2018-2019 Annual environmental monitoring summary for the ... · RECOMMENDED CITATION: McGrath E, Bennett H, Campos C, Newcombe E, Scheel M, Elvines D 2019. 2018-2019 Annual environmental

REPORT NO. 3323

2018-2019 ANNUAL ENVIRONMENTAL MONITORING SUMMARY FOR THE WAITATA REACH SALMON FARM

CAWTHRON INSTITUTE | REPORT NO. 3323 JUNE 2019

2018-2019 ANNUAL ENVIRONMENTAL MONITORING SUMMARY FOR THE WAITATA REACH SALMON FARM

EMILY MCGRATH, HOLLY BENNETT, CARLOS CAMPOS, EMMA

NEWCOMBE, MAXIMILIAN SCHEEL, DEANNA ELVINES

Prepared for The New Zealand King Salmon Co. Ltd.

CAWTHRON INSTITUTE 98 Halifax Street East, Nelson 7010 | Private Bag 2, Nelson 7042 | New Zealand Ph. +64 3 548 2319 | Fax. +64 3 546 9464 www.cawthron.org.nz

REVIEWED BY: Anna Berthelsen

APPROVED FOR RELEASE BY: Grant Hopkins

ISSUE DATE: 04 June 2019

RECOMMENDED CITATION: McGrath E, Bennett H, Campos C, Newcombe E, Scheel M, Elvines D 2019. 2018-2019 Annual environmental monitoring summary for the Waitata Reach salmon farm. Prepared for the New Zealand King Salmon Co. Ltd. Cawthron Report No. 3323. 25 p. plus appendices.

© COPYRIGHT: This publication must not be reproduced or distributed, electronically or otherwise, in whole or in part without the written permission of the Copyright Holder, which is the party that commissioned the report.


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TABLE OF CONTENTS

1. BACKGROUND ............................................................................................................. 1

2. KEY SAMPLING DETAILS AND RESULTS ................................................................... 2

2.1. Soft sediments ................................................................................................................................................ 2 2.1.1. Type 2 (annual) monitoring ....................................................................................................................... 2 2.1.2. Type 3 monitoring.................................................................................................................................... 10

2.2. Water column ............................................................................................................................................... 13 2.2.1. Water column monitoring results ............................................................................................................. 15

3. ELIGIBILITY FOR FEED INCREASE ............................................................................18

4. KEY FINDINGS .............................................................................................................21

5. REFERENCES .............................................................................................................23

6. APPENDICES ...............................................................................................................26

LIST OF FIGURES

Figure 1. Monthly feed and nitrogen inputs at the Waitata Reach salmon farm for the 12 months preceding soft-sediment sampling in January 2019. .......................................................... 1

Figure 2. Soft-sediment sampling locations at the Waitata Reach salmon farm site. ‘PS-Ctl’ = Pelorus Sound Control. ....................................................................................................... 3

Figure 3. Time series of monthly feed discharge (tonnes, shown by shaded area under curve) and maximum Enrichment Stage (ES) score (indicated by individual symbols) for each annual monitoring event at the Waitata Reach salmon farm since the farm was established .......................................................................................................................... 6

Figure 4. Approximate locations of Type 3 soft-sediment sampling stations for the Waitata Reach salmon farm ........................................................................................................... 11

Figure 5. Water column sampling surveys for the three water column monitoring types (routine, full-suite and fine-scale), during 2018. .............................................................................. 14

Figure 6. NZ King Salmon and MDC routine and full-suite water-quality monitoring stations in outer Pelorus Sound ......................................................................................................... 15

LIST OF TABLES

Table 1. Average Enrichment Stage (ES) scores and 95% confidence intervals (95% CI) calculated for indicator variables, and overall, for each of the Waitata Reach salmon farm stations sampled in January 2019 .............................................................................. 5

Table 2. Summary of visual assessment and indicator variables measured for each of the Waitata Reach salmon farm stations during the January 2019 monitoring survey. ........... 7

Table 3. Total recoverable copper and zinc concentrations (mg/kg dry weight) in bulk sediment from Waitata Reach salmon farm pen station samples, January 2019. ............................. 9

Table 4. Water column sampling stations for the routine, full-suite and fine-scale monitoring components ....................................................................................................................... 14

Table 5. Summary of water column compliance for parameters measured at each of the Waitata Reach salmon farm monitoring stations .............................................................. 18

Table 6. Summary of consent conditions required to be met in order for the Waitata Reach salmon farm (WTA) to qualify for a feed increase. ........................................................... 19

JUNE 2019 REPORT NO. 3323 | CAWTHRON INSTITUTE

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LIST OF APPENDICES

Appendix 1. Methodology for soft-sediment sampling .......................................................................... 26 Appendix 2. Comprehensive discussion of results of the January 2019 soft-sediment monitoring

survey at the Waitata Reach (WTA) salmon farm. ........................................................... 32 Appendix 3. Water column sampling methodology and compliance framework. ................................. 48 Appendix 4. Additional detail on the results the 2018 Waitata (WTA) salmon farm water column

monitoring. ........................................................................................................................ 54 Appendix 5. Time series plots for eutrophication indicators, collected as part of the ongoing

monitoring programme ...................................................................................................... 69


1

1. BACKGROUND

This report presents the environmental monitoring results for the Waitata Reach

(WTA) salmon farm located in Pelorus Sound (consent number U140294). The WTA

farm was established in December 2015, making this the third annual monitoring

report for this site. Data presented include an assessment of depositional effects on

soft-sediment habitats and effects on the water column. Results from reef habitat

monitoring are reported separately in Dunmore (2019).

In terms of its hydrodynamics, WTA is assessed as a high-flow site. The average

mid-water current speeds are c. 21 cm/s. Water depth at the farm site is between

50-60 m and the net pens extend from the surface to a depth of c. 20 m.

A total of 2,164 tonnes of fish feed was discharged at the WTA site in 2018 (shown by

month in Figure 1), which is within the maximum allowable annual discharge (3,000

tonnes) for this farm (and 822 tonnes less than the total feed discharged in 2017).

Feed input peaked in May 2018 (294 tonnes), then steadily decreased between June

and October, after which the farm lay fallow (between production cycles) for 1 month

(November 2018). Nitrogen input averaged 6.4% of feed input from January 2018 to

January 2019 (range 1.1 to 19.3 tonnes per month), totalling 140 tonnes of nitrogen

discharged during this period1.

Figure 1. Monthly feed and nitrogen inputs at the Waitata Reach salmon farm for the 12 months preceding soft-sediment sampling in January 2019. Feed and nitrogen input data provided by NZ King Salmon.

1 The maximum annual tonnage of nitrogen that may be discharged in any year is 7% of the maximum feed

tonnage (3000 tonnes at WTA), equating to 210 tonnes of nitrogen.


2

2. KEY SAMPLING DETAILS AND RESULTS

An overview of the key sampling details and results are provided in this section. More

comprehensive discussion of methodology and monitoring results are provided in the

relevant appendices.

2.1. Soft sediments

2.1.1. Type 2 (annual) monitoring

Annual soft-sediment monitoring at WTA was undertaken on 30 January 2019.

Sampling stations comprised three stations immediately adjacent to the net pens:

Pen 1, Pen 2 and Pen 3 to monitor benthic impacts at the salmon farm, as well as

two stations to monitor enrichment within the outer limit of effects (OLE): 600 N and

600 S (see Figure 2). Although not a requirement under the Best Management

Practice (BMP) guidelines (MPI 2015), one station (150 N) was also sampled at the

Zone 2/3 boundary, 150 m along the north transect, to monitor the enrichment

footprint in the early stages of operation.

Five reference or ‘control’ stations were sampled, one near-field (PS-Ctl-6) and three

far-field (PS-Ctl-3, PS-Ctl-4, and PS-Ctl-5). An additional reference station (PS-Ctl-8)

was established during the 2019 monitoring round in the middle of Waitata Reach

(Figure 2), in a higher flow environment, likely to be more comparable to the WTA

and Kopaua (KOP) farms (high flow) than the other reference sites.

Sediments at all stations were assessed for organic content, redox potential, total free

sulphides and infauna community metrics (see Appendix 1 for all sampling details). In

addition, copper and zinc concentrations were also measured beneath the net pens.

The environmental monitoring results from soft-sediment habitats are used to

determine whether the farm is compliant with the benthic environmental quality

standards (EQS: benthic) specified in the consent conditions and the best

management practice guidelines developed for salmon farming in the Marlborough

Sounds region (see Appendix 1 for EQS: benthic).


3

Figure 2. Soft-sediment sampling locations at the Waitata Reach salmon farm site. ‘PS-Ctl’ =

Pelorus Sound Control. Position accuracy is ± 5 m. Note that the Pen 3 station has moved due to the change in farm configuration.

Enrichment of soft-sediment habitats near Waitata Reach salmon farm

A summary of key findings is provided below, while detailed monitoring results are

provided in Appendix 2.

Measured levels of enrichment beneath the pens were within the allowable

Enrichment Stage (ES) scores (i.e. ES ≤ 5) at all three sampling stations (Table 1).

ES scores at the pen stations have either stayed the same (Pen 1) or decreased

(Pens 2 and 3 by ES 0.5 and 0.3, respectively) since the previous monitoring round

(Bennett et al. 2018a). See Figure 3 for a comparison of ES scores with feed levels

over time.

Further from the pens, at the 150 N (Zone 2/3 boundary) and outer limit of effects

(600 N and 600 S, OLE) stations, ES scores were within the EQS (i.e. ES ≤ 4.0 and <

3.0, for Zone 2/3 and the OLE stations respectively; Table 1). The overall ES score at

150 N is 0.2 higher than the previous monitoring round (Bennett et al. 2018a)2.

Enrichment levels have also increased at the 600 N station (by ES 0.1). Meanwhile,

2 ES score statistically comparable to the previous year one-way PERMANOVA: Pseudo-f (1, 5) = 0.9, p = 0.41).

We also note that infauna abundance is not significantly higher than at corresponding pen stations and number of taxa > 75 % of number at relevant / appropriate reference stations (as per consent requirements).


4

ES levels at the 600 S station have decreased (by ES 0.3), when compared to the

previous annual monitoring assessment (Figure 3, Bennett et al. 2018a)3. Although

ES scores remain within the consented EQS for the OLE, both OLE stations had

elevated total free sulphides compared to reference stations (Table 2 summarises all

observations for the WTA sites). Macrofaunal abundance was slightly elevated at

600 N, while macrofauna abundance at 600 S doubled since last year and was c. 10-

fold higher than reference and baseline values (Morrisey et al. 2015).

Community compositional changes were also evident at both OLE stations,

particularly 600 S. In the previous monitoring round, dorvilleid polychaetes were the

most abundant taxa at 600 S. This year, while other enrichment-tolerant taxa such as

nematodes and dorvilleids are still abundant, scavenging amphipods and tanaid

crustaceans are now the most abundant taxa. Macrofaunal community composition

has always differed at 600 S compared to other stations (possibly due to the large

particle size of sediments here), however it is likely farm deposition is causing a

fertilisation effect at this site. This is supported by changes in sediment chemistry,

which suggest an enrichment effect at both OLE stations.

However, we note that under the BMP guidelines, background / natural conditions are

assessed as enrichment stage (rather than individual variables), and the industry

operational goal is for the overall ES at the OLE to be ES < 3.0. In the context of ES

scores both OLE stations are compliant (i.e. ES < 3.0)4. The WTA consent requires

that ES < 3.0 is maintained at the OLE and that conditions remain statistically

comparable with relevant / appropriate reference stations. Conditions (assessed as

ES scores as per the BMP guidelines) at both OLE stations remain statistically

comparable with relevant reference stations5.

3 ES scores at both OLE station statistically comparable to the previous year (one-way PERMANOVA: Pseudo-f

(1, 11) = 0.3, p = 0.63). 4 See Section 2.1.2 for discussion relating to the use of ES < 3.0 as a proxy for “natural conditions”. 5 600 N: one-way PERMANOVA: Pseudo-f (5, 17) = 3.1, p = 0.05, 600 S: one-way PERMANOVA: Pseudo-f (5,

17) = 2.9, p = 0.06, 600 N:


5

Table 1. Average Enrichment Stage (ES) scores and 95% confidence intervals (95% CI) calculated for indicator variables, and overall, for each of the Waitata Reach salmon farm stations sampled in January 2019. Full breakdowns of indicator variable contributions are provided in Appendix 2. All stations were compliant with the EQS.

Station Organic

loading ES Sediment

chemistry ES Macrofauna

ES Overall

ES

Compliant with EQS?

Pen 1 4.0 (0.0) 4.4 (0.1) 2.9 (0.4) 3.3 (0.3) ✓

Pen 2 3.0 (0.0) 3.3 (0.1) 2.6 (0.2) 2.8 (0.2) ✓

Pen 3 3.3 (0.7) 3.6 (0.3) 1.9 (0.1) 2.4 (0.0) ✓

Zone of maximal effect (ZME); EQS ≤ 5.0

150 N* 3.3 (0.7) 3.7 (0.1) 2.2 (0.2) 2.6 (0.2) ✓

Zone 2/3 boundary EQS ≤ 4.0

600 N 3.0 (0.0) 3.1 (0.2) 1.9 (0.1) 2.2 (0.1) ✓

600 S 3.0 (0.0) 2.5 (0.6) 2.0 (0.1) 2.2 (0.2) ✓

Outer limit of effects (OLE); EQS < 3.0

*sampling at this station is not a requirement under the BMP guidelines.


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Figure 3. Time series of monthly feed discharge (tonnes, shown by shaded area under curve) and maximum Enrichment Stage (ES) score (indicated by individual symbols) for each annual monitoring event at the Waitata Reach salmon farm since the farm was established. ES scores reported are maximums recorded in the zone of maximal effect (ZME)/Pen stations (pink diamond symbol), the outer limit of effects (OLE)/600 m stations (blue cross symbol), and Pelorus Sound reference stations (coloured dots). The consented environmental quality standards (EQS) for the ZME (ES 5) and OLE (ES 3) are shown as red dashed lines. Feed data were provided by NZ King Salmon. Note that ES scores prior to 2018 do not implement the calculation rules from appendix 10.2 (bullet point 2, b and c) from MPI (2015).


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Table 2. Summary of visual assessment and indicator variables measured for each of the Waitata Reach salmon farm stations during the January 2019 monitoring survey. All comparisons are made to the PS-Ctl-3, PS-Ctl-4, PS-Ctl-5, PS-Ctl-6 and PS-Ctl-8 reference station values. Reference station comparisons are made to the 2017-2018 values (Bennett et al. 2018a), with the exception of PS-Ctl-8 which is made to baseline values (Morrissey et al. 2015). %OM = percent organic matter. See Appendix 2 for representative images of the soft-sediment habitat at each site.

Station Bacteria Out- gassing

Observed epifauna

Other observations Organic loading

Sediment chemistry Macrofauna

Pen 1 None No Blue and green-lipped mussels

Soft muddy grey sediment with dark patches, burrow holes, fish faeces or feed

%OM elevated

Redox negative, sulphides highly elevated

Total abundance comparable (average 75 individuals per core). Reduced taxa richness in some samples (13-19 taxa per core). Slightly impacted community composition.


Soft muddy grey sediment, burrow holes

%OM marginally elevated

Redox positive, sulphides highly elevated

Total abundance variable but average is marginally elevated (119 individuals per core). Taxa richness slightly reduced in some samples (12-32 taxa per core). Slightly impacted community composition.


Soft muddy grey sediment with dark patches, burrow holes

%OM elevated


Total abundance variable but average marginally elevated (132 individuals per core). Taxa richness comparable in some samples (21-33 taxa per core). Slightly impacted community composition.

