biomass & in-feed treatment modelling report · pdf filebiomass & in-feed treatment...

BIOMASS & IN-FEED TREATMENTMODELLING REPORT

Proposed Finfish Pen Site at Dounie, Sound of Jura

Prepared for

Kames Fish Farming Ltd

KilmelfordArgyll

PA34 4XA

Caerthann HouseGrosvenor CrescentConnelArgyll PA37 1PQ

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

TransTech Limitedwww.transtechltd. com

Quality 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:

PhD, BSc (hons)

Issue Date: 13 August 2016

Issue No: 2016v1

Dounie AutoDEPOMOD Modelling Report 2016v1 p2/17

CONTENTS

1. Summary .................................................................................................................................. 42. Introduction .............................................................................................................................. 43. Dounie site information............................................................................................................. 64. Hydrographic data .................................................................................................................... 75. AutoDEPOMOD ....................................................................................................................... 8

5.1 Site set-up ......................................................................................................................... 85.2 Model grid generation ........................................................................................................ 85.3 Benthic modelling .............................................................................................................. 85.4 In-feed treatment modelling ............................................................................................. 11

5.4.1 Slice ....................................................................................................................... 116. Transects and sample stations ............................................................................................... 14APPENDIX 1 ............................................................................................................................... 16APPENDIX 2 ............................................................................................................................... 17

List of Figures

Figure 1. Plot of AutoDEPOMOD benthic model Run 2 (neap-spring) ........................................................ 9Figure 2. Plot of AutoDEPOMOD benthic model Run 5 (neap- spring) ........................................................ 9Figure 3. Dounie EmBZ concentrations for Run 1 at 118 days – no blanking file ...................................... 11Figure 4. Dounie EmBZ concentrations for Run 2 at 118 days – with blanking file ................................... 12Figure 5. Dounie EmBZ concentrations for Run 3 at 223 days – with blanking file ................................... 12Figure 6. Dounie EmBZ concentrations for Run 4 at 118 days – with blanking file ................................... 13Figure 7. Dounie EmBZ concentrations for Run 5 at 223 days – with blanking file ................................... 13Figure 8. Plot showing primary and spare transect positions and the respective sample stations ............ 15Figure 9. Cross sections of the primary and spare transects ..................................................................... 15

List of Tables

Table 1. Details and position of the three selected sample stations along the primary transect ............... 14Table 2. Details and position of the three selected sample stations along the spare transect .................. 14

List of Abbreviations

ATT Admiralty Total TideBGS British Geological SurveyCD Chart DatumGMT Greenwich Mean TimeLST Lowest Spring TideMSL Mean Sea LevelOS Ordnance SurveyPE Pen EdgeSEPA Scottish Environment Protection Agency


1. Summary

1. This modelling report has been prepared in order to meet the specific requirements of theScottish Environment Protection Agency ( SEPA) for the assessment of applications forbiomass consent and the consent to use chemical treatments against sea lice forsalmonids held in marine pens.

2. The predictive model, AutoDEPOMOD, was used to determine the Allowable Zone ofEffects ( AZE) footprint, the maximum allowable biomass and the level of EmamectinBenzoate ( Slice) treatment that may be used at the proposed Dounie site in compliancewith the Environmental Quality Standards ( EQS) set by SEPA.

3. The maximum permitted biomass was predicted to be 2500.0 tonnes.

4. The recommended consent mass for Emamectin Benzoate is 1245. 5 g, equating to atreatable fish biomass of 3558. 7 tonnes ( 1.42 x Biomax).

Benthic Pass = 2500.0 TSlice Pass = 3558.7 TStocking Density = 16.4 kg/m3


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 Dounie site.

The hydrographic data used in the modelling were collected by TransTech and SEPA hasvalidated this for modelling purposes.

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


3. Dounie site information

Site details

Site name: DounieLocation: Dounie, Sound of Jura, ArgyllProposed in-feed treatment use: Emamectin Benzoate

Proposed pen group details

Group centre position: 175235. 8 E, 691882. 8 NNW corner pen centre position: 175244. 0 E, 692010. 0 NNumber of pens: 12Pen group configuration: 2 x 6Pen dimensions: 100 m circularWorking Depth: 16.0 mGrid size: 50 m x 50 mPen group orientation: 195.0o Grid North ( from NW corner cage centre) Pen group distance from shore: 56.5 m (from pen edge to 0 mCD at closest point)

Hydrographic data

Current meter position: 175313. 8 E, 692010. 5 N149.6 m from group centre)

Sub surface cell height above bed: 25.6 m (5.56 m below LST) Selected net bottom cell height above bed: 15.6 m (16.37 m below MSL) Near bed cell height above bed: 2.6 mDepth at deployment site: 31.06 mCDRecord used for modelling: 15 days ( 17/09/15 14:00 to 02/10/15 14:00 GMT) Current meter averaging interval: 20 min

Additional data

Correction to Grid N from Magnetic N: 0.75oMean Tidal Level at Site: 0.91 m (Carsaig 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 was copiedinto the supplied SEPA spreadsheet template for 20 minute interval data ( temp-20min-HGv3.xls). Dates and times of spring and neap high waters ( shown below) were determinedusing the Admiralty Total Tide software ( ATT). Predictions were obtained for Carsaig Bay56°02'N 5°38'W), the closest secondary port to the Dounie site ( predictions based on Oban).

