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Indicator 2.10.2

Requirement

The UoC shall calculate the feed and farm-related GHG emissions of production following the method outlined in Appendix 9 (9.4).

How Do I Interpret This Requirement?

  • Consistent and transparent measurement of GHG emissions following a life cycle assessment approach is necessary to underpin effective GHG reduction and management and to inform broader efforts to understand and reduce the GHG impact of global food systems.

  • This indicator ensures that all ASC certified sites undertake this important first step in contributing to efforts to combat climate change.

  • ASC does not require the use of any particular GHG calculation framework or tool or conformance with any particular GHG methodology or standard. However, some methodological requirements are stipulated in Appendix 9 to ensure a sufficient level of consistency, completeness and accuracy of GHG calculations.

  • Certificate Holders should consider the reporting format of the ASC Farm Standard GHG Data Submission Template in undertaking their calculations.

  • This includes the characterisation of GHG emissions in three distinct ways:

    • By scope (based on Scope 1, Scope 2, and Scope 3 GHG emissions as defined in the GHG Protocol),

    • By category (e.g., land use change emissions, if known; if unknown, emissions may be characterised as ‘unspecified’), and

    • By input (e.g., broad categories of feed ingredients, energy inputs, etc.).

    • To the extent possible, Certificate Holders are encouraged to calculate GHG emissions specific to the certified site. However, in some cases, this may be difficult to do. For example, fuel purchased may be used to supply vessels servicing many sites, potentially both certified and non-certified sites, or even multiple sites or companies.

      • In these cases, a portion of the overall input may be allocated to the certified site based on a logical allocation basis.

        • For example, dividing energy inputs between sites based on the relative number of vessel trips or using the site’s relative share of production among the group of sites serviced.

        • For feed inputs, because the certified site’s feed use records are needed for certification, data used for GHG calculations should be specific to the certified site.

    • GHG profiles from hatcheries are not required.

      • The hatchery or juvenile stage of the aquaculture supply chain typically accounts for a very small percentage of overall GHG emissions, and due to the varied nature of sourcing juveniles, requiring their inclusion in calculations could result in confusion and unnecessary burden.

        • Instead, sites may account for juvenile inputs as described in Appendix 9.

      • GHG calculations may optionally still include hatchery-specific data, and efforts to reduce GHG emissions at the hatchery stage may also be included to demonstrate efforts in the site’s GHG management plan for Indicator 2.10.4.

    • GHG emissions should first be calculated relative to live weight production, as kg CO~2~-equivalent (CO~2~e) emissions per tonne of live weight production. As a final step, emissions are converted to an edible weight basis.

      • This step is facilitated by the ASC Farm Standard GHG Data Submission Template.

      • By default, the muscle fraction of the animal is the conversion factor, such that a muscle fraction of 0.5 results in an edible weight GHG value double that of the live weight basis value.

      • If, however, a portion of the non-edible fraction of the animal is used for other purposes (e.g., by-product meal), a portion of emissions may be allocated to the non-edible product.

        • In these cases, the allocation is undertaken directly within the ASC Farm Standard GHG Data Submission Template following both allocation methods: dividing emissions between edible and non-edible product on the basis of their relative mass, and on the basis of their relative economic value as expressed by their revenue generation.

      • This allocation step is not applicable to bivalve and abalone shells; for these species, the muscle fraction alone is used for converting results to an edible weight basis.

Evidence of Implementation

  • GHG profiles for feeds used, specific to the feed supplier and species or species group and updated on an annual basis, as required to be shared by the feed supplier according to Criterion 1.21 of the ASC Feed Standard and using the format of the ASC Feed Standard GHG Data Submission Template.

  • For marine salmonids only: GHG profiles for any supplying grow-out site(s) as required to be shared by the previous grow-out site(s).

  • Documentation of the source of any GHG emission factors used.

  • This may be documentation of calculation tools (e.g., the ASC GHG Calculator) or documentation of specific emission factors and their source if calculating emissions manually.

  • Documentation of the input variables used (e.g., quantity of electricity).

  • Inputs of energy should reflect those calculated in Indicator 2.10.1. All input variables should be supported by evidence such as invoices or feed use records if requested.

