PART A – Freshwater catfish survey of Tahbilk Lagoon, including management recommendations Pam Clunie, Fern Hames, John McKenzie and Graeme Hackett, ARI 2008 Arthur Rylah Institute for Environmental Research Report for the Goulburn Broken Catchment Management Authority Arthur Rylah Institute for Environmental Research Technical Series PART A – Freshwater catfish survey of Tahbilk Lagoon, including management recommendations Pam Clunie, Fern Hames, John McKenzie and Graeme Hackett Arthur Rylah Institute for Environmental Research 123 Brown Street, Heidelberg, Victoria 3084 August 2008 In partnership with: Arthur Rylah Institute for Environmental Research Department of Sustainability and Environment Heidelberg, Victoria Report produced by: Arthur Rylah Institute for Environmental Research Department of Sustainability and Environment PO Box 137 Heidelberg, Victoria 3084 Phone (03) 9450 8600 Website: www.dse.vic.gov.au/ari © State of Victoria, Department of Sustainability and Environment 2008 This publication is copyright. Apart from fair dealing for the purposes of private study, research, criticism or review as permitted under the Copyright Act 1968 , no part may be reproduced, copied, transmitted in any form or by any means (electronic, mechanical or graphic) without the prior written permission of the State of Victoria, Department of Sustainability and Environment. All requests and enquires should be directed to the Customer Service Centre, 136 186 or email [email protected] Citation: Clunie, P., Hames, F., McKenzie, J. and Hackett, G. (2008) PART A - Freshwater catfish survey of Tahbilk Lagoon, including management recommendations. Arthur Rylah Institute for Environmental Research Technical Report Series. Department of Sustainability and Environment, Heidelberg, Victoria Disclaimer: This publication may be of assistance to you but the State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication. Front cover photo: Tahbilk Lagoon (Fern Hames). Authorised by: Victorian Government, Melbourne Part A - Freshwater catfish survey of Tahbilk Lagoon and management recommendations Contents Acknowledgements ........................................................................................................................................3 Summary ...........................................................................................................................................................4 Introduction......................................................................................................................................................6 1.1 Background...................................................................................................................................... 6 1.2 Tahbilk Lagoon ............................................................................................................................... 6 1.3 Key Stakeholders and Managers ................................................................................................. 9 1.4 Key Management Issues..............................................................................................................10 1.4.1 Threatened Flora and Fauna............................................................................................. 10 1.4.2 Aquatic Fauna ...................................................................................................................... 10 1.4.3 Freshwater Catfish.............................................................................................................. 13 1.4.2 Water Management ............................................................................................................. 15 1.4.4 Fish Passage ......................................................................................................................... 16 1.4.5 Aquatic Weeds ..................................................................................................................... 18 1.4.7 Land Management............................................................................................................... 18 2 Methods ..................................................................................................................................................19 2.1 Study Area .....................................................................................................................................19 2.2 Fish Surveys...................................................................................................................................19 2.3 Water Quality ................................................................................................................................19 3 Results.....................................................................................................................................................21 3.1 Fish Surveys...................................................................................................................................21 3.2 Water Quality ................................................................................................................................26 3.3 Habitat descriptions ...........................................................................................................................26 4 Discussion..............................................................................................................................................27 4.1 Fish Community ...........................................................................................................................27 4.1.1 Freshwater Catfish.............................................................................................................. 27 4.1.2 Murray-Darling rainbowfish ............................................................................................. 29 4.1.3 Introduced Fish ................................................................................................................... 29 4.2 Watershield....................................................................................................................................32 4.3 Water Management ......................................................................................................................32 4.4 Fish Passage...................................................................................................................................33 4.5 Aquatic Weeds ..............................................................................................................................33 5 Conclusions and Recommendations...............................................................................................35 References.......................................................................................................................................................41 Appendix 1 – DSE Wetland Categories within Tahbilk Lagoon........................................................43 Appendix 2 – Land Tenure around Tahbilk Lagoon (G-MW map)....................................................44 Appendix 3 – Ecological Vegetation Classes in the vicinity of Tahbilk Lagoon .........................45 Appendix 4 – Floodways in the vicinity of Tahbilk Lagoon.............................................................46 Appendix 5 – Habitat descriptions and photos for fyke net sites ..................................................47 Arthur Rylah Institute for Environmental Research, DSE 2 Part A - Freshwater catfish survey of Tahbilk Lagoon and management recommendations Acknowledgements Simon Casanelia and Wayne Tennant of the Goulburn Broken Catchment Management Authority provided funding support for this project and background information on road crossings at Tahbilk. Bob McMaster and Alister Purbick, of Tahbilk Winery initiated the project by seeking advice on management of the site with respect to Freshwater catfish, fish passage and carp. Bob has been generous with his time, endless in his enthusiasm for enhancing the ecological values at Tahbilk, and has provided much background information. Tahbilk Winery has also supported this survey by facilitating access. Erin Simpson of Goulburn-Murray Water has provided information on the G-MW draft Tahbilk Management Plan, site tenure, water delivery and weed control. Mike Braysher, Ivor Stuart and Jason Higham represent the MDBC Carp Management Plan for Tahbilk and have provided welcome and insightful advice on fish passage. Arthur Rylah Institute for Environmental Research, DSE 3 Part A - Freshwater catfish survey of Tahbilk Lagoon and management recommendations Summary Tahbilk Lagoon is a significant site, with a suite of recognised values, in particular the presence of the threatened Freshwater catfish Tandanus tandanus , the Watershield Brasenia schreberi , threatened Ecological Vegetation Classes (EVCs) and wetlands. The Goulburn-Broken Catchment Management Authority (GBCMA) provided funding in February 2008 for Freshwater Ecology, Arthur Rylah Institute for Environmental Research, to conduct fish surveys primarily designed to assess the status of a known population of Freshwater catfish. The GBCMA also sought guidance regarding appropriate management recommendations