The same thing we do every high tide, Pinky: look for the Black-legged Kittiwake.
To no avail. Rosabel Miró, Ariel Aguirre and Darién Montañez didn't get to Costa del Este until two hours after high tide, and by then not even the Kelp Gull was visible. At least two Herring Gulls an four Ring-billed Gulls were around, though, and the flock of South American Black Skimmers was up to 25 individuals.