  • Documentation of conversion factor and, if applicable, allocation factors, used to convert GHG calculations from a live weight basis to an edible weight basis.

  • Documentation of power purchase agreements, if applicable, to demonstrate use of electricity from specific dedicated sources rather than the national or regional electricity grid.

Auditors Should Confirm

  • Records of GHG profiles from feed suppliers and (for marine salmonids) prior grow-out sites are available.

  • GHG emissions are calculated in kg CO~2~e relative to live weight production and edible weight product and recorded using the ASC Farm Standard GHG Data Submission Template.

  • If using a tool other than the ASC GHG Calculator, documentation showing how the tool conforms to the methodological requirements outlined in Appendix 9;

  • This may be a signed declaration from the tool provider or highlighted elements in the tool’s user documentation.

  • Values input into the ASC GHG Calculator, another tool, or manual calculations are supported with evidence (e.g., fuel purchase invoices).

  • If undertaking calculations manually, demonstration of the calculations undertaken, including the use of GHG data from feed suppliers and (for marine salmonids) prior grow-out sites in conformance with the requirements of Appendix 9.

  • The scope of included activities reflects the requirements outlined in Appendix 9.

  • GHG emissions are not adjusted using carbon credits or offsets.

Useful Resources

  • Certificate Holders are encouraged to use the ASC GHG Calculator, available at https://ghg.asc-aqua.org, to ensure compliance with regards to calculation scope, methods, data sources and reporting format. Use of this tool is voluntary; other tools, consultants, or internal procedures may be used if documentation is available to demonstrate compliance with the requirements in Appendix 9.

  • Recommended factors for converting GHG emissions from a live weight basis to an edible weight basis may be sourced from supplemental material of Gephart et al. (2021). Other conversion factors may be used if they reflect the actual edible yield (i.e., muscle fraction) of the animal.

  • A range of methodological frameworks and standards are available to guide life cycle assessments and GHG accounting. Use of any of these is optional, provided that calculations are still in compliance with the requirements of Appendix 9. Examples include:

    • General life cycle assessment methods in ISO 14040 and ISO 14044

    • The GHG Protocol from the World Resources Institute

    • ISO 14067 and marine fish product category rules in ISO 22948

    • The Product Environmental Footprint (PEF) marine fish product category rules

    • PAS 2050 and seafood product category rules in PAS 2050-2

Indicator 2.10.1

Requirement

The UoC shall calculate the energy use of production following the method outlined in Appendix 9 (9.3).

How Do I Interpret This Requirement?

  • Tracking use of energy inputs is a necessary step in calculating the GHG emissions associated with aquaculture production and products.

  • Energy inputs include all those sources of energy used for the purpose of production, including electricity and energy carriers such as diesel or natural gas.

  • To the extent possible, Certificate Holders are encouraged to calculate energy use specific to the certified site. However, in some cases, this may be difficult to do. For example, fuel purchased may be used to supply vessels servicing many sites, potentially both certified and non-certified sites or even multiple sites or companies.

  • In these cases, a portion of the overall input may be allocated to the certified site based on a logical allocation basis.

  • For example, dividing energy inputs between sites based on the relative number of vessel trips or using the site’s relative share of production among the group of sites serviced.

  • Energy inputs to hatcheries are not included in calculations of on-site energy use. However, in cases where the juvenile stage of the supply chain is integrated with grow-out, sites may choose to include this stage in their calculations to simplify calculations.

Evidence of Implementation

  • Documentation of energy intensity factors (e.g., MJ of energy per L of diesel) used if they are different to the default values used in the ASC Farm Standard Energy Use Data Submission Template.

  • Evidence to support the quantity of each energy input specified in calculations is available on request, along with any allocation of energy inputs between multiple sites if applicable.

  • This may be, for example, fuel purchase invoices or electricity use records.

Auditors Should Confirm

  • The energy use value is calculated and reported in MJ of energy per tonne of live weight production.

  • Energy use of production is calculated for either (a) the most recent completed production cycle; or (b) three consecutive years of production.

  • Documentation is provided to support input variables and calculations.

  • The ASC Farm Standard Energy Use Data Submission Template is used to demonstrate results.

