Ninth and Little Waterhouse Islands


Site description (2008 baseline):

Site location and context
This IBA consists of two neighbouring islands in Bass Strait off Bridport, northern Tasmania. Ninth Island is north-west of Bridport and Little Waterhouse Island is about 30 km to the north-east, with a few rocks and reefs between. This IBA excludes many other islands in the 200 km stretch of the Waterhouse Group as these have significantly lower numbers of nesting seabirds, collectively totalling 21,700 pairs of Short-tailed Shearwater, 5300 pairs of White-faced Storm-Petrel, 159 pairs of Black-faced Cormorant and 42 pairs of Pacific Gull. The nearest neighbouring island, Waterhouse Island, has been heavily grazed by sheep and supports few seabirds. Ninth Island (32 ha) has adequate soil for burrowing seabirds, under a substantial layer of fireweed. There is private land, a hut and permanent fresh water on Ninth Island. Little Waterhouse Island (2.5 ha) has little soil and no burrowing habitat.

Key biodiversity
The 15 species recorded on Ninth include 14,312 pairs of White-faced Storm-Petrel, 10-15,000 pairs of Common Diving-Petrel, 3913 pairs of Little Penguin, 97,000 pairs of Short-tailed Shearwater, 1800 pairs of Crested Tern, 12 pairs of Sooty Oystercatcher, Brown Quail, at least 10 pairs of Cape Barren Geese and a pair of Caspian Tern. Little Waterhouse is a roosting site for Australian Pelican, and if it remained undisturbed, it would almost certainly act as an occasional alternative breeding location for this species (W.Wakefield pers. comm. in Parks & Wildlife 2001).

Non-bird biodiversity: Southern Grass Skink occurs on Ninth Island, where the dominant vegetation is Senecio lautus, and rabbits roam in small numbers. Poa poiformis, Rhagodia candolleana and Disphyma crassifolium are the dominant plants at Little Waterhouse Island.



Pressure/threats to key biodiversity
The impacts of human visitation should be assessed. Visitors should be made aware of the seabird conservation value and threats to these islands. The sustainability of the muttonbird harvest should be assessed.

Conservation responses/actions for key biodiversity
Ninth Island has been adversely affected by grazing and frequent fires in the past. In the aftermath of the 1995 Iron Baron oil spill, which killed more than 2000 Little Penguin, DPIW and others continue to monitor the island. As a Conservation Area readily accessed by fishermen, Ninth Island should have its status upgraded to Nature Reserve, to properly protect its large and varied populations of breeding seabirds.

Protected areas
Little Waterhouse Island Nature Reserve.

Land ownership
Some of Ninth Island is privately owned. The remainder of Ninth Island and all of Little Waterhouse Island is Crown Land.

Site access / Land-owner requests
Permission to visit should be obtained from DPIW.

Acknowledgements
The nomination was prepared by Peter Britton. Rachael Alderman and Rosemary Gales of DPIW kindly commented on the nomination.


Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Ninth and Little Waterhouse Islands (Australia). Downloaded from https://datazone.birdlife.org/site/factsheet/ninth-and-little-waterhouse-islands-iba-australia on 22/11/2024.