150 N None No None

Soft muddy grey sediment, burrow holes, fish faeces or feed



Total abundance variable but average marginally elevated (109 individuals per core). Taxa richness comparable in some samples (20-34 taxa per core). Slightly impacted community composition.

600 N None No

Cushion star, flatfish, colonial ascidians/sponges, finger sponge

Light grey sand with shell hash and debris and burrow holes


Redox positive, sulphides elevated

Total abundance marginally elevated (average 140 individuals per core). Taxa richness comparable (average 22-47 taxa per core). Minimal community compositional changes.

600 S None No 11-armed sea star, sea cucumbers

Light grey sand with shell hash and debris, small cobbles

%OM normal Redox positive, sulphides elevated

Total abundance very high (average 846 individuals per core). Taxa richness slightly elevated (average 59 taxa per core). Slight change in community composition potentially indicating recovery


8

Table 2 continued. Summary of visual assessment and indicator variables measured for each of the Waitata Reach salmon farm stations during the January 2019 monitoring survey. All comparisons are made to the PS-Ctl-3, PS-Ctl-4, PS-Ctl-5, PS-Ctl-6 and PS-Ctl-8 reference station values. Reference station comparisons are made to the 2017-2018 values (Bennett et al. 2018a), with the exception of PS-Ctl-8 which is made to baseline values (Morrissey et al. 2015). %OM = percent organic matter. See Appendix 2 for representative images of the soft-sediment habitat at each site.

Station Bacteria Out- gassing

Observed epifauna

Other observations Organic loading

Sediment chemistry Macrofauna

PS-Ctl-3 None No None Burrow holes, trail marks


Redox reduced, sulphides comparable

Total abundance and taxa per core comparable, no change in community composition.

PS-Ctl-4 None No

Hydroids, ascidians, scallops, cushion stars, purple fanworm, hermit crabs

Burrow holes %OM marginally elevated

Redox and sulphides elevated

Total abundance and taxa per core comparable, no change in community composition.

PS-Ctl-5 None No None Patchy diatom mat coverage


Redox reduced in some samples, sulphides comparable

Total abundance high in some samples (56-323 individuals per core), taxa per core comparable. No major change in community composition.

PS-Ctl-6 None No None Patchy diatom mat coverage, burrow holes, trail marks

% OM marginally elevated – significantly elevated in one sample

Redox reduced, sulphides elevated

Total abundance comparable, taxa per core elevated in some samples (c. two-fold higher in one sample, c. five-fold higher in another). No major change in community composition.

PS-Ctl-8 None No None Burrow holes %OM very slightly elevated

Redox reduced, sulphides slightly elevated in some samples

Total abundance slightly elevated in some samples, taxa per core comparable. No change in community composition.


9

Copper and zinc beneath the Waitata Reach pens

Total recoverable copper and zinc concentrations (5.8 to 7.6 mg/kg and 49 to 65

mg/kg for copper and zinc, respectively; Table 3) were below the ANZECC (2000)

ISQG-Low trigger level (65 mg/kg and 200 mg/kg, respectively) for possible biological

effects. Copper concentrations are lower than values reported at the same stations

last year (range 7.7 to 9.3 mg/kg; Bennett et al. 2018a), while zinc concentrations are

similar (49 to 69 mg/kg; Bennett et al. 2018a). These concentrations are elevated

compared to baseline levels of 5.2 to 6.7 mg/kg and 34 to 48 mg/kg for copper and

zinc, respectively; Morrisey et al. (2015). However, both copper and zinc levels are

comparable with previous reference concentrations in the outer Marlborough Sounds

(Sneddon & Tremblay 2011).

Table 3. Total recoverable copper and zinc concentrations (mg/kg dry weight) in bulk sediment from Waitata Reach salmon farm pen station samples, January 2019.

Sample Copper Zinc

Pen 1 7.6 65

Pen 2 6.3 52

Pen 3 5.8 49

ANZECC ISQG-Low 65 200

ANZECC ISQG-High 270 410


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2.1.2. Type 3 monitoring

In addition to Type 2 monitoring, a spatial footprint mapping exercise was carried out

(Type 3 monitoring) to reassess the appropriateness of the zone boundaries, and the

shape of the WTA depositional footprint after three years of farm operation at the

initial feed level (consent conditions 39b, 66i and 67j, also see Keeley and Taylor

(2011) and Elvines (2018))6. Type 3 monitoring was carried out within, and just

beyond, the EQS compliance zones (see Figure 4 for sampling locations and types)

to:

• map the distribution and extent of the depositional footprint at the initial feed level

specified in the consent

• determine whether the spatial arrangement of monitoring stations captures the

maximum extent of the footprint at this feed level

• cross-check the actual footprint against the predicted footprint.

Full sampling details are provided in the MEMAMP (Bennett et al. 2018b) and results

are provided in Appendix 2.

6 We note that feed levels were reduced to > 15% below the recommended initial feed level in 2018 due to fish

mortalities as a result of a harmful algal bloom event and warm summer water temperatures in Pelorus Sound (see Elvines 2018 for further information).


11

Figure 4. Approximate locations of Type 3 soft-sediment sampling stations for the Waitata Reach salmon farm (including all Type 2 monitoring stations ‘T2’, except for reference stations). Sampling locations were allocated throughout and beyond the outer limit of the predicted depositional footprint at the initial feed level (~3,000 tonnes per year6). Consented maximum distances of EQS Compliance Zone 2/3 (150 m) and Zone 3/4 (600 m) boundaries are shown. Sampling undertaken at each station type: T3a samples = full suite7, T3b samples = full suite (with 2 infauna archived), T3c = redox, sulphides and odour / visual observations of sediment core.

WTA depositional footprint – individual variables

Type 3 monitoring demonstrates that after three years of operation at the

recommended initial feed level (RIFL, ~3,000 tonnes per annum), the WTA footprint is

larger than predicted, extending beyond the consented outer limit of effects (OLE) at

600 m north and south. At 800 m north of the pens, total free sulphide concentrations

were at least two-fold higher than reference station values. Macrofaunal abundance

and richness were also elevated compared to reference conditions. Community

composition reflected low to moderate enrichment levels with an abundance of worms

belonging to the Paraonidae family and nematodes. Although lower than observed to

the north of the farm, sulphide concentrations south of the farm remained elevated

compared to background levels (with the exception of PS-CTL-4, which also had

elevated sulphide concentrations). These elevated sulphides to the south alongside

elevated macrofaunal abundance and richness at 600 S (and 100 m south of 600 S)

suggest a fertilisation effect as a result of the WTA farm in this direction too8.

7 Full-suite analysis includes all parameters outlined in Appendix 1, Section A2.1 (except for copper and zinc). 8 We note that macrofaunal community composition at 600 S has always differed at this site compared to other

stations (likely due to the large particle size of sediments here). However, changes in sediment chemistry suggest that natural conditions have not been maintained.


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Community composition beyond the 600 S OLE was dominated by dorvilleid

polychaetes and nematodes, reflecting a moderately enriched community.

The abovementioned variables (sulphides, infaunal abundance, number of taxa and

community composition) demonstrate that enrichment effects extend beyond the OLE

and the predicted depositional footprint modelled for the recommended initial feed

level in Ellis et al. (2011). Elevated sulphide concentrations, macrofaunal abundance

and taxa richness were also seen c. 60 to 80 m inshore and 30 to 80 m offshore (east

and west) of the predicted depositional footprint. This demonstrates that the WTA

footprint also extends further east and west than predicted.

As above, individual variables (total free sulphides and macrofaunal community

composition) demonstrate that the WTA depositional footprint extends at least 800 m

north and south of the WTA farm. The observed footprint is also at least 90 m wider

than predicted in the AEE (Ellis et al. 2011). Overall, the area experiencing minor to

moderate enrichment is at least 38 ha; this is 14 ha greater than the consented

depositional footprint (24 ha), which is greater than the 10% flexibility provided by

Condition 39b. An increase in feed use at this site is likely to result in further

enrichment beyond the present OLE monitoring stations, where no routine sampling

is currently undertaken.

Review of monitoring stations and EQS compliance zones

We note some ambiguity in the OLE EQS as set out in the consent:

• Under the BMP guidelines, the industry operational goal is for the OLE to be

ES < 3.0, and natural conditions are to be maintained. Importantly, background

conditions are assessed as Enrichment Stage (rather than individual variables).

• The WTA consent requires that ES < 3.0 is maintained at the OLE, and by

contrast, that conditions remain statistically comparable with relevant / appropriate

reference stations. In the context of the consent, it is not clear if the intent is to

measure conditions as ES, or as individual variables. We have assumed that

conditions are measured as ES as they are under the BMP guidelines (rather than

individual variables), and in this context, the OLE stations are statistically

comparable with relevant / appropriate reference stations (See Section 2.1.1).

Considering only ES scores at the compliance monitoring stations, the WTA

depositional footprint is well within the EQS across all zones (ES > 3.0 only measured

at one station within the ZME where ES 5.0 is acceptable). Conditions (measured as

ES, as per the BMP guidelines) also remain statistically comparable with relevant /

appropriate reference stations. On this basis, an amendment of zone dimensions and

area is not required at this stage. However, It is important to note that ‘background’

ES scores for this area (i.e. as measured at reference stations during this monitoring

round) ranged from 2.1 to 2.6, and therefore using ES < 3.0 as an indicator of ‘natural


13

conditions’ implies that a degree of enrichment outside of the consented OLE is

acceptable.

Recommendations

While the OLE stations were expected to receive low levels of deposition, farm-

related enrichment was detected beyond the predicted depositional footprint.

However, due to the dispersive nature of the WTA farm site, and the low background

enrichment levels at the site, this is unsurprising. It is for the regulatory body to

decide as to whether the observed level of enrichment, as indicated by total free

sulphides and macrofaunal community data, is acceptable beyond the OLE. If the

spatial extent of enrichment is not considered to be acceptable, additional sampling is

recommended to explicitly map the shape and extent of the actual depositional

footprint during the next annual monitoring to inform zoning amendments.

In addition, we recommend a footprint mapping exercise is undertaken at 5 yearly

intervals, or as otherwise required (i.e. prior to feed increase), as per the BMP

guidelines.

2.2. Water column

The water column monitoring results for WTA are used to determine whether the farm

is compliant with water quality standards (WQS) set out in the resource consent for

this farm (see Appendix 3 for EQS: water quality).

Water sampling stations for WTA are summarised in Table 4 with station locations

shown in Figure 6. Full sample collection details are provided in Appendix 3, but an

overview of the sampling regime is provided below and illustrated in Figure 5:

• Routine (long-term) monitoring for chlorophyll-a (chl-a), dissolved oxygen (DO)

and total nitrogen (TN) was undertaken monthly.

• Full-suite (long-term) monitoring, for a larger suite of analytes (see Appendix 3

for the list of analytes sampled for) was carried out in February, March, August

and September9.

• Fine-scale (targeted) monitoring was undertaken alongside long-term

monitoring in March and August.

9 According to the MEMAMP, full-suite monitoring should have taken place in July, however

due to an administrative error this was postponed until September.


14

Figure 5. Water column sampling surveys for the three water column monitoring types (routine, full-suite and fine-scale), during 2018.

Table 4. Water column sampling stations for the routine, full-suite and fine-scale monitoring

components. Additional sampling stations in proximity are also listed; these stations are not sampled under this consent, and results are only reported where additional context is relevant. This survey design includes two of the Marlborough District Council (MDC) state of environment (SoE) monitoring stations (NZKS06/PLS-6 and NZKS07/PLS-7) that are sampled by MDC. In addition, results from the SoE monitoring station (PLS-10) and monitoring stations in proximity to the Kopaua farm (in Richmond Bay) are included to provide a more broad-scale overview where relevant (e.g. physical water column properties in the general area, phytoplankton measures).

Description Station name

a) Waitata sampling stations

Net pen (down current) NZKS08

100 m (down current)* WTA100

250 m (down current)*

500 m (up & down current)*

WTA250

NZKS09/10

500 m (seaward) NZKS11

Cumulative effect (CE) station NZKS12

Far-field station NZKS06 (PLS-6)** (Waitata Reach)

Far-field station NZKS07 (PLS-7)** (Pelorus Sound entrance)

b) Other sampling stations***

Kopaua (KOP) net pen NZKS01 (Richmond Bay)

500 m up & down current of KOP NZKS02/03 (Richmond Bay)

500 m seaward of KOP NZKS04 (Richmond Bay)

Cumulative effect reference (CE-Ref) station NZKS05 (Richmond Bay)

Cumulative effect reference (CE-Ref) station PLS-10*** (Waitata Reach)

* Sampled during fine-scale monitoring, in March and August only.

** Also MDC SoE monitoring station. Hereafter referred to only using NZKS06/NZKS07.

*** Results are only included in this report where the additional context is relevant.


15

Figure 6. NZ King Salmon and MDC routine and full-suite water-quality monitoring stations in outer

Pelorus Sound. Waitata Reach salmon farm sampling stations are indicated by magenta circles, with far-field reference stations indicated as blue triangles (stations for the Kopaua farm in Richmond Bay are also shown [black circles]). Location of the net pen station is indicative only (location is tidally-dependent). Rectangles indicate locations of the farms.

2.2.1. Water column monitoring results

Box 1 provides a summary of water column monitoring results in the context of

specific monitoring objectives or other compliance measures as detailed in the WTA

farm resource consent. Key findings are expanded in the following paragraphs and a

more comprehensive account of the 2018 WTA water column results is provided in

Appendix 4.


16

Box 1. Compliance overview for 2019 Waitata farm water column

Has the Waitata farm caused elevated nutrient concentrations beyond 250 m from the

edge of the net pens?

No. Refer Appendix 4, Section A4.3 for monthly results of total nitrogen (TN) and all fine-

scale sampling results.

Has there been a statistically significant shift towards a eutrophic state (in Pelorus

Sound)?

No. Statistical significance testing on nutrient changes was undertaken by Broekhuizen and

Plew (2018). They found evidence of a subtle increase of suspended inorganic solids in

Pelorus Sound since mid-2014 (most notably, inner Pelorus Sound), and some evidence of

increased nitrate concurrent with a reduction in ammonium in Pelorus Sound. We consider

that Broekhuizen and Plew’s findings do not constitute evidence of a shift towards a

eutrophic state ‘beyond that which is likely to occur naturally’ (Consent condition 43e). The

two parameters that increased did so only slightly, and the decrease in ammonium was such

that trends in dissolved inorganic nitrogen were not able to be determined at most sites

(Broekhuizen and Plew 2018).

Prior to the 2015/16 salmon farm developments, the Marlborough Sounds were said to be in

an oligotrophic-mesotrophic state (EPA 2013 and references therein). Broekhuizen and Plew

concluded that ‘the nutrient and chlorophyll concentrations are consistent with the view that

these sounds are near the oligotrophic-mesotrophic boundary, in terms of trophic

classification’.

Have the TN WQS been breached in three successive months?

No. All of the samples from Pelorus Sound in 2018 had TN concentrations below the WQS

threshold. See Appendix 4, Section A4.3 for monthly results of TN and all fine-scale

sampling results.

Have the Dissolved Oxygen (DO) saturation WQS been breached in three successive

months?

No. See Appendix 4, Section A4.2 for month-by-month and depth-related results.

Have the chlorophyll-I (chl-a) WQS been breached in three successive months?

No. There was only one occasion (August) when chl-a concentration was at the WQS

threshold (3.5 mg/m3) at the CE-Ref site (NZKS12). This coincided with elevated

phytoplankton biomass dominated by diatoms. See Appendix 4 Section A4.4. for monthly

results at all stations.

