Like Debra, my first thought was dissolved oxygen crash. However, the crashes I've had haven't discriminated by species. Larger catfish seem to go along with bluegill of all sizes.
What has your weather been like? You say it has warmed up. However, cloudy and no wind for three or four days, along with a heavy fish population, could possibly be a DO crash.
It's not about the fish. It's about the pond. Take care of the pond and the fish will be fine. PB subscriber since before it was in color.
Without a sense of urgency, Nothing ever gets done.
Boy, if I say "sic em", you'd better look for something to bite. Sam Shelley Rancher and Farmer Muleshoe Texas 1892-1985 RIP
| 
