North East Anglesey Feeding Frenzy!

Hello. For the last couple of days I have noticed very large numbers of birds feeding off the coast between Point Lynas and Moelfre. Yesterday from dawn, in fairly settled conditions I noticed at least 2,500 Kittiwakes, 500 Black Headed Gulls, 250 Gannets and 2000 auks off Point Lynas. All these birds were milling around off the point. At one point I noticed at least ten different feeding flocks, with many more further out. With this number of birds there were obviously a few nice scarcities mixed in, at least two juvenile Sabines Gull (one sat on the sea) , three Little Gulls, Mediterranean Gull, one Black Tern, one juvenile Long-tailed Skua, 15 Manx Shearwaters along with small numbers of Common, Arctic and Sandwich Tern. Quite a spectacle, and great to sift through the flocks looking for the good ones (If you like that kind of thing, and I do!). Could be lots more lurking out there, I hope to get back over there today.
So what are they feeding on? Could be mackerel, or food being chased by mackerel?

Like these I caught yesterday! I dont do bird photography, but no problem with fish! And very tasty they were too! There are large numbers of mackerel been caught off Moelfre at the moment and bass and sandeel. This may explain the presence of two pods of Bottle-nosed Dolphin totalling 10 animals off Moelfre yesterday and up to 30 Porpoise off Point Lynas too. All these cetaceans were actively feeding near the coast and well worth seeing in their own right. Also 60 Sandwich Terns between Traeth Lligwy and Moelfre still.
So if, like me, you like your seabirds, cetaceans and fish this area is well worth a visit at the moment!