I know this won't help any, but this photo was taken May 26th of this year.
I had this same issue last Spring, and it was gone in a matter of weeks. A few of the LMB did have worms in their stomach, and it was in only one area of my lake, and it was in the exact same place as the year before.
This last weekend, there were no LMB with spots, and I had no dead fish. Found only 1 fish with worms. Weird deal to me too.
