I have found a few largemouth bass and hybrid bream the last few weeks with a yellowish fungus/growth slowly swimming and a few dead, mainly bass. Any ideas on what it is or the cause.

Texas Panhandle, 3/4 acre pond. Pics are below

What's your water temp? Did you catch and relase any in the last few weeks?

Looks like coldwater water mold aka fungus.

Water is cold probably 40's and colder depending on the weather. Half the pond froze a few weeks ago about 1.5" thick.

Yeah fungal then.

Did you any catch and release in the last few weeks?

Bass are very susceptible to fungal infections if their slime coat is compromised from handling, as their immune system is running below par in cold water. That said I've even seen this happen even without handling in coldwater.

Any fish I catch in coldwater i handle as little as possible. Lip hold at the most.

Treatment?

Not really anything you can do in a pond and even tank fungal treatments aren't always successful. Up here in the north we sometimes see fish like this after the ice goes out -- especially if there is oxygen stress.

Hey Ranger Rick are these possibly Florida strain or intergrades? If so they may be more easily stressed by cold water.

Not sure on the strain. They came from a hatchery in Arkansas as fingerlings in March 2014 along with some hybrid bream.

No haven't fished in the last couple months. There has been a couple blue herrings and hawks hanging around though.

I have also been running a couple aeration pods 24/7 Vertex.

Are those diffusers set in deep water? Did you have them running during the ice-over?

You may have super-cooled the pond and disrupted their deep water winter refuge by destratifying during the cold snap. The fungal growth could be a reflection of that event.

I would shut them down this time of year with water temps below 60. I doubt you get anything besides skim ice temporarily right? This could be your stressor.

In Texas? Ice covered pond?

I do agree it could be a stressor in cold water.

Yes, fairly deep. One is at 8ft and the other 11ft. I will keep them off till the water temps start to rise in the spring.


Thank you guys for the help!