Prime Seal Island is a long island, with a high central ridge and an area of 1220 ha, in south-eastern Australia. It is part of Tasmania’s Prime Seal Island Group, lying in eastern Bass Strait west of Flinders in the Furneaux Group. Geologically, it is limestone overlying granite and has notable karst features, including caves. It is leased for farming and is extensively grazed by sheep and cattle as well as the native Tasmanian pademelons.[1]