Whilst on my way home from the local trout fishery I decided to stop by a local fishing spot on the Ijsselmeer in the Nethrlands. What I found was that there were literally shoals of Ide everywhere jumping about from the little tiddlers to the big boys. I tried just about every fly that I could think off that is normally sucessful for Ide fishing & managed to hook up just one small fish. The fish seemed to be feeding on something in between the rocks on the bottom. I thought that might be some emerging insect & tried various buzzers but to no avail. I am open to hearing the theories.

Hi Runer Are you sure the ide were feeding, or were they spawning?
Sometimes fish like to clean themselves off after spawning, perhaps that could of been mistaken for feeding.
However if they were feeding sometimes fish can be preoccupied by only one food source, and it is almost impossible to catch them on any other bait.

Or they could of been feeding on other fishes eggs that have recently spawned. Those eggs may have been washed between the rocks.

Well I am sure they were feeding as there were lots of boils on the surface. Additionally I did see browinsh insects flying about near the surface ( but none on the surface) so I am not sure if a hatch was on or what the hatch was. I tried a quail pupa buzzer but that had no takes and I was hesitant to use a dry. Wrt eggs in between the stones - does sound plausible but I wonder which species would be spawning at this time of the year as the Roach, chub, pearch etc have already spawned.