Yes seabirds can drink saltwater. On land they prefer to drink (and bathe) in fresh water, but at sea they don't have much alternative, says Ben Hoare.
How do they cope with all the salt?
They avoid hypernatraemia, or salt poisoning, by getting rid of the excess salt through a pair of glands above the eyes. Many birds have salt glands, but they are much larger in species that make long trips offshore, such as tubenoses (albatrosses, petrels, shearwaters and fulmars) and auks the family that includes puffins and guillemots).
After being excreted, the super salty waste fluid flows down through the nostrils - you can see it dripping off the tip of the bill like tears.