Key findings

There is no evidence of region-wide increases in turbidity across the time series to

date (Appendix 5) that might indicate reductions in water quality resulting from

eutrophication.

Dissolved oxygen (DO) saturation levels at the net pen station ranged from 76.2%

(February) to 100.2% (September) and were within the first step DO WQS (> 70%,

Table 5) in all months. Exceedances of the WQS were intermittent throughout the

year. During February, all stations 500 m from the WTA farm (NZKS09–NZKS11)


17

exceeded the first step WQS of DO > 90% and the FF Ref exceeded the second step

WQS. In March, all stations 500 m from the WTA farm and the CE-Ref exceeded the

second step WQS. In August, two stations 500 m from the farm (NZKS10 and

NZKS11) and the CE-Ref site also exceeded the second step WQS (Table 5).

However, DO thresholds were not exceeded in three consecutive months and

therefore an ‘amber alert’ status was not reached.

There was evidence of an effect of the WTA farm on mid-water DO beyond 500 m

from the farm. However, there was no evidence of region-wide reductions in DO

across the time series to date (see Appendix 5), indicating no changes in water

quality resulting from eutrophication.

Nutrient concentrations did not show clear spatial trends with distance from the WTA

farm. Concentrations of nitrogen species at the net pen were similar to or lower than

reference and upstream concentrations and there were no discernible localised

effects of the farm on these water quality parameters. In fine-scale sampling, nutrient

concentrations were very variable both between samples and among stations. This is

likely to be associated with the strong water flows observed during sampling causing

irregular dispersal of farm wastes away from the farm.

All phytoplankton data for Pelorus Sound were reviewed to assess biomass and

coarse community structure (including results for the Kopaua salmon farm monitoring

stations). Chl-a in Pelorus Sound samples across all months of 2018 were below the

WQS (i.e. ≤ 3.5 mg/m3; Table 5). As in the previous year’s sampling, the highest

recorded value (3.5 mg/m3) was in August, when the sampling appeared to coincide

with the spring diatom maxima (see Appendix 4, Figure A4.5, Table A4.4).

Diatoms usually dominate the phytoplankton biomass, except in winter when the

category ‘other’ often dominates (Broekhuizen & Plew 2018). In February and March

2018, however, phytoplankton communities across near-farm and reference stations

were dominated by dinoflagellates (constituting between 43 and 96% of the

measured phytoplankton biomass). This effect largely disappeared in August and

September. A bloom of the dinoflagellate Alexandrium catenella occurred in Pelorus

Sound in May; however, we note that this species of Alexandrium was not detected in

monitoring for NZ King Salmon. Dinoflagellate biomass in February and March was

dominated by Prorocentrum spp. While this genus is known to be potentially toxin-

producing10, the Cawthron Institute biotoxin laboratory does not classify Prorocentrum

spp. from these samples as toxin-producing. Future monitoring will indicate whether

the dinoflagellate dominance seen here is repeated in subsequent years.

10 http://www.fao.org/3/y5486e/y5486e0h.htm


18

Table 5. Summary of water column compliance for parameters measured at each of the Waitata Reach salmon farm monitoring stations. Ticks indicate that measured concentrations were within the water quality standards (WQS) thresholds on all occasions. Sampling months during which WQS thresholds were exceeded are named.

NZKS08 NZKS09 NZKS10/11 NZKS12 NZKS06 NZKS07

Net pen 500 m 500 m CE FF FF

DO ✓ Feb, Mar Feb, Mar, Aug Mar, Aug Feb ✓

WQS > 70 % > 90 %

TN n/a ✓ ✓ ✓ ✓ ✓

WQS n/a ≤ 300 mg-N/m3

Chl-a ✓ ✓ ✓ ✓ ✓ ✓

WQS ≤ 3.5 mg/m3

3. ELIGIBILITY FOR FEED INCREASE

After three years of operation at or near (±15%) the maximum initial feed discharge

level (3,000 tonnes per annum at WTA), the WTA farm may qualify for a feed

increase, if certain criteria are met. These criteria are compliance with consent

Conditions 36 to 44, which are summarised in Table 6 along with discussion around

whether the WTA farm meets these conditions.


19

Table 6. Summary of consent conditions required to be met in order for the Waitata Reach salmon farm (WTA) to qualify for a feed increase. Discussion around whether the WTA farm meets the conditions is provided along with references for further information.

Condition Summary Eligibility description Reference

36 Annual tonnage of feed may only be increased if

Conditions 37-44 are met as well as any specifications

from the 2018 MEMAMP.

See below.

37a Annual tonnage of feed may only be increased if:

a. The farm shall have operated at or near (±15%) its

current maximum annual feed discharge level for at

least 3 years; and

Feed levels reduced to > 15 % below recommended

initial feed level in 2018. Feed levels therefore not

‘stable’ over past three years. Scientific advice

(Elvines 2018) recommended that the intent of

condition 37 can be maintained without condition 37a

being fully met.

Elvines 2018, Section 1

and previous annual

monitoring reports

(Elvines et al. 2017,

Bennett et al. 2018)

37b Annual tonnage of feed may only be increased if:

b. Annual monitoring results of the Enrichment Stage

(ES) from the most recent two successive years shall

be comparable, based on the monitoring undertaken in

Condition 66, assessed as follows. The Enrichment

Stage (ES) from the annual monitoring, assessed in

accordance with Condition 40, shall statistically not be

significantly more than the ES from the previous year,

based on the average result for all sampling stations

(Figure 3) within each compliance Zone. This

requirement must be met for each of the Environmental

Quality Standards (EQS) compliance Zones for which

ES are specified in Condition 40.

ES scores at pen stations were similar to or less than

previous year.

ES score at Zone 2/3 (150 N) was statistically

comparable to previous year.

ES scores at Zone 3/4 (600 N and 600 S) was

statistically comparable to previous year.

Type 2 monitoring

results (Section 2.1.1

and Appendix 2)

37c Annual tonnage of feed may only be increased if:

c. The marine farm complies with all the EQS specified in

Condition 40 and is less than the relevant maximum

EQS for each Zone.

Individual variables demonstrate natural conditions

have not been maintained at the OLE. However,

according to ES scores the WTA depositional

footprint is well within the EQS across all zones (ES

> 3.0 only measured at one station within the ZME

where ES 5.0 is acceptable).

Type 2 monitoring


and Appendix 2.

Type 3 monitoring

results (Section 2.1.2).


20

Condition Summary Eligibility description Reference

38 The discharge of feed, marine biofouling and antifouling

at the marine farm shall meet the requirements of

Conditions 39 - 44 relating EQS at all times.

Discharge of feed and levels of copper and zinc

beneath pens meet requirements.

Marine biofouling was not assessed at WTA under

this monitoring programme.

Type 2 monitoring


and Appendix 2).

39, 40 EQS Compliance Zones shall be defined for the marine

farm. At all times, the seabed beneath and in the vicinity

of the marine farm shall comply with the EQS specified in

Table 3 (of the consent).

EQS compliance zones defined. Amendment of

compliance zones may be required pending decision

on Type 3 monitoring results:

- Based on the individual indicator measurements the EQS compliance zones

need amending,

- Based on ES scores alone, the WTA EQS

compliance zones do not need amending,

but additional monitoring stations further than

600m are recommended when feed levels

are higher.

Type 3 monitoring

results (Section 2.1.2).

41, 42 Composite samples of sediments beneath and beside the

net pens shall be assessed against the ANZECC (2000)

ISQG-Low criteria for copper and zinc, as a first-tier

trigger level. Where total metals analysis of composite

sediment samples exceeds the ANZECC (2000) ISQG-

Low criteria for copper and zinc, the MEM-AMP (refer

Conditions 65-66) shall include a hierarchical schedule of

monitoring of increasing focus and intensity and,

ultimately, management action based on the decision

hierarchy contained in Figure 5.

Compliant. Type 2 monitoring


and Appendix 2)

43, 44 The marine farm shall be operated at all times in such a

way as to achieve and comply with the Water Quality

Objectives in the water column.

Compliant. Water column monitoring

(Section 2.2.1 and

Appendix 4)


21

4. KEY FINDINGS

All soft-sediment sampling stations at the WTA farm were compliant with the EQS

specified in the consent conditions. Although enrichment levels at the outer limit of

effects (600 N and 600 S) were similar to the previous year, sediment chemistry and

macrofaunal abundance were elevated, suggesting natural conditions have not been

maintained. Additional sampling (for Type 3 monitoring) confirmed that enrichment

effects (elevated sulphide concentrations and macrofaunal abundance) extend

beyond the OLE and the predicted depositional footprint modelled for the

recommended initial feed level. However, under the BMP guidelines, background

conditions are assessed as Enrichment Stage scores (rather than individual

variables), and the industry operational goal (and consent requirement) is for the OLE

to be ES < 3.0. With the exception of the pen 1 station (within the ZME), ES scores at

all sampling stations were < 3.0.

Based on natural conditions being measured as ES, an amendment of zone

dimensions and area is not required at this stage. Nevertheless, clarification is

required on the EQS at the OLE as to whether the observed level of enrichment

beyond the OLE is acceptable, despite conditions being within the industry

operational goal (and consented EQS) of ES 3.0, and comparable to reference sites

as measured by ES. If the spatial extent of enrichment is not considered to be

acceptable, additional sampling is recommended to explicitly map the shape and

extent of the actual depositional footprint during the next annual monitoring to inform

zoning amendments. We also recommend that a footprint mapping exercise is

undertaken at 5 yearly intervals, or as otherwise required (i.e. prior to feed increase),

as per the BMP guidelines.

None of the WQS for total nitrogen (TN), dissolved oxygen (DO) and chlorophyll-a

(chl-a) were exceeded in three successive months, i.e. an amber state was not

triggered. High nutrient results from the far-field reference station NZKS07 (PLS07)

indicated that this is not a suitable reference station for the WTA farm site (although

the site provides useful context as it reflects water quality characteristics in the outer

sounds). However, no recommendations are made for the water column sampling

design for the next sampling round, pending finalisation of a working group review of

the water column approaches as they relate to the Marlborough Sounds salmon

farming industry.

According to ES scores the WTA farm qualifies for a feed increase (i.e. consent

Conditions 36 to 44 are met). However, individual variables demonstrate natural

conditions have not been maintained at the OLE and that the overall area

experiencing minor to moderate enrichment at WTA is at least 14 ha greater than the

consented depositional footprint. As a result, ambiguity remains as to whether

Conditions 37c and 40 are met. It is for the regulatory body to decide as to whether

the observed level of enrichment is acceptable beyond the OLE, and therefore


22

whether the WTA farm qualifies for a feed increase. We note that an increase in feed

use at this site is likely to result in further enrichment beyond the present OLE

monitoring stations.


23

5. REFERENCES

ANZECC 2000. Australian and New Zealand guidelines for fresh and marine water

quality 2000 Volume 1. National Water Quality Management Strategy Paper

No. 4. Australian and New Zealand Environment and Conservation Council

and Agriculture and Resource Management Council of Australia and New

Zealand, Canberra.

Bennett H, Elvines D, Knight B 2018a. 2017-2018 Annual environmental monitoring

report for the Waitata reach salmon farm. Prepared for New Zealand King

Salmon Co. Ltd. Cawthron Report No. 3146. 43 p. plus appendices.

Bennett H, Newcombe E, Elvines D, Dunmore R 2018b. Marine environmental

monitoring - adaptive management plan for salmon farms Ngamahau, Kopaua

and Waitata (2018-2019). Prepared for The New Zealand King Salmon Co.

Ltd. Cawthron Report No. 3211. 34 p. plus appendices.

Bradford JM, Chang FH, Baldwin R, Chapman B, Downes M, Woods P 1987.

Hydrology, plankton, and nutrients in Pelorus Sound, New Zealand, July 1981

and May 1982. New Zealand Journal of Marine and Freshwater Research

21(2): 223–233.

Broekhuizen N, Plew D 2018. Marlborough Sounds water quality monitoring: review

of Marlborough District Council monitoring data 2011 – 2018. Prepared for

Marlborough District Council. NIWA Client Report 2018248HN. 159 p plus

appendices.

Cornet-Barthaux V, Armand L, Queguiner B 2007. Biovolume and biomass estimates

of key diatoms in the Southern Ocean. Aquatic Microbial Ecology 48 (3): 295-

308.

Dunmore R 2019. Reef environmental monitoring results for the New Zealand King

Salmon Company Ltd salmon farms: 2018. Prepared for the New Zealand

King Salmon Company Ltd. Cawthron Report No. 3291. 84 p. plus

appendices.

Ellis J, Clark D, Keeley N, Taylor D, Atalah J, Forrest R, Goodwin E 2011.

Assessment of effects of farming salmon at Waitata Bay, Pelorus Sound:

deposition and benthic effects. Prepared for New Zealand King Salmon

Company Limited. Cawthron Report No. 1986. 59p.


24

Elvines D, Knight B 2017. Marine Environmental Monitoring - Adaptive Management

Plan for salmon farms Ngamahau, Kopaua and Waitata (2017-2018).

Prepared for New Zealand King Salmon Company Limited. Cawthron Report

No. 3050. 35 p. plus appendices.

Elvines D, Knight B, Berthelsen A, Fletcher L 2017. Waitata Reach salmon farm:

annual monitoring report (2016–2017). Prepared for The New Zealand King

Salmon Co. Ltd. Cawthron Report No. 2999. 42 p. plus appendices.

Elvines D 2018. Advice on feed increase criteria for consent conditions for the

Waitata salmon farm. Cawthron Advice Letter 1816 to New Zealand King

Salmon Company Ltd dated 17 May 2017. 3 p.

EPA (Environmental Protection Agency) 2013. Final report and decision of the Board

of Inquiry: Volume 1; New Zealand King Salmon requests for plan changes

and applications for resource consents. Decision date 22 February 2013.

Hillebrand H, Dürselen CD, Kirschtel D, Pollingher D, Zohary T 1999. Biovolume

calculation for pelagic and benthic microalgae. Journal of Phycology, 35: 403-

424.

Karlson B, Cusack C, Bresnan E 2010. Microscopic and molecular methods for

quantitative phytoplankton analysis. UNESCO. 113 p.

Keeley N, Taylor D 2011. The New Zealand King Salmon Company Limited:

Assessment of environmental effects - benthic. Prepared for The New Zealand

King Salmon Co. Ltd. Cawthron Report No.1285. 73 p plus appendices.

Keeley N 2012. Assessment of enrichment stage and compliance for salmon farms–

2011. Prepared for New Zealand King Salmon Company Limited. Report No.

2080. 15 p.

Keeley N, Macleod C, Forrest B 2012. Combining best professional judgement and

quantile regression splines to improve characterisation of macrofaunal

responses to enrichment. Ecological Indicators 12: 154-166.

Menden-Deuer S, Lessard EJ 2000. Carbon to volume relationships for

dinoflagellates, diatoms, and other protist plankton. Limnology and

Oceanography 45(3): 569-579.

Morrisey D, Broekhuizen N, Grange K, Stenton-Dozey J 2014. Baseline monitoring

plan for new salmon farm sites, Marlborough Sounds, NIWA Client Report No:

NEL2013-015, 78 p. plus appendices.

Morrisey D, Stenton-Dozey J, Broekhuizen N, Anderson T, Brown S, Plew D 2015.

Baseline monitoring report for new salmon farm sites, Marlborough Sounds.

NIWA Client Report No. NEL-2014-020. Prepared for the New Zealand King

Salmon Co. Ltd. 247 p.


25

Ministry of Primary Industries (MPI) 2015. Best Management Practice guidelines for

salmon farms in the Marlborough Sounds: Part 1: Benthic environmental

quality standards and monitoring protocol (Version 1.0 January 2015).

