientists, which laid eggs in one of the ship's aquariums. This event provided researchers with a rare opportunity to observe the development of pteropod eggs for the first time. "The team is very excited to have the little creature and to observe and care for it, so it can tell all the secrets that have been hidden," said Dr. Laura Herraiz Borreguero, an oceanographer at CSIRO and the Australian Antarctic Program Partnership (AAPP).
The expedition's discoveries expand knowledge about deep-sea biodiversity and offer new perspectives on extreme ecosystems. The researchers managed to capture hand-sized sea spiders and sea stars the size of dinner plates. Despite being called spiders, these arthropods are more closely related to crustaceans. Their bodies are so small that even parts of their organs, including the intestine and reproductive system, are housed in their legs. Some species can reach a leg span of up to 50 centimeters.
Sea pigs, measuring between 4 and 15 centimeters, were also collected. They inhabit the ocean floor at depths of 1 to 6 kilometers and feed on marine snow, a constant rain of organic matter that falls from the upper layers of the ocean. Their soft, plump bodies and short appendages resembling legs give them their pig-like nickname.
The RSV Nuyina's specialized equipment, including a tank with seawater known as a wet well, allowed scientists to keep even the most fragile creatures alive for study. This is the vessel's first mission dedicated specifically to marine science, equipped with technology to explore the depths of the Southern Ocean and capture delicate marine species without damaging them.
Alongside collecting deep-sea animals, the researchers took seawater samples near the Denman Glacier to analyze temperature, salinity, oxygen levels, and metals at various depths. "To really understand how much heat is entering the ice shelf, we need to be as close as possible to understand these processes and the properties of the ocean," Dr. Herraiz Borreguero explained.
The expedition was over halfway through its course and was primarily focused on understanding the impact of warm water on the Denman Glacier. Preliminary observations suggested that the climate system in this region of Antarctica was changing due to the presence of warmer waters. "It is really important that we observe the change so that we keep questioning the climate models we rely on for our mitigation and adaptation strategies," Dr. Herraiz Borreguero concluded.
The article was written with the assistance of a news analysis system.