Benthic flora and fauna of the Patea Shoals region, South Taranaki Bight Prepared for Trans-Tasman Resources Ltd October 2013 (Updated November 2015) Authors/Contributors: J. Beaumont, T.J. Anderson, A.B. MacDiarmid For any information regarding this report please contact: Tara J. Anderson NIWA Nelson +64-3-545 7746 National Institute of Water & Atmospheric Research Ltd 301 Evans Bay Parade, Greta Point Wellington 6021 Private Bag 14901, Kilbirnie Wellington 6241 New Zealand Phone +64-4-386 0300 Fax +64-4-386 0574 NIWA Client Report No: WLG2012-55 Report date: October 2013 NIWA Project: TTR11301 © All rights reserved. This publication may not be reproduced or copied in any form without the permission of the copyright owner(s). Such permission is only to be given in accordance with the terms of the client’s contract with NIWA. This copyright extends to all forms of copying and any storage of material in any kind of information retrieval system. Whilst NIWA has used all reasonable endeavours to ensure that the information contained in this document is accurate, NIWA does not give any express or implied warranty as to the completeness of the information contained herein, or that it will be suitable for any purpose(s) other than those specifically contemplated during the Project or agreed by NIWA and the Client. 30 November 2015 12.33 p.m. Contents Executive summary ............................................................................................................. 9 1 Introduction ............................................................................................................ 12 1.1 Background ............................................................................................................. 12 1.1.1 Iron ore and seabed extraction ............................................................... 12 1.2 Previous research on the benthic fauna of the South Taranaki Bight .................... 13 1.3 NIWA’s brief ............................................................................................................ 13 2 Methods .................................................................................................................. 13 2.1 Study site ................................................................................................................ 13 2.2 Survey Design .......................................................................................................... 14 2.3 Sampling Methods .................................................................................................. 17 2.3.1 Coastcam observations ........................................................................... 17 2.3.2 Sediment and Infaunal Sampling ............................................................. 19 2.3.3 Epibenthic sampling ................................................................................ 22 2.4 Data analysis ........................................................................................................... 24 2.4.1 Distribution plots ..................................................................................... 24 2.4.2 Multivariate analyses .............................................................................. 24 3 Results .................................................................................................................... 25 3.1 Coastcam observations ........................................................................................... 25 3.1.1 Benthic habitat and assemblages ............................................................ 25 3.1.2 Multivariate analysis: Coastcam2 data ................................................... 33 3.2 Dredge assemblages ............................................................................................... 39 3.2.1 Dredge assemblage structure ................................................................. 39 3.2.2 Distribution of taxonomic groups: Dredge data ...................................... 44 3.2.3 Multivariate analysis: Dredge data.......................................................... 57 3.3 Sediment core data ................................................................................................. 62 3.3.1 Sediment characteristics ......................................................................... 63 3.3.2 Infaunal assemblage structure ................................................................ 66 3.3.3 Infaunal distributions - Macrofaunal in the 0-5 cm core fraction ........... 70 3.3.4 Multivariate analysis of macro faunal data: 0-5 cm core fraction .......... 81 3.3.5 Distribution plots of macro faunal data: 5–10 cm core fraction ............. 86 3.3.6 Multivariate analysis of macro faunal data: 5 – 10 cm core fraction ...... 88 3.3.7 Macrofaunal data: 10–15 cm core fraction ............................................. 89 3.3.8 Meiofauna ............................................................................................... 89 3.3.9 Multivariate analysis: Meiofauna ............................................................ 94 4 Recolonisation experiment ...................................................................................... 98 Benthic flora and fauna of the Patea Shoals region, South Taranaki Bight 4.1 Introduction ............................................................................................................ 98 4.1.1 Pilot studies ............................................................................................. 99 4.1.2 This study ............................................................................................... 101 4.2 Methods ................................................................................................................ 101 4.2.1 Study sites ............................................................................................. 101 4.2.2 Sampling ................................................................................................ 105 4.2.3 Sample processing ................................................................................. 105 4.2.4 Data analyses ......................................................................................... 106 4.3 Results ................................................................................................................... 106 4.3.1 Environmental data/predictor variables ............................................... 108 4.3.2 Multivariate analysis ............................................................................. 110 4.4 Discussion ............................................................................................................. 116 5 Overall Discussion .................................................................................................. 117 6 Conclusions ........................................................................................................... 120 7 Acknowledgements ............................................................................................... 122 8 References ............................................................................................................. 123 Appendix A Revised multivariate analyses (Feb 2014). ................................................ 127 Appendix B Summary of physical and biological sampling ........................................... 144 Appendix C GRADISTAT size scale ............................................................................... 152 Appendix D Functional groups for Coastcam2 analysis ................................................ 153 Appendix E Bryozoa species list .................................................................................. 154 Appendix F Mollusca species list ................................................................................ 163 Appendix G Annelida and other worm-like phyla species list ....................................... 168 Appendix H Decapod species list ................................................................................. 173 Appendix I Porifera (sponge) species list .................................................................... 175 Appendix J Ascidia species list ................................................................................... 177 Appendix K Echinoderm species list ............................................................................ 178 Appendix L Fish species list ........................................................................................ 180 Appendix M Non-decapod crustacean species/family list ............................................. 181 Appendix N Algae species list...................................................................................... 184 Appendix O Cnidaria species list ................................................................................. 186 Appendix P Additional taxa: species list ...................................................................... 187 Appendix Q Distribution plots of phyla in 5-10 cm core fraction ................................... 188 Appendix R Lyall Bay trials ......................................................................................... 190 Appendix S Taranaki Trials ......................................................................................... 191 Appendix T SIMPER results ........................................................................................ 192 Tables Table 1: Temporal summary of the sites surveyed by gear type within the STB between