This is Janusz Pond a few years ago. It borders the Polesian National Park in Western #Polesia. A few ponds like Janusz were included in the park on its formation in 1990 and they look much wilder.
This is Janusz Pond today. All the water has been let out exposing the muddy bottom. The company that operated the pond did not extend its lease and the whole fish operation was shut down.
There is very little water left in the deepest part of the pond. Animal tracks suggest that deer still come here to drink. Or maybe to eat those small bright dots lying all around.
On closer look the spots turn out to be dead swan mussels (Anodonta cygnea), a species found only in very clean water.
Those mussels are some of the largest freshwater mussels, reaching 20 cm in length. The pocket knife placed for comparison is 9 cm long.
@RoboticistDuck They're used as animal feed, I'd have to check on use by humans. Probably not very tasty .
@szescstopni are they edible?