Boxen Island and Big Black Reef (23911)
Australia, Australasia
Site overview
KBA status: confirmed
Global KBA criteria: D1a
Year of last assessment: 2009
National site name: Boxen Island and Big Black Reef
Central coordinates: Latitude: -40.3793, Longitude: 147.8982
System: marine, terrestrial
Elevation (m): 0 to 6
Area of KBA (km2): 0.08099
Protected area coverage (%): 86.88
KBA classification: Global
Legacy site: Yes
Site details
Site description: The IBA consists of Boxen Island, Double Rock and Big Black Reef which are isolated islets located to the west of Cape Barren Island in the Bass Strait. Boxen Island (6.74ha) is a flat dolerite island with a series of depressions and rises surrounded by a 30m wide rocky shoreline (at low tide). The beach is made up of pebbles and leads up to the vegetation which is dominated by Poa poiformis. There is a water filled depression in the centre of the island and no burrowing birds due to the lack of soil. Double Rock is an exposed rock north-west of Boxen. Big Black Reef (0.54ha) is a small, triangular, flat, dolerite islet with no burrowing habitat. The vegetation is set on dolerite pebbles and rocks (Brothers et al. 2001).
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that meets the thresholds for at least one criterion described in the Global Standard for the Identification of KBAs.
Additional biodiversity: At least 21 species of bird have been recorded at Boxen Island and Big Black Reef. Notable amongst the species that breed in the IBA are moderate numbers of Little Penguin (975 pairs on Boxen Island and one pair on Big Black Reef) and small numbers of Pacific Gull (four pairs on Boxen Island and one pair on Big Black Reef) and Sooty Oystercatcher (six pairs on Boxen Island and three pairs on Big Black Reef) (Brothers et al. 2001). Non-bird biodiversity: Boxen Island vegetation is dominated by Poa poriformis inland and Aizoaceae succulents on the coast. The Metallic Skink was recorded on Boxen Island. Big Black Reef is dominated by Tetragonia sp. and Bulbine semibarbata with a patch of Atriplex cinerea at the western end. No mammals or reptiles were recorded on the islet (Brothers et al. 2001).
Other site values: Boxen Island and Big Black Reef are both unallocated Crown Land managed by the Tasmanian Department of Primary Industries and Water. Permission should be sought from the Dept of Primary Industries & Water.
Habitats
Land use: not utilised (100%)
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Marine Coastal/Supratidal | 31 | |
| Shrubland | 6 | |
| Grassland | 63 |
Threats
Summary of threats to biodiversity at KBA: Investigate the impact of human access including fishing nets (gill nets) and introduction of invasive alien species.
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Biological resource use | Fishing & harvesting aquatic resources | Unintentional effects: large scale (species being assessed is not the target) [harvest] | Ongoing |
| Human intrusions & disturbance | Recreational activities | Ongoing |
Additional information
References: Brothers, N., Pemberton, D., Pryor, H. & Halley, V. (2001) Tasmania's Offshore Islands: seabirds and other natural features. Tasmanian Museum and Art Gallery: Hobart.
Contributors: The nomination was prepared by Birds Australia and Rachael Alderman and Rosemary Gales of DPIW kindly commented on the nomination.