Fish Farm Consent Modelling. Poll na Gille

Transcription

1 Poll na Gille February 2014 Report Written by Environental Manager Marine Harvest Scotland Fars Office Blar Mhor Industrial Estate Fort Willia, PH33 7PT Tel: + 44(0) Fax: + 44(0) co

2 CONTENTS Page EXECUTIVE SUMMARY 1 1 INTRODUCTION 2 2 MODEL INPUT DETAILS HYDROGRAPHIC DATA SITE DETAILS RUN DETAILS 7 3 MODELLING RESULTS BIOMASS RESULTS TRANSECT AND SAMPLING STATIONS IN-FEED TREATMENTS SLICE CALICIDE BATH MODEL RESULTS 13 5 RESULTS AND CONCLUSIONS 13 REFERENCES 17 1

3 List of Figures Figure 1 Location of Poll na Gille Salon Far... 2 Figure 2 Poll na Gille current direction frequency fro the surface current eter... 4 Figure 3 Current velocity tie series fro the surface current eter record... 5 Figure 4 Poll na Gille bathyetry and cage layout... 7 Figure 5 Benthic ipact for run 1, Int-Neap current data... 9 Figure 6 Location of the selected and spare transects Figure 7 Cross-sections of both the selected and spare transects respectively Figure 8 Poll na Gille EBZ concentrations for run 1 (118 days) List of Tables Table 1 Suary of Results for Poll na Gille... 1 Table 2 A suary of the ean and residual currents recorded at Poll na Gille... 4 Table 3 Poll na Gille Project Inforation... 6 Table 4 Strait Paraeters... 7 Table 5 Selected and Spare Transect Starting Points Table 6a&b The details of the three selected and spare survey stations respectively Table 7 Poll na Gille Modelling Results Suarised

4 EXECUTIVE SUMMARY This report has been prepared by Marine Harvest ( Scotland) Ltd. to eet the requireents of the Scottish Environent Protection Agency ( SEPA) for the purpose of assessing an application to change equipent, and consequently increase bioass, and for consent to use sufficient sealice treatents in a arine salon far, via AutoDepood and dispersion odelling. The report describes bioass, in-feed and bath treatent odelling results for the Poll na Gille site, a suary of which is provided in Table 1 below. The report held centrally, and previously accredited, by SEPA ( AMMR11v02) details odelling ethods used. Table 1 Suary of Results for Poll na Gille Site Nae: Site location: SITE DETAILS Poll na Gille Sound of Shuna Peak bioass ( T): 2,262 CAGE DETAILS Nuber of cages: 16 Cage diensions: 100 circuference Working Depth ( ): 12 Cage group configuration: Surface Currents Middle Currents Seabed Currents HYDROGRAPHIC SUMMARY Average Speed (/s) 8x2 50 ooring atrix 0.068/s Residual Direction 0.032/s at 234 G Wind-Influence Average Speed (/s) slight 0.061/s Residual Direction 0.022/s at 255 G Average Speed (/s) 0.081/s Residual Direction 0.045/s at 343 G BENTHIC MODELLING Max fish bioass proposed ( T) 2,262 Max Average Stocking Density (kg/³) Distance to the 30ITI contour () 57 Direction of transect ( G) IN-FEED TREATMENTS Recoended consent ass EBZ ( g) Equivalent Fish Bioass ( T) 6150 Maxiu Treatent Aount EBZ ( g) 792 BATH TREATMENTS Recoended consent ass in 3 hrs Azaethiphos Recoended consent ass in 24 hrs Azaethiphos Recoended consent ass in 3 hrs Cyperethrin 269.6g cage/treatent, 2 treatent/day cage/treatent, 2 treatent/day 48.8g 7 cages/treatent 1

5 Recoended consent ass in 3 hrs Deltaethrin 18.3g 6 cages/treatent 1 INTRODUCTION This report has been prepared by Marine Harvest to eet the requireents of the Scottish Environent Protection Agency ( SEPA) for the purpose of assessing an application to change equipent, and consequently increase bioass, and for consent to use sufficient sealice treatents, via AutoDepood and dispersion odelling. The report describes odelling results for the Poll na Gille site in Loch Shuna ( Figure 1) to deterine EQScopliant bioass and sea-lice treatent levels for the proposed equipent. Report nuber AMMR11v02 which is held centrally, and has been previously accredited, by SEPA, provides details of the generic odelling ethods used. Figure 1 Location of Poll na Gille Salon Far 2

