There are no sea shells in the deepest parts of the ocean (at least not big enough for us to see). Shells are mostly made out of calcium carbonate, and beneath 4-5 km depth in the ocean (the Challenger Deep is ~10,902m) the pressure makes the calcium carbonate dissolve. Marine snail shells falling from above will never reach the seafloor – they’ll just dissolve on the way. Anything living in the depths will never see a snail, and only silica-based shells will survive. #ocean#snails
