ENVIRONMENTAL LICENCE #9957 FOR GREEN HEAD PERMIT 18093
Final Broadscale Monitoring Report
24th April 2019
Report to
EPA TASMANIA/ HUON AQUACULTURE COMPANY PTY LTD
BY
AQUACULTURE, MANAGEMENT & DEVELOPMENT PTY LTD
EL 9957/Permit 18093 Final Report April 2019
Document Distribution
Document Date Name Company Version Copies Type 8/4/2019 Various Huon Aquaculture Draft V1.1 1 Mark Churchill/Stephen 9/4/2019 EPA Draft V1.2 1 Gallagher/David Horner
DISCLAIMER: The present report is provided for the exclusive use of EPA Tasmania/Huon Aquaculture Company P/L as part of the requirements for the Monthly Broadscale Reporting as part of the conditions of the Environmental Licence for the operation of Emergency Permit 18093 under the Living Marine Resources Act 1995. Aquaculture, Management & Development P/L disclaims all liability for any adverse consequences arising from the use of information contained within this report by any third party. Dr. Dom O’Brien Managing Director. AMD 24th April 2019
EL 9957/Permit 18093 Final Report April 2019
Contents
1 Environmental Licence (EL) Holder ...... 1
2 Operational Summary ...... 1
3 Summary of Activity ...... 3
4 ROV monitoring surveys ...... 10
5 Broadscale Water Column Characteristics ...... 17
6 Seagrass surveys (provided by Aquenal) ...... 32
List of Figures Figure 1 - One of the pens in-situ within the Permit, showing the four internal ‘pods’ with individual feeder systems, with a white Dissolved Oxygen string marker buoy in the foreground ...... 4 Figure 2 - Mooring and pen layout in the 4-pod grid ...... 4 Figure 3 - General location and bathymetric map (taken from Navionics website) of the Green Head/Lime Bay area also showing lease areas 117 (East) and 128 (West). Note the pens were located in depths greater than 20m (white shading)...... 5 Figure 4 - Map of the Permit area (ABCD) showing approximate location of harvest pens. Black outline -lease boundary, Red outline - zone boundary. Co-ordinates GDA94 Zone 55...... 6 Figure 5 - Spot bathymetry survey results superimposed onto the Navionics chart confirming predicted depths for the Permit area...... 6 Figure 6 - Current speed at 6m depth in the Permit area ...... 7 Figure 7 - ROV location maps, showing all ROV survey sites. Top left, November sites with incorrect IF5 site. Top right, detail of final survey (December) pen sites. Bottom left, baseline sites showing triplicate ‘compliance’ sites and controls. Bottom right, December All final survey sites ...... 12 Figure 8 - Map of actual handfish ROV tracks with reference to EPA transect start points...... 16 Figure 9 - Map of the water quality monitoring stations associated with Environmental Licence 9957/1...... 17 Figure 10 - Temperature, Dissolved Oxygen and conductivity averages for individual sites (at 5m depth) ...... 19 Figure 11 - Temperature and conductivity for different depths for all sites...... 20 Figure 12 - Graphs of NOx, Ammonia and Total Kjeldahl N concentrations at surface, midwater (labelled 10m) and seafloor depths ...... 21 Figure 13 - Graphs of DRP, Silica and Chlorophyll a concentrations at surface, midwater (labelled 10m) and seafloor depths ...... 22 Figure 14 - Ammonia levels vs fish biomass in Permit area (dotted line represents fish biomass) ...... 23 Figure 15 - Comparison of integrated sample lab analysis with Sonde probe measurement for Chlorophyll a at all sites for the survey period...... 25 Figure 16 - A. Abundance of Phytoplankton groups by mean cell count for all surveys, B. Relative abundance of groups for all surveys by mean cell count ...... 26 Figure 17 - A. Total cell abundance of Phytoplankton groups for all surveys, B. Relative total cell abundance of groups for all surveys ...... 28 Figure 18 - Total number of phytoplankton cells at each site when the fish pens were stocked. There is no data for NB5 as integrated samples were not taken during these surveys...... 29 Figure 19 – Dissolved oxygen (saturation and concentration) and temperature at sites DLS1 & DLS2 for the period of stocking of the permit area...... 31 Figure 20 - Representative imagery from December 2018 Seagrass surveys (frame grabs) on following 3 pages ...... 39
EL 9957/Permit 18093 Final Report April 2019
List of Tables Table 1 - General velocity statistics for ADCP deployment ...... 7 Table 2 - Stocking biomass, harvest biomass and feed fed to Fish Pens ...... 9 Table 3 - Dive position summary for all ROV surveys ...... 11 Table 4 - Interpretation summaries for all ROV surveys...... 13 Table 5 - Laboratory Limits of Reporting for the water analytes ...... 20 Table 6 - Comparison of nutrient maxima against EPA Bruny Bioregion DGV's...... 24 Table 7 - Epiphyte coverage qualitative scale ...... 32 Table 8 - Summary of seagrass observations. Seagrass and Caulerpa coverage estimates represent average assessed across ten replicate frame grabs per dive. Average epiphyte scores represent average assessed across ten replicate frame grabs per dive. See ...... 34 Table 9 - Survey coordinates for December 2018 seagrass surveys, based on the Mapping Grid of Australia Zone 55 (Datum GDA94)...... 35 Table 10 - Frame grab analysis of December 2018 seagrass footage ...... 36
EL 9957/Permit 18093 Final Report April 2019
1 Environmental Licence (EL) Holder
Huon Aquaculture Company P/L. EL 9957
2 Operational Summary
Contractor: AQUACULTURE, MANAGEMENT & DEVELOPMENT PTY LTD (AMD) ACN 079 618 385 Phone 0421 331797 e-mail: [email protected]
Client: EPA Tasmania 134, Macquarie St, Hobart. TAS 7000 Liaison: Stephen Gallagher; Mark Churchill
Field work: Huon Aquaculture Company (Huon) and EPA Tasmania.
Personnel: Adam Smark, Bill Joyes, Darryl Boothey (all Huon), Dom O’Brien (AMD)
Dates of fieldwork: Baseline Environmental Survey – July 2018 Water quality monitoring -Huon surveys from August 2018 through to February 2019. ROV monitoring surveys – July, October, November and December 2018
Laboratory Analysis: Nutrients in water - Analytical State Laboratories (AST), Hobart, TAS. Phytoplankton description and counts - Analytical State Laboratories (AST), Hobart, TAS.