Useful Resources

  • Certificate Holders are encouraged to use the ASC Farm Standard Energy Use Data Submission Template for calculating the energy intensity of production after energy inputs are quantified.

  • Additional energy intensity factors for a range of energy inputs are available from the UK Department of Energy Security and Net Zero.

Indicator 2.6.10

Requirement

The UoC shall, after the determination of the water quality baseline, conduct monitoring of the water quality parameters listed below, following the method outlined in Appendix 8 (8.8):3434An exemption applies if the mean of Secchi Disk (SD) depth calculated over any rolling two-year period remains ≥10m. – Total Nitrogen (TN); and, – Total Phosphorous (TP); and, – Dissolved Oxygen (DO); and, – Secchi Disk (SD) depth; and, – Chlorophyll-a (Chl-a).

How Do I Interpret This Requirement?

  • Quarterly monitoring ensures the UoC can capture any seasonal or inter-annual variations in the data collected.

  • Measurements should be timed to coincide with, or immediately follow, annual turnover events when the waterbody is not permanently stratified (holomictic).

  • The UoC should calibrate equipment used to measure DO, TN, TP, SD and Chl-a according to the technical specifications of the equipment.

  • The UoC should conduct measurements of the parameters in-situ.

  • Samples may be sent for laboratory analysis, however variability with sample maintenance during transit can lead to inconsistent results. This is particularly evident with DO and Chl-a samples.

Evidence of Implementation

  • Documentation outlining the sampling plan to conduct quarterly monitoring and that is in accordance with Appendix 8 (8.8).

  • Quarterly monitoring data has been collected and submitted to the ASC Water Quality Calculator. Data should be submitted at least annually.

  • Evidence that quarterly monitoring data has been timed with annual turnover events (where applicable).

  • That equipment to measure DO, TN, TP, SD and Chl-a has been calibrated according to technical specifications.

Auditors Should Confirm

  • The sampling methodology to conduct quarterly monitoring is in accordance with Appendix 8 (8.8).

  • The UoC has conducted quarterly monitoring of the water quality parameters and submitted data to the ASC Water Quality Calculator at least annually.

  • Evidence has been provided demonstrating the UoC has calibrated equipment to measure DO, TN, TP, SD and Chl-a in accordance with the technical specifications.

Useful Resources

  • Paerl, H.W., Scott, J.T., McCarthy, M.J., Newell, S.E., Gardner, W.S., Havens, K.E., Hoffman, D.K., Wilhelm, S.W. and Wurtsbaugh, W.A., 2016. It takes two to tango: when and where dual nutrient (N & P) reductions are needed to protect lakes and downstream ecosystems. Environmental science & technology, 50(20), pp.10805-10813.

  • Information on the appropriate use of Secchi Disks can be found here: ‘What is a Secchi disk’, accessed November 22, 2023: <https://www.nalms.org/secchidipin/monitoring-methods/the-secchi-disk/what-is-a-secchi-disk/>

  • Example of a method for Chl-a measurements made using ethanol extraction followed by spectrophotometric measurement at wavelengths 665 and 750nm (using accredited methods: EPA method 445.0: Method 445.0 In Vitro Determination of Chlorophyll a and Pheophytin ain Marine and Freshwater Algae by Fluorescence, accessed November 22, 2023: https://cfpub.epa.gov/si/si_public_record_report.cfm?Lab=NERL&dirEntryId=309417

  • Cost effective example for measuring using in-situ Chl-a using a field spectroflurometer include the FluoroSense handheld fluorometer manufactured by Turner Designs and the YSI handheld meter with EXO1 (#599080) or EXO2 (#599201) sondes.

  • Hamdhani, H., Eppehimer, D.E., Walker, D. and Bogan, M.T. (2021) Performance of a Handheld Chlorophyll-a Fluorometer: Potential Use for Rapid Algae Monitoring. Water, 13, 1409: https://doi.org/10.3390/w13101409

  • Kuha, J., Järvinen, M., Salmi, P. and Karjalainen, J. (2020). Calibration of in situ chlorophyll fluorometers for organic matter. Restoration of Eutrophic Lakes, 847, 4377-4387: <https://doi.org/10.1007/s10750-019-04086-z>

Indicator 2.6.9

Requirement

The UoC shall conduct a water quality survey and determine the water quality baseline, including the trophic status, following the method outlined in Appendix 8 (8.8).

