The deep sea remains one of the most underexplored regions of our planet. So, naturally, that’s where you’d expect to find some very bizarre things happening—like three thousand metric tons of pure eel.

Researchers with Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO) got wind (or wave?) of the eel aggregation in 2007, during underwater surveys to map the seabed and biodiversity in southern Tasmania. Follow-up surveys in 2015 and 2018 found that, indeed, an unusually high number of basketwork eels liked to gather at Patience Seamount within Australia’s Huon Marine Park. And in a recent study published in Royal Society Open Science , CSIRO researchers for the first time properly quantified the eel aggregation. But they’re still unsure why the eels are there, although one likely hypothesis is that they’ve gathered to mate.

A basketwork eel.…