Monitoring Equipment for Huon surveys: A Getac mobile GIS unit with attached Novatel Smart Antenna Differential GPS was used to locate all sites for both ROV and seabed sampling. Sonde profiles (dissolved oxygen, temperature, salinity & turbidity), were taken using a YSI Exo 3 series Sonde. The probe measured from the water surface down to within 1m of the seafloor at all sites. Nutrients and Chlorophyll a were sampled at the surface, 10m depth and seafloor using a Niskin bottle with graduated cord to ensure that the deeper samples were taken just above (estimated 1m above) the seafloor. The water samples were subsequently analysed for nutrients by AST laboratories Hobart. Huon survey phytoplankton samples were taken at 3 depths (Surface, 10m and Seafloor) from Aug-Nov 2018. All other samples (Huon post November and all EPA) were depth integrated from the surface down to 12m depth. Hobo Dissolved oxygen loggers (U26-001) were deployed immediately upstream and downstream of the Permit pens at 10m depth and 1m above the seafloor in order to provide temporal oxygen profiles across the site. ROV equipment: Filming was carried out using a Blue-ROV-02 Remotely Operated Inspection System accompanied by two optimised LED arrays adjustable lights. In the event of mechanical failure in the Blue ROV during the surveys, a VideoRay Remotely Operated Inspection System using a colour video camera with 170 degrees of tilt range, 350 lines of resolution and 0.5 lux of sensitivity, accompanied by two 20-watt adjustable halogen lights was employed. A GoPro Hero 4+ was mounted onto both ROV units and also used to capture footage.
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Reporting: Seagrass reporting provided by Aquenal P/L. All other reporting is provided by Dr. Dom O’Brien AMD.
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3 Summary of Activity
Huon is presently reviewing its marine operations in SE Tasmania in order to improve the biosecurity of its stock, predominantly in response to the increased incidence of Pilchard Orthomyxovirus (POMV) in the region. The company has been operating offshore, high exposure marine farms in Storm Bay for 4 to 5 years, and during this development of offshore sites has developed new strategies to cope with the conditions being experienced in that region. Huon would normally have transferred harvest fish (for this EL, the 2017 year class) from Storm Bay leases to harvest pods located at company’s harvest station at Hideaway Bay in the lower Huon River. As there were relatively recent cases of POMV infection in these fish and despite current mortality levels being low, it was considered prudent on biosecurity grounds to avoid/minimise transfer of these fish to Hideaway Bay which is relatively close to newly introduced 2018/smolt year class (YC) populations for both Huon and Tassal, at a considerable cost to Huon.
By transferring the Storm Bay fish to Huon’s Norfolk Bay marine farming permit area the potential transmission pathway to the lower Channel was avoided. Huon transferred the Storm Bay fish to Norfolk Bay in the Ronja Huon well boat using the closed valve system and taking a wide berth of Tassal’s leases at Nubeena such that any risk to Tassal stocks was avoided. There is a separation distance of more than 25kms between the proposed Permit area and Tassal’s Nubeena leases.
The company was also keen to avoid; residential areas where they may be some resistance to the deployment of the harvest pens or there may be water quality concerns such as the Derwent Estuary, and, inshore bays along the outside of Bruny Island where the company might encounter resistance from commercial and recreational fishing groups or tourism ventures.
Taking all these factors into account, Huon identified the site at Green Head at the entrance of Norfolk Bay as covering all essential variables related to bio-security, and making a reasonable compromise for the remainder. Additionally, the site was identified as; relatively sheltered, having strong current flow, providing adequate depth for the harvest pods, being a reasonable distance from any residential areas (the closest being at Primrose Sands), and, there was also previous aquaculture and environmental experience of the site, through Aquaculture, Management & Development P/L, and Saltwater Seafoods Tasmania P/L who previously farmed shellfish at the site.
Huon were granted marine farming Permit 18093 by Secretary DPIPWE on 7 August 2018. The permit authorised the occupation of an area at Green Head, Norfolk Bay, to deploy marine farming equipment and farm Atlantic salmon. The permit was issued for the period 7 August to 31 December 2018.
Huon were also granted an environmental licence from EPA Tasmania on 17 August 2018 (EL9957/1) for marine farming Permit 18093. Huon were required by EPA Tasmania to conduct a baseline environmental survey for the permit area. The baseline environmental survey was conducted in July 2018 prior to the deployment of equipment and introduction of fish to the permit area. EL9957/1 required Huon to undertake ongoing water quality, seafloor and seagrass monitoring during the permit period and for a time following expiry of the permit (during January and February 2019).
The equipment deployed in the Permit area was based on harvest pens currently deployed at Hideaway Bay (Figure 1).
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Figure 1 - One of the pens in-situ within the Permit, showing the four internal ‘pods’ with individual feeder systems, with a white Dissolved Oxygen string marker buoy in the foreground The pens were 57-60m square, with the pods being approximately 25m square. The nets were 12- 15m deep with a predator net on the outside being approximately 16-18.5m in depth at the deepest point. These pens and mooring systems have been designed to withstand sheltered to moderately exposed waters (significant wave height up to 2-3m). They were moored with steel spade anchors to the seafloor. There was no ancillary machinery apart from the feed hoppers located on the harvest pens, with all pumps being carried on-board the vessels (Ronja Huon and Captain Bill) servicing the pens. A cross section of the pens and moorings is provided in Figure 2.
Figure 2 - Mooring and pen layout in the 4-pod grid
The fish were transported to the harvest system by the well-boat, the Ronja Huon (Ronja) which transferred between 1-2 weeks’ worth of harvest stock to the facility in one trip. Therefore, the Ronja visited the harvest system only once every one to two weeks. The fish were harvested on to trucks carried on the harvest vessel, the Captain Bill. After harvest the Captain Bill transported the trucks to Hideaway Bay for disembarkation.
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Harvesting took place 5 out of 7 days a week from Sunday to Thursday, and the harvesting operations were normally undertaken between 4pm and 9pm, the preferred time for harvest due to animal welfare (night-time is the time of least stress for such transfer related operations).
The only noise to be generated by the facility was when the fish were being loaded into the facility and when they were harvested. The Ronja and Captain Bill had a full suite of noise profiling undertaken, demonstrating compliance with all EPA noise regulations. A smaller craft was used to access the lease during daytime prior to the harvest to remove all mortalities from the harvest pod prior to harvest.
All lighting at the facility was only associated with vessel movements and activities (again, loading and harvesting). All lights on vessels were down-lights required under OHS regulations whilst operating at night-time. In the initial few days of harvesting additional covers were added to the lights on the Captain Bill to further minimise any incident light emanating from the facility after 6pm.
Maps of the lease 117 and Permit area are provided in Figure 3 and Figure 4. The coordinates for the proposed Permit area are included in Figure 4.
Figure 3 - General location and bathymetric map (taken from Navionics website) of the Green Head/Lime Bay area also showing lease areas 117 (East) and 128 (West). Note the pens were located in depths greater than 20m (white shading).
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Figure 4 - Map of the Permit area (ABCD) showing approximate location of harvest pens. Black outline -lease boundary, Red outline - zone boundary. Co-ordinates GDA94 Zone 55.
Previous bathymetric and regulatory shellfish surveys of the area undertaken by contractors Aquaculture, Management & Development P/L provides confirmation of the bathymetry provided by commercially available charts such as Navionics (see Figure 5).
Figure 5 - Spot bathymetry survey results superimposed onto the Navionics chart confirming predicted depths for the Permit area.
