Research scientist and redditor bradyboh shared this interesting photo of a large pond that drains/sinks every dry season, leaving an eerie horizontal ‘wet’ line across the tree trunks.

Brady says the pond is somewhere in middle Tennessee but can’t share the exact location since it’s a biological research site. He adds that the pond ‘sinks’ with the water table and can go from full to empty in a matter of weeks. His research team comes here (along with several other similar sites) to collect biological samples. They are studying amphibian disease dynamics, with seasonality being a variable they are particularly interested in.

Brady also says that because the pond drains annually, fish don’t live in it which is exactly why amphibians love it, because there are no fish to eat their eggs/tadpoles.