Prepared for the Ministry for Primary Industries by the Benthic Standards

Working Group (N Keeley, M Gillard, N Broekhuizen, R Ford, R Schuckard, S

Urlich).

Rott E 1981. Some results from phytoplankton counting intercalibrations.

Schweizeriche Zeitschrift für Hydrologie 43: 1.

Sneddon R, Tremblay L 2011. The New Zealand King Salmon Co. Ltd: Assessment

of environmental effects – copper and zinc. Prepared for The New Zealand

King Salmon Company Ltd. Cawthron Report No. 1984. 53 p. plus

appendices.


26

6. APPENDICES

Appendix 1. Methodology for soft-sediment sampling.

A1.1 Background

The following sub-sections provide detail on the soft-sediment sampling methodology,

described in the most recent marine environmental monitoring - adaptive

management plan (MEMAMP) for the site (Bennett et al. 2018b). Further rationale

and details related to the general monitoring procedures can be found in the Best

Management Practice (BMP) guidelines developed for salmon farming in the

Marlborough Sounds (MPI 2015).

A1.2 Sampling protocol

Three replicate sediment grab samples were collected at each sampling station using

a van Veen grab. Each grab sample was examined for sediment colour, odour,

texture and bacterial coverage. The top 30 mm of one sediment core (63 mm

diameter) was analysed for organic content as % ash-free dry weight (AFDW), redox

potential (EhNHE, mV), and total free sulphides (µM). In addition, composited triplicate

samples from the pen stations were analysed for total recoverable copper and zinc

concentrations. Laboratory analytical methods for sediment samples can be found in

Table A1.1.

A separate core (10 cm deep and 113 cm2 surface area) was collected from each

grab to describe the macrofaunal community assemblages. Core contents were

sieved to 0.5 mm and preserved in a solution of 95% ethanol and 5% glyoxal.

Animals were identified and counted by specialists at the Cawthron taxonomy

laboratory.

Two additional replicate samples (‘d’ and ‘e’ replicates) were collected from each pen

station to determine the redox potential (measured in the field), and to obtain organic

content and macrofauna samples for archive purposes.

Video footage of the seabed was taken at each station to qualitatively assess the

level of visible bacterial coverage, general seabed condition and presence of

sediment outgassing. The sea surface was also scanned for visible sediment

outgassing as this could provide further evidence of particularly enriched conditions.

General observations of epibiota (surface-dwelling animals) were also made.


27

A1.3 Data analysis: Assessment of Enrichment Stage

Seabed condition can be placed along an enrichment gradient that has been

quantitatively defined according to Enrichment Stage (ES). The ES assessment

references a selection of informative chemical and biological indicator variables11.

For each indicator variable (raw data), an equivalent ES score was calculated using

previously described relationships (MPI 2015)12. Average ES scores were then

calculated for:

• sediment chemistry variables (redox and sulphides).

• macrofauna composition variables: abundance (N), total number of taxa (S/core),

richness (d), Margalef richness index (d), evenness (J’), diversity (H’) and biotic

indices (AMBI, mAMBI and BQI).

• organic content (% AFDW).

The overall ES score for a given sample was then calculated by determining the

weighted average13 of those three groups of variables. Finally, the overall ES for the

sampling station was calculated from the average of the replicate samples with the

degree of certainty reflected in the associated 95% confidence interval.

Table A1.1 Laboratory analytical methods for sediment samples (January 2019) processed by either Hill Laboratories (a) or Cawthron Institute (b).

Analyte Method Default detection limit

Sediment samples

Organic matter (as ash-free dry weight) a

Ignition in muffle furnace 550°C, 6hr, gravimetric. APHA 2540 G 22nd ed. 2012. Calculation: 100 – Ash (dry wt).

0.04 g/100 g

Total recoverable copper & zinc a

Dried sample. Nitric/ hydrochloric acid digestion, ICP-MS, trace level. US EPA 200.2.

0.2 - 2 mg/kg (Cu)

0.4 - 4 mg/kg (Zn)

Total free sulphides b Cawthron Protocol 60.102. Sample solubilised in high pH solution with chelating agent and anti-oxidant. Measured in millivolt (mV) using a sulphide specific electrode and calibrated using a sulphide standard.

11 There are risks associated with placing emphasis on any individual indicator variables of ES. This is

particularly true for chemical indicators, which tend to be more spatially and temporally variable. As such, the derived overall ES value is considered a more robust measure of the general seabed state.

12 We note that ES calculations in the previous monitoring reports for this site did not implement the rules from appendix 10.2: bullet points 2b and 2c from MPI (2015).

13 Weighting used in the current assessment is the same as that used in previous years: organic loading = 0.1, sediment chemistry = 0.2, macrofauna composition = 0.7.


28

A1.4 Compliance framework for soft-sediment monitoring results.

The environmental monitoring results from soft-sediment habitats monitoring are used

to determine whether the farms are compliant with the environmental quality

standards (EQS: benthic) specified in the WTA resource consent conditions.

A1.4.1 Enrichment

The EQS (benthic) are based on a seabed impact ‘zones concept’; an approach that

provides an upper limit to the spatial extent and magnitude of seabed impacts (see

Keeley 2012). The EQS in the consent conditions (Table A1.2) set precise

parameters for the allowable environmental states within the zones. In addition, best

management practice guidelines–benthic (BMP; MPI 2015) exist for salmon farming

in the Marlborough Sounds. The BMP was developed after the consent conditions

were written; thus, some aspects of the monitoring design or compliance framework

are inconsistent with that outlined in the BMP. Where discrepancies or uncertainty

exists as to the consistency or intent of the EQS or management action, the rationale

in the BMP will be consulted for guidance (as per Bennett et al. [2018b] and see

Table A1.2 3b).


29

Table A1.2 Environmental quality standards (EQS) for each zone at the Waitata Reach salmon farm (consent U140294) (Table 3a). EQS descriptors for the OLE as worded in the consent conditions, and the best management practice guidelines (BMP; MPI 2015, Table 3b). The EQS descriptors from the BMP correspond to varying levels of management response.

Table A1.2a.

Compliance

Monitoring

Location

Consented EQS

Zones 1 & 2

Beside and

beneath the net

pens (ZME as

per the BMP)

Measured beneath

the edge of the net

pens

ES ≤ 5

No more than one replicate core with no taxa (azoic).

No obvious spontaneous out-gassing (H2S/methane)

Bacteria mat (Beggiatoa) coverage not greater than

localised/patchy in distribution.

Zone 3*

Near to the net

pens

Measured at the

Zone 2/3 boundary

ES ≤ 4.0

Infauna abundance is not significantly higher than at

corresponding ‘Pen’ station.

Number of taxa > 75% of number at relevant /

appropriate reference station(s).

Zone 4

Outside the

footprint area

(OLE as per the

BMP)

Measured at the

Zone 3/4 boundary

stations

ES < 3.0

Conditions remain statistically comparable with relevant

appropriate reference station(s).

Table A1.2b.

Consented EQS for

the OLE

BMP EQS for the OLE

ES threshold /

industry

operational goal

ES < 3.0 Overall ES <3.014 (i.e. maintain natural conditions).

EQS descriptors Conditions remain

statistically

comparable with

relevant /

appropriate

reference station(s)

Alert: A statistically significant increase relative to

appropriate reference station(s)15.

Minor: Overall ES ≥ 3.0,

AND

Mean ES 0.4 higher than previous year, and increase

is significant relative to appropriate reference stations.

*Note that sampling at this station is not a requirement under the BMP guidelines.

14 … Natural (i.e. non-farm impacted) seabed in the Marlborough Sounds varies from about ES 1.5–2.5 (but no

greater than ES 2.9) … (MPI 2015) 15 Statistically significant increase relative to appropriate reference station(s) implies the use of a BACI-type

analysis to test for a significant Station:Survey interaction term. More than one reference station may be included in the analysis.


30

A1.4.2 Copper and zinc

Compliance for copper and zinc levels follows the decision hierarchy in the BMP

guidelines (MPI 2015), as shown in Figure A1.1. The BMP guidelines state that the

ANZECC (2000) ISQG-Low criteria for copper and zinc are the most appropriate

trigger values for sediments beneath farms (Table A1.3, Figure A1.1). Therefore,

these guideline thresholds should be used to trigger further action if exceeded.

Table A1.3. ANZECC (2000) Interim Sediment Quality Guideline concentrations for copper and zinc

(mg/kg).

ISQG-Low ISQG-High

Copper 65 270

Zinc 200 410


31

Figure A1.1 Decision response hierarchy for metals tiered monitoring approach (from MPI 2015).

Copper is the example shown here.

Cage-edge or beneath-cage

composite sample

Sediment total metals analysis

Re-analyse individual triplicate

samples sieved at 250 m

No

Acid soluble Cu analysis of

individual triplicates of bulk

fraction e.g. 1M HCl

No further

action this

monitoring

round

Management action to

reduce inputs of copper

to benthic sediments

Spatial survey to delineate

ISQG-Low contour for AE-Cu

Below

ISQG-Low?

No

All below

ISQG-Low?Yes

Re-analyse individual

triplicate samples for bulk

sediment concentration

No

All below

ISQG-Low?Yes

Measure bulk sediment

recoverable copper

Measure fine sediment

recoverable copper

How much Cu is

contributed by the

coarse fraction?

Evidence for chance

inclusion of large paint

flakes

No

Mean

AE-Cu Below

ISQG-Low?

Yes

Estimate of

bioavailability

Flagged to complete

next monitoring round

to at least level 3

1

2

3

4 Reduction of inputs

Establishment of

sediment Cu contours

Flagged to complete


to at least level 2

5

Yes

No

ISQG-L

contour <50m or zone

equivalent?

Yes

Flagged to complete


to at least level 5

Management action to further

reduce inputs of copper

to benthic sediments

Ecotoxicological studies to refine

site-specific trigger levels for long-

term protection of benthic habitats

Replacement of ISQG-L with

site-specific Cu trigger level

6Refinement of site-

appropriate trigger level

for sediment Cu

Distance of ISQG-L

contour from cage

edge

LEVEL


32

Appendix 2. Comprehensive discussion of results of the January 2019 soft-sediment monitoring survey at the Waitata Reach (WTA) salmon farm.

A2.1 Qualitative description of soft-sediment habitats

Video footage of the seabed beneath the WTA pen stations showed fine-textured,

light grey sediments, with occasional darker patches evident (Figure A2.1). There

was no outgassing or Beggiatoa-like bacteria seen at the pen stations.

Burrow holes were observed at all three pen stations. A few small yellow-brown

globules resembling fish faeces were observed on the surface of the sediment at Pen

1 (Figure A2.1). Epifaunal diversity was low; clusters of blue and green-lipped

mussels (Mytilus galloprovincialis and Perna canaliculus) were the most conspicuous

feature across all pen stations (Figure A2.1), and a hermit crab (likely Pagurus sp.)

was noted at Pen 3.

The substrate at the 150 N station was similar in appearance to beneath the net

pens; soft muddy sediment that was predominantly light grey in colour, with darker

patches evident. There was also a small amount of shell hash present at this site.

Yellow-brown globules resembling fish faeces or feed were also observed at this

station, and epifaunal diversity was low.

Substrate at the OLE stations (600 N and 600 S) comprised light grey sand with shell

hash. Worm casts and burrow holes were evident at 600 N only and epifaunal

diversity was greatest at this site with a cushion star (Patiriella regularis), an

unidentified flounder (likely Rhombosolea sp.), colonial ascidians or sponges and a

finger sponge observed. Patches of brown drift algae were also observed. The 600 S

station had considerable shell debris and small cobbles present (Figure A2.1);

epifaunal observations included an 11-armed sea star (Coscinasterias muricata) and

sea cucumbers.

Reference stations (near-field: PS-Ctl-6; and far-field: PS-Ctl-3, PS-Ctl-4 and

PS-Ctl-5) are situated in low-flow environments (in contrast to the WTA farm site) and

were all characterised by fine-textured, light grey sediments. Patches of diatom mats

were evident at all reference stations, except for PS-Ctl-3 and PS-Ctl-4 (Figure A2.1).

Burrow holes, mounds and trail marks were occasionally observed at PS-Ctl-3 and

PS-Ctl-6, with fewer evident at PS-Ctl-4 and PS-Ctl-5. Epifauna were largely lacking

at the reference stations apart from PS-Ctl-4, where hydroids, colonial ascidians,

scallops (Pecten novaezelandiae), cushion stars (Patiriella regularis), a purple fan

worm (Sabellidae) and hermit crabs (PS-Ctl-4) were seen.

PS-Ctl-8 (established during the current monitoring round) is in a higher flow

environment, and therefore a better comparison to the WTA site. This site was also


33

characterised by fine-textured, light grey sediments with occasional burrow holes and

trail marks.

Figure A2.1. Representative images of the seafloor at each of the Waitata Reach (WTA) salmon farm

monitoring stations, January 2019.


34

Figure A2.1 continued. Representative images of the seafloor at each of the Waitata Reach (WTA)

salmon farm monitoring stations, January 2019.


35

Figure A2.1 continued. Representative image of the seafloor at the Waitata Reach (WTA) reference

station PS-Ctl-8, January 2019.

A2.2 Assessment of enrichment to soft-sediment habitats

The average overall ES scores at the three pen stations were ES 3.3, 2.8, and 2.4 for

Pen 1, Pen 2 and Pen 3, respectively (Table 1), indicating moderate enrichment

levels. The overall ES scores for all pen stations were within the EQS (ES ≤ 5.0) for

this zone. While the ES score at Pen 1 remained the same as the previous monitoring

round, the ES scores at Pen 2 and Pen 3 decreased from 3.3 and 2.7, respectively

(Bennett et al. 2018a).

Indicators were consistent with moderate levels of enrichment at all pen stations.

Organic matter was slightly elevated compared to reference stations (Figure A2.2).

Total free sulphides were moderately elevated in an absolute sense. While in 2018

the levels of total free sulphides and organic content at Pen 3 were disparate from

values at the other pen stations, this year both parameters were comparable among

all stations. While redox values decreased at Pen 1, redox potential increased at Pen

2 and Pen 3, compared to the previous monitoring round (February 2018).

Total macrofaunal abundance at the pen stations was variable (on average 75 to 133

individuals per core; Figure A2.2) but marginally elevated compared to reference

station values (average of 40 to 85 individuals per core, with one site containing an

average of 158 individuals per core) and baseline values (average 26 to 108

individuals per core, Morrisey et al. 2015). The number of taxa at Pen 1 was slightly

lower than the other pen stations with an average of 16 taxa per core as compared to

22 and 28 for Pens 2 and 3, respectively. These values were only slightly lower than

at reference stations (14 to 41 taxa per core, Figure A 2.2) and were comparable to

baseline conditions (average 13–31 taxa per core, Morrisey et al. 2015). Slight

compositional changes were evident at Pens 1 and 2, reflected by low diversity and

evenness as well as high AMBI values compared to the reference stations. However,

all pen stations were characterised by decreased macrofaunal abundance and

increased richness and evenness compared to the 2018 monitoring round, indicating

a level of recovery at these sites over the past 12 months.


36

The overall ES score at 150 N (Zone 2/3 boundary) was ES 2.6 (Table 1), indicating

mild enrichment. This ES score is higher than the score in the previous monitoring

round at this station (ES 2.4, Bennett et al. 2018a) but remains statistically

comparable to the previous year16 and well below the allowable ES (≤ 4.0) for this

zone (Table 1). Total free sulphide concentrations were very elevated compared to

reference stations (Figure A2.2) and to the previous annual monitoring assessment

(Bennett et al. 2018a). Macrofauna abundances (average 109 individuals per sample)

were only slightly elevated compared to reference (Figure A2.2) and baseline levels

(Morrisey et al. 2015) but were reduced from the previous year. We note that infauna

abundance is not significantly higher than at corresponding pen stations and number

of taxa remains more than 75 % of number at relevant / appropriate reference

stations (as per consent requirements).