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Huon deployed an Acoustic Doppler Current Profiler (ADCP) in the SE part of the permit area between 23/8/18 to the 17/9/18. An example of the strong tidal flow experienced at the site is provided in Figure 6. The graph depicts only 5 days of data, but in temporal pattern and velocity these are representative of both the deployment period and the whole water column (Table 1).
Figure 6 - Current speed at 6m depth in the Permit area Table 1 - General velocity statistics for ADCP deployment
Depth (m) 24 to 27 21 to 24 18 to 21 15 to 18 12 to 15 9 to 12 6 to 9 3 to 6 0 to 3 Vel (cm/s) Mean 7.3 7.7 8.2 9.0 9.8 10.5 10.5 8.9 37.7 Max 37.2 38.3 40 39.5 35.9 38.4 40.6 35.2 91 Min 0 0 0 0 0 0 0 0 0.1 %flow<3cm/s 21.5 21.6 19.2 15.9 13.1 11.1 11.1 13.4 1.9 %flow<5cm/s 39.5 38.9 36.0 31.3 27.0 23.9 23.2 29.4 5.1 %flow>10cm/s 27.0 29.6 32.4 37.0 43.0 46.3 47.7 37.3 86.9
The current data confirms that the Permit area is exposed to strong tidal related flows from the surface right through to the seafloor. These flows should tend to disperse, dilute and quickly re- oxygenate both; the sediments under the pens (organic faecal loadings), and, any ammonia produced (from the gills - nitrogen excretion) by the fish in the pens.
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As part of the permit application process Huon consulted with the Tasmanian Seafood Industry Council (TSIC) and the Tasmanian Association for Recreational Fishers TARFish and other commercial operators in the area including tourism operators.
Huon recognises that it operates in a shared environment and consulted widely with community groups, local residents, local council and others. The company used letter box drops and one on one meetings. Huon identified relevant groups by engaging with local council. Residents were identified by their proximity to the site. Factors discussed included but were not restricted to; changes to road traffic, potential sources of possible noise and light at night, conservation of threatened species (e.g., Handfish), and how Huon would mitigate these concerns. Given that the Permit was a short term undertaking the company was confident that this program of consultation and engagement facilitated the negotiation of any reasonable concerns raised by other users and helped resolve them to the satisfaction of all reasonable parties.
The Permit area was stocked with Atlantic salmon between the 26th August and 6th November (10 weeks approximately). Huon harvested only Atlantic Salmon within the permit area. Each pen held on average 220T or 51T/pod, with a maximum biomass recorded in two weeks in late September/early October of 390T/pen or 95T/pod (Table 2). All fish were harvest sized at 4-6kg weight and sourced from the Storm Bay lease, Marine Farm 261.
The harvest pens were fed at a maximum daily feed rate of approximately 400kg per pen, this was well below the anticipated feed rate and included the period of two weeks maximum stocking. Over the full Permit harvesting period this equated to only 20T of feed per pen position over a 10 week period. For comparison, this is equivalent to less than a quarter of the feed input to a 168m pen, and the harvest pen is 50% larger in surface area than the 168m pen, so it was anticipated that there should be significantly less organic accumulation under the harvest pen.
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Table 2 - Stocking biomass, harvest biomass and feed fed to Fish Pens
Grand Total Closing Biomass Gross harvested Amount eaten [kg] in biomass, incl. discards period Closing Week [kg] in period 2018/34 278,235 0 0.00 2018/35 293,431 234,799 5,132.00 2018/36 459,427 278,138 3,153.00 2018/37 621,070 290,124 2,837.00 2018/38 780,406 297,708 4,203.00 2018/39 713,420 282,481 4,199.00 2018/40 289,841 271,155 5,322.00 2018/41 498,691 284,135 4,443.00 2018/42 224,397 270,585 3,107.00 2018/43 444,640 267,332 4,788.00 2018/44 179,145 269,317 2,311.00 2018/45 0 147,312 0.00 2018/46 0 0 0.00 2018/47 0 0 0.00 2018/48 0 0 0.00 2018/49 0 0 0.00 2018/50 0 0 0.00 2018/51 0 0 0.00 2018/52 0 0 0.00 2019/01 0 0 0.00 Grand Total 0 2,893,087 39,495.00
At the start of the Permit period there was only low level POMV infection in the lower Channel at another company’s lease, but Huon had yet to experience any POMV infection in 2018YC stocks. At the beginning of November however, it became evident that the level of incidence of POMV had increased in the Huon/Channel area in general and was detected in Huon 18YC stock. Further the harvest fish at Storm Bay had continued to return negative tests for POMV. Therefore, in view of the reduced bio-security risk Huon were able to return their Storm Bay harvesting operations back to Hideaway Bay and reduce the time of harvesting operations within the Permit area in Norfolk Bay by approximately three weeks. It is also worth noting that since that time Huon has experienced very low mortality and overall incidence of disease in the stocks in the Huon and Channel, which has been an encouraging sign that the increased bio-security measures being undertaken, of which the temporary harvesting operations in Norfolk Bay was a part, are indeed proving worthwhile.
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4 ROV monitoring surveys
Four ROV ‘video’ surveys were undertaken before and during the Permit period; 1) baseline environmental survey, including handfish and seagrass surveys (July 2018) 2) during stocking (October 2018), 3) immediately post stocking (November 2018), and, 4) final survey at least a month post stocking (December 2018), including a repeat seagrass survey.
The seagrass surveys are described in Section 6, and the handfish survey results are described at the end of the present section.
ROV dive position summary/maps for all seafloor surveys are provided in Table 3 and Figure 7.
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Table 3 - Dive position summary for all ROV surveys SURVEY TIME TYPE SITE Baseline, Oct, Nov, Dec 35m compliance point 1.2 Baseline, Oct, Nov, Dec 35m compliance point 2.2 Baseline, Oct, Nov, Dec 35m compliance point 3.2 Baseline, Oct, Nov, Dec 35m compliance point 4.2 Baseline, Oct, Nov, Dec 35m compliance point 5.2 Baseline, Oct, Nov, Dec 35m compliance point 6.2 Baseline, Oct, Nov, Dec 35m compliance point 7.2 Baseline, Oct, Nov, Dec 35m compliance point 8.2 Baseline Control site C1.1 Baseline Control site C1.2 Baseline Control site C1.3 Baseline Control site C2.1 Baseline Control site C2.2 Baseline Control site C2.3 Baseline Control site C3.1 Baseline Control site C3.2 Baseline Control site C3.3 Baseline, Nov, Dec Internal farm site IF1 Baseline, Nov, Dec Internal farm site IF2 Dec Internal farm site IF2.2 Dec Internal farm site IF2.3 Baseline, Nov, Dec Internal farm site IF3 Baseline, Nov, Dec Internal farm site IF4 Baseline, Nov, Dec Internal farm site IF5 Dec Internal farm site IF5.2 Dec Internal farm site IF5.3 Baseline, Nov, Dec Internal farm site IF6 Baseline Handfish site H1 Baseline Handfish site H2 Baseline Handfish site H3 Baseline Handfish site H4 Baseline Handfish site H5 Baseline Handfish site H6 Baseline, Dec Seagrass site S1 Baseline, Dec Seagrass site S2 Baseline, Dec Seagrass site S3
Note: Grid = UTM; Datum = GDA 94 Zone 55. IF5 was incorrectly sited at the November survey (refer to Figure 7). Note triplicate positions and control positions only undertaken during the baseline survey are not included. For those positions please also refer to Figure 7.
