Manning River Helmeted Turtle 2019 Autumn Survey Report Ecology I Environment I Heritage Citation: Redleaf Environmental (2019) Manning River Helmeted Turtle 2019 Autumn Survey Report. Prepared for the NSW Office of Environment and Heritage. Contact Details Dr Darren Fielder B.App.Sci, PhD M 0407 234 986 F 07 4659 5839 E [email protected] Mrs Sarah Grady M 0417 602 693 F 07 4659 5839 E [email protected] A PO Box 3564 Toowoomba 4350 Cover Photo: Rowleys River, Strike-A-Light Station. Darren Fielder Redleaf Environmental © Red Leaf Projects Pty Ltd trading as Redleaf Environmental Apart from fair dealing for the purposes of private study, research, criticism, or review as permitted under the Copyright Act, no part of this report, its attachments or appendices may be reproduced by any process without the written consent of Redleaf Environmental. All enquiries should be directed to Redleaf Environmental. A person using Redleaf Environmental documents or data accepts the risk of: a) Using the documents or data in electronic form without requesting and checking them for accuracy against the original hard copy version. b) Using the documents or data for any purpose not agreed to in writing by Redleaf Environmental. www.Redleafenv.com.au Page | ii Ecology I Environment I Heritage DOCUMENT CONTROL Report title Manning River Helmeted Turtle 2019 Autumn Survey Report Document ID Project Number OEH19001 File Path NSW Office of Environment Client Client Contact Andrew Steed and Heritage Prepared Rev Date Revision Details/Status Verifier Approver by 1 26/04/2019 Draft report issued to OEH DF SG DF 2 3 Current Revision Final Report Approval Signature Signature Name Dr Darren Fielder Name Mrs Sarah Grady Senior Environmental Title Principal Scientist Title Scientist www.Redleafenv.com.au Page | iii Ecology I Environment I Heritage Contents Contents iv 1 Introduction 1 1.1 Background 1 1.2 Project objectives 2 2 Methods 5 3 Field assessment 6 3.1 Survey limitations 6 3.2 Snorkel surveys 6 3.3 Landholder Consent 8 4 Results 9 4.1 Overall results for 2018-2019 9 4.2 Catch per unit effort 10 4.3 Manning River Helmeted Turtle 10 5 Discussion 12 5.1 Turtle reproduction and population demographics 12 5.1.1 Recruitment 12 5.1.2 Sex ratios 12 5.1.3 Mating behaviour 12 5.2 Threatening processes 12 5.2.1 Nest predation 12 5.2.2 Eye cataracts 13 5.2.3 Habitat modification 13 5.2.4 Competition and hybridisation with Emydura macquarii 14 6 Conservation considerations 15 6.1 Future management actions 15 7 References 16 Appendix A – Site photos 18 Incidental records and photos 23 www.Redleafenv.com.au Page | iv Ecology I Environment I Heritage 1 Introduction 1.1 Background Redleaf Environmental was engaged by the NSW Office of Environment and Heritage to conduct a second season of surveys during March-April 2019 for the endangered Manning River Helmeted Turtle Myuchelys purvisi across sites in the Manning River Catchment (Table 1 and Figure 1). The first survey in April 2018 is reported separately (Redleaf Environmental 2018). However, both datasets are included here to provide a clearer understanding of the findings from across two seasons of data collection. Adult female, Cooplacurripa River Immature turtle, Rowleys River Table 1 Site location details Site Year Location River Latitude Longitude 1 2018 Rocks Crossing TSR Nowendoc - 31.7612581 152.0746012 2 2018 Dalrae Station, 5077 Nowendoc Road, Upper Nowendoc - Nowendoc 31.6964033 151.9630584 3 2018 Cooplacurripa Station Lower TSR Cooplacurripa - 31.6228902 151.9468186 4 2018 Mummel River Yard Creek Crown Land Mummel - 31.5177815 151.9188222 5 2018 Rowleys River, 4802 Cells Road, Cells River Rowleys - 31.6495959 152.0605029 6 2018 Cooplacurripa Station, Nowendoc Road Upper Cooplacurripa - TSR 31.6043379 151.8929738 7a 2018 Dalrae Station, 5077 Nowendoc Road, Lower Nowendoc Nowendoc -31.699116 151.9895817 8 2018 Obergs Trail Barakee National Park Nowendoc - 31.6631927 151.8923409 9 2018 Nowendoc TSR North, Nowendoc Township Nowendoc - 31.5092892 151.7046865 10 2018 Carabeen Creek Management Trail, Mummel Mummel - Gulf National Park 31.4274119 151.876412 www.Redleafenv.com.au Page | 1 Ecology I Environment I Heritage Site Year Location River Latitude Longitude 11 2019 Top Station 12 km east of Nowendoc Cooplacurripa -31.494886 151.811267 12 2019 Cooplacurripa Station on Mummel Mummel -31.533029 151.924824 13 2019 Cooplacurripa Station on Mummel Mummel -31.532394 151.924375 14 2019 Cooplacurripa Station on Mummel Mummel -31.530164 151.922087 15 2019 Cooplacurripa Station on Mummel Mummel -31.538683 151.930723 16 2019 Cooplacurripa Station, 1.7 km SW of the Cooplacurripa -31.620943 151.910175 homestead 17 2019 Cooplacurripa Station, 1.7 km SW of the Cooplacurripa -31.623829 151.910843 homestead 18 2019 Cooplacurripa Station, 1.7 km SW of the Cooplacurripa -31.616711 151.916009 homestead 19 2019 Strike A Light Station, at the pump hole Rowleys -31.591396 152.047116 20 2019 Strike A Light Station, downstream from the Rowleys -31.596236 152.050387 pump hole 21 2019 Strike A Light Station, downstream from the Rowleys -31.598184 152.050607 pump hole 22 2019 Terranbella Station, at the homestead Rowleys -31.553014 152.065233 23 2019 Strike A Light Station, at the norther property Rowleys -31.577712 152.053312 boundary. 