At the time I took this photo, I thought I was looking at a Black-legged Kittiwake. When I got home and looked at the picture, I noticed what looks to me like part of a red leg showing. This leads me to think that it might be a Red-legged Kittiwake. I would be more enthusiastic about this if Red-legged Kittiwakes were not so uncommon in Southeast Alaska. They are not listed as occuring in Southeast in Armstrong’s Birds of Alaska and they are listed as Accidental in one of the local bird lists. Unfortunately I did not pay close attention to the gray on its wings when it took off and flew further up into the estuary (the primaries should be gray underneath if this is a Red-legged Kittiwake). However, what I can see of the underside in this photo does not look very gray to me.
This bird would have been visible from shore, but I doubt I can find it again amongst the hundreds or thousands of Gulls around Indian River. That’s assuming it even sticks around at all.