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Figure 7 - ROV location maps, showing all ROV survey sites. Top left, November sites with incorrect IF5 site. Top right, detail of final survey (December) pen sites. Bottom left, baseline sites showing triplicate ‘compliance’ sites and controls. Bottom right, December All final survey sites Note: 1.1 – 8.3 are 35m compliance sites, IF1-6 are internal Permit area sites (IF2, 2.2, 2.3 and IF5 5.2, 5.3 under pen sites, December survey), c1.1-3.3 are control sites 12
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Summary of ROV Surveys Results
Interpretation of the observations for the individual ROV surveys are provided in Table 4. A summary of the general patterns/observations for the Permit period is provided below.
General Through all surveys all sites were composed of fine silt containing many burrows, worm tubes and tiny tree-like structures. Drift algae was common and abundant through the earlier surveys becoming sparse at all sites in December. The general fauna was highly depauperate with a significant presence of introduced species of which Euchone sp. and Asterias amurensis (Northern Pacific Sea star) are the dominant species.
Sediments Overall there was no sign of any disturbance at the compliance sites. The only sites that showed signs of change were the internal Pen sites where small patches of darker sediments were observed post stocking and these reduced to darker sediments around the entrances to burrows by the final survey. In addition, the pen sites (IF2, IF5) also had clumps of small mussel shells. The state of the sediments under the pens was therefore very good in comparison at least to stocked pens in other sheltered waters, however, this more than likely reflects the short time period for which the area was stocked, the low feed rate for these pens, and the relatively strong tidal currents experienced in the Permit area.
Fauna/Flora Post baseline there was a general decrease and almost absence of brittle stars at all sites from October through to the final survey in December, and there also appeared to be a decrease in the numbers of Coccinasterias sp. (the 11-armed starfish) post baseline survey, although individuals of both species were observed on occasion in post baseline surveys. One or two Nudibranchs appeared in the post stocking survey in November, and these then increased in numbers with an accompanying increase in their egg masses in the December survey. Although the presence of Nudibranchs and the absence of the brittle stars has at times been linked to fish farms, the low level of organic deposition shown in this area together with the timing of the incidence in the increase in Nudibranchs, and the fact that these changes appeared to occur at all sites within the individual surveys suggests that seasonal factors (among others) may have also influenced these changes. The whole survey area was depauperate in flora except for the occasional Caulerpa plant. As previously stated though, drift algae (mainly red) was abundant at the majority of sites during the first three surveys and this only reduced significantly in the December (last) survey. There is nothing evident to associate this drift algae with the presence of the fish farm.
Table 4 - Interpretation summaries for all ROV surveys. All sites shared the common features of brown silt, with many burrows and suspected worm tubes. The seafloor at all sites was relatively even, with numerous small troughs and elevations around the larger burrows. Baseline Small crabs (mostly spider crabs), brittle stars (except for c2) and Northern Pacific sea stars (Asterias amurensis) were widespread across the survey area. Eleven-armed sea stars (Coccinasterias sp.) and gobies were relatively common across the whole area, with Coccinasterias sp. observed at sites 5, 7 & c2 and at most internal sites, and gobies only absent
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at c1 & site 3. There was also the very occasional hermit crab, nudibranch ascidian and scallop. Apart from Gobies there the only fish observed were single Flathead at sites 5, 7 & IF6. Apart from the introduced Japanese sea star, the only other introduced fauna observed were two specimens of the screw shell Maoricolpus roseus at sites 2 & 3. Given the information provided for the October survey then it is highly probable that there were also numerous Euchone sp. at many of the sites. Most “algae” appeared to be drift algae with a significant component of seagrass stalks. However, there was also some blanched fine algae present at most sites, predominantly at c1. This may have been consolidated drift algae but did appear to be attached to the substrate in some way. In summary, the whole survey area was largely uniform with the three control sites also appearing to be largely reflective of conditions within and surrounding the lease itself. Only c1 showed some slight differences in substrate type through the presence of some shell grit in the silt. There was no obvious visual evidence for any significant physical or biological effects or debris from the fish harvest pens at the compliance sites, with only one empty mussel shell observed at site 1.2. The compliance sites were all composed of fine silt containing many burrows, worm tubes and tiny tree-like structures. The present description of the fauna takes into account observations from the baseline survey and infauna descriptions. For the baseline ROV survey the generic description of ‘many suspected worm tubes’ was employed for tiny tubes which were not necessarily raised above the surface but could be seen with the camera directly above. The subsequent infaunal description associated with the baseline survey described the presence of numerous Euchone sp. worms, an introduced species from the Sabellidae family. It is certainly likely that the ROV October tiny tubes are in fact these Euchone sp. tubes and there was some evidence especially at sites Survey – 1.2 and 8.2 for the ‘fan-like’ appendages being retracted into the tubes as the ROV passed over them. At these two sites were also definite observations of what would be presumed to Stocked be Euchone sp. ‘fans’ at the surface as well as the occasional observation at sites 3.2, 4.2 & Permit 7.2. Further, there was also evidence of these tiny tubes at the remainder of the sites. Apart area from the suspected Euchone sp. the general fauna was highly depauperate and mostly dominated by the Northern Pacific sea star, Asterias amurensis with an occasional small crab and Goby at one or two sites only. These general faunal observations are very similar to those made for the baseline survey with the exception that brittle stars appeared to be largely absent or at least not evident during the present survey. A. amurensis, and Coccinasterias sp. (11-armed starfish) were noted at numerous sites for the baseline survey, and it would appear that A. amurensis is still common in the area. There were possibly fewer Coccinasterias sp. observed during the present survey when compared to the baseline survey. In all and as described for the baseline survey the area has a significant presence of introduced species of which Euchone sp. and A. amurensis are the dominant species. There was no obvious visual evidence for any significant physical or biological effects or debris from the fish harvest pens at the compliance sites. Small mussel shells were present at IF2 and IF3, with them being relatively common at IF2 and few at IF3. There were also a few instances of darker sediments around burrows and the occasional small patch of grey to black sediments at Internal Farm sites IF2 and IF3. November As for the previous 6 weekly survey all sites were composed of fine silt containing many Survey burrows, worm tubes and tiny tree-like structures. Old drift algae was common at most sites post de- and abundant across sites 5.2, 6.2, 7.2, 8.2, IF1, IF5 and IF6, preventing a detailed description stocking of the seafloor at sites 6.2, 7.2, IF5 and IF6 in particular. of Permit Many probable Euchone sp. were observed across most sites and at other sites their probable tubes were evident. Apart from the suspected Euchone sp. the general fauna was highly area depauperate and mostly dominated by the Northern Pacific sea star, A. amurensis with small flathead at a number of sites and a very occasional Nudibranch, Goby or suspected Whiting at one or two sites only. These general faunal observations are very similar to those made for the baseline survey with the exception again that brittle stars were only observed at one site during the present survey.