6 2 MODEL INPUT DETAILS 2.1 HYDROGRAPHIC DATA The Poll na Gille site data were collected by Marine Harvest for the purpose of assessing a consent application with the AutoDepood software. Methods of the data collection and analysis followed current SEPA guidelines ( SEPA, 2005); the data used were of 15 days duration and were analysed using both the appropriate SEPA hydrographic excel teplate for 20 inute data and the hg-analysis spreadsheet, also provided by SEPA. The Adiralty Hydrographic Office tide prediction software Total Tide was used to deterine the start dates of spring and neap tides and to deterine the ties of high water and ean tidal height for the area (see Table 3). Following SEPA guidelines the start points in the current eter record used for odelling are those closest to idday on the day of the interediate spring tides and the interediate neap tides. In the current eter data used, after hourly averaging, the ties of interediate HW spring and HW neap corresponded to records 169 and 1 respectively. Prior to coenceent of odelling the current data required correction to Grid North and was thus corrected by 0W. The hourly averaged current data for the surface, iddle and botto bins were then saved as space deliited files, as detailed in AMMR11v02 and following the default AutoDepood file structure. Using the hg-analysis spreadsheet the ean speed and the residual current speed and direction were established for each of the three current eter depths. The ean and residual currents, and the histogra frequency peaks are suarised in Table 2 below. The data showed a residual current in the south-westerly direction at near-surface (Figure 2) and also at id-depth, at near-bed depths this was found to be north-westerly. A slight correlation was found between the surface current speeds and the wind speeds ( Figure 2); however a tidal pattern can still be seen. The wind direction was predoinantly fro the south and the ean wind speed over this period was 1.8/s. 3

7 Figure 2 Poll na Gille current direction frequency fro the surface current eter SURFACE Mean speed 0.068/s 0.032/s at Residual Speed 234 G Residual Parallel 0.019/s Residual Noral 0.026/s Tidal Aplitude Parallel 0.096/s Tidal Aplitude Noral 0.039/s Frequency Peak 190 G MIDDLE Mean Speed 0.061/s 0.022/s at Residual 255 G Frequency Peak 190 G BOTTOM Mean Speed 0.081/s 0.045/s at Residual 343 G Frequency Peak 340 G Table 2 A suary of the ean and residual currents recorded at Poll na Gille 4

8 Figure 3 Current velocity tie series fro the surface current eter record 5

9 2.2 SITE DETAILS The Poll na Gille site is situated Loch Shuna ( Figure 1). Marine Harvest proposes to install pens in a 50 atrix and so the AutoDepood and the Bath Treatent odels have been run to deterine EQS-copliant bioass and edicinal consents for this new equipent. Details of the site are provided in Table 3. The receiving water is defined as a strait. The width of the strait and the distance both to the shore and to the head of the loch were calculated fro digital Adiralty Charts and are shown in Table 4. SITE DETAILS Site Nae: Poll na Gille Site location: Loch Shuna Peak bioass (T): 2262 Proposed feed load (T/yr): 3532 (7331 for slice) Proposed treatent use: Azaethiphos, Cyperethrin, Deltaethrin & Eaectin Benzoate CAGE DETAILS Group location: E N Nuber of cages: 16 Cage diensions: 100 cages, 50 grid Working Depth ( ): 12 Cage group configuration: 8x2 Cage group orientation ( G): 9.2 Cage group distance to shore (k): 240 Water depth at site (): 26 HYDROGRAPHIC DATA Current eter position: E N Depth at deployent position ( ): 30.4 Surface bin centre height above bed (): 25.3 Middle bin centre height above bed (): 19.1 Botto bin centre height above bed (): 2.8 Duration of record: Current eter averaging interval: ADDITIONAL DATA 15 days: 24/09/09 to 09/10/09 20 in Magnetic correction to grid North: 1.5W Predicted Spring Tide 2.0 (26/9) Predicted Neap Tide 2.9 (4/10) Predicted Spring Tide 2.0 (11/10) Mean Tidal Level at Site (): 1.7 Closest Standard Port Loch Melfort Date of Interediate- Spring Tides: 04/10/2009 Date of Interediate-Neap Tides: 26/09/2009 Table 3 Poll na Gille Project Inforation 6

10 STRAIT PARAMETERS Distance to Head 3.77k Table 4 Strait Paraeters 2.3 RUN DETAILS A new project was created in AutoDepood and naed PNG2014a. The site and cage details provided in Table 3 were entered into the appropriate files and all other data were set to default. The resulting site bathyetry and cage layout is shown in Figure 4. Modelling of both the bioass and cheotherapeutants was undertaken following the ethods outlined in the Methods Report AMMR11v02 which is held centrally by SEPA. Details of the odelling results have been provided in the next section according to SEPA requireents. Figure 4 Poll na Gille bathyetry and cage layout Two types of treatent are used to control sea lice infestation in arine salon fars and these require different odelling approaches. The in-feed treatents Calicide ( active ingredient Teflubenzuron) and Slice ( active ingredient Eaectin Benzoate) require deposition odelling using AutoDepood to predict the cheical accuulation on the 7

11 seabed beneath the fish cages associated with fish faeces and uneaten treated feed. The bath treatents Salosan ( cheical nae Azaethiphos), Excis ( cheical nae Cyperethrin) and Alphaax ( Deltaethrin), where the salon are iersed in a diluted solution of the treatent cheical require dispersion odelling to predict the concentration in the water colun after release. Results fro both AutoDepood and the Bath odel have been provided in the next section. Marine Harvest does not intend to apply for the use of Teflubenzuron at Poll na Gille due to the very liited consent ass likely to be granted at the site as a result of resuspension. 8

12 3 MODELLING RESULTS 3.1 BIOMASS RESULTS AutoDepood was run initially with the copany s preferred stocking density of kg/3, and proposed cage layout, using the odel s auto-distribute bioass function. The odel did not require to iterate to an EQS-coplaint solution as a pass was achieved at this stocking density and pen volue for the resultant axiu allowable bioass of 2262 tonnes. At this bioass the odel predicts the 80% solids area to be 43,4642 while the flux in this area is expected to be 1,565g/2/ year. The proposed layout and tonnage results in a benthic cage area of 31,2502 with a iniu ITI of 3.9 within the area. The flux in the benthic cage group area is predicted to be larger than the trigger value ( 10,000g/2/ year) at 10,660g/2/ year. The benthic sapling area ( ITI = 30) is expected to be 54, while the flux inside this area will be 191.8g/2/ year. The plotted AutoDepood output for the passing Int-Spring run 2 is shown in Figure 5. A suary with all of this inforation can be found in PNG2014a_ arine_su_v3.xls and in Table 7 of this report. Figure 5 Benthic ipact for run 2, Int-Spring current data The ass of solids released in run 1 is estiated to be 923,635kg with 42% ( 382,476kg) predicted to reain within the 1k2 odelling grid, thus only 58% ( 541,159kg) of the input load is predicted to be transported fro the odel grid as a result of resuspension. The site is classed as oderately flushed with a vector average residual of 0.032/s at 234 G indicating that this waste aterial is likely to be dispersed away fro the cages in a westerly direction with the tidal flow pushing it North also towards the head of the loch. 9

13 3.1.1 TRANSECT AND SAMPLING STATIONS Two transect profiles were created ( Figure 6) as part of SEPA s requireents to deterine site-specific sapling locations. The selected and spare transect inforation have been saved to the PNG2014a- BcnstFI- S-2_000.xls file located in the apping folder. Details of both transect starting points are provided in Table 5 below. Figure 6 Location of the selected and spare transects Transect Start Point Coordinates Main Spare NGR Easting NGR Northing Bearing G CD Depth ) Table 5 Selected and Spare Transect Starting Points 10

14 Table 6 describe the location and details of the three selected and spare survey stations. Figure 7 shows the cross-sections of the selected and spare transects, and the relevant survey stations. SELECTED NGR Easting NGR Northing EQS st Station) S EQS 2nd Station) S EQS rd Station) S Distance ( ) CD depth () Modelled ITI SPARE NGR Easting NGR Northing Distance EQS st Station) S EQS 2nd Station) S EQS rd Station) S ) CD depth ) Modelled ITI Table 6a&b The details of the three selected and spare survey stations respectively Figure 7 Cross- sections of both the selected and spare transects respectively 11

15 3.2 IN-FEED TREATMENTS SLICE The SLICE aspect of AutoDepood was run initially for a Total Allowable Quantity sufficient to treat 2.7 ties the proposed peak bioass (2152.5g & 6150 tonnes respectively). Marine Harvest have followed SEPA s guidance and used the axiu feedload for the site in the odel, resulting in a feedload of 7,331T. The odel did not require to iterate to an EQScoplaint solution as a pass was achieved at this quantity and bioass. The predicted area inside the g/kg contour (68,9122) was saller than the predicted far field AZE area 151,7272). The ean concentration of Slice in the near field AZE exceeds the EQS trigger value of 7.63g/kg by 112.7g/kg and thus enhanced onitoring will be required at the site if Slice is used. The plotted AutoDepood output for this run is shown in Figure 8. A further run for 223 days duration was perfored to obtain a site residual curve for this bioass. Figure 8 Poll na Gille EBZ concentrations for run 1 (118 days) The ass of EBZ reaining on the bed at the end of run 1 was 786g. For Slice, in the absence of resuspension, 74% or g of the input EBZ load would reain on the seabed after 118 days. This indicates that alost a half of the original input load is lost through resuspension ( 37%). The ass of EBZ lost fro the grid ( g) represents an equivalent area of 8.7k2 if it assued to distribute evenly at the far field EQS concentration of 0.763g/kg sedient. Due to the ain direction of the near surface current ost of this aterial will ost likely be transported towards the head of the loch. 12

16 3.2.2 CALICIDE Teflubenzuron odelling was undertaken for Poll na Gille using the odelled peak bioass and a pass was predicted at this tonnage. However, due to the predicted export of the cheical fro the odel grid, and using the precautionary approach encouraged by SEPA for sites in unconstrained areas, the recoended consent ass for Teflubenzuron would not be practical and therefore it s use would not be recoended at the site. Because of this, the Teflubenzuron odelling files have not been provided. 3.3 BATH MODEL RESULTS Cage details for Poll na Gille are given in section 2. The initial cage treatent depth used for the bath treatents was 5. Using the results fro the analysis of the surface current eter data in the short ter bath treatent odel EQS copliance for both Deltaethrin and Cyperethrin at this cage depth was predicted. EQS copliance for Azaethiphos was predicted at a cage depth of 1.7. Cyperethrin & Deltaethrin Results: Cage Treatent Depth = 5 Perissible Quantity of Cyperethrin = 48.8g; 7 cage/3 hours Perissible Quantity of Deltaethrin = 18.3g; 6 cage/3 hours Azaethiphos Results: Cage treatent depth = 1.7 Perissible Quantity of Azaethiphos = 269.6g; 2 cage/3 hours Perissible Quantity of Azaethiphos = 270.5g; 2 cage/24 hours The perissible quantity of Cyperethrin or Deltaethrin ( 6 cage/3hrs) eans that full treatent of the 16 pens at the site, would take approxiately three days to coplete. The bath treatent odel files are saved in the folder PNG2014a\ Bath 5 RESULTS AND CONCLUSIONS It is recoended that the bioass and treatent aounts are consented at this site as given below in Table 7. The results of the odelling perfored at this site are given in the file: PNG2014a_arine_su_v3.xls in the Poll na Gille folder. BENTHIC MODELLING: 13

17 Max fish bioass proposed ( T) 2,262 Cage depth () 12 Max Average Stocking Density ( kg/³) Maxiu nuber of cages 16 loss of solids fro odel grid (%) 58.0 Cage area equivalent (²) 31,250 Flux in the cage area (g/²/y) 10,660 ITI in the cage area 3.9 Flux under cages exceeds trigger value by 6% 80% solids area (²) 43,464 Flux in the 80% solids area (g/²/y) 1,565 ITI in the 80% solids area 9.9 Benthic sapling area (²) 54, Flux in the benthic sapling area (g/²/y) ITI in benthic sapling area 30 SITE SPECIFIC SAMPLING: Transect start coordinates E N Direction ( T) CD Depth () 30.5 Distance to the 30ITI contour () 57 SPARE TRANSECT INFORMATION E Transect start coordinates N Direction ( T) CD Depth () 26.2 Distance to the 30ITI contour () 25 IN-FEED TREATMENTS Peak fish bioass at site (T) 2262 Near Field AZE (²) Far Field AZE (²) Recoended consent ass EBZ (g) Equivalent Fish Bioass ( T) 6150 Maxiu Treatent Aount EBZ (g) 792 Area of Ipact at Far Field EQS (²) loss of EBZ fro odel grid (%) 37 BATH TREATMENTS Recoended consent ass in 3 hrs Azaethiphos Recoended consent ass in 24 hrs Azaethiphos Recoended consent ass in 3 hrs Cyperethrin 269.6g cage/treatent, 2 treatent/ day cage/treatent, 2 treatent/day 48.8g 7 cages/treatent 14

18 Recoended consent ass in 3 hrs Deltaethrin 18.3g 6 cages/treatent Table 7 Poll na Gille Modelling Results Suarised 15

19 16

20 REFERENCES SEPA Regulation and onitoring of arine cage fish faring in Scotland - a procedures anual: Annex G Models for assessing the use of edicines in bath treatents ( January 2007). SEPA, Regulation and onitoring of arine cage fish faring in Scotland - a procedures anual: Annex H - Methods for Modelling In-Feed Anti-Parasitics and Benthic Effects (June 2005) SEPA, Regulation and onitoring of arine cage fish faring in Scotland - a procedures anual: Attachent VIII Hydrographic data requireents for applications to discharge fro Marine Cage Fish Far (May 2005). UKHO, Adiralty Tide Tables; volue 1 UK and Ireland. United Kingdo Hydrographic Office, Taunton. 17