TRUMPETER BAY MF261 - Block SB2: BASELINE ENVIRONMENTAL ASSESSMENT DRAFT FINAL REPORT (VERSION 2.0) March 2019 Report to: Huon Aquaculture Group Pty Ltd Prepared by: AQUENAL PTY LTD AQUENAL www.aquenal.com.au MF261 BLS SB2 March 2019 Document Distribution Document Date Name Company Version Copies Type Huon Aquaculture 8 March 2019 Adam Smark Electronic 1.0 1 Group Pty Ltd 8 March 2019 Mark Churchill EPA Electronic 1.0 1 Huon Aquaculture 18 March 2019 Adam Smark Electronic 2.0 1 Group Pty Ltd 18 March 2019 Mark Churchill EPA Electronic 2.0 1 COPYRIGHT: The concepts and information contained in this document are the property of Aquenal Pty Ltd. Use or copying of this document in whole or in part without the written permission of Aquenal Pty Ltd constitutes an infringement of copyright. DISCLAIMER: This report has been prepared on behalf of and for the exclusive use of Aquenal Pty Ltd’s client and is subject to and issued in connection with the provisions of the agreement between Aquenal Pty Ltd and its Client. Aquenal Pty Ltd accepts no liability or responsibility whatsoever for or in respect of any use of or reliance upon this report by any third party. MF261 BLS SB2 March 2019 Contents 1 Summary ................................................................................................................................................................... 6 2 Operational Summary ............................................................................................................................................... 9 3 Location and Survey Maps ...................................................................................................................................... 10 4 Current Measurements ........................................................................................................................................... 11 5 Bathymetric Profile ................................................................................................................................................. 15 6 Seabed Characteristics and habitat profile ............................................................................................................. 16 7 Underwater Video Survey ....................................................................................................................................... 17 7.1 Filming summary ............................................................................................................................................. 17 7.2 Observations from filming ............................................................................................................................... 17 8 Sediment Chemistry ................................................................................................................................................ 25 8.1 Visual Assessment ........................................................................................................................................... 25 8.2 Redox Potential ............................................................................................................................................... 30 8.3 Sulphide Analysis ............................................................................................................................................. 30 8.4 Particle Size Analysis ....................................................................................................................................... 31 8.5 Organic Content .............................................................................................................................................. 33 8.6 Heavy Metal Analysis ...................................................................................................................................... 33 9 Gazameda gunnii survey ......................................................................................................................................... 36 10 Biological Analysis - Benthic Fauna ......................................................................................................................... 38 11 Inshore Reef Surveys ............................................................................................................................................... 42 12 Deep Reef Surveys................................................................................................................................................... 48 13 References ............................................................................................................................................................... 51 List of Figures Figure 1 Location and Survey Map – MF261 – SB2, Trumpeter Bay. Sites 1.1 – 10.1 indicate the 35 m compliance triplicates, c2n – c6 indicate control triplicates; IF1-IF10 indicate internal sites. Red line = zone boundary; black rectangle = amended SB2 lease boundary; dashed black rectangle = old SB2 lease boundary. Survey coordinates are included in Appendix 1 and Appendix 2. ........................................................................................................... 10 Figure 2 Polar plots of current velocity and direction, T2 (May – June 2014). The plots are read as if the current flow moves from the outer circle towards the centre of the graph. .............................................................................. 13 Figure 3 Polar plots of current velocity and direction, T4 (May – June 2014). The plots are read as if the current flow moves from the outer circle towards the centre of the graph. .............................................................................. 14 Figure 4 Bathymetric profile for MF261 – SB2. Green line indicates the lease boundary. ............................................... 15 Figure 5 Survey habitat map. Red outline – Zone boundary; black rectangle – Amended lease or block boundary for MF261 – SB2............................................................................................................................................................ 16 Figure 6 Redox potential at 30 mm depth in sediment cores. ......................................................................................... 30 Figure 7 Sulphide concentrations in sediment core samples. .......................................................................................... 31 Figure 8 Particle size analyses of the top 100 mm of sediment. Lines represent mean percentage cumulative volume for size fractions at each site, based on pooled replicates for compliance and control sites (n=3). For internal farm sites, lines represent cumulative volume based on a single sample from each site. ..................................... 32 Figure 9 Organic content in sediment core samples ........................................................................................................ 33 Figure 10 Location of grab samples taken during Gazameda gunnii survey for MF261 - Block SB2, highlighting the sample sites where dead shells were collected (10, 19, 28, 30, 32, 37 and 38). Note that sites G1-G30 were sampled in July 2015, while G31-G38 were sampled in January 2019. .................................................................. 36 MF261 BLS SB2 March 2019 Figure 11 Photograph of dead G. gunnii shells collected during the survey of MF261-Block SB2, from 2015 (a) and 2019 (b) surveys. .............................................................................................................................................................. 37 Figure 12 Results of MDS analysis using benthic infauna data collected from three replicate grabs at each compliance and control site for MF261 – SB2. Green ellipses indicate community similarity at the level of 50%, based on cluster analysis. ....................................................................................................................................................... 39 Figure 13 Benthic faunal analysis of seabed samples – MF261 – SB2. K – dominance curves. Analysis based on pooled triplicate data for compliance and control sites and single samples taken at internal farm sites. ......................... 41 Figure 14 Survey map showing locations of Edgar-Barrett (R1-R3) and deep reef (R4a-R4b) survey locations. Black rectangle – Amended lease or block boundary for MF261 – SB2. .......................................................................... 43 Figure 15. Representative habitats along deep reef survey transect. .............................................................................. 48 List of Tables Table 1 Summarised current and velocity data for Trumpeter T2 (May 2014) and T4 (March 2014). ............................. 12 Table 2 Descriptions of dives performed at MF261 – Block SB2. ..................................................................................... 17 Table 3 Description of each ROV dive performed at Trumpeter Bay MF261 – Block SB2. Video analysis and interpretation provided by Huon Aquaculture. ...................................................................................................... 21 Table 4 Visual description of sediment cores at MF261 – Block SB2. .............................................................................. 26 Table 5 Results of heavy metal analysis of sediment samples and the ANZECC 2000 trigger values. .............................. 35 Table 6 Summary of benthic faunal analysis. The category ‘other’ included anthozoans,