[1][2] Large numbers of fur seals were seen on the island in 1798 by Matthew Flinders and sealers were later reported visiting the island early in the 19th century.

[5] Improvements on the island include airstrips and a small residence.

[4] With the Forsyth and Gull islands, the Passage Island forms part of the Forsyth, Passage and Gull Islands Important Bird Area (IBA), identified as such by BirdLife International because it supports over 1% of the world populations of little penguins and black-faced cormorants.

Recorded breeding seabird, wader and waterbird species include little penguin, short-tailed shearwater, Pacific gull, silver gull, sooty oystercatcher and Cape Barren goose.

Apart from cattle, mammals present are the introduced European rabbit, house mouse and a species of rat.