https://www.livescience.com/antarctic-ice-shelf-lifeforms-found
> Deep beneath Antarctica’s ice shelves, researchers have discovered dozens of life-forms thriving on a tiny patch of the seafloor —— an unprecedented level of species diversity in an environment that has never seen sunlight.
> the Alfred Wegener Institute used boiling hot water to bore through 200 meters of ice on the Ekström Ice Shelf in 2018.
100 metres further down was the sea floor.
> The pieces that had been pulled from underneath the ice shelf, when examined with a microscope, were clearly from different animals. All told, Barnes identified 77 different species, far more than he should have reasonably found. This one sample was even richer with species than he would have expected from a survey of the sea floor closer to the sunlight. … This is like a whole research cruise worth of samples, yet it came from just one drill hole.
> Many of the species identified were bryozoans, or stationary filter feeders such as Melicerita obliqua, and tube-feeding worms such as Paralaeospira sicula.
> Finding such rich life underneath the ever-present ice sheet is one thing, but explaining why it is there is another matter entirely. Marine life, especially filter feeders like bryozoans, sponges and jellyfish, should, in theory, become scarcer with distance from the open sea.
> these animals are feasting on microorganisms like ciliates and dinoflagellates that are swept underneath the ice shelf by oceanic currents
> the oldest remnants were 5,800 years old, from carbon dating
Abstract at https://www.sciencedirect.com/science/article/abs/pii/S0960982221015396?dgcid=author