BIOMASS & IN-FEED TREATMENTS MODELLING REPORT

BIOMASS & IN-FEED TREATMENTSMODELLING REPORT

Calbha 5 Finfish Pen Site, Eddrachillis Bay, Sutherland

Prepared for

Loch Duart Ltd

Badcall Salmon HouseScourie

SutherlandIV27 4TH

Caerthann HouseGrosvenor CrescentConnelArgyll PA37 1 PQ

Registered in Scotland, No: SC175087Tel: +44 (0)1631 720699 E-mail: mail@transtechltd. com

TransTech Limitedwww.transtechltd. com

uality Assurance

The data used in this document and their input and reporting have undergone a qualityassurance review which follows established TransTech Ltd procedures. The informationand results presented herein constitute an accurate representation of the data collected.

TransTech is registered with SEPA for marine pen site Biomass ( Ref: AMMR08v02) andChemical discharge modelling ( Ref: AMMR08v01).

Document Details

Author:

Garret Macfarlane

PhD, BSc (hons)

Issue Date: 28 July 2018

Issue No: 2018v1

Calbha 5 AutoDEPOMOD Modelling Report 2018v1 p2/14

CONTENTS

1. Summary ...............................................................................................................................................42. Introduction ...........................................................................................................................................43. Calbha 5 site information ....................................................................................................................54. Hydrographic data ................................................................................................................................65. AutoDEPOMOD ...................................................................................................................................7

5.1 Site set-up ................................................................................................................... 75.2 Model grid generation .................................................................................................. 75.3 Benthic modelling ......................................................................................................................75.4 Slice modelling ............................................................................................................ 9

6. Transects and sample stations ....................................................................................................... 11APPENDIX 1 ............................................................................................................................................. 13APPENDIX 2 ............................................................................................................................................. 14

List of Figures

Figure 1. Plot of AutoDEPOMOD benthic model Run 14 ........................................................................... 8Figure 2. Calbha 5 EmBZ concentrations for Run 3 at 118 days ............................................................... 9Figure 3. Calbha 5 EmBZ concentrations for Run 4 at 223 days ............................................................. 10Figure 4. Plot showing primary and spare transect positions and the respective sample stations .......... 12Figure 5. Cross sections of the primary and spare transects ................................................................... 12

List of Tables

Table 1. Details and position of the three selected sample stations along the primary transect ............ 11Table 2. Details and position of the three selected sample stations along the spare transect ............... 11

List of Abbreviations

ATT Admiralty Total TideAZE Allowable Zone of EffectsBGS British Geological SurveyCD Chart DatumEmBz Emamectin Benzoate ( Slice) GMT Greenwich Mean TimeLST Lowest Spring TideMSL Mean Sea LevelOS Ordnance SurveyOSGB36 Ordnance Survey Great Britain 1936PE Pen EdgeSEPA Scottish Environment Protection Agency


1. Summary

1. This report has been prepared in order to meet the specific requirements of the ScottishEnvironment Protection Agency ( SEPA) for the assessment of applications for biomassconsent for salmonids held in marine pens.

2. The predictive model, AutoDEPOMOD, was used to determine the Allowable Zone ofEffects ( AZE) footprint, the maximum allowable biomass at the Calbha 5 site incompliance with the Environmental Quality Standards ( EQS) set by SEPA.

3. AutoDEPOMOD predicted a benthic pass for a biomass consent of 680.5 tonnes.

4. The recommended consent mass for Emamectin Benzoate is 893.2 g, equating to atreatable fish biomass of 2551. 9 tonnes ( 3.75 x Biomax).

2. Introduction

This report has been prepared in order to meet the specific requirements of the ScottishEnvironment Protection Agency ( SEPA) for the assessment of applications for biomass consentand the consent to use chemical treatments against sea lice in marine salmonid farms. Thebiomass and chemical treatment levels must comply with the EQS that are in place to protect themarine environment.

Treatment of sea lice infestation in marine salmonid farms is currently carried out using twodifferent methods; the in-feed treatment ( Slice) and bath treatments ( Salmosan, Excis andDeltamethrin). Each method requires a different form of predictive modelling.

This report describes the results of predictive modelling for the AZE footprint and the maximumpermissible quantity of the in-feed treatment Slice at the Calbha 5 site.

All hydrographic data used for the modelling was provided by Loch Duart Ltd. A hydrographicreport was produced by the Fish Vet Group, who carried out the ADCP deployment, and thedata were validated by SEPA for modelling purposes in May 2012.

The methods described in this report closely adhere to those set out in Annex H of the SEPAFish Farming Manual ( 2005), and the results are reported to satisfy consent applicationrequirements.