Further from the farm structures, at the OLE (600 N and 600 S), the overall ES scores

(ES 2.2) were within the allowable ES (< 3.0) for this zone. Enrichment levels have

increased at the 600 N station (by ES 0.1) and decreased at the 600 S station (by ES

0.3), when compared to the previous annual monitoring assessment in February 2018

(Figure A2.2, Bennett et al. 2018a). However, we note that ES scores at both OLE

station statistically comparable to the previous year17. Both stations had elevated total

free sulphides when compared to reference levels, particularly the high flow reference

station (PS Ctl-8).

Average macrofaunal abundance was elevated at both OLE stations, particularly at

600 S (average of 847 individuals per sample as compared to 140 individuals per

sample at 600 N; Figure A2.2). Macrofaunal abundance and taxa richness metrics

were elevated at both OLE stations compared to all sampling stations during baseline

monitoring in 2014 (Morrisey et al. 2015) and from the previous annual monitoring

assessment (42-51 taxa per core; Bennett et al. 2018a). However, macrofaunal

community composition at 600 N was largely similar to reference stations.

Meanwhile, community compositional changes were evident at 600 S. In the previous

monitoring round, Dorvilleid polychaetes were the most abundant taxa. This year,

while other enrichment tolerant taxa such as dorvilleids and nematodes are still

abundant, scavenging amphipods and tanaid crustacean18 are now the most

abundant taxa at this site. Macrofaunal community composition has always differed at

600 S compared to other stations (likely due to the large particle size of sediments

here), however it is likely farm deposition is causing a slight fertilisation effect at this

site. This is supported by changes in sediment chemistry, which suggests that natural

conditions have not been maintained at both OLE stations.

16 one-way PERMANOVA: Pseudo-f (1, 5) = 0.9, p = 0.41. 17 one-way PERMANOVA: Pseudo-f (1, 11) = 0.3, p = 0.63. 18 Amphipod and tanaid crustacean abundances were not elevated at any other sites at Waitata Reach.


37

We note that under the BMP guidelines, background / natural conditions are

assessed as enrichment stage (rather than individual variables), and the industry

operational goal is for the OLE to be ES < 3.0. In the context of ES scores these sites

are compliant (i.e. ES < 3.0)19. The WTA consent requires that ES < 3.0 is maintained

at the OLE and that conditions remain statistically comparable with relevant /

appropriate reference stations. Conditions (assessment as ES scores as per the BMP

guidelines) at both OLE stations are statistically comparable with relevant /

appropriate reference stations20.

19 See Section 2.1.2 for discussion on issues associated with using ES <3.0 as a proxy for “natural conditions”. 20 600 S: one-way PERMANOVA: Pseudo-f (5, 17) = 2.9, p = 0.06, 600 N: one-way PERMANOVA: Pseudo-f (5,

17) = 3.1, p = 0.05.


38

Figure A2.2. Sediment organic matter (% ash-free dry weight; AFDW), redox potential (EhNHE, mV),

total free sulphides (µM) and macrofauna statistics determined at the Waitata Reach (WTA) salmon farm monitoring stations, January 2019. PS-Ctl = Pelorus Sound control. Error bars = ± 1 SE, n = 3.


39

Table A2.1. Detailed Enrichment Stage (ES) calculations for each station at the Waitata Reach salmon farm, January 2019. For details about how these values were calculated, see MPI (2015). Underlined text are cases where best professional judgement (BPJ; Keeley et al. 2012b) was used. Note that ES calculations in previous annual monitoring reports did not implement the rules from appendix 10.2: bullet points 2b&c from MPI (2015).

SITE INFORMATION

Date:

Farm/site: Waitata Reach

Flow env: High flow

ES equivalents

Station: Rep. TOM Redox TFS N S J' d H' AMBI M-AMBI BQI TOM_ES Redox TFS N S j d H' AMBI M-AMBI BQI

Organic

Loading

Sediment

chemistry

Macro

fauna

Overall

ES

WTA Pen 1 A 6.9 -85 798 75 19 0.83 4.17 2.45 2.44 0.53 5.08 4 4.89 3.75 1.14 3.9 1.41 3.49 2.02 1.76 3.49 3.04 4 4.32 2.53 3.04

WTA Pen 1 B 6.7 -106 923 112 17 0.66 3.39 1.86 3.62 0.4 4.69 4 5.08 3.84 1.45 4.04 2.22 3.99 2.54 2.98 4.41 3.26 4 4.46 3.11 3.47

WTA Pen 1 C 6.8 -138 691 37 13 0.76 3.32 1.94 3.68 0.39 3.71 4 5.37 3.65 0.6 4.31 1.74 4.03 2.45 3.04 4.47 3.91 4 4.51 3.07 3.45

WTA Pen 2 A 5.9 162 1578 28 12 0.8 3.3 1.99 2.39 0.47 4.42 3 2.67 4.19 0.39 4.38 1.55 4.04 2.41 1.71 3.96 3.43 3 3.43 2.73 2.9

WTA Pen 2 B 6.4 190 1361 244 32 0.58 5.64 2.01 3.47 0.48 5.24 3 2.42 4.09 2.04 n/c 2.6 2.6 2.38 2.82 3.88 2.95 3 3.25 2.75 2.88

WTA Pen 2 C 5.2 133 520 84 22 0.81 4.74 2.49 3.25 0.5 5.94 3 2.93 3.47 1.23 n/c 1.5 3.13 1.99 2.59 3.72 2.59 3 3.2 2.39 2.62

WTA Pen 3 A 7.2 152 940 156 33 0.81 6.34 2.82 1.78 0.67 9.96 4 2.76 3.85 1.7 n/c 1.5 2.24 1.83 1.09 2.65 1.59 4 3.31 1.8 2.32

WTA Pen 3 B 5.4 81 940 70 21 0.83 4.71 2.54 1.76 0.59 8.36 3 3.4 3.85 1.09 n/c 1.41 3.15 1.96 1.07 3.1 1.78 3 3.63 1.94 2.38

WTA Pen 3 C 5.8 39 1013 172 31 0.81 5.83 2.79 1.68 0.66 9.48 3 3.78 3.9 1.78 n/c 1.5 2.5 1.84 0.99 2.68 1.62 3 3.84 1.85 2.36

WTA 150 N A 6.5 79 1466 60 20 0.83 4.64 2.49 1.83 0.58 6.21 4 3.42 4.14 0.97 3.83 1.41 3.2 1.99 1.15 3.19 2.47 4 3.78 2.27 2.75

WTA 150 N B 4.2 96 1700 88 20 0.83 4.24 2.48 2.06 0.57 8.17 3 3.27 4.23 1.26 3.83 1.41 3.45 1.99 1.38 3.29 1.82 3 3.75 2.3 2.66

WTA 150 N C 5.4 103 1264 180 34 0.78 6.35 2.76 2.6 0.61 8.16 3 3.2 4.04 1.81 n/c 1.65 2.24 1.85 1.93 2.98 1.82 3 3.62 2.04 2.45

WTA 600 N A 5.5 202 483 136 31 0.83 6.11 2.84 2.03 0.64 9.56 3 2.31 3.42 1.6 n/c 1.41 2.35 1.82 1.34 2.78 1.61 3 2.87 1.84 2.16

WTA 600 N B 5.7 186 811 200 47 0.78 8.68 3.01 2.03 0.72 10.2 3 2.46 3.76 1.89 n/c 1.65 1.57 1.78 1.35 2.34 1.59 3 3.11 1.74 2.14

WTA 600 N C 5.9 86 288 84 22 0.75 4.74 2.33 1.56 0.59 9.45 3 3.36 3.09 1.23 n/c 1.79 3.13 2.1 0.87 3.13 1.62 3 3.22 1.98 2.33

WTA 600 S A 5.9 252 172 1193 79 0.72 11 3.14 2.52 0.83 9.3 3 1.86 2.75 3.26 n/c 1.93 1.5 1.76 1.85 1.91 1.63 3 2.31 1.98 2.15

WTA 600 S B 5.2 276 148 294 44 0.77 7.57 2.9 2.68 0.66 8.54 3 1.64 2.66 2.19 n/c 1.69 1.76 1.81 2.02 2.69 1.74 3 2.15 1.99 2.12

WTA 600 S C 5.1 106 334 1052 54 0.69 7.62 2.76 2.31 0.71 9.7 3 3.17 3.18 3.16 n/c 2.08 1.75 1.85 1.63 2.42 1.6 3 3.18 2.07 2.39

Jan-19


40

Table A2.1. continued Detailed Enrichment Stage (ES) calculations for each station at the Waitata Reach salmon farm, January 2019. For details about how these values were calculated, see MPI (2015). Underlined text are cases where best professional judgement (BPJ; Keeley et al. 2012) was used. Note that ES calculations in previous annual monitoring reports did not implement the rules from appendix 10.2: bullet points 2b&c from MPI (2015).

SITE INFORMATION

Date:

Farm/site: Waitata Reach

Flow env: High flow

ES equivalents

Station: Rep. TOM Redox TFS N S J' d H' AMBI M-AMBI BQI TOM_ES Redox TFS N S j d H' AMBI M-AMBI BQI

Organic

Loading

Sediment

chemistr

y

Macrof

auna

Overal

l ES

PS Ctl -3 A 5.5 -53 71 44 18 0.82 4.49 2.36 1.65 0.57 8.26 3 4.61 2.18 0.73 3.97 1.45 3.29 2.08 0.96 3.25 1.8 3 3.39 2.19 2.51

PS Ctl -3 B 5.4 -55 71 37 18 0.89 4.71 2.58 2.38 0.55 6.48 3 4.62 2.18 0.6 3.97 1.12 3.15 1.94 1.7 3.41 2.35 3 3.4 2.28 2.58

PS Ctl -3 C 5.4 -128 71 40 14 0.84 3.52 2.21 1.89 0.53 6.71 3 5.28 2.18 0.66 4.24 1.36 3.9 2.19 1.2 3.55 2.26 3 3.73 2.42 2.74

PS Ctl -4 A 5.1 -15 108 323 40 0.74 6.75 2.72 2.29 0.65 8.93 3 4.26 2.45 2.26 n/c 1.84 2.06 1.87 1.61 2.74 1.68 3 3.36 2.01 2.38

PS Ctl -4 B 5.3 -114 136 56 22 0.88 5.22 2.72 1.76 0.62 8.84 3 5.16 2.6 0.92 n/c 1.17 2.84 1.87 1.07 2.96 1.69 3 3.88 1.79 2.33

PS Ctl -4 C 5.1 3 185 96 26 0.71 5.48 2.31 2.85 0.52 7.17 3 4.1 2.8 1.33 n/c 1.98 2.69 2.11 2.19 3.58 2.1 3 3.45 2.28 2.59

PS Ctl -5 A 5.3 -65 71 54 24 0.91 5.77 2.9 1.86 0.63 9.04 3 4.71 2.18 0.89 n/c 1.02 2.53 1.8 1.17 2.84 1.66 3 3.45 1.7 2.18

PS Ctl -5 B 5.1 17 71 79 24 0.86 5.26 2.74 1.76 0.62 8.71 3 3.98 2.18 1.18 n/c 1.26 2.82 1.86 1.08 2.9 1.71 3 3.08 1.83 2.2

PS Ctl -5 C 5.1 -68 71 55 23 0.92 5.49 2.87 1.73 0.64 7.78 3 4.74 2.18 0.9 n/c 0.98 2.69 1.81 1.04 2.83 1.91 3 3.46 1.74 2.21

PS Ctl -6 A 5.5 -83 216 74 22 0.83 4.88 2.57 2.24 0.57 7.84 3 4.88 2.9 1.13 n/c 1.41 3.05 1.94 1.56 3.25 1.9 3 3.89 2.03 2.5

PS Ctl -6 B 17.5 -92 216 48 20 0.88 4.91 2.63 2.33 0.56 7.65 7 4.96 2.9 0.8 3.83 1.17 3.03 1.91 1.65 3.3 1.95 7 3.93 2.2 3.03

PS Ctl -6 C 5.8 -53 185 133 41 0.89 8.18 3.32 1.9 0.74 11.2 3 4.61 2.8 1.58 n/c 1.12 1.63 1.76 1.21 2.26 1.65 3 3.7 1.6 2.16

PS Ctl -8 A 4.8 37 71 53 26 0.92 6.3 3 1.19 0.69 10.5 3 3.8 2.18 0.88 n/c 0.98 2.26 1.78 0.49 2.5 1.59 3 2.99 1.5 1.95

PS Ctl -8 B 4.7 -80 71 85 29 0.89 6.3 3 1.66 0.68 10 3 4.85 2.18 1.24 n/c 1.12 2.26 1.78 0.97 2.59 1.59 3 3.52 1.65 2.16

PS Ctl -8 C 4.6 -59 121 62 24 0.85 5.57 2.71 1.56 0.63 9.8 3 4.66 2.53 1 n/c 1.31 2.64 1.87 0.87 2.84 1.6 3 3.59 1.73 2.23

Jan-19


41

Table A2.2. Summary of the average (SE) sediment physical and chemical properties, macrofauna variables and calculated indices for the Waitata Reach salmon farm stations during the January 2019 monitoring survey.

Units Pen1 Pen 2 Pen 3 150 N 600 N 600 S

Depth m 50 54 56 56 56 39

Se

dim

en

ts AFDW % 6.8 (0.1) 5.8 (0.3) 6.1 (0.5) 5.4 (0.7) 5.7 (0.1) 5.4 (0.3)

Redox EhNHE, mV -109.7 (15.4) 161.7 (16.5) 90.7 (33) 92.7 (7.1) 158 (36.3) 211.3 (53.1)

Sulphides µM 804 (67) 1153 (322.6) 964.3 (24.3) 1476.7 (126) 527.3 (152.6) 218 (58.4)

Bacterial mat - No No No No No No

Out-gassing - No No No No No No

Odour - Mild Mild No No No No

Ma

cro

fau

na

sta

tis

tic

s

Abundance No./core 74.7 (21.7) 118.7 (64.7) 132.7 (31.7) 109.3 (36.2) 140 (33.5) 846.3 (279.2)

No. taxa No./core 16.3 (1.8) 22 (5.8) 28.3 (3.7) 24.7 (4.7) 33.3 (7.3) 59 (10.4)

Evenness Stat. 0.8 (0.0) 0.7 (0.1) 0.8 (0.0) 0.8 (0.0) 0.8 (0.0) 0.7 (0.0)

Richness Stat. 3.6 (0.3) 4.6 (0.7) 5.6 (0.5) 5.1 (0.6) 6.5 (1.2) 8.7 (1.1)

SWDI Index 2.1 (0.2) 2.2 (0.2) 2.7 (0.1) 2.6 (0.1) 2.7 (0.2) 2.9 (0.1)

AMBI Index 3.2 (0.4) 3 (0.3) 1.7 (0.0) 2.2 (0.2) 1.9 (0.2) 2.5 (0.1)

mAMBI Index 0.4 (0.0) 0.5 (0.0) 0.6 (0.0) 0.6 (0.0) 0.7 (0.0) 0.7 (0.0)

BQI Index 4.5 (0.4) 5.2 (0.4) 9.3 (0.5) 7.5 (0.7) 9.7 (0.2) 9.2 (0.3)


42

Table A2.2. continued Summary of the average (SE) sediment physical and chemical properties, macrofauna variables and calculated indices for the Waitata Reach salmon farm reference stations during the January 2019 monitoring survey.

