I’ve got this green film/algae looking stuff on one of my sloughs down in the Trinity River bottoms. Mallards and teal flocking on it. Anyone know what it is?

Maybe string algae.

Does it look like this?

No I’m string algae and it doesn’t look like the pic above. The best I can describe is that it looks like pollen. When I take pics of it, you can’t see it on there.

Hmmmm, like a translucent film on the water??

Below is duckweed in the trinity river bottoms north of lewisville, but sounds like your seeing planktonic algae or cyanobacteria. The type known as blue green algae can have an iridescent film look to it and not always blue. It can poison and kill a dog. I goose hunting a state park lake in Kansas on a couple "special hunts" opened up for hunting due to blue green algae blooms caused by an excess of goose poop in the lake.

Fish killing stuff there though. Chokes off oxygen.

Sure does. That pond I posted is always covered like that. It is crystal clear under the duckweed with no other vegetation under water and no fish or aquatic life in it whatsoever. I have never seen ducks on it either.

Too bad that’s a nice pond

If it's something that's private, kill it. It's really not hard to, but it's not really cheap to do so