How Do I Interpret This Requirement?

  • The data collected as part of the 24-month site level monitoring survey is submitted by the UoC to the ASC Water Quality Calculator.

  • The water quality baseline is based on 24-months of monitoring data from the site level monitoring survey. However, the following phased approach is permitted when sites do not have sufficient data prior to the initial audit:

    • The water quality baseline is characterised by the ASC Water Quality Calculator, in accordance with Appendix 8 (8.8).

    • The baseline should be conducted per site and per waterbody. The results should then be shared with members of the WQMN.

    • The baseline determines whether primary production in the waterbody is limited by nitrogen (N), phosphorous (P), or if it is co-limited. Other factors (than N or P) may be limiting primary productivity in a waterbody.

    • The UoC should present evidence of these other limiting factors (e.g. temperature or altitude) where applicable.

  • Harmful algal blooms (HABs) and Adverse Turnover Events (ATEs) are required to be reported as part of the baseline characterisation. The number of ATEs and HABs that have occurred can be recorded by conducting the following:

    • Reviewing news media and consulting local stakeholders. Alternatively, reviewing data collected by regulatory bodies where available.

    • Reporting the number of ATEs and HABs which have resulted in fish mortality events (farmed or wild) or the mortality of other aquatic species.

    • Reporting instances where fish mortality events or loss of other aquatic species can be attributed to natural phenomena. These instances will not count towards the frequency limits for ATEs and HABs.

    • Reporting the number of ATEs and HABs, as determined by national or regional regulatory/scientific organisations.

Evidence of Implementation

  • The methodology and analytical methods used to conduct site level monitoring survey are in accordance with Appendix 8 (8.8).

  • The sampling methodology for collecting 24-months of data for the site level monitoring survey, if this is not available at the initial audit.

  • The results of the site level monitoring survey, as determined by the ASC Water Quality Calculator.

  • The results of the 24-month baseline characterisation, as determined by the ASC Water Quality Calculator.

  • Records of HABs and ATEs from the last 10 years.

Auditors Should Confirm

  • A water quality monitoring survey has been conducted by the UoC. Results are presented from the ASC Water Quality Calculator.

  • A sampling methodology has been presented for collecting 24-months of data for the site level monitoring survey, if this is not available at the initial audit.

  • The data collected for the site level monitoring survey followed the methodology and analytical measures outlined in Appendix 8 (8.8).

  • A water quality baseline has been characterised. Results are presented from the ASC Water Quality Calculator.

  • The results of the review by the UoC into adverse turnover events and harmful algal blooms in the waterbody.

Useful Resources

  • Vollenweider, R.A., Rinaldi, A. and Montanari, G. (1992) Eutrophication, structure and dynamics of a marine coastal system: results of ten-year monitoring along the Emilia-Romagna Coast (Northwest Adriatic Sea). Marine Coastal Eutrophication, Proceedings of an International Conference, Bologna, Italy, 21–24 March 1990, Pages 63-106: <https://doi.org/10.1016/B978-0-444-89990-3.50014-6>

  • More information about the equations used for TSI assessment, including the relevant peer-reviewed scientific literature, is provided in Carlson, R.E. and Simpson, J. (1996) A Coordinator’s Guide to Volunteer Lake Monitoring Methods. North American Lake Management Society, 96 p.

Indicator 2.6.8

Requirement

The UoC shall establish a Water Quality Monitoring Network (WQMN), following the method outlined in Appendix 8 (8.7). An exception applies where a WQMN is already established, in which case the UoC shall participate in the WQMN.

How Do I Interpret This Requirement?

  • Evidence of spatial management at a national/regional level for water quality can be used by the UoC to demonstrate that the intent of Indicator 2.6.8 has been met. To use this evidence, the following should be met:

    • The boundaries of waterbodies are defined.

      • Waterbodies are managed to ensure water quality remains at a ‘Good’ or ‘Very Good’ status.

      • Where required, corrective actions are implemented by the regulator and complied with to ensure water quality status improves.