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A. amurensis, was noted at all sites for the present survey (as for the baseline survey), with their numbers appearing to be slightly raised at IF3, with numbers indicated as many instead of few to reflect this apparent difference. No Coccinasterias sp. were observed during the present survey. In all and as described for the baseline survey the area has a significant presence of introduced species of which Euchone sp. and A. amurensis are the dominant species. There was no obvious visual evidence for any significant physical or biological effects or significant debris at the compliance sites. At the pen sites (IF2, IF5) small mussel shells were evident, and there were also a few instances of darker sediments around burrows at most of these pen sites. As for the previous surveys all sites were composed of fine silt containing many burrows, worm tubes and tiny tree-like structures. Old drift algae were sparse compared to the previous survey at all sites. Occasional Caulerpa sp. fronds were also observed at one or two compliance and pen sites. Again, as for the previous surveys many probable Euchone sp. were observed across most sites and at other sites their probable tubes were evident. Apart from the suspected Euchone sp. the general fauna was highly depauperate and mostly dominated by the Northern Pacific sea December star A. amurensis, and mollusc (probably Nudibranch) egg masses which appeared numerous Survey across most sites. There was also the occasional cushion star, Flathead or Goby at one or two post sites only. These general faunal observations are very similar to those made for the baseline months survey with the exception again that brittle stars were only observed at one site and that recovery mollusc egg sacs were more abundant and numerous during the present survey. A. amurensis, was noted at all sites for the present survey (as for all the previous surveys at the site including the baseline survey). Only one Coccinasterias sp. starfish was observed (at site IF2) during the present survey. In all, and as described for the baseline survey the area has a significant presence of introduced species of which Euchone sp. and A. amurensis are the dominant species. Nudibranchs and their suspected egg masses were more numerous during the present survey and their presence may be due to seasonal factors and may be influenced to some degree by the increase in organic matter from the fish farm. The actual state of the sediments under the pens was very good given the short fallowing period, and may also reflect the short time period for which the area was stocked and the comparatively low feed input to the Permit area.
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Handfish Survey
A targeted ROV handfish survey was also undertaken as part of the baseline survey. The sites surveyed are provided in Figure 8. No handfish individuals or handfish egg masses were observed along any of the transects. In addition, no handfish individuals or handfish egg masses were observed at any of the general baseline monitoring sites included in the full baseline survey from either the internal lease sites, the compliance sites or the control sites.
Figure 8 - Map of actual handfish ROV tracks with reference to EPA transect start points
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5 Broadscale Water Column Characteristics
A map of the survey sites for the Broadscale water quality monitoring program and the temporal dissolved oxygen profiling adjacent to the Permit area is provided in Figure 9.
Figure 9 - Map of the water quality monitoring stations associated with Environmental Licence 9957/1. Key: NB1- NB6: monthly monitoring stations. DLS1-DLS2: continuous temperature and dissolved oxygen loggers at either end of the permit (white rectangle).
Huon conducted monthly water quality monitoring from August 2018 until February 2019. Where pertinent, information provided by the EPA for sites NB2 to NB6 from surveys carried out from August to early January are also provided.
Sonde Data for 5m depth is provided in Figure 10, and depth comparisons where relevant variables are provided in Figure 11. The trends and observations derived from both the raw data and the graphs are:
1) Dissolved Oxygen DO was highly consistent for all sites between surveys with possible evidence for a 1-2% (only) decrease in level during stocking at NB4 and a decrease in level at NB5 during mid-December. Through the monitoring period the DO levels were representative of normal well oxygenated coastal waters ranging from 95% to 103% saturation. The collective lowest levels of DO were recorded prior and post stocking. 2) Water temperatures for each survey were consistent across all sites. Temperatures rose from approximately 9oC to 20oC during the monitoring period, although the range was 9oC to 15oC during the period of stocking. For the majority of the surveys the
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waters appeared to be well mixed at all sites, however there was evidence for the presence of a thermocline in the late October and mid-December surveys. 3) Conductivity/Salinity was consistent across all sites and consistently higher than 32.5ppth (>50,000uS/cm). There was a slight increase in salinity from winter through to summer. There also appeared to be a concomitant halocline with the October thermocline although this was not repeated in mid-December. 4) Chlorophyll a data ranged from 0-0.2ug/L at the surface to a maximum only of 0.5ug/L across all depths at all sites. As stated in the previous Monthly Reports this data is simply provided as a future comparison to the lab data to assess the utility of probe derived chlorophyll a data. There was, however, no apparent increase in Chlorophyll a associated with the presence of the fish pens. 5) Turbidity levels were consistent across all sites and very low (generally <0.5FNU) at all sites for all surveys. There was no apparent increase in Turbidity associated with the presence of the fish pens. 6) With regard to EPA Tasmania Default Guideline Values (DGV) for Aquatic Ecosystems for the Bruny Bioregion and/or the Tasmanian Coastal and Marine Waters, then; maximum temperatures are approximately 3oC higher than the DGV, and minimum temperatures in Spring are 3oC below. Spring salinity values are 2 to 23 parts per thousand below the DGV and Spring oxygen values exceed the upper values by almost 1mg/L.
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Figure 10 - Temperature, Dissolved Oxygen and conductivity averages for individual sites (at 5m depth)
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Figure 11 - Temperature and conductivity for different depths for all sites
Water column nutrient results for three depth categories; Seafloor, 10m or mid water depth and Surface, are provided in Figure 12 and Figure 13. Please note that where the sample value is below the level of detection, then the value used for the graphs is represented by the limit of reporting (LoR). The various LoR’s for the measured variables are provided in Table 5. Table 5 - Laboratory Limits of Reporting for the water analytes
NB: LoR for Silica is 0.1mg/L
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Figure 12 - Graphs of NOx, Ammonia and Total Kjeldahl N concentrations at surface, midwater (labelled 10m) and seafloor depths
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Figure 13 - Graphs of DRP, Silica and Chlorophyll a concentrations at surface, midwater (labelled 10m) and seafloor depths
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The general trends and possible deviations from background levels for the individual variables, can be described as follows: 1) Nitrates – during Spring increases at some sites were evident in three of the surveys. These increases were well below the DGV for the region (refer also to Table 6), and all three were (to differing degrees) consistent across most sites, that is they could not necessarily be attributed directly to the presence of the fish farm. 2) Ammonia - also showed variation between sites in four of the surveys (3 at the surface, 1 at depth for NB4/NB1). Given the potential for the fish in the pens to contribute to these loadings, then a comparison of the temporal relationship between stocking biomass levels and ammonia peaks is provided in Figure 14 to enable further assessment. From Figure 14, although there is an increase above background levels at the surface at NB4/NB1 (relatively close to the harvest facility) during the peak biomass period in late October, there is evidence that this site is prone to higher surface ammonia levels even when there are no fish present, e.g., from December through to-February. This together with the fact that there is evidence for a thermocline during that period makes it difficult to verify the precise source of this increase.