Units PS-Ctl-3 PS-Ctl-4 PS-Ctl-5 PS-Ctl-6 PS-Ctl-8

Depth m 35 33 20 26 51

Se

dim

en

ts

AFDW % 5.4 (0.0) 5.2 (0.1) 5.2 (0.1) 9.6 (4) 4.7 (0.1)

Redox EhNHE, mV -78.7 (24.7) -42 (36.4) -38.7 (27.8) -76 (11.8) -34 (36)

Sulphides µM 71 (0.0) 143 (22.5) 71 (0.0) 205.7 (10.3) 87.7 (16.7)

Bacterial mat - No No No No No

Out-gassing - No No No No No

Odour - No No No No No

Ma

cro

fau

na

sta

tis

tic

s

Abundance No./core 40.3 (2) 158.3 (83.1) 62.7 (8.2) 85 (25.1) 66.7 (9.5)

No. taxa No./core 16.7 (1.3) 29.3 (5.5) 23.7 (0.3) 27.7 (6.7) 26.3 (1.5)

Evenness Stat. 0.8 (0.0) 0.8 (0.1) 0.9 (0.0) 0.9 (0.0) 0.9 (0.0)

Richness Stat. 4.2 (0.4) 5.8 (0.5) 5.5 (0.1) 6 (1.1) 6.1 (0.2)

SWDI Index 2.4 (0.1) 2.6 (0.1) 2.8 (0.1) 2.8 (0.2) 2.9 (0.1)

AMBI Index 2 (0.2) 2.3 (0.3) 1.8 (0.0) 2.2 (0.1) 1.5 (0.1)

mAMBI Index 0.5 (0.0) 0.6 (0.0) 0.6 (0.0) 0.6 (0.1) 0.7 (0.0)

BQI Index 7.2 (0.6) 8.3 (0.6) 8.5 (0.4) 8.9 (1.2) 10.1 (0.2)


43

Figure A2.3. Representative images of the seafloor at each of the Type 3 soft-sediment sampling stations at the Waitata Reach salmon farm (WTA), January 2019. Drop camera footage was not obtained from stations T3a3, T3b1 and T3b2.


44

Figure A2.3 continued. Representative images of the seafloor at each of the Type 3 soft-sediment

sampling stations at the Waitata Reach salmon farm (WTA), January 2019.


45

Figure A2.4. Sediment organic matter (% ash-free dry weight; AFDW), redox potential (EhNHE, mV),

total free sulphides (µM) and macrofauna statistics determined at the Type 3 soft-sediment sampling stations at the Waitata Reach salmon farm (WTA), January 2019. PS-Ctl = Pelorus Sound control. Error bars = ± 1 SE, n = 3.


46

Table A2.3. Detailed Enrichment Stage (ES) calculations for the Type 3 soft-sediment sampling stations at the Waitata Reach salmon farm (WTA), January 2019. For details about how these values were calculated, see MPI (2015). Underlined text are cases where best professional judgement (BPJ; Keeley et al. 2012b) was used. Note that ES calculations in previous annual monitoring reports did not implement the rules from appendix 10.2: bullet points 2b and 2c from MPI (2015).

SITE INFORMATION

Date: Jan-19 Variable group weightings:

Farm/site: Waitata Bay 0.1 0.2 0.7

Flow environment: HF

RAW DATA (to be entered) ES equivalents

Station: Rep TOM Redox Sulphides N S j d H' AMBI M-AMBI BQI TOM Redox Sulphides N S j d H' AMBI M-AMBI BQI

Organic

Loading

Sediment

chemistry

Macro

fauna Overall ES

T3a1 A 4.5 262 117 789 69 0.69 10.19 2.91 2.52 0.91 12.33 3 1.77 2.5 2.94 n/c 2.08 1 1.8 1.85 1.75 1 3 2.14 1.77 1.97

T3a1 B 5.3 260 502 692 63 0.72 9.48 2.99 2.71 0.87 9.27 3 1.79 3.45 2.84 n/c 1.93 1.2 1.78 2.04 1.79 1.64 3 2.62 1.89 2.15

T3a1 C 5.8 316 68 443 38 0.68 6.07 2.47 3.45 0.65 6.11 3 1.28 2.15 2.5 n/c 2.12 2.37 2 2.8 2.77 2.51 3 1.72 2.44 2.35

T3a2 A 5.2 250 216 125 26 0.79 5.18 2.56 1.84 0.71 9.21 3 1.88 2.9 1.53 n/c 1.6 2.87 1.94 1.16 2.39 1.64 3 2.39 1.88 2.09

T3a2 B 5.8 106 585 279 51 0.8 8.88 3.16 2.06 0.88 11 3 3.17 3.55 2.15 n/c 1.55 1.57 1.76 1.38 1.78 1.62 3 3.36 1.69 2.15

T3a2 C 5.4 116 399 237 41 0.8 7.32 2.96 1.97 0.82 10.45 3 3.08 3.3 2.02 n/c 1.55 1.84 1.79 1.29 1.93 1.59 3 3.19 1.72 2.14

T3a3 A 5.4 108 585 153 34 0.83 6.56 2.94 1.83 0.79 10.54 3 3.16 3.55 1.69 n/c 1.41 2.14 1.79 1.14 2.02 1.59 3 3.35 1.68 2.15

T3a3 B 5.2 199 342 116 33 0.88 6.73 3.08 1.58 0.82 10.6 3 2.34 3.2 1.48 n/c 1.17 2.06 1.77 0.89 1.92 1.6 3 2.77 1.55 1.94

T3a3 C 5.3 17 399 139 36 0.82 7.09 2.94 1.64 0.82 11.81 3 3.98 3.3 1.61 n/c 1.45 1.92 1.79 0.95 1.94 1.73 3 3.64 1.63 2.17

T3a4 A 5.7 103 542 239 35 0.79 6.21 2.8 2.94 0.71 7.86 3 3.2 3.5 2.03 n/c 1.6 2.3 1.84 2.28 2.42 1.89 3 3.35 2.05 2.41

T3a4 B 5.6 89 632 188 43 0.84 8.02 3.15 2.39 0.82 9.17 3 3.33 3.6 1.84 n/c 1.36 1.65 1.76 1.72 1.92 1.65 3 3.46 1.7 2.18

T3b1 A 5.6 100 1082 309 40 0.85 6.8 3.15 2.46 0.8 9.5 3 3.23 3.94 2.23 n/c 1.31 2.04 1.76 1.79 1.98 1.62 3 3.59 1.82 2.29

T3b2 A 5.6 39 1851 119 16 0.57 3.14 1.57 4.89 0.34 4.35 3 3.78 4.29 1.49 4.1 2.65 4.14 2.9 4.27 4.75 3.48 3 4.03 3.47 3.54

T3b3 A 5.9 197 159 328 46 0.79 7.77 3.03 2.15 0.84 9.81 3 2.36 2.7 2.27 n/c 1.6 1.71 1.77 1.47 1.87 1.6 3 2.53 1.76 2.03

T3b4 A 5.8 79 317 191 30 0.78 5.52 2.64 1.91 0.74 9.47 3 3.42 3.15 1.86 n/c 1.65 2.67 1.9 1.23 2.27 1.62 3 3.28 1.88 2.28

T3b5 A 5 102 200 240 41 0.74 7.3 2.73 1.78 0.81 11.07 3 3.21 2.85 2.03 n/c 1.84 1.85 1.86 1.09 1.98 1.63 3 3.03 1.75 2.13

T3b6 A 5 227.7 171 445 50 0.72 8.04 2.83 3.16 0.76 7.65 3 2.08 2.75 2.5 n/c 1.93 1.65 1.82 2.5 2.14 1.95 3 2.41 2.07 2.23

T3b7 A 5.1 121 117 97 30 0.8 6.34 2.73 1.7 0.76 10.26 3 3.04 2.5 1.34 n/c 1.55 2.24 1.86 1.02 2.16 1.59 3 2.77 1.68 2.03


47

Table A2.4. Summary of the average (SE) sediment physical and chemical properties, macrofauna variables and calculated indices for the Type 3 soft-sediment sampling stations at the Waitata Reach salmon farm (WTA) during the January 2019 monitoring survey.

Units T3a1 T3a2 T3a3 T3a4 T3b1 T3b2 T3b3 T3b4 T3b5 T3b6 T3b7

Depth m 56 54 39 28 44 55 61 44 57 36 59

Se

dim

en

ts AFDW % 5.2 (0.4) 5.5 (0.2) 5.3 (0.1) 5.7 (0.1) 5.6 5.6 5.9 5.8 5 5 5.1

Redox EhNHE, mV 279.3 (18.3) 157.3 (46.4) 108 (52.5) 96 (7) 100 39 197 79 102 227.7 121

Sulphides* µM 229 (137.2) 400 (106.5) 442 (73.4) 587 (45) 1082 1851 159 317 200 171 117

Bacterial mat - N N N N N Mild N N N N N

Outgassing - N N N N N N N N N N N

Odour - N N n/a* n/a* N N N N N N N

Ma

cro

fau

na

sta

tis

tic

s

Abundance No./core 641.3 (103) 213.7 (46) 136 (10.8) 213.5 (25.5) 309 119 328 191 240 445 97

No. taxa No./core 56.7 (9.5) 39.3 (7.3) 34.3 (0.9) 39 (4) 40 16 46 30 41 50 30

Evenness Stat. 0.7 (0.0) 0.8 (0.0) 0.8 (0.0) 0.8 (0.0) 0.8 0.6 0.8 0.8 0.7 0.7 0.8

Richness Stat. 8.6 (1.3) 7.1 (1.1) 6.8 (0.2) 7.1 (0.9) 6.8 3.1 7.8 5.5 7.3 8 6.3

SWDI Index 2.8 (0.2) 2.9 (0.2) 3 (0.0) 3 (0.2) 3.1 1.6 3 2.6 2.7 2.8 2.7

AMBI Index 2.9 (0.3) 2 (0.1) 1.7 (0.1) 2.7 (0.3) 2.5 4.9 2.1 1.9 1.8 3.2 1.7

mAMBI Index 0.8 (0.1) 0.8 (0.1) 0.8 (0.0) 0.8 (0.1) 0.8 0.3 0.8 0.7 0.8 0.8 0.8

BQI Index 9.2 (1.8) 10.2 (0.5) 11 (0.4) 8.5 (0.7) 9.5 4.3 9.8 9.5 11.1 7.6 10.3


48

Appendix 3. Water column sampling methodology and compliance framework.

A3.1 Background

The following sub-sections provide detail on the water column sampling methodology.

The WTA water column sampling stations established in the baseline monitoring

(Morrisey et al. 2014, 2015) were for the ongoing NZ King Salmon routine and full-

suite monitoring programmes (see Table 4 and Figure 6 in Section 2.2 for an

overview of the sampling regime). This design includes two of the MDC state of

environment (SoE) monitoring stations (NZKS06/PLS-6 and NZKS07/PLS-7) that are

sampled by MDC. In addition, results from the SoE monitoring station (PLS-10) and

monitoring stations in proximity to the Kopaua farm (in Richmond Bay) are included

where a more broad-scale overview is relevant (e.g. physical water column properties

in the general area, phytoplankton measures).

Extra sampling stations for fine-scale water column monitoring were included in this

design during the fine-scale sampling months (March and August).

A3.2 Sampling protocol

• On all sampling occasions, water column depth profile data were collected at

each station using a conductivity-temperature-depth (CTD) instrument with an

attached DO sensor. Parameters measured were salinity, temperature, turbidity21

and DO. In addition, single, surface-integrated samples were taken over the upper

15 m of the water column (obtained using a weighted hose) and analysed for total

nitrogen (TN) and chlorophyll-a (chl-a). Additional parameters measured in

February, March, July and August included silicate (DRSi), nitrogen species and

phosphorus species (Table A3.1), as well as phytoplankton composition and

biomass. Samples were stored on ice, except for phytoplankton samples, which

were preserved with Lugol’s acidified iodine solution and kept cool.

For the fine-scale monitoring (March and August), variations to the sampling

procedure were as follows:

• In addition to the surface-integrated sample at each station, a single water sample

from near the seabed (‘near-bed’) was collected using a van Dorn sampler.

• Duplicate surface-integrated samples were collected in March 2018 from the pen

station, and the 100 m, 250 m and 500 m downstream stations22. Replicate

samples were taken from a single, well-mixed, bucket of seawater. Each bucket

comprised a unique deployment of the 15 m hose sampler. The variability

21 Turbidity was used as a proxy for clarity, as turbidity data show the water column profile rather than just

surface characteristics. 22 Sometimes additional 500 m or reference stations were sampled with replication, but not consistently.


49

between the replicates thus represents that introduced by ‘water parcel’ or

horizontal ‘spatial’ variability occurring at the sampling station during the time it

takes to be sampled. Because single samples were collected in August, means

from the two samples were used for March data. Chl-a and phytoplankton were

not sampled in replicate or in near-bed samples.

• Monthly routine and full-suite samples were collected by MDC staff, at the same

time as wide-scale SoE monitoring in Pelorus Sound (led by MDC). Cawthron

staff carried out sampling for fine-scale monitoring alongside MDC in March and

August 2018.

Table A3.1. Parameters to be measured at the sampling locations during the 2018-2019 monitoring. S = surface integrated water samples, N = near-bed water samples, CTD = profiles taken throughout the water column with electronic sensors. Italicised parameters (under fine-scale sampling) were removed from the sampling plan under the current MEMAMP (Bennett et al 2018b) and were therefore sampled in March only (under the previous MEMAMP; Elvines & Knight 2017). Note that July full-suite surveys were postponed until September. Nutrient samples from December are missing from the dataset as the samples were lost by the courier in transit. Phytoplankton sampling was delayed from February until early March, but are labelled here as ‘February’ to distinguish them from the subsequent March sampling event.

Monitoring

component

Routine and full-suite Fine-scale

Station Net pen

(NZKS08)

500 m

(NZKS

09, 10,

11)

NZKS12 NZKS06, 07 100 & 250 m

Parameter

TP Mar, Aug (N) - - - Mar, Aug (N)

DRP Mar, Aug (N) - - Mar, Aug (N) Mar, Aug (N)

DRSi Mar, Aug (S) - - Mar, Aug (S) Mar (N)

Phytoplankton Feb, Mar, Aug,

Sep (S)

- Feb, Mar, Aug, Sep (S) Mar (N)

NO2/NO3 Feb (S), Mar (S, N), Aug (S, N), Sep (S) Mar, Aug (S, N)

NH4 Feb (S), Mar (S, N), Aug (S, N), Sep (S) Mar, Aug (S, N)

Urea-N Mar, Aug (S) Mar, Aug (S)

PN Mar, Aug (S) Mar, Aug (S)

Turbidity * Feb, Mar, Aug, Sep (CTD) Mar, Aug (CTD)

Temp Feb, Mar, Aug, Sep (CTD) Mar, Aug (CTD)

Sal Feb, Mar, Aug, Sep (CTD) Mar, Aug (CTD)

Chl-a Monthly (S) Mar (N)

TN Monthly (S) Mar, Aug (S, N) Mar, Aug (S, N)

DO Monthly (CTD) Mar, Aug (CTD)


50

A3.3 Sample analysis

Samples were analysed for nutrients using routine methods (Table A3.2). In addition,

the remaining filtered sample water was archived at the laboratory in case follow-up

nutrient analyses were required (i.e. if an amber alert was triggered—see Elvines &

Knight 2017).

