Surveys of the South Shetland Islands, Antarctica in 1987 provided data on the size and location of penguin and Antarctic Blue-eyed Shag colonies and the breeding status of other seabirds. Our estimate of 1,618,370 to 2,084.570 breeding Chinstrap Penguins, the most abundant penguin in the study area. is two to three times the previous estimate. Other seabird species were also found to be more widespread and abundant than previously reported. We hypothesize that this trend is largely an artifact of low search effort in the past.