Tourists have the potential to detrimentally impact breeding seabirds, particularly at popular destinations such as on the Great Barrier Reef. Michaelmas Cay is a significant seabird rookery and prime tourist destination on the reef. In 1990, Queensland Parks & Wildlife Service erected a fence to separate tourists from fragile nesting habitat. We used two independent assessments during different breeding seasons to determine the potential impacts of tourism on two pelagic seabird species breeding on the cay. In the first quasi-experiment, egg losses by sooty terns (Sterna fuscata) and common noddies (Anous stolidus) were monitored at four distances (3, 6, 18 and 36 m) from a tourist enclosure. Our second quasi-experiment involved monitoring adult provisioning rates, chick growth and chick survival of sooty terns at two locations, one adjacent to the tourist fence and one 50 m away. At plots 3–6 m from the fence, we observed higher among-week variation in egg loss but no differences in total egg loss as compared with the more distant plots. The only difference observed between plots during our second quasi-experiment was that nest predation was higher at the tourist fence plot. Our research suggests that as long as the effects observed do not influence post-fledging survival or gull predation does not impact under different conditions, current management protocols are appropriately facilitating shared usage between wildlife and the tourism industry at Michaelmas Cay.