Dancing sand of Pyana river (RUS)

[АлександрД]

Pyana river. Nizhniy Novgorod region. Around 500km from Moscow.
River is interesting by shape - total lenght around 436 km, but distance from the mouth to the source just 60 km
Many karst caves and sources along this river.

Here 14 min video from that river:

 

[АлександрД]

had found another fresh video

 

[CT-Rich]

Neat looking place. There are similar fountains in Florida. Is there a reason there are no fish, or was that just coincidental?

 

[АлександрД]

On the first video you can see (0:35) the shoal of small fishes.
Also I`d seen one photo (not mine) with sturgeon fish on that river
I think the clean (and very cold) water near the sources is not the favorite fishes region.
More of it in the anoter places.