Algal taxonomic composition (species abundance) was determined from a subsample

of the 15 m depth integrated sample. Algal taxonomic composition was determined by

a modified Utermöhl method based on published Intergovernmental Oceanographic

Commission (IOC) methods (Karlson et al. 2010). For this process, each sample is

analysed using inverted light microscopy to identify and enumerate all taxa detected

in the sample to the finest practicable taxonomic level by IANZ accredited staff.

Sample bio-volume was estimated for recorded species and used to estimate cell

carbon content (biomass) (Table A3.2).

Table A3.2. Laboratory analytical methods for water samples processed by the NIWA laboratory in Hamilton.

Analyte Method Default

detection limit

Chlorophyll-a (c) (chl-a)

Acetone pigment extraction, spectrofluorometric measurement. A*10200H.

0.1 mg/m3

Dissolved reactive silicon (c) (DRSi)

Molybdosilicate / ascorbic acid reduction. APHA4500Si.

1 mg/m3

Total phosphorus (c) (TP)

Persulphate digest, molybdenum blue FIA. Lachat. 1 mg/m3

Urea nitrogen(c) (Urea-N)

Automated diacetyl-monoxime colorimetry. MSeawater.

1 mg/m3

Nitrate and nitrite nitrogen (c) (NO3-N)

DRP,NH4-N,NO3-N, Simultaneous Auto-analysis. Astoria.

1 mg/m3

Ammonium nitrogen (c) (NH4-N)


1 mg/m3

Dissolved reactive phosphorus (c) (DRP)


1 mg/m3

Total nitrogen (c) (TN)

Persulphate digest, auto cadmium reduction, FIA. Lachat.

10 mg/m3

Particulate nitrogen (c) (PN)

Calculation of TN – TDN (TDN determined by persulphate digest, auto cadmium reduction, FIA). Lachat.

10 mg/m3

Dissolved inorganic nitrogen (DIN)

Derived using NO3-N + NO2-N + NH4-N.

Phytoplankton biovolume (b)

From Morrisey et al. (2015): Estimated for each taxon using formulae representing the geometrical solids that approximated cell shape (Rott 1981, Hillebrand et al. 1999).

Phytoplankton carbon biomass (b)

From Morrisey et al. (2015): Cell numbers and biovolumes were used to calculate cell carbon using regression equations of Meden-deuer and Lessard (2000) for dinoflagellates and cyanobacteria, and that of Cornet- Barthaux et al. (2007) for diatoms.


51

A3.4 Compliance framework for water quality monitoring results

The environmental monitoring results from water quality monitoring are used to

determine whether the farms are compliant with the environmental quality standards

(EQS: water) specified in the consent conditions.

A3.4.1 Water quality standards

Initial water quality standards (WQS) developed by Morrisey et al. (2015) for the

Waitata (WTA), Kopaua (KOP) and Ngamahau (NGA) sites set specific thresholds for

three parameters: chl-a, DO and TN. If these thresholds are exceeded in three

consecutive months, then an ‘amber state’ is reached, and further action must be

taken (see MEMAMP, Elvines & Knight 2017). The current WQS are discussed and

specified in the MEMAMP and are summarised in Table A3.3.

Because WQS only exist for TN, chl-a and DO, the additional parameters/analytes

that are measured in February and July (full-suite monitoring) cannot be measured

against WQS for compliance as required by the consent (Condition 66c):

Monitoring in order to determine compliance with the WQS in Condition 44.

Throughout the term of the consent this shall include long-term water column

monitoring for nutrient (NH4-N, NO3-N, NO2-N, DRP, Si, TN and TP) and

chlorophyll a concentrations, phytoplankton composition and biomass,

salinity, clarity, temperature, turbidity and dissolved oxygen (DO) at locations

stipulated in Condition 63c. The precise location of the long- term monitoring

stations and the range of specific nutrient parameters monitored may,

however, be adjusted over time in response to monitoring results and/or in

response to modelling considered necessary by the Peer Review Panel in

accordance with Condition 70c. This monitoring is to be undertaken at least

four times per year with at least two surveys occurring during mid-summer

periods of highest salmon feed discharge rates and at least two surveys

occurring periods associated with winter/spring and/or autumn diatom

maxima.

Discussion of results from fine-scale sampling for additional parameters/analytes is

limited to spatial patterns, to fulfil consent Condition 66e:

Targeted water column surveys to quantify the localised effect of the marine

farm on surrounding water quality, for the purpose of obtaining information

regarding marine farm-specific, near-farm mixing properties in order to

provide a context for evaluating compliance with the WQS in Condition 44.

This shall involve a series of fine-scale surveys in the vicinity of the marine

farm (within 1km from the net pens) measuring: salinity, clarity, temperature,

chlorophyll a, turbidity, dissolved oxygen (DO), nutrient concentrations (NH4-


52

N, NO3-N, NO2-N, DRP, Si, TN and TP) phytoplankton composition and

biomass along transects that move away from the marine farm and span

potential nutrient gradients. The surveys shall be undertaken at least twice

per year and continued for at least two years after the marine farm has

reached stable maximum feed discharge levels and no future increases are

proposed. With respect the monitoring objective, the monitoring approach

may be adjusted over time in accordance with the written recommendation of

the Peer Review Panel.

Table A3.3. Water quality standards (WQS) for chlorophyll-a (chl-a), total nitrogen (TN) and dissolved oxygen (DO) for the Kopaua, Waitata Reach and Ngamahau Bay salmon farm consents, 2017–2018. The second step threshold takes into account reference values. Further discussion of the WQS and how they are applied can be found in the MEMAMP (Elvines & Knight 2017).

chl-a TN DO

WQS ≤ 3.5 mg/m3 ≤ 300 mg TN/m3 > 90% > 70%

Second step

threshold

n/a To be determined ≤ 1.2% lower than

applicable reference

stations (e.g. far-field,

upstream 500 m)

Sample 0-15 m depth integrated

sample

0-15 m depth integrated

sample

All depths,

bin mean of

1 m.

All depths,

bin mean of

1 m.

Location All stations Stations > 250 m from farm

(Stations < 250 m may

exceed these levels)

Stations

> 250 m

from farm

Stations

< 250 m

from farm

Tolerance Three consecutive months: at any one station, or at any station within the same

sound for three consecutive months

A3.4.2 Water quality objectives

In addition to WQS that are set for some parameters, there are also water quality

objectives specified in the consent (Condition 43):

43. The marine farm shall be operated at all times in such a way as to

achieve the following Water Quality Objectives in the water column:


53

a. To not cause an increase in the frequency, intensity or duration of

phytoplankton blooms (i.e. chlorophyll-a concentrations ≥ 5 mg/m3)

[Note: water clarity as affected by chlorophyll-a concentrations is

addressed by this objective];

b. To not cause a change in the typical seasonal patterns of

phytoplankton community structure (i.e. diatoms vs. dinoflagellates),

and with no increased frequency of harmful algal blooms (HABs)

(i.e. exceeding toxicity thresholds for HAB species);

c. To not cause reduction in dissolved oxygen concentrations to levels

that are potentially harmful to marine biota [Note: Near bottom

dissolved oxygen under the net pens is addressed separately

through the EQS – Seabed Deposition];

d. To not cause elevation of nutrient concentrations outside the

confines of established natural variation for the location and time of

year, beyond 250 m from the edge of the net pens;

e. To not cause a statistically significant shift, beyond that which is

likely to occur naturally, from an oligotrophic/mesotrophic state

towards a eutrophic state;

f. To not cause an obvious or noxious build-up of macroalgal (e.g. sea

lettuce) biomass [Note: to be monitored in accordance with

Condition 66h].


54

Appendix 4. Additional detail on the results the 2018 Waitata (WTA) salmon farm water column monitoring.

A4.1 Salinity, temperature, and turbidity

Overall, water column profile data indicate a generally well mixed water column (see

Figure A4.1). This is expected due to the strong tidal currents experienced in Waitata

Reach and its margins. Poorly-mixed waters in Pelorus Sound would be represented

by stronger temperature and salinity gradients with depth as illustrated by Bradford et

al. (1987). However, the water column profiles show warming of surface waters over

the period October 2018–January 2019.

The salinity gradient along Waitata Reach did not exceed 1 PSU during winter

months and this is characteristic of periods of low freshwater input to Pelorus Sound

(Proctor & Hadfield 1998; see Figure A4.1 and Figure A4.2).

There was no substantial variation in temperature with depth at all sites. Salinity and

turbidity at NZKS06 (far-field reference station in the inner sound) in March were

slightly lower than at the remaining sites (Figure A4.2). However, there is no evidence

of region-wide increases in turbidity across the time series that might indicate

reductions in water quality resulting from eutrophication (Appendix 5).

.


55

Figure A4.1. Water column profile salinity (PSU), temperature (°C), and turbidity (NTU) (1 m-depth

binned downcast data) at Waitata sampling stations in February, March, August and September 2018. March and August data were collected using a SBE 19+ CTD, and February and September data using a YSI EXO Sonde CTD. CE = cumulative effect, FF = far-field, Ref = reference.


56

Figure A4.2. Average temperature and salinity characteristics from 1.5–15 m depth for each routine sampling station in Pelorus Sound. March and August data are from a Seabird 19+ CTD, while all other data are from a YSI EXO Sonde CTD. Note data from some stations are excluded where a different CTD instrument was used (i.e. data for June). CE = cumulative effect, FF = far-field, Ref = reference.


57

A4.2 Dissolved oxygen

No near-bed reductions in DO saturations were observed. However, there were lower

DO saturations recorded within the surface 10 m at the net pen station in February,

most likely due to salmon respiration (Figure A4.3). In March, lower DO

concentrations (< 90%) were observed at all sites, excluding the NZKS06 and

NZKS07 far-field reference sites (Table A4.1, Figure A4.3). Despite these

exceedances, an amber status was not triggered.

Large reductions in DO seen in March were at the net pen, 100 m downstream, and

500 m downstream (NZKS 02), indicating that the reduced DO was caused by

salmon respiration. The largest reductions in DO were apparent in approximately 18–

25 m at NZKS02 and NZKS05, which both sit to the south of the farm, in Richmond

Bay. Sampling was undertaken around mid-day, approximately an hour before high

tide. Effects of the farm were therefore likely to be strongest to the south of the farm,

and the tide had been consistently moving into the sound for approximately 5 hours.

This is consistent with the observed low DO, even at the CE Ref station, being

caused by farmed fish. Feed inputs in March were moderate (approx. 188 tonnes,

Figure 1), and much lower than in summer months.

There was no evidence of region-wide reductions in DO across the time series to

date (Appendix 5), indicating no changes in water quality resulting from

eutrophication.

When considering monthly DO data relative to the applicable WQS, at the WTA net

pen (NZKS08), the DO saturations ranged from 76.2% (February) to 100.2%

(September). The minimum DO saturations were within the DO WQS in all months

(i.e. > 70%). All stations 500 m from the WTA farm (NZKS09–NZKS11) and the FF-

Ref exceeded the WQS of DO >90% during February. In March, all stations 500 m

from the WTA farm and the CE-Ref exceeded the WQS. In August, two stations 500

m from the farm (NZKS10 and NZKS11) and the CE-Ref site also exceeded the

WQS. The second step DO WQS threshold (WQS [2]) was exceeded in March and

August (Table A.4.1).

Note that in March the water column profiles at the far-field control stations were

taken with the YSI EXO Sonde CTD instrument (used by MDC) while at the near-farm

stations parameters were measured with the Seabird 19+ instrument (used by

Cawthron). The YSI instrument consistently measures higher dissolved oxygen than

the Seabird, and this is very likely to have contributed to the apparent exceedance of

the WQS [2] in March. The tendency of the YSI instrument to record higher DO than

the Seabird was taken into account following the March monitoring; the far field

reference stations are now sampled with the Seabird CTD during fine-scale

monitoring months (as occurred in August) to improve comparability of far-field and

near-farm data (although as discussed below, PLS07 appears to be a problematic


58

reference station for near-farm effects for some other parameters). This tendency for

the Seabird to measure lower DO than the YSI instruments also potentially overstates

the degree of reduction in DO observed from CTD profiles in March, as described

above. It may be appropriate to further consider the implications of the differing

instrumentation as part of the finalisation or implementation of the BMP guidelines.

However, the pattern of low DO, and extent of the footprint out to the CE Ref remain

an important observation.


59

Table A4.1. Minimum dissolved oxygen (DO) saturation (%, 1 m depth binned downcast data) at all stations. Both the first step (WQS [1]) and second step (WQS [2]; see Appendix 3). WQS are shown where applicable. Bolded values indicate those below the WQS (1), shaded values indicate those also below the WQS (2). CE = cumulative effect, FF = far-field, Ref = reference.

Waitata Reach farm (WTA) Kopaua farm (KOP) Far-field reference

NZKS08 NZKS09 NZKS10 NZKS11 NZKS12 NZKS01 NZKS02 NZKS03 NZKS04 NZKS05 NZKS06 NZKS07 WQS (2) *

Month Net pen 500 m

south

500 m

north

500 m

east CE-Ref

Net pen

500 m

south

500 m

north

500 m

east CE-Ref FF-Ref FF-Ref

Jan 92.8 92.5 94.2 92.5 98 93.1 94.4 92.2 94.3 97.6 92.9 94.6

Feb 76.2 87.8 88.3 88.1 90.2 79.6 89.2 87.3 89 91.5 86.1 90.7 ≥ 87.2**

Mar 78.5† 80.3† 83.4† 74.5† 74.7† 76.8† 70.5† 81.4† 74.4† 68.5† 91.8 90.7 ≥ 86.8

Apr 91 91.2 91.8 91.7 93.4 81.4 92.6 90.7 92.9 93.4 91.9 91.3

May 85.5 91.5 91.6 91.8 93.9 84.1 92.6 91.1 92.8 93.3 91.5 91.8

Jun n/d n/d 93.2 n/d n/d n/d n/d n/d n/d n/d n/d n/d

Jul 93 93.1 93.2 93 94.4 92.5 94.7 93.2 95 95.5 93.7 93.3

Aug 82.4† 90.3† 84.4† 87.5† 89.8† 90.5† 91† 90.8† 90.9† 90.9† 97.3† 98.3† ≥ 93.0

Sep 100.2 101.2 101.5 101.1 102.5 101.6 101.7 101.4 102 103.6 100.9 101.3

Oct 97.7 98.1 98.4 98.4 101 97.9 99.3 98.5 99.4 103 98 99.1

Nov 99.5 97.4 98.8 99 104.4 101.1 103.2 99.1 101.8 104.8 100.8 99.7

Dec 97.4 96.6 96.8 97.8 106.5 101.2 102.5 98.4 102 104.6 97.6 97.5

WQS

(1) > 70% > 90% > 70% > 90% n/a

† Seabird 19+ CTD values. All other values are from the YSI EXO Sonde CTD.

* The second step WQS threshold is month specific and is calculated by subtracting 1.2% from the average of applicable reference station DO saturations (also

see Table A3.3). **Calculated from FF Ref data only.


10

Figure A4.3 Dissolved oxygen (% saturation) (1 m binned depth binned downcast data) at routine and

fine-scale sampling stations in February, March, August and September 2018. d/s = downstream, u/s = upstream, CE = cumulative effect, FF = far-field, Ref = reference.


61

A4.3 Nutrients

A4.3.1 Monthly results - total nitrogen (TN)

All WTA total nitrogen (TN) concentrations, including those from beside the net pen

(NZKS08), were within the TN WQS (i.e. ≤ 300 mg-N/m3, Table A4.2). The highest

mean concentration recorded in samples from the net pen (NZKS08) was 285 mg-

N/m3 in July 2017. On many occasions, the highest mean TN concentrations were

recorded at the reference station NZKS07. In November, TN concentrations at the net

pen stations (NZKS08 and NZKS01) were the same as the concentration at this

reference station.

