Researchers in Antarctica accidentally crashed an amphipod party when they went exploring 500 meters (1,640 feet) below the surface of the ice – a few kilometers off the Ross Ice Shelf – and discovered a hidden underwater ecosystem. The team, made up of researchers from Te Herenga Waka – Victoria University of Wellington, NIWA, and GNS, were met with swarms of small, shrimp-like creatures as their probe plunged into an Antarctic river, one of many that sit beneath the continent's ice giants.

The newly-discovered underwater ecosystem sits in a network of hidden freshwater lakes and rivers that scientists have known about for some time (some of which are home to fossil sea water). However, being so difficult to access means this was the first time this particular environment was able to be directly surveyed, and taking a peek into the hidden depths proved to be quite the journey of discovery.

“We’ve done experiments in other parts of the ice shelf and thought we had a handle on things, but this time big surprises were thrown up,” said Professor Craig Stevens, a NIWA Physical Oceanographer, in a release from NIWA.

“For a while, we thought something was wrong with the camera but when the focus improved, we noticed a swarm of arthropods around 5 millimeters [0.2 inches] in size.”

Footage shows the swarms of shrimp-like animals as they burst into view (albeit, rather blurrily). They are amphipods, a group of animals that join lobsters, crabs, and mites as the arthropods. While Stevens told IFLScience that those in shot are “not likely to be new to science,” there are some intriguing questions to be answered about their existence.

“What is interesting is where their food is coming from and why their presence was so variable over the 10 days we observed,” he said. As for what’s on the menu for these transient populations, the team is having e-DNA analysis done on water from the site to look for clues as to what nutrients could be keeping them fed.

“We were jumping up and down because having all those animals swimming around our equipment means that there’s clearly an important ecosystem there,” Stevens continued. “We’ve taken some water samples back to the lab to look at the DNA and other properties of the water to see what makes it unique, as we were observing something not seen in other systems close by.”

While the discovery of the underwater ecosystem was a surprise, it’s not unique in that there are lots of environments similar to it that we already know about on Earth, even if they are a doozy to get to. Now, it seems the hidden ecosystem’s surprise party goers have whetted the team’s appetite for exploration deep beneath the Antarctic ice.

“Getting to observe and sample this river was like being the first to enter a hidden world. On the ice shelf surface there is a little valley snaking down to the coast,” said Dr Huw Horgan, Associate Professor of geophysical glaciology at the Antarctic Research Centre at Te Herenga Waka, and the project’s lead, who was also the first person to spot the estuary in which the hidden ecosystem was found.

“Beneath this, there is a cathedral-like cavern, hundreds of meters high, teeming with life. All this hidden under the vast ice shelf. It was an incredibly exciting expedition because of the rare opportunity it offered to study this type of environment. We’ve left instruments there that should provide observations for years to come.”

[H/T: Guardian]