What is it?

I stopped at the Park, though I didn't really feel like it. Both my ears are plugged now so everything sounds far away, & I've still got lots of pressure in my sinuses. Hope it'll be better in a day or two. I was watching this gull for quite awhile. It was standing on the sand where the waves were coming ashore & it kept pulling something out of the water; at first I thought it was a piece of bread. Some of the other gulls must have wondered too, as they started coming after this one, who grabbed it, flew off a little way and landed in the water. In this photo it looks more like a leaf, or maybe part of a brown paper bag. I'm not sure why it was so determined to hang onto it, but it eventually flew off with it in it's mouth. It's probably nest building.  :)