Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations Dying Bluegill

For the second year now our adult bluegill have what appears to me to be a fungus. It forms a large white ring around there mouth and eventually seems to "melt" there mouths shut and they die. It kills about 20 or so a week(that I can see) and as I said earlier it's primarily the larger adult bluegill. Is this just a somewhat normal cycle only killing off the old fish? It happened the same time of year last year and lasted about 3 weeks. We still have a good population of adults that come to feed so I'm not worried about the population crashing but I'm definetely curious as to the what's and why's.

I have a few large BG and redear to die this time of the year and I have always thought it was the stress of the spawn.

Sounds like an aeromonas bacteria. If it is isolated I wouldn't worry too much and let it go it's course as there is nothing you can really do.

It's apparently stress medidated as most diseases are. It could be caused by spawning stress if it is spawning time, or if it is before spawning rapidly changing water temps can stress fish.

Were any of these fish caught and released in the fall or winter? If so, that may have caused your problem. Bass and bluegill if handled in under 50 degree F. water in the fall or winter can develop fungus etc. on areas of hook wounds or where they are handled later in the spring when the water warms up the bacteria and fungus explode in growth. In cold water warmwater fish have compromised immune systems and can have problems later.