Cruise ship passengers who saw the otherworldly animals off the coast of AntarcticaFind a new studio.
The giant ghost jellyfish (Stygiomedusa gigantea), one of the seabeds largest invertebrate predators (opens in a new tab)he met the guests while traveling in a submersible deployed by cruise line operator Viking in early 2022. Researchers estimated the jellyfish measured longer than 16 feet (5 meters), with one stretching to at least 33 feet ( 10 m) long. , according to a study published on January 30 in the journal polar research (opens in a new tab).
The study’s first author, Daniel Moore, first became aware that guests had encountered the giant ghost when he saw an image of one on a guest’s camera. “I instantly recognized it for what it was, and given the rarity of the sightings, I was overwhelmed with excitement,” Moore, one of Viking’s lead scientists, told Live Science in an email.
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Giant ghost jellyfish live in all oceans except the Arctic Ocean. However, because these cryptic creatures often swim far below the surface, humans barely see them. The new study describes direct observations of three different jellyfish made during submersible dives off the Antarctic Peninsula.
“In each sighting, the jellyfish appears to be swimming slowly, gently pulsing its bell to propel itself,” Moore said. “They do not appear to have shown any inclination toward the submersible lights or reaction to our presence.”
The jellyfish were seen at depths of 260 feet (80 m), 285 feet (87 m), and 920 feet (280 m). Giant ghost jellyfish primarily occupy depths below 1,000 m (3,280 ft), but are found higher up in the Southern Ocean or Southern Ocean. It is not yet known why they hang out in relatively shallow water around Antarctica.
Moore noted that one possible explanation is that the jellyfish swim higher to expose themselves to ultraviolet radiation, which will rid them of parasites. Another hypothesis put forward by Moore is that deep water rising up around the Antarctic continent simply carries them up. Moore hopes that his observations will lead to a better understanding of the lives of giant ghost jellyfish.
The practice of cruise lines taking passengers to Antarctica has raised some controversy. he US Coast Guard (opens in a new tab) announced on February 2 that it has joined international partners to investigate four deaths and other casualties involving US citizens on Antarctic passenger ships between November 15 and December 15. on January 1, 2022. This includes one death on the Viking Polaris, operated by Viking, after a big waves hit the boat.
The US Coast Guard describes Antarctica as a “uniquely high risk” environment and aims to improve marine safety and prevent similar incidents in the future. The waters surrounding Antarctica can be treacherous and the continent has a history that calls for intrepid explorers in famous expeditions.