Rodondo Island
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BIODIVERSITY & OIL SPILL RESPONSE SURVEY January 2015 NATURE CONSERVATION REPORT SERIES 15/04 RODONDO ISLAND BASS STRAIT NATURAL AND CULTURAL HERITAGE DIVISION DEPARTMENT OF PRIMARY INDUSTRIES, PARKS, WATER AND ENVIRONMENT RODONDO ISLAND – Oil Spill & Biodiversity Survey, January 2015 RODONDO ISLAND BASS STRAIT Biodiversity & Oil Spill Response Survey, January 2015 NATURE CONSERVATION REPORT SERIES 15/04 Natural and Cultural Heritage Division, DPIPWE, Tasmania. © Department of Primary Industries, Parks, Water and Environment ISBN: 978-1-74380-006-5 (Electronic publication only) ISSN: 1838-7403 Cite as: Carlyon, K., Visoiu, M., Hawkins, C., Richards, K. and Alderman, R. (2015) Rodondo Island, Bass Strait: Biodiversity & Oil Spill Response Survey, January 2015. Natural and Cultural Heritage Division, DPIPWE, Hobart. Nature Conservation Report Series 15/04. Main cover photo: Micah Visoiu Inside cover: Clare Hawkins Unless otherwise credited, the copyright of all images remains with the Department of Primary Industries, Parks, Water and Environment. This work is copyright. It may be reproduced for study, research or training purposes subject to an acknowledgement of the source and no commercial use or sale. Requests and enquiries concerning reproduction and rights should be addressed to the Branch Manager, Wildlife Management Branch, DPIPWE. Page | 2 RODONDO ISLAND – Oil Spill & Biodiversity Survey, January 2015 SUMMARY Rodondo Island was surveyed in January 2015 by staff from the Natural and Cultural Heritage Division of the Department of Primary Industries, Parks, Water and Environment (DPIPWE) to evaluate potential response and mitigation options should an oil spill occur in the region that had the potential to impact on the island’s natural values. Spatial information relevant to species that may be vulnerable in the event of an oil spill in the area has been added to the Australian Maritime Safety Authority’s Oil Spill Response Atlas and all species records added to the DPIPWE Natural Values Atlas. Beyond those species vulnerable to oil spill impacts, surveys included a broad assessment of the island’s biodiversity values, as this remote island had not been comprehensively surveyed for over 25 years. The survey confirmed that undertaking an effective response to oiled wildlife on Rodondo Island would be challenging, due to the island’s topography, the isolation of the area and strong local tidal currents and exposure to large oceanic swell. The logistics involved are described. Such a response would likely involve the Tasmanian DPIPWE and EPA, and primarily constitute a vessel-based effort, monitoring impacted coastline and significant seal and seabird colonies. Tidal River or Port Welshpool (Vic) might potentially be used as a staging area. The broader biodiversity survey identified a huge variety of bird, reptile, invertebrate and plant species, of which a number had not been previously recorded on Rodondo, and several had not been recorded in Tasmania. The vegetation is described and mapped. The survey also provided an opportunity to observe breeding activity by Australasian gannets on Bass Pyramid – a first confirmed record for this location. Page | 3 RODONDO ISLAND – Oil Spill & Biodiversity Survey, January 2015 CONTENTS Summary ....................................................................................................................................................................... 3 Introduction ................................................................................................................................................................. 5 Expedition description ............................................................................................................................................... 8 Survey Methods ......................................................................................................................................................... 12 Birds ........................................................................................................................................................................ 12 Mammals ................................................................................................................................................................. 12 Lizards ..................................................................................................................................................................... 13 Invertebrates ......................................................................................................................................................... 14 Flora ........................................................................................................................................................................ 15 Results and Discussion ............................................................................................................................................ 16 Birds ........................................................................................................................................................................ 16 Terrestrial mammals............................................................................................................................................ 20 Marine mammals................................................................................................................................................... 21 Reptiles ................................................................................................................................................................... 22 Invertebrates ......................................................................................................................................................... 28 Flora ........................................................................................................................................................................ 32 Oil Spill Risk .......................................................................................................................................................... 40 Bass Pyramid .......................................................................................................................................................... 42 Logistics ....................................................................................................................................................................... 44 Environmental Conditions ................................................................................................................................. 44 Access and staging................................................................................................................................................ 44 Communications .................................................................................................................................................. 45 Accommodation ................................................................................................................................................... 46 Oiled wildlife ......................................................................................................................................................... 46 Rodondo Island summary ................................................................................................................................... 49 Acknowledgements .................................................................................................................................................. 50 References .................................................................................................................................................................. 51 Page | 4 RODONDO ISLAND – Oil Spill & Biodiversity Survey, January 2015 INTRODUCTION Rodondo Island, just 10 km south of Victoria’s Wilsons Promontory in north-east Bass Strait, yet within the northern limits of Tasmanian jurisdiction (see Fig. 1), is considered to be of outstanding state significance. A Tasmanian Nature Reserve, this island has escaped both fire and human disturbance, resulting in a unique flora and fauna assemblage that is unlike that on neighbouring islands or the nearby ‘Prom’. It is one of 12 small Bass Strait island reserves covered by the Bass Strait Island Nature Reserves - Draft Management Plan, October 2000 (PWS, 2000), where it is listed as significant due to the absence of fire, and because it supports climax blue gum (Eucalyptus globulus) and giant honeymyrtle (Melaleuca armillaris) communities, which are considered extremely rare. It is situated just 3.8 km from the southern boundary of Victoria’s Wilsons Promontory Marine National Park. The island is an impressive conical mass of granite, just over one kilometre at its widest point and rising to over 350 m at the central summit (summit coordinates: 44702 E, 5657410 N). It is ringed by steep cliffs varying from 70 to 200 m in height. Rodondo and nearby Curtis Island were isolated about 14,000 years B.P., following the sea level rise that succeeded the last ice age. This is longer than the Tasmania-Victoria separation (~12,750 B.P.) and the Furneaux-Tasmania separation (~10,000 B.P.) (Rawlinson 1973), meaning these islands are surrounded by the deepest water in Bass Strait (73 m deep; Jennings, 1959). The island is in close proximity to the busiest commercial shipping lanes in Tasmanian