Please note that the site name in the temp-20min-HGv3.xls is Dounie_ 2015v1 as this file wascreated in 2015.

Predicted spring tide HW 30/09/2015 18:28 GMT 2.1 mPredicted neap tide HW 22/09/2015 23:25 GMT 1.3 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 241 and 49 respectively in the temp- 20min- HGv3. xlsfile.

Predicted intermediate- spring tide 27/09/2015 12:20 GMTPredicted intermediate- neap tide 19/09/2015 12:20 GMT

Admiralty Total Tide Mean sea level ( MSL) at the site is Chart Datum + 0.91 m and the lowestspring tide during the deployment ( LST) is Chart Datum + 0.1 m. The raw current meter directiondata were corrected from magnetic north to grid north by subtracting 0.75º ( obtained fromhttp:// www. geomag. bgs.ac.uk/gifs/gma_calc.html) from the magnetic north direction data.

The current meter data is summarised below:

Mean and residual currents for 17/09/15 14:00 - 02/10/15 14:00 GMT ( analysed usingHGdata_analysis_v7.xls (version 7.11)):

Sub surface ( 25.6 m above seabed)

Mean speed 0.182 m/sResidual current 0.052 m/s at 59.0o Grid N

Pen bottom (15.6 m above seabed)

Mean Speed 0.180 m/sResidual current 0.047 m/s at 54.5o Grid N

Near bed (2.6 m above seabed)

Mean Speed 0.164 m/sResidual current 0.025 m/s at 20.9o Grid N


IAUser

http://www.geomag.bgs.ac.uk/gifs/gma_calc.html

5. AutoDEPOMOD

5.1 Site set-up

A new project was created in AutoDEPOMOD ( v2.0.52, 17-Aug-2005) and namedDounie_ 2016v1. All of the relevant bathymetric and current meter files were set up in theirrespective directories and the pen information was entered into Dounie_ 2016v1- 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

Grid limits were defined as 174650 E to 175650 E and 691500 N to 692500 N.

The . csv and an appropriate . ini file was saved into the Dounie_ 2016v1\ depomod\ gridgen folder, as required by AutoDEPOMOD to generate the grid over which the pens would be laid. The gridwas 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 = Initial run 1 and refine at 10Convergence value = 1 TInitial runs with Neap- Spring and redo for Spring- Neap

Benthic Modelling Feed Parameters:

Auto-distribute Biomass = ONStocking Density = 16.36247 kg/m3Pen Volume Adjustment = 1

An AutoDEPOMOD MAX result was obtained for the neap- spring and spring- neap model runsRuns 2 and 3) at a biomass of 2500.0 tonnes

The run with the smallest area of impact at the 30 ITI was Run 3 (spring- neap). The model wasre-run using a blanking file as the benthic footprint was predicted to overlay land ( see figure 1).


174800 175000 175200 175400 175600

691600

691800

692000

692200

692400

20

0

2

5

10

20

30

40

50

60

70

80

90

100

100.00

184.90

191.80

279.60

5000. 00

Figure 1. Plot of AutoDEPOMOD benthic model Run 3 (spring- neap)

For the modelling with the blanking file a MAX prediction was achieved at a biomass of 2500. 0tonnes for both the neap- spring and spring- neap runs ( Runs 5 and 7). The run with the smallestarea of impact at the 30 ITI EQS was Run 5 (spring-neap).

The maximum feed input for Run 5 ( figure 2) was defined by the model as 17500 kg/day. The80% solids area was predicted as 25478 m2 with a flux in the area of 185 g/m2/yr.

174800 175000 175200 175400 175600

691600

691800

692000

692200

692400

20

0

2

5

10

20

30

40

50

60

70

80

90

100

100.00

182.50

191.80

283.80

Figure 2. Plot of AutoDEPOMOD benthic model Run 5 (spring- neap)

N

Fluxg/m2/yr)

Depthm)

N

Fluxg/m2/yr)

Depthm)


At the 2500.0 tonnes biomass, the pen area equivalent contour flux was 280 g/m2/yr, at a meanITI of 26.6 with a pen area of 23063 m2. The benthic sampling area, where the ITI = 30.0, showed a flux of 191.8 g/m2/yr inside an area of 25289. 8 m2.

A summary of the results can be found in Dounie_ 2016v1_ marine_ sum_ v3.xls in appendix 1.


5.4 In-feed treatment modelling

5.4.1 Slice

Run details used for Slice modelling:

Biomass = 12500.0 T (5 x maximum biomass) Food load = 6387. 5 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 Allowable Zones of Effect ( AZE) for Emamectin Benzoate were predictedby the model as 40681 m2 and 123718 m2 respectively.