    • Examples of spatial management at a national/regional level include the European Union Water Framework Directive.

    • It is the responsibility of the UoC to conduct outreach to ASC Certified sites and non-certified sites belong to ASC Certificate Holders if a Water Quality Monitoring Network (WQMN) has not been established.

  • Examples of outreach can include:

    • Copies of correspondence (written and email).

    • Agendas and minutes of meetings.

    • Third-party stakeholder testimony.

  • As per Appendix 8, section 8.7, a Terms of Reference (ToR) document shall be drafted and agreed upon by all members of the WQMN upon formation, which includes the following:

    • The membership list and commitments from members to meet the WQMN requirements, as outlined in Appendix 8 (8.7.1).

    • The assignment of a focal point, who will coordinate data sharing, the drafting of the ToR and agreement to the ToR by all members of the WQMN.

    • The focal point should ideally be a rotating position, though determination is left to discretion of the WQMN membership.

    • A commitment to review the ToR on a regular basis (for example every 12 months) or as and when required, such as when changes in membership of the WQMN occur, or when the waterbody demonstrates evidence of excessive nutrient loading, eutrophication or trophic status shifts.

Evidence of Implementation

  • An agreed map of the WUM by members of the WQMN, which includes the components outlined in Appendix 8 (8.7).

  • The map should be updated on an annual basis where required.

  • Evidence of outreach efforts and responses (where applicable) to ASC Certified site and non-certified sites belong to ASC Certificate Holders if a WQMN needs to be established.

  • If a WQMN has been established, the UoC presents evidence that they have joined the WQMN or the UoC can demonstrate the spatial management of water quality at a national/regional level.

  • A ToR has been agreed upon by all members of the WQMN, which includes commitments to the WQMN requirements, as outlined in Appendix 8 (8.7.1).

Auditors Should Confirm

  • A map of the WUM has been developed by the WQMN and presented by the UoC, which includes the components outlined in Appendix 8 (8.7).

  • Evidence of outreach efforts and responses to ASC Certified site and non-certified sites belong to ASC Certificate Holders if a WQMN needs to be established.

  • Auditor discretion should be used to determine if sufficient levels of outreach has been conducted, when such outreach has not been reciprocated.

  • Evidence that the UoC has formed/joined a WQMN, or that the UoC presents evidence that water quality is managed at a national/regional level.

  • A ToR has been presented, which has been agreed upon by all members of the WQMN. The ToR includes commitments to the WQMN requirements, as outlined in Appendix 8 (8.7.1).

Indicator 2.6.7

Requirement

The UoC shall ensure that the person conducting water quality monitoring has the necessary competencies, experience and training. The UoC shall ensure that the person defining the WUM has the necessary competencies. In cases where regulatory requirements are defined, the UoC shall ensure that the person defining the WUM complies with these requirements.

How Do I Interpret This Requirement?

  • To demonstrate competence, personnel responsible for conducting water quality analysis and defining the WUM should be able to:

    • Perform the required sampling and/or analysis.

    • Operate sampling/analytical equipment.

      • Develop, change, verify and validate methods.

    • Use suitable reference standards.

    • Analyse sampling and calibration results, including statements of conformity and interpretations.

      • Record, review and authorise the release of results.

    • Contribute to or produce reports that can clearly and concisely explain whether the results meet the requirements.

      • Have completed relevant training modules.

Evidence of Implementation

  • The personnel responsible for conducting water quality analysis and defining the WUM have competencies to do so, for example a suitable level of education and/or experience.

    • Where applicable, the personnel meet national requirements/qualifications for the spatial definition and/or management of waterbodies.

  • Relevant training modules have been completed by the personnel responsible for conducting water quality analysis and defining the WUM.

Auditors Should Confirm

  • The personnel responsible for conducting water quality analysis and defining the WUM have the necessary competencies.

    • Where applicable, national requirements/qualifications are met by the personnel defining the WUM.

  • Evidence has been presented that relevant training modules have been completed.

Indicator 2.6.6

Requirement

The UoC shall define the Waterbody Unit of Management (WUM), following the method outlined in Appendix 8 (8.6). An exception applies where a WUM is already defined, in which case the UoC shall provide evidence of the defined WUM.

How Do I