24 2019 Les McKensie, big waterhole Bobin Creek -31.672922 152.262506 25 2019 Les McKensie, campground Bobin Creek -31.676915 152.262489 26 2019 Les McKensie, downstream Bobin Creek -31.679686 152.264692 27 2019 Les McKensie, upstream waterhole Bobin Creek -31.674775 152.248673 28 2019 Dingo Bend Dingo Creek -31.737224 152.300521 29 2019 Peter Fotheringham Station Mummel -31.566489 151.951919 30 2019 Terranbella Station, 1 km upstream from Rowleys -31.542625 152.064824 homestead 1.2 Project objectives The aim of this project is to assist the recovery of the Manning River Helmeted Turtle (Myuchelys purvisi), a species endemic to the Manning River system and listed as endangered under the NSW Biodiversity Conservation Act, 2016. It has been assigned to the Data-deficient stream of the Saving our Species program that is administered by the NSW Office of Environment and Heritage. The specific aims are: • Build a better understanding of the distribution of Myuchelys purvisi in the Manning valley • Build a better understanding of the distribution of Emydura macquarii in the Manning valley • Understand the extent, prevalence and severity of threat to Myuchelys purvisi • Provide the basis for the development of site-based management activities • Contribution to movement of this species from the data-deficient management stream. These objectives form part of a larger program to manage Myuchelys purvisi. Data collected as part of this scope will be used to inform a change in management streams and subsequent management and a monitoring actions. www.Redleafenv.com.au Page | 2 Ecology I Environment I Heritage To help achieve these aims, the project aimed to undertake trapping and hand capture of M. purvisi at numerous locations to determine the extent of its distribution, its population demographics and health and the threats to the species, in particular, the distribution and abundance of, and possible hybridisation with, the Macquarie turtle, Emydura macquarii, which is believed to have been introduced to the Manning River system. The results of these surveys will help to identify specific locations where targeted programs will be implemented to further assist the recovery of the M. purvisi. The surveys will provide the basis of an ongoing monitoring program where capture effort at selected locations will be replicated in subsequent years. The number of populations and population sizes are unknown. Available records, potential habitat and topography suggest that there are populations in at least five of the seven sub-catchments of the Manning River, however there has been a lack of targeted surveys in the more remote and inaccessible upper catchments so the habitat value of upper catchment areas is unknown as is the presence of this species in conservation reserves. Recently the abundance of M. purvisi appears to have declined dramatically (J. Cann pers. comm. April 2016). The total population size of M. purvisi is inferred to be moderately low. Terrestrial movements between river systems are unlikely. Thus, the distribution of M. purvisi is inferred to be severely fragmented (NSW Scientific Committee 2017). Myuchelys purvisi faces multiple threats including predation, illegal collecting, habitat degradation and, potentially, disease as well as competition and hybridisation with E. macquarii. Short-necked turtles are thought to be particularly vulnerable to fox predation because they are unable to fully retract their limbs and head (Spencer and Thompson 2005). Nest predation rates for M. purvisi are unknown. Recent detection of the nests of Bell’s Turtle (M. bellii) found a predation rate of nearly 90%, with 6 female turtles found preyed on near the entrance to a fox den (M. Dillon, Northern Tablelands Local Land Services, pers. comm. December 2017). www.Redleafenv.com.au Page | 3 Ecology I Environment I Heritage Figure 1: Location map of the Manning River Turtle survey sites. www.Redleafenv.com.au Page | 4 Ecology I Environment I Heritage 2 Methods The surveys were conducted under approved scientific and ethics approvals: • Fisheries Permit: P18/0011-1.0 (Fisheries Management Act 1994) • Scientific Licence: SL102062 (Biodiversity Conservation Act 2016) • Ethics approval: 180313/02 through OEH Animal Ethics Committee (2019) Redleaf’s ecologists used a combination of trapping and snorkelling across 20 locations in 2019 and 10 locations from 2018. The techniques used at each site were dependent upon the clarity of the water, suitability for fyke nets and accessibility to the aquatic environment. In some locations where water clarity was good, both trapping and snorkelling were undertaken to provide information on the detectability of M.