A4.3.2 Fine-scale sampling results – nitrogen

There were no clear trends in the near-bed samples at WTA sites for any of the

nutrients analysed. Overall, nutrient concentrations at the net pen were similar to or

lower than reference and upstream concentrations. All stations around the farm were

sampled within a few hours after high tide, when currents are typically the strongest.

Tidal eddies created from currents obstructed by farm structures at this site are likely

to influence the dispersal of salmon farm wastes. This could be driving the high

variability observed in the samples, and the unclear spatial gradients observed across

the farm sampling stations.

During the August fine scale sampling event, nutrient concentrations at the surface

were highly variable, both between samples and among sampling stations. This

variability was much less evident in near-bed samples.

At the surface, concentrations of particulate nitrogen (PN) and total nitrogen (TN)

showed the highest reductions with distance from the farm in fine-scale sampling,

particularly in March (Figure A4.4). Slight reductions were also observed for these

nitrogen forms in August downstream to 250 m from the farm however the station at

500 m had elevated concentrations and no trend with distance from the farm can be

established.

Concentrations of ammoniacal nitrogen (NH4-N) at the net pen were higher than

concentrations at the FF-Ref stations in surface water samples. However, in near bed

samples, concentrations of this nitrogen form at the farm were at the same level or

lower than concentrations at the reference sites.

Urea-N showed no clear decreasing trend away from the farm during fine-scale

sampling in August. Interestingly, the FF-Ref station NZKS07 had the highest Urea-N

concentration recorded at the surface.


10

Table A4.2. Surface integrated results for total nitrogen (mg/m3) for all months (except December). No values exceeded the WQS. CE = cumulative effect, FF = far-field, Ref = reference.

WTA KOP REF

NZ

KS

08

NZ

KS

09

NZ

KS

10

NZ

KS

11

NZ

KS

12

NZ

KS

01

NZ

KS

02

NZ

KS

03

NZ

KS

04

NZ

KS

05

NZ

KS

06

(PL

S-6

)

NZ

KS

07

(PL

S-7

)

Month

Ne

t p

en

50

0 m

so

uth

50

0 m

no

rth

50

0 m

ea

st

CE

-Re

f

Ne

t p

en

50

0 m

so

uth

50

0 m

no

rth

50

0 m

ea

st

CE

-Re

f

FF

-Re

f

FF

-Re

f

Jan 129 142 122 126 110 131 118 126 123 133 122 141

Feb 174 131 137 138 127 180 133 145 144 139 171 199

Mar* 169 138 126 135 125 170 137 131 159 139 213 425

Apr 201 173 247 186 182 194 187 183 172 161 194 235

May 255 225 260 215 199 219 147 168 191 187 223 340

Jun 165 140 185 187 183 188 161 165 150 190 170 194

Jul 285 249 205 216 238 205 222 207 179 196 193 272

Aug 184 160 240 158 133 156 161 166 158 165 217 256

Sep 174 146 161 161 126 118 130 123 118 126 241 259

Oct 247 124 135 143 123 156 136 121 120 129 171 201

Nov 158 143 140 137 120 158 141 148 148 143 141 158

Dec n/d n/d n/d n/d n/d n/d n/d n/d n/d n/d n/d n/d

WQS n/a ≤ 300 mg-N/m3 n/a ≤ 300 mg-N/m3 n/a n/a

* Mean value across duplicate samples.

A4.3.2 Fine scale sampling results – phosphorus

In March, concentrations of total phosphorus (TP) in near-bed samples at 100 m from

the farm were lower than concentrations at the net pen and elevated again at 500 m

downstream from the net pen site (Figure A4.4). In August, there was no spatial

gradient evident in TP or dissolved reactive phosphorous (DRP) concentrations

across near-bed samples.


63

Figure A4.4. Concentrations (mg/m3) of nutrients in integrated surface samples and near-bed samples

at WTA in March and August 2018. CE = cumulative effect, FF = far-field, Ref = reference. PN* refers to particulate nitrogen calculated from other parameters, rather than measured directly. Note: only surface integrated samples had replication. d/s = downstream, u/s = upstream, s/w = seaward, CE = cumulative effect, FF = far-field, Ref = reference.


10

A4.4 Chlorophyll-a

It is relevant to review all phytoplankton-related data for a single region together. As

such, the results for the KOP salmon farm monitoring stations are also included here.

Chl-a in Pelorus Sound samples across all months of 2018 were below the WQS (i.e.

≤ 3.5 mg/m3; Table A4.3; Figure A4.5). As in the previous year’s sampling, the

exception was August, when the sampling appeared to coincide with the spring

diatom maxima (see Section A4.5).

Table A4.3. Surface integrated results for chlorophyll-a (mg/m3) from NZ King Salmon stations in Pelorus Sound in 2018. CE = cumulative effect, FF = far-field, Ref = reference. No values were above the chl-a WQS threshold (i.e. > 3.5 mg/m3).

Month

WTA KOP Ref

NZ

KS

08

NZ

KS

09

NZ

KS

10

NZ

KS

11

NZ

KS

12

NZ

KS

01

NZ

KS

02

NZ

KS

03

NZ

KS

04

NZ

KS

05

NZ

KS

06

(PL

S-6

)

NZ

KS

07

(PL

S-7

)

Net

pe

n

500 m

so

uth

500 m

no

rth

500 m

east

CE

-Ref

Net

pe

n

500 m

so

uth

500 m

no

rth

500 m

east

CE

-Ref

FF

-Ref

FF

-Ref

Jan 1.2 1.3 1.2 1.8 1.4 1.1 1.2 1.6 1.5 1.7 1.2 1.5

Feb 1.2 1.6 1.9 2 2.9 1.1 1.5 1.5 1.6 1.6 1 1.2

Mar* 1.1 1.1 1.2 1 1 0.9 1 1.2 1.5 1 1.1 1.4

Apr 1.1 1.4 1.1 1.6 1.4 0.8 1.3 1.3 1.5 1.1 1.5 0.6

May 1 0.9 1 0.9 1.3 0.7 1.2 1.1 1.1 1 1.2 0.8

Jun 0.6 0.6 0.9 0.8 0.8 0.5 0.6 0.4 0.6 0.5 0.7 0.5

Jul 0.7 0.8 0.5 0.7 0.7 0.6 0.6 0.7 0.6 0.5 0.6 0.5

Aug 1.5 2.5 2.1 2.7 3.5 2.3 2.8 2.9 2.2 1.9 1.7 1.4

Sep 1 1 1.1 1 1 1 0.9 1.1 1.1 1.2 0.9 1

Oct 0.8 1.2 1.4 1.7 1.4 1.6 1.6 2 2 1.7 1.3 1.6

Nov 1.1 0.8 1.5 1.4 0.8 1.2 2.7 1.7 2.8 2.9 1.2 1.2

Dec n/d n/d n/d n/d n/d n/d n/d n/d n/d n/d n/d n/d

WQS ≤ 3.5 mg/m3

* Mean value from duplicate.

A4.5 Phytoplankton biomass and composition

Estimated phytoplankton biomass values around the WTA and KOP farm sites in

February, March, August, and September (Table A4.4) were consistent with the

range of data from the MDC monitoring stations (Broekhuizen & Plew 2018). The

highest values occurred at the CE Reference site NZKS12 in February and August

(February—113 C/m3, August —143 mg C/m3) and at the KOP net pen in September

(107 C/m3). Moderately high phytoplankton biomasses were also recorded in August


65

at NZKS05 (CE Ref) and NZKS06 (FF Ref) (Table A4.4). These peak biomasses

were spread throughout the year, and across sampling station types.

Very high dominance of dinoflagellates occurred in February and March (Figure A4.5,

Table A4.5), where they constituted between 43 and 96% of the measured

phytoplankton biomass. This is quite distinct from the previous years’ communities.

The highest relative abundances of dinoflagellates in WTA monitoring were at the site

500 m east of the farm (NKSS11), the far-field reference station (NZKS06) and the

site 500 m north of the farm (NZKS10).

Phytoplankton generally take some time (hours to days) to increase their abundance

and biomass in response to an increase in available nutrients. Therefore, a response

of community structure to nutrient enrichment would not be expected to occur so

rapidly that it was more apparent immediately adjacent to pens than further afield.

Nutrient inputs from farming could potentially drive or exacerbate changes to

community structure, but the available data are insufficient to indicate that farm-

derived nutrients are the cause of the change in structure seen here. Moreover,

surveys in August and September yielded results more similar to previous years’

surveys. Future monitoring will indicate whether this pattern is repeated in

subsequent years.


10

Figure A4.5. Phytoplankton composition (as a percentage of total phytoplankton biomass; see Table A4.5) recorded in 2016–2018. The KOP monitoring

stations were sampled additionally in May 2017 when the fine-scale sampling was undertaken at this site. The number of sites sampled has changed in the monitoring design since August 2017. In 2017 ‘full suite’ monitoring was undertaken in July, while in 2018 it was undertaken in September.


67

Table A4.4 Estimated surface phytoplankton biomass (mg/cm3) for two major taxon groupings of diatoms and dinoflagellates recorded at the Pelorus Sound monitoring stations in 2018. d/s = downstream, CE = cumulative effect, FF = far-field, Ref = reference, n/d = no data, blank = not sampled.

NZKS

08

NZKS

09

NZKS

10

NZKS

11

NZKS

12

NZKS

06

NZKS

07

NZKS

01

NZKS

02

NZKS

03

NZKS

04

NZKS

05

WTA

net pen

500 m

south

500 m

north

500 m

east

CE- Ref FF-Ref FF-Ref KOP

net pen

500 m

south

500 m

north

500 m

west

CE-Ref

Feb 18

Diatom 9.9 7.3 3.7 1.7 29.8 3.9 15.9 2.4 9.0 18.5 7.0 4.6

Dinoflagellate 46.2 34.5 46.9 44.5 82.1 37.4 45.2 24.0 11.5 31.2 13.4 23.1

Other 1.5 2.0 5.2 0.2 1.0 1.2 1.6 2.3 1.2 2.7 2.0 1.7

March 18

Diatom 6.4 5.2 22.5 11.3

Dinoflagellate 21.7 16.6 17.0 23.4

Other 0.7 0.7 0.1 0.6

Aug 18

Diatom 48.6 132.0 71.4 49.2 68.7

Dinoflagellate 3.8 10.6 6.9 1.0 17.6

Other 0.1 0.6 0.4 8.0

Sept 18

Diatom 29.8 44.9 26.2 36.6 88.6 65.9

Dinoflagellate 8.8 2.4 10.7 9.3 13.3 3.8

Other 0.0 0.7 0.9 1.5 4.7 5.4


10

Table A4.5. Phytoplankton composition (as a percent of total estimated phytoplankton biomass; Table A4.4) recorded at the Pelorus Sound monitoring stations in 2018. d/s = downstream, CE = cumulative effect, FF = far-field, Ref = reference, blank cells = not sampled.

NZKS

08

NZKS

09

NZKS

10

NZKS

11

NZKS

12

NZKS

06

NZKS

07

NZKS

01

NZKS

02

NZKS

03

NZKS

04

NZKS

05

WTA

net pen

500 m

south

500 m

north

500 m

east

CE- Ref FF-Ref FF-Ref KOP

net pen

500 m

south

500 m

north

500 m

west

CE-Ref

Feb 2018

Diatom 17 17 7 4 26 9 25 8 42 35 31 16 Dinoflagellate 80 79 84 96 73 88 72 84 53 59 60 78 Other 3 5 9 0 1 3 3 8 5 5 9 6

March 2018

Diatom 22 23 57 32 Dinoflagellate 75 74 43 66 Other 2 3 0 2

Aug 2018

Diatom 93 92 91 97 83 73 Dinoflagellate 7 7 9 2 12 19 Other 0 0 0 1 4 8

Sept 2018

Diatom 77 94 69 77 88 88 Dinoflagellate 23 5 28 20 11 5 Other 0 1 2 3 0 7


69

Appendix 5. Time series plots for eutrophication indicators, collected as part of the ongoing monitoring programme. While these data are best

displayed on the interactive platform (which has greater colour clarity, plot size and functionality) the main purpose of including the

plots in this report is to give a general overview of the collective data series through time.

Figure A5.1. Turbidity (FNU: averaged in the surface 15 m) for the outer Pelorus Sound sampling stations. Measurements taken from the YSI EXO Sonde

instrument used by MDC. Note that negative values are due to a large calibration offset for the YSI CTD sensor. CE = cumulative effect, FF = far-field, Ref = reference, PLS10 = SoE cumulative effect reference station.


70

Figure A5.2. Dissolved oxygen (DO) saturation (%) in the surface 15 m of the water column at all outer Pelorus Sound sampling stations. Measurements were taken from an in situ DO sensor attached to a YSI EXO Sonde or seabird (SBE 19+) CTD. CE = cumulative effect, FF = far-field, Ref = reference, PLS10 = SoE cumulative effect reference station.


71

Figure A5.3. Dissolved oxygen (DO) saturation (%) in the bottom 2 m of the water column at all outer Pelorus Sound sampling stations. Measurements were taken from an in situ DO sensor attached to a YSI EXO Sonde or seabird (SBE 19+) CTD. Saturation values are averaged from all records within the bottom 2 m of the water column profile at each station. CE = cumulative effect, FF = far-field, Ref = reference, PLS10 = SoE cumulative effect reference station.


72

Figure A5.4. Total nitrogen (TN) concentrations (mg/m3) recorded from 15 m surface-integrated samples in all outer Pelorus Sound sampling stations. CE = cumulative effect, FF = far-field, Ref = reference, PLS10 = SoE cumulative effect reference station.


73

Figure A5.5. Ammonium (NH4) concentrations (mg/m3) recorded from 15 m surface-integrated samples in all outer Pelorus Sound sampling stations. CE = cumulative effect, FF = far-field, Ref = reference, PLS10 = SoE cumulative effect reference station.


74

Figure A5.6. Nitrate (NO3) + Nitrite (NO2) concentrations (mg/m3) recorded from 15 m surface-integrated samples in all outer Pelorus Sound sampling stations. CE = cumulative effect, FF = far-field, Ref = reference, PLS10 = SoE cumulative effect reference station.


75

Figure A5.7. Dissolved reactive phosphorus (DRP) concentrations (mg/m3) in 15 m surface integrated samples from in all outer Pelorus Sound sampling stations. CE = cumulative effect, FF = far-field, Ref = reference, PLS10 = SoE cumulative effect reference station.


76

Figure A5.8. Dissolved reactive silica (DRSi) concentrations (mg/m3) recorded from 15 m surface-integrated samples from in all outer Pelorus Sound sampling stations. CE = cumulative effect, FF = far-field, Ref = reference, PLS10 = SoE cumulative effect reference station.


77

Figure A5.9. Fluorescence (µg/L, 15 m depth average) for the outer Pelorus Sound sampling stations. Measurements taken from the YSI EXO Sonde instrument used by MDC, except in March and August where measurements are from the Cawthron Seabird 19+. CE = cumulative effect, FF = far-field, Ref = reference, PLS10 = SoE cumulative effect reference station.


78

–

Figure A5.10. Chlorophyll-a (mg/m3, surface to 15 m) for the outer Pelorus Sound sampling stations. Measurements taken from the YSI EXO Sonde instrument used by MDC, except in March and August where measurements are from the Cawthron Seabird 19+ CTD. CE = cumulative effect, FF = far-field, Ref = reference, PLS10 = SoE cumulative effect reference station.

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