Icelandic gulls

We went for a walk along the seafront sculpture trail this afternoon - although it was rather cold, so hat, scarf and gloves required. We spotted a group of gulls on the water, then suddenly 2 circles of still water interrupted the slight ripples on the surface and the gulls went MAD - flying, and diving for fish. We were hoping that we might see whatever was causing this strange phenomenon, but we didn't. This is a close up of 2 of the gulls, with their reflections.