Established in 1832, Machias Seal Island lighthouse was originally two towers. The current single concrete tower was first lit in 1916 and is staffed by two lightkeepers working month on, month off. Disputed ownership with the U.S. keeps the Canadians onsite, the only lightkeepers in the Maritimes. A Canadian Migratory Bird Sanctuary since 1944, it is an important seabird nesting site for puffins, murres, razorbills, storm petrels, eiders, etc. Tours from both Maine and Grand Manan bring 30 visitors a day during the nesting season and also pass by other rocky islands where seals haulout.