I haven't seen this before in my pond that I can remember.

We have been away on vacation and on the ride home yesterday, our home watching friend called and informed us that tadpoles were dead and dying all around the pond banks. She didn't see any fish dying though.

I got home just a little before dark and saw that hundreds, possibly thousands, were floated and bloated. I saw no signs of struggling fish last night or yet today which is a great relief for now at least. The tadpoles appear to be large bullfrog tadpoles, some of which have some back and some even have front legs.

My pond is about 2.5 feet low vertically. This is the most water I've seen gone since about 2011ish. We had an exteme and extended heat wave and drought leading to a massive fish kill for us. This year in my section of mid-Missouri, we've had a terrible drought that has been ongoing since back into the Spring.

My current max depth at full pool is around 15ft. I'd say. I have two aeration diffusers set in about 10 and 11 ft. of water when at full pool so they are now shallower than normal. I only use a Hi-Blow 120 for 2.5 acres but it does appear to put out quite a bit of air. There are large healthy bubbling boils on the surface above them.

Also, we may have had multiple days of 100 or near 100 degree weather in mid-Missouri over the past week. When our friend had been swimming during the week, she said the water down deeper was still relatively cool as was the water at the diffusers when she floated over them.

I don't know what caused it. I am wondering if maybe the tadpoles stay very shallow by nature and just died from excessive heat? I would think that if's it is an oxygen deficiency, I'd see larger fish critters dying or maybe tadpoles are much more susceptible to oxygen depletion than most pond fish?