Slice Results

A blanking file was required as deposition of Emamectin Benzoate was predicted to overlay landsee figure 3). For the run shown in figure 3 (Run 1) AutoDEPOMOD predicted a 118 day MAX

result for the far field EQS at a biomass of 12500.0 tonnes, giving a recommended consentmass of 4375. 0 g EmBZ.

174800 175000 175200 175400 175600

691600

691800

692000

692200

692400

100

0

2

5

10

20

30

40

50

60

70

80

90

100

0.763

7.630

Figure 3. Dounie EmBZ concentrations for Run 1 at 118 days – no blanking file

The 118 day iteration was re-run with a blanking file ( figure 4). This produced anAutoDEPOMOD MAX result ( Run 2) and a recommended consent mass of 4375. 0 g EmBZ. Thepredicted area inside the 0.763 g/kg contour is 38485 m2, which is smaller than the 123718 m2of the far field AZE.

At a treatable biomass of 12500. 0 tonnes, the model predicted a higher concentration than thenear field AZE trigger value of 7.63 µg/ kg, where the mean concentration is 26.8 µg/ kg.

N

EmBZ Concentrationµg/ kg wet sediment)

Depthm)


174800 175000 175200 175400 175600

691600

691800

692000

692200

692400

100

0

2

5

10

20

30

40

50

60

70

80

90

100

0.763

7.630

Figure 4. Dounie EmBZ concentrations for Run 2 at 118 days – with blanking file

The mass balance of EmBZ for Run 2 was predicted to be 131 g, meaning that 71.01 % of theinput load ( 4375 g) is transported from the model grid as a result of resuspension. Given thatpredicted transport exceeds 922 g ( the limit according to SEPA guidance) the maximumbiomass that can be treated is 3558.7 tonnes ( consent mass = 1245.5 g).

For the 223 day model run ( figure 5) a MAX result was also predicted at a treatable biomass of12500. 0 tonnes.

174800 175000 175200 175400 175600

691600

691800

692000

692200

692400

100

0

2

5

10

20

30

40

50

60

70

80

90

100

0.763

7.630


N


Depthm)

N


Depthm)


Slice was re-run for a treatable biomass of 3558.7 tonnes ( Runs 4 and 5). The plots are provided infigures 6 and 7 below.

174800 175000 175200 175400 175600

691600

691800

692000

692200

692400

100

0

2

5

10

20

30

40

50

60

70

80

90

100

0.763

7.630


174800 175000 175200 175400 175600

691600

691800

692000

692200

692400

0.763

7.630


The results for Run 4 are presented in the Dounie_ 2016v1_ marine_ sum_v3(1).xls spreadsheetand are also shown in appendix 2.

The results for Run 2 can be found in Dounie_ 2016v1_ marine_ sum_v3(2).xls.

N


Depthm)

N


Depthm)


6. Transects and sample stations

Primary and spare sampling transects were created for the site ( tables 1 and 2) using BenthicRun 5.

Details of the primary transect:

Transect start co-ordinates ( PE) 175292. 4 E 691958. 2 N56 04.0502 N 05 36.6949 W

Transect bearing and length 48.0o Grid North and 100.0 mDepth (PE) 22.8 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 175311. 5 175318. 9 175326. 3NGR Northing 691975. 4 691982. 1 691988. 8Latitude 56 04.0600 56 04.0639 56 04.0677Longitude 05 36.6774 05 36.6707 05 36.6639Distance ( m) 25.7 35.7 45.7Depth ( mCD) 19.7 19.7 19.6Modelled ITI 19.2 30.0 59.0

Details of the spare transect:

Transect start co-ordinates ( PE) 175228. 2 E 691739. 4 N56 03.9307 N 05 36.7457 W

Transect bearing and length 166.0o Grid North and 100.0 mDepth (PE) 23.9 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 175235. 5 175237. 9 175240. 4NGR Northing 691709. 9 691700. 3 691690. 6Latitude 56 03.9151 56 03.9100 56 03.9048Longitude 05 36.7372 05 36.7344 05 36.7315Distance ( m) 30.4 40.4 50.4Depth ( mCD) 20.3 19.1 17.4Modelled ITI 24.8 30.0 42.1

The position of both the primary and spare transects and the relative sample stations in relationto the site are shown in figures 8 and 9.


Figure 8. Plot showing primary and spare transect positions and the respective sample stations

Figure 9. Cross sections of the primary and spare transects

The benthic sampling has been packaged inDounie_ 2016v1\ depomod\ mapping\ XLS\Dounie_ 2016v1- BcnstFI- S-5_002.xls.

SPARE

PRIMARY


PPENDIX 1

Dounie_ 2016v1_ marine_ sum_v3(1).xls (Version 3.13) Benthic Worksheet

These are cornerpen centre positions


APPENDIX 2

Dounie_ 2016v1_ marine_ sum_v3(1).xls (Version 3.13) Treatment Worksheet


biomass & in-feed treatment modelling report · pdf filebiomass & in-feed treatment...

Documents