In early October 2014 the seagulls (herring gulls) were diving into the sea off Rhos-on-Sea. This is unusual for seagulls, although common for terns, gannets and other seabirds. The previous week there had a been a big mackerel run at the same location, and the initial thoughts were that the gulls were feeding on the white bait or indeed the mackerel. But I thought this could not be the case as the target was static. I took my camera down to the low tide mark to check out on what they were feeding, and discovered they were feeding on starfish. The seagulls would swim in shallow water before plunge-diving to the larder below. They must have eaten several thousand star-fish over the course of the few days when the water levels were just right.
Video of Seagulls Feeding Frenzy in Colwyn Bay