Figure 14 - Ammonia levels vs fish biomass in Permit area (dotted line represents fish biomass)
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For the midwater and seafloor depth categories the ammonia levels appear to be consistent between sites for individual surveys, with the possibility that in mid- October there is a slightly elevated level at NB1/NB4 sites when compared to the controls at NB5 & NB6. All ammonia levels at all seafloor and 10m depth sites then return to background post stocking, except for NB5 in February where levels as high as NB4 during mid-October are again encountered. 3) Kjeldahl N remained within a tight concentration range throughout the monitoring period and where values changed from survey to survey then these changes were consistent across most sites including controls. 4) Dissolved Reactive Phosphorus (Orthophosphate) values also fell within a narrow concentration range and inter survey variation was also generally repeated at all sites. Where there were intra survey increases, again at the surface in early to mid-October, then the overall pattern was very similar to that described for Ammonia above, i.e., an equally large increase in DRP in February. Again, the levels remained under the DGV at all times. There was a decrease in general DRP levels in mid-summer. 5) Silica levels were higher than the general DGV ‘s for the region throughout the monitoring period (Table 6), and site NB6 had generally lower silica levels than the other sites. 6) With regard to EPA Tasmania Default Guideline Values (DGV) for Aquatic Ecosystems for the Bruny Bioregion and/or the Tasmanian Coastal and Marine Waters (refer to Table 6): maximum nitrate levels were well below the DGV, maximum phosphate levels were also below the DGV, and, Silica levels were consistently above the DGV, for all sites. Table 6 - Comparison of nutrient maxima against EPA Bruny Bioregion DGV's. Na2SiO3- EPA Default Guideline Values (DGV) NO3-N PO4-P Si for Bruny Bioregion All in (ug/L) Spring Guideline value 102.2 22.2 56 Surface maximum value recorded 24 17 69 Seafloor maximum value recorded 35 15 69 Summer Guideline value 74.2 18 82.3 Surface maximum value recorded 5 14 115 Seafloor maximum value recorded 5 9 115
7) Chlorophyll a. For the integrated and depth specific samples there were no obvious, consistent trends or increases in levels across the sites that might be associated with the presence of the fish pens. Chlorophyll a levels did appear to be generally higher at NB6 than all other sites for most surveys. Comparison of the Sonde probe results with the integrated samples results (Figure 15), shows that there may be some general similarities in trend results, with higher levels in both sets of data at the beginning and end of the monitoring period. However, the evidence for higher levels at NB6 compared to the other sites is not supported in the Sonde results. Further, the Sonde results were consistently lower than the laboratory analysed samples. Given the ease of collecting the Sonde data
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and the fact that it can be continuously collected remotely, it would be worthwhile to further assess the relationship between laboratory methods of analysis and the Sonde data to ascertain if the there is a good consistent relationship between the values derived from both types of analysis.
Figure 15 - Comparison of integrated sample lab analysis with Sonde probe measurement for Chlorophyll a at all sites for the survey period.
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Phytoplankton
Huon phytoplankton surveys from September through to November included point samples for three depths - surface, 10m and seafloor (depth precise) and were not directly comparable with EPA integrated samples which are taken from the top 10-12m of the water. Huon changed to integrated samples from December on to be directly comparable with the EPA integrated samples, and all graphs presented below provide only the integrated samples results. It should also be noted that the Huon data is a composite of sites NB1-NB6, whereas EPA data includes only NB2-NB6 as the EPA surveys do not include NB1.
A
B
Figure 16 - A. Abundance of Phytoplankton groups by mean cell count for all surveys, B. Relative abundance of groups for all surveys by mean cell count
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As presented in the previous reports there was a significant shift in the phytoplankton community between September and October at the surface, with the Cryptophyte Chroomonas sp. increasing across all sites (refer to previous survey report). Various Nanoflagellates were also more numerous in October although appearing to be concentrated at only one or two sites. The integrated samples (Figure 16) do not show such an increase in Cryptophytes until November. During November the total number of cells dropped significantly from the October count with Nanoflagellates becoming the dominant group in the surface samples but in the present integrated samples the Cryptophytes become dominant numerically. Through December to late January there appears to be a gradual return of abundance levels of the various groups to August levels, however, the differences in the two mid-December surveys (only one day apart) demonstrate the variability in phytoplankton cell counts at these scales with numbers and groups showing significant variation across the two days.
In Figure 16 and for previous monthly reports the phytoplankton groups are described by mean cell counts for individual species within the groups. This enables the fish farmer to more easily assess comparative changes in individual species in and amongst the groups and be alerted to possible group/species specific increases within the lesser (overall) numerically abundant groups, as these can contain some of the major toxic algal species, e.g., Raphidophytes, whose numbers increased in January. However in order to better represent the numerical relationships between the groups the data should be presented as the sum totals of cells within each group providing a comparison of total abundance between the groups. This is provided in Figure 17, and shows that in terms of total cells per group across the sampling period that Bacillariophytes were the dominant group in the water column followed by Dinophytes. Only in November and late January were total cell counts of Bacillariophytes lower than other groups, i.e., Chryptophytes in November, and Dinophytes in late January.
A comparison of the total numbers of cells of all groups per site during the period when fish were on the Permit area, this is presented in Figure 18. This graph confirms the Chlorophyll a data in that phytoplankton cell counts are consistently greater at the NB6 control site than the sites close to the fish pens, even when these are stocked.
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A
B
Figure 17 - A. Total cell abundance of Phytoplankton groups for all surveys, B. Relative total cell abundance of groups for all surveys
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Figure 18 - Total number of phytoplankton cells at each site when the fish pens were stocked. There is no data for NB5 as integrated samples were not taken during these surveys.
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Upstream Downstream DO profiles
Four ‘Hobo’ combined dissolved oxygen (DO as % saturation and mg/L concentration) and temperature probes were deployed on two string moorings within 50m of the harvest pens, at sites DLS 1 & 2 (upstream and downstream sites, refer to Figure 9). The probes on each string were deployed at 10m depth and 1-2m above the seafloor. Results for all probes are presented graphically in Figure 19 with the two DLS1 probes labelled by SE, and the two DLS2 probes by NW.
A problem during the deployment of the NW10m probe meant that there was no data for this probe from mid-September to mid-October. However, prior to mid-September both probes at 10m depth provided almost identical profiles and therefore it is probable that the SE probe at 10m depth is representative of the general conditions (DO levels and extent of temporal variation) both up and downstream of the facility.
