AQUADYNAMIC SOLUTIONS SDN BHD – FINAL REPORT Aquadynamic Solutions Effects of Pen Waste Capture Systems on Oxygen Consumption in Macquarie Harbour, Tasmania. Final Report Tassal Group LTD P a g e | 1 Waste Capture System Effects on Oxygen Demand – Tassal Group LTD 1 CONTENTS 2 Table of figures ..................................................................................................................................... 3 3 Executive Summary ............................................................................................................................... 5 4 Introduction .......................................................................................................................................... 9 4.1 Oxygen Demand and Waste Capture Systems.............................................................................. 9 4.2 Overall Study Objectives ............................................................................................................. 11 5 Approach and Methodology ............................................................................................................... 12 5.1 Characteristics and Volume of Waste Captured ......................................................................... 12 5.2 Pelagic Oxygen Demand Associated with Waste Capture Systems ............................................ 12 5.2.1 Approach and Design POD .................................................................................................. 12 5.2.2 POD Field Collection and Incubation .................................................................................. 14 5.3 Benthic Oxygen Demand Associated with Waste Capture Systems ........................................... 15 5.3.1 Approach and Design BnOD ................................................................................................ 15 5.3.2 BnOD Field Collection and Incubation ................................................................................ 17 6 RESULTS............................................................................................................................................... 19 7 DISCUSSION ......................................................................................................................................... 23 7.1 Pelagic Demand........................................................................................................................... 23 7.2 Benthic Demand .......................................................................................................................... 24 8 CONCLUSIONS ..................................................................................................................................... 31 9 REFERENCES ........................................................................................................................................ 34 10 Appendix - A .................................................................................................................................... 36 10.1 Physical parameters .................................................................................................................... 36 10.1.1 Temperature ....................................................................................................................... 36 10.1.2 Dissolved Oxygen Saturation .............................................................................................. 40 10.1.3 Salinity ................................................................................................................................. 44 10.1.4 Gordon River Flow .............................................................................................................. 48 10.1.5 Rainfall ................................................................................................................................ 48 10.2 Chemical Parameters .................................................................................................................. 49 10.2.1 Dissolved Organic Carbon (DOC) ......................................................................................... 49 10.2.2 Total Organic Carbon (TOC) ................................................................................................ 52 10.2.3 Total Suspended Solid (TSS) ................................................................................................ 54 P a g e | 2 AQUADYNAMIC SOLUTIONS SDN BHD – FINAL REPORT 2 TABLE OF FIGURES Figure 1 - Total number of days each cage had waste capture liners installed on both the Gordon (MF219) and Middle Harbour (MF214) Leases. .......................................................................................... 10 Figure 2 - Pelagic Oxygen Demand Sampling Sites collected from June to November 2017. .................... 13 Figure 3 - Benthic Oxygen Demand Sampling Sites Collected in February and March 2018...................... 16 Figure 4 - Sampling design for time series study around Tassal Lease MF 219. Circles represent fish cage positions on Lease MF 219 (from ADS 2018). ............................................................................................. 17 Figure 5 - Moisture Content of captured solids from Nov 2017 to April 2018. Red solid line indicates mean moisture content (61.7%) and dashed lines indicate 1 SE. ............................................................... 19 Figure 6 - BOD5 vs TSS of raw farm waste collected from waste capture cages on Tassal Leases. ........... 20 Figure 7 - % Organic Matter of captured solids from Nov 2017 to April 2018. Red solid line indicates mean % organic matter (55.1%) and dashed lines indicate 1 SE. ............................................................... 20 th th Figure 8 -Organic Carbon % of captured solids from Nov 11 2017 to November 29 , 2017. .................. 21 Figure 9 - Pelagic Oxygen Demand with depth under Gordon Lease Cages associated with waste capture liners. Left column represents POD during waste collection activities and POD during non-waste collection periods. Right column represents POD under cages with Waste Capture Systems and those without Waste Capture Systems. ............................................................................................................... 22 -2 -1 -2 -1 Figure 10 - Benthic oxygen consumption (as both mg O2 m h and µmol m h ) at various cages on lease MF219. Cages are ordered based on installation date of waste capture systems (WCS). The solid -2 -1 red line indicates the mean O2 consumption of all cages (596.626 µmol m h ) with 1 SE (37.904) indicated by red dashed lines. .................................................................................................................... 25 Figure 11 – From MHDOWG 2014 Figure 3.6 “Rates of oxygen consumption at harbour and farm scales (2 cages at each farm) in November 2012. Note that the second of the Farm 2 (MF219 Gordon Lease)) sites was fallowed during the survey.” Red dotted line indicates the mean oxygen consumption rate recorded at control sites and the solid line represents mean rates under cage sites during the February 2018 survey. ................................................................................................................................................ 25 Figure 12 - Benthic Oxygen Demand along the Gordon River Transect (incubated in March 2018) and Central Harbour Control Sites (incubated February 2018). Green line represents the mean Benthic Oxygen Demand along the Gordon River Transect (dashed lines 1 SE). .................................................... 29 Figure 13 - Cumulative volume of Macquarie Harbour with depth. ........................................................... 30 Figure 14 3 hours moving average temperature from Sept 2017 to April 2018 collected by Sense T at Franklin. ...................................................................................................................................................... 36 Figure 15 3 hours moving average temperature from Sept 2017 to April 2018 collected by Sense T at Table Head Central. ..................................................................................................................................... 37 Figure 16 3 hours moving average temperature from Sept 2017 to April 2018 collected by Sense T at Strahan. ....................................................................................................................................................... 37 Figure 17 (a), (b), (c) and (d) Monthly temperature collected every meter depth at sampling sites from Sept 2017 to April 2018. ............................................................................................................................. 39 Figure 18 3 hours moving average DO saturation from Sept 2017 to April 2018 collected by Sense T at Franklin. ...................................................................................................................................................... 40 Figure 19 3 hours moving average DO saturation from Sept 2017 to April 2018 collected by Sense T at Table Head Central. ..................................................................................................................................... 41 P a g e | 3 Waste Capture System Effects on Oxygen Demand – Tassal Group LTD Figure 20 3 hours moving average DO saturation from Sept 2017 to April 2018 collected by Sense T at Strahan. ......................................................................................................................................................