Benthic Pass = 680.5 TSlice Pass = 2551.9 TStocking Density = 9.8 kg/m3


3. Calbha 5 site information

Site details

Site name: Calbha 5Location: Eddrachillis Bay, Sutherland

Pen group details

Group centre: 215602. 7 E, 937270. 2 NNW pen centre position: 215551. 7 E, 937308. 7 NNumber of pens: 12Reported pen group configuration: 2 x 6Pen dimensions: 24 m squareWorking Depth: 10.0 mGrid size ( x by y): 25 m x 26.5 mPen group orientation: 139.0oPen group distance from shore: 113 m ( from pen edge to 0 mCD at closest

point)

Hydrographic data

Current meter position: 215578. 0 E, 937253.0 N30.2 m from group centre)

Sub surface cell height above bed: 29.69 m (5.2 m below LST) Selected pen bottom cell height above bed: 27.69 m (9.1 m below MSL) Near bed cell height above bed: 2.69 mDepth at deployment site: 34.2 mCDRecord used for modelling: 15 days ( 27/02/09 00:00 to 14/03/09 00:00) Current meter averaging interval: 20 min

Additional data

Correction to Grid N from Magnetic N: 2.0oMean Tidal Level at Site: 2.6 m (Badcall Bay)


4. Hydrographic data

Hydrographic data were collected over a 15 day period which incorporated both the spring andneap components of the tidal cycle. Data were collected at 20 minute intervals and copied intothe temp-20min- HGv3.xls spreadsheet to generate the . dat files required by AutoDEPOMOD. Dates and times of spring and neap high waters ( shown below) were determined using theAdmiralty Total Tide software ( ATT). Predictions were obtained for Badcall Bay ( 58°19'N5°08'W), the closest secondary port to the Calbha 5 site (predictions based on Ullapool).

Predicted spring tide HW 12/03/2009 07:35 GMT 4.8 mPredicted neap tide HW 05/03/2009 13:52 GMT 3.5 m

In accordance with SEPA modelling guidelines, current meter records to be used must start atmidday on the day of the intermediate- spring and intermediate- neap tide. The hourly averagedrecords that correspond to these times are 252 and 84 respectively in the temp-20min-HGv3.xlsfile.

Predicted intermediate- spring tide 09/03/2009 11:40 GMTPredicted intermediate- neap tide 02/03/2009 11:40 GMT

Admiralty Total Tide Mean sea level ( MSL) at the site is Chart Datum + 2.6 m and the lowestspring tide during the deployment ( LST) is Chart Datum + 0.7 m. The raw current meter directiondata were corrected from magnetic north to grid north by subtracting 2.0o from the magneticnorth direction data.

The current meter data is summarised below:

Mean and residual currents for 27/02/09 00:00 – 14/03/09 00:00 ( analysed usingHGdata_analysis_v7.xls (Version 7.11)):

Sub surface (29.69 m above seabed)

Mean speed 0.04 m/sResidual current 0.007 m/s at 225.6o Grid N

Pen bottom (27.69 m above seabed)

Mean Speed 0.03 m/sResidual current 0.006 m/s at 218.6o Grid N

Near bed (2.69 m above seabed)

Mean Speed 0.02 m/sResidual current 0.004 m/s at 143.5o Grid N


5. AutoDEPOMOD

5.1 Site set-up

A new project was created in AutoDEPOMOD ( v2.0.52, 17-Aug -2005) and namedCalbha5_ 2018v1. All of the relevant bathymetric and current meter files were set up in theirrespective directories and the pen information was entered into Calbha5_ 2018v1- FFMTv3. 0.xls. Pen positions and orientations were then checked by looking at the AutoDEPOMOD profile toensure that they were in the correct position.

5.2 Model grid generation

The grid limits were set to 215280 E to 216280 E and 936750 N to 937750 N.

The . csv and an appropriate . ini file was saved into the Calbha5_ 2018v1\ depomod\ gridgenfolder, as required by AutoDEPOMOD to generate the grid over which the pens would be laid. The grid was then generated with a cell size of 25 m and is shown in figure 1.

5.3 Benthic modelling

In the Model Parameters page of AutoDEPOMOD, the current meter data files in the Partrackdirectory were selected.

Run details used for biomass consent modelling:

No. of particles = Single run at 10Convergence value = 1 TSpring- Neap run

Benthic Modelling Feed Parameters:

Equally- distribute Biomass = ONStocking Density = 10.8507 kg/m3Pen Volume Adjustment = 1

A maximum biomass of 750.0 tonnes was specified for the modelling by setting the stockingdensity to 10.8507 kg/m3. The model iterated to a PASS prediction of 680.5 tonnes for the neap-spring and spring-neap runs respectively ( Runs 13 and 14). The run with the smallest area ofimpact at the 30 ITI EQS was Run 14 (spring- neap).

The maximum feed input for Run 14 (figure 1) was defined by the model as 4763.3 kg/day. The80% solids area was predicted as 21361 m2 with a flux in the area of 1537 g/m2/yr.

At the 680.5 tonnes biomass, the pen area equivalent contour flux was 12118 g/m2/yr, at a meanITI of 1.0 with a pen area of 7524 m2. The benthic sampling area, where the ITI = 30.0, showeda flux of 191.8 g/m2/yr inside an area of 36786 m2. A summary of the results can be found inCalbha5_ 2018v1_ marine_sum_v3.xls Benthic Worksheet in appendix 1.


215400 215600 215800 216000 216200

936800

937000

937200

937400

937600

100

0

2

5

10

20

30

42

50

60

100.0

191.8

1536.9

5000.0

10000.0

12118.0

15000.0

20000.0

25000.0

Figure 1. Plot of AutoDEPOMOD benthic model Run 14

N

Fluxg/m2/yr )

Depth ( m)


5.4 Slice modelling

Run details used for Slice modelling:

Biomass = 3402.5 T (5 x maximum biomass) Food load = 1738.605 T over 12 monthsNo of Particles = 10Convergence value = 1 TRun duration = 118 days followed by 223 days

EmBZ EQS values:

Near- field = 7.63 µg/ kg wet weight sediment ( trigger) Far-field = 0.763 µg/ kg wet weight sediment

The near and far-field AZE for Emamectin Benzoate were predicted by the model as 20000 m2and 87424 m2 respectively.

Slice Results

AutoDEPOMOD predicted a 118 day PASS result ( Run 3, figure 2) for the far-field EQS at atreatable biomass of 2551.9 tonnes, giving a recommended EmBZ consent mass of 893.2 g. The predicted area inside the 0.763 g/kg contour is 87142 m2, which is smaller than the 87424m2 of the far-field AZE.

At a biomass of 2551. 9 tonnes, the model predicted a higher concentration than the near- fieldAZE trigger value of 7.63 µg/ kg, where the mean concentration is 237. 1 µg/ kg.

A summary of the proposed in-feed chemical results can be found in appendix 2Calbha5_ 2018v1_ marine_ sum_ v3.xls (Version 3.13) Treatment Worksheet).

215400 215600 215800 216000 216200

936800

937000

937200

937400

937600

100

0

2

5

10

20

30

42

50

60

0.763

7.630

Figure 2. Calbha 5 EmBZ concentrations for Run 3 at 118 days

N

EmBZ Concentrationµg/ kg wet sediment)

Depthm)


The mass balance of EmBZ for Run 3 was predicted as 640 g, meaning that 2.35 % ( 20.97 g) ofthe input load is predicted to be transported from the model grid as a result of resuspension.

For the 223 day model run a MAX result was achieved at a treatable biomass of 2551.9 tonnes. This run is shown in figure 3.

215400 215600 215800 216000 216200

936800

937000

937200

937400

937600

100

0

2

5

10

20

30

42

50

60

0.763

7.630

Figure 3. Calbha 5 EmBZ concentrations for Run 4 at 223 days

N

EmBZ Concentrationµg/ kg wet sediment)

Depthm)


6. Transects and sample stations

Primary and spare sampling transects were created for the site ( tables 1 and 2) using BenthicRun 14.

Details of the primary transect:

Transect start co-ordinates ( PE) 215639. 6 E 937208. 1 N58 17.0813 N 05 08.7776 W

Transect bearing and length 139.0o Grid North and 100.0 mDepth ( PE) 35.5 mCD

Table 1. Details and position of the three selected sample stations along the primary transect

1st StationEQS- 10m)

S2

2nd StationEQS) S1

3rd StationEQS+ 10m)

S3

NGR Easting 215666. 8 215673. 3 215679. 9NGR Northing 937176. 9 937169. 4 937161. 8Latitude 58 17.0652 58 17.0613 58 17.0574Longitude 05 08.7483 05 08.7413 05 08.7342Distance ( m) 41.4 51.4 61.4Depth ( mCD) 34.1 33.8 33.7Modelled ITI 25.7 30.0 34.7

Details of the spare transect:

Transect start co-ordinates ( PE) 215545. 6 E 937314. 6 N58 17.1362 N 05 08.8787 W

Transect bearing and length 319.0o Grid North and 100.0 mDepth ( PE) 31.4 mCD

Table 2. Details and position of the three selected sample stations along the spare transect

1st StationEQS-10m)

S5

2nd StationEQS) S4

3rd StationEQS+10m)

S6

NGR Easting 215510. 8 215504. 2 215497. 7NGR Northing 937354. 6 937362. 1 937369. 7Latitude 58 17.1569 58 17.1607 58 17.1646Longitude 05 08.9161 05 08.9232 05 08.9303Distance ( m) 53.0 63.0 73.0Depth ( mCD) 29.0 28.6 28.1Modelled ITI 20.4 30.0 37.0

The position of both the primary and spare transects and the relative sample stations in relationto the site are shown in figures 4 and 5.


Figure 4. Plot showing primary and spare transect positions and the respective sample stations

Figure 5. Cross sections of the primary and spare transects

The benthic sampling has been packaged inCalbha5_ 2018v1\ depomod\ mapping\ XLS\Calbha5_ 2018v1- BcnstFI- S-14_000.xls.

SPARE

PRIMARY


APPENDIX 1

Calbha5_2018v1_marine_sum_v3.xls (Version 3.13) Benthic Worksheet

These are cornerpen centre positions


APPENDIX 2

Calbha5_2018v1_marine_sum_v3.xls (Version 3.13) Treatment Worksheet


BIOMASS & IN-FEED TREATMENTS MODELLING REPORT

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