General observations from the graphs include: 1) DO levels are highly variable through the day at this site which would reflect the strong tidal currents present at that particular part of Norfolk Bay. 2) The general trend, as might be expected, was for the temperature to rise and the DO concentration to fall (the latter most likely as a consequence of the temperature rise) from August through to the end of October. DO % saturation remained at or just below 100% throughout the monitoring period, although there were periods with up to 20% saturation variability in levels on a daily basis, especially in late October. This variability was also evident in the DO concentration results. 3) DO levels on the seafloor were generally slightly lower than for 10m depth. There was also less variability in seafloor DO levels when compared to 10m depth. Overall for the whole monitoring period, DO and temperature levels were consistent with depth that is the two seafloor probes were almost in direct agreement, and the two 10m depth probes also provided similar results. 4) There appears to be a period of a week in early September when the DO levels decreased and the temperature increased contrary to the general trend. As this change in DO levels for this period is also reflected in the water temperatures then this is most likely to be a broader environmental change rather than anything to be associated with the fish pens. 5) In general the temperatures at depth and 10m were consistent through the monitoring period until the second week in October when seafloor temperatures diverged from those at 10m depth, and were 1.5oC below the 10m depth temperatures by the end of the recordings. 6) There was a decrease in DO levels (influenced by tide on a daily basis) at 10m depth from the 12th October to the end of recording. As this was the period of maximum fish biomass then this may be partially responsible for the decrease. However, there is strong evidence for changed environmental conditions through this period as demonstrated by the increased temperatures in the Hobo probe at 10m and the evidence for a relatively strong thermocline and associated halocline through this period as discussed in the Sonde results section above.
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Figure 19 – Dissolved oxygen (saturation and concentration) and temperature at sites DLS1 & DLS2 for the period of stocking of the permit area.
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6 Seagrass surveys (provided by Aquenal)
Methods Seagrass surveys were undertaken at three sites adjacent to the Permit area for the baseline environmental survey conducted in July 2018 and the December 2018 survey, approximately six weeks following removal of all fish from the Permit area. At each site, three ROV survey dives were undertaken, each approximately 30 m in length (see Table 9 for survey coordinates). During review of video footage, coverage of seagrass and Caulerpa was estimated from ten frame grabs randomly distributed thorough the course of the dive. Epiphyte coverage was also assessed from these frame grabs, according to a qualitative scale (Table 7). The dominant flora and fauna were also recorded during review of seagrass footage. Table 7 - Epiphyte coverage qualitative scale Epiphyte scale Description 1 Very low, virtually clean plants 2 Low; minimal epiphytic growth 3 Medium; obvious epiphytic growth 4 High; most plants covered 5 Very high, plants completely covered
Results and interpretation A summary of observations made from seagrass survey dives undertaken in December 2018 are provided in Table 8 below. As observed in the baseline environmental survey conducted in July 2018, there was considerable variation in seagrass abundance and habitat type across the three sites. Seagrass (Zostera tasmanica) abundance was highest at site S1, where dense seagrass patches (average cover 65 % across sites) were interspersed amongst patches of unvegetated sand.
A mixed seagrass/Caulerpa assemblage was present at site S2, interspersed with patches of unvegetated sand. Small areas of low-profile reef were also evident at site S2. Coverage of seagrass averaged 13 % across the three survey dives at S2, while Caulerpa averaged 27 %.
At site S3, coverage of seagrass was low (<10%) and no Caulerpa was recorded from frame grabs. The dominant habitat type at this site was unvegetated sand, with coarse shell grit and dead bivalve shells present.
Epiphytes were scored as medium on most dives and there was no strong difference between survey locations (see Table 10 for raw data). Epiphyte coverage scores averaged 2.7 across all sites, compared to 3.4 in July 2018.
A range of flora and fauna were observed across the three survey sites (see Table 8). Asterias amurensis were observed at all sites, with densities lower than recorded in July 2018. Stalked ascidians (Sycozoa sp.) were evident at each site, with overall numbers slightly lower compared to the July 2018 survey. Variation in abundance of stalked ascidians is likely due to
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minor variation in the ROV track between surveys. No handfish or handfish egg masses were detected at any site during review of video footage.
Overall, patterns of seagrass and epiphyte coverage were generally comparable with the July 2018 survey (Aquenal. MF117 Green Head Baseline Environmental Assessment. Draft Final Report, September 2018. 50 pp). Representative imagery from the December 2018 seagrass survey is included in Figure 20.
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Table 8 - Summary of seagrass observations. Seagrass and Caulerpa coverage estimates represent average assessed across ten replicate frame grabs per dive. Average
epiphyte scores represent average assessed across ten replicate frame grabs per dive. See
(per (per
%
sp.; per sp.;
Dive Flora/Fauna
Sycozoa
Seagrass coverage coverage Seagrass (%) Caulerpa score Epiphyte Asterias amurensis transect) ascidians Stalked ( transect) Fauna: Solitary ascidians (Ascidia sydneiensis), little rock whiting (Neodax balteatus), toothbrush leatherjacket S1.1 78 0 3 6 0 (Acanthaluteres vittiger), bridled leatherjacket (Acanthaluteres spilomelanurus) Flora: Zostera tasmanica, C. longifolia, Caulocystis uvifera Fauna: Solitary ascidians (Ascidia sydneiensis), occasional sponge, little rock whiting (Neodax balteatus), toothbrush leatherjacket (Acanthaluteres vittiger), bridled leatherjacket (Acanthaluteres spilomelanurus), 6-spine leatherjacket S1.2 78 1.5 2.9 9 0 (Meuschenia freycineti), big-bellied seahorse (Hippocampus abdominalis), red mullet (Upeneichthys vlamingii), pipefish, blue-throat wrasse (Notalabrus tetricus) Flora: Zostera tasmanica, Caulerpa longifolia, C. simpliciuscula, C. trifaria Fauna: Solitary ascidians (Ascidia sydneiensis), flat oyster (Ostrea angasi), shaw's cowfish (Aracana aurita) S1.3 40.2 8 2.1 2 3 Flora: Zostera tasmanica, Caulerpa longifolia, C. trifaria, Caulocystis uvifera Fauna: Myxicola infundibulum S2.1 15.5 19.5 3.3 1 1 Flora: Zostera tasmanica, Caulerpa longifolia, Caulerpa simpliciuscula, C. geminata Fauna: Blue-throat wrasse (Notolabrus tetricus), long-finned pike (Dinolestes lewini), little rock whiting (Neodax balteatus) S2.2 14.2 27.5 2.9 0 0 Flora: Zostera tasmanica, Halophila australis, Caulerpa longifolia, Caulerpa simpliciuscula, C. geminata, Caulocystis uvifera Fauna: Blue-throat wrasse (Notolabrus tetricus), purple urchin (Heliocidaris erythrogramma) S2.3 9 33 3.2 0 0 Flora: Zostera tasmanica, Halophila australis, Caulerpa longifolia, C. geminata, Caulocystis uvifera, Cystophora retroflexa Fauna: Solitary ascidians (Ascidia sydneiensis), occasional sponge, flat oyster (Ostrea angasi), gobiidae sp. S3.1 6.1 0 2.3 3 0 Flora: Zostera tasmanica Fauna: Solitary ascidians (Ascidia sydneiensis), occasional sponge, Myxicola infundibulum, gobiidae sp. S3.2 2.2 0 2 12 0 Flora: Zostera tasmanica, Codium fragile Fauna: Solitary ascidians (Ascidia sydneiensis), occasional sponge, Myxicola infundibulum, biscuit star (Tosia sp.), S3.3 4 0 2.6 5 1 gobiidae sp. Flora: Zostera tasmanica, Caulerpa longifolia, Ulva sp.
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Table 9 - Survey coordinates for December 2018 seagrass surveys, based on the Mapping Grid of Australia Zone 55 (Datum GDA94). Start End Name Easting Northing Easting Northing S1.1 555509 5246361 555497 5246332 S1.2 555509 5246361 555538 5246355 S1.3 555509 5246361 555535 5246377 S2.1 556393 5245662 556364 5245652 S2.2 556393 5245662 556423 5245651 S2.3 556393 5245662 556393 5245629 S3.1 557124 5245135 557098 5245158 S3.2 557124 5245135 557134 5245101 S3.3 557124 5245135 557096 5245111
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Table 10 - Frame grab analysis of December 2018 seagrass footage
b
Dive Flora/Fauna
%
Replicate frame gra frame Replicate (%) coverage Seagrass Caulerpa score Epiphyte (per amurensis Asterias transect) ascidians Stalked per sp.; (Sycozoa transect) 1 70 0 3 2 80 0 2 Fauna: 3 80 0 3 Solitary ascidians (Ascidia sydneiensis), little rock 4 90 0 2 whiting (Neodax balteatus), toothbrush 5 80 0 3 leatherjacket (Acanthaluteres vittiger), bridled S1.1 6 0 leatherjacket (Acanthaluteres spilomelanurus) 6 90 0 4 7 80 0 4 Flora: 8 80 0 3 Zostera tasmanica, C. longifolia, Caulocystis uvifera 9 60 0 4 10 70 0 2 1 80 0 2 Fauna: 2 60 10 4 Solitary ascidians (Ascidia sydneiensis), occasional sponge, little rock whiting (Neodax balteatus), 3 100 0 3 toothbrush leatherjacket (Acanthaluteres vittiger), 4 70 5 3 bridled leatherjacket (Acanthaluteres 5 80 0 2 spilomelanurus), 6-spine leatherjacket (Meuschenia freycineti), big-bellied seahorse S1.2 6 50 0 2 9 0 (Hippocampus abdominalis), red mullet 7 80 0 3 (Upeneichthys vlamingii), pipefish, blue-throat 8 80 0 4 wrasse (Notalabrus tetricus) 9 90 0 3 Flora: 10 90 0 3 Zostera tasmanica, Caulerpa longifolia, C. simpliciuscula, C. trifaria 1 40 5 4 2 10 10 2 3 70 0 2 Fauna: 4 50 0 2 Solitary ascidians (Ascidia sydneiensis), flat oyster 5 50 10 2 (Ostrea angasi), shaw's cowfish (Aracana aurita) S1.3 2 3 6 2 5 1 Flora: 7 50 0 2 Zostera tasmanica, Caulerpa longifolia, C. trifaria, 8 50 0 2 Caulocystis uvifera 9 50 20 2 10 30 30 2 1 40 0 5
2 10 80 3 Fauna: Myxicola infundibulum 3 5 70 4 S2.1 1 1 4 20 30 4 Flora: Zostera tasmanica, Caulerpa longifolia, Caulerpa simpliciuscula, C. geminata 5 30 5 4
6 0 10 4
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b
Dive Flora/Fauna
%
Replicate frame gra frame Replicate (%) coverage Seagrass Caulerpa score Epiphyte (per amurensis Asterias transect) ascidians Stalked per sp.; (Sycozoa transect) 7 5 0 4 8 5 0 2 9 0 0 1 10 40 0 2 1 2 0 1 2 0 5 3 3 5 15 4 Fauna: Blue-throat wrasse (Notolabrus tetricus), 4 10 10 3 long-finned pike (Dinolestes lewini), little rock 5 20 70 3 whiting (Neodax balteatus) S2.2 0 0 6 30 30 2 Flora: Zostera tasmanica, Halophila australis, 7 20 20 5 Caulerpa longifolia, Caulerpa simpliciuscula, C. 8 40 40 4 geminata, Caulocystis uvifera 9 10 60 2 10 5 25 2 1 20 0 4 2 20 70 3 3 10 30 4 Fauna: Blue-throat wrasse (Notolabrus tetricus), 4 10 20 2 purple urchin (Heliocidaris erythrogramma) 5 5 60 3 S2.3 0 0 6 25 50 4 Flora: Zostera tasmanica, Halophila australis, Caulerpa longifolia, C. geminata, Caulocystis 7 0 40 4 uvifera, Cystophora retroflexa 8 0 40 2 9 0 0 2 10 0 20 4 1 5 0 1 2 2 0 3 3 5 0 3 Fauna: 4 5 0 1 Solitary ascidians (Ascidia sydneiensis), occasional 5 5 0 2 sponge, flat oyster (Ostrea angasi), gobiidae sp. S3.1 3 0 6 2 0 2 Flora: 7 5 0 2 Zostera tasmanica 8 2 0 3 9 10 0 3 10 20 0 3
1 0 0 2 Fauna: Solitary ascidians (Ascidia sydneiensis), occasional 2 2 0 2 sponge, Myxicola infundibulum, gobiidae sp. S3.2 12 0
3 0 0 1 Flora: 4 0 0 2 Zostera tasmanica, Codium fragile
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b
Dive Flora/Fauna
%
Replicate frame gra frame Replicate (%) coverage Seagrass Caulerpa score Epiphyte (per amurensis Asterias transect) ascidians Stalked per sp.; (Sycozoa transect) 5 5 0 3
6 10 0 2 7 5 0 2 8 0 0 2 9 0 0 2 10 0 0 2 1 2 0 3 2 2 0 2 3 5 0 2 Fauna: 4 10 0 2 Solitary ascidians (Ascidia sydneiensis), occasional 5 10 0 2 sponge, Myxicola infundibulum, biscuit star (Tosia S3.3 5 1 sp.), gobiidae sp. 6 5 0 3 7 2 0 3 Flora: 8 2 0 3 Zostera tasmanica, Caulerpa longifolia, Ulva sp. 9 2 0 3 10 0 0 3
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Figure 20 - Representative imagery from December 2018 Seagrass surveys (frame grabs) on following 3 pages
S1.1
S1.2
S1.3
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S2.1
S2.2
S2.3
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S3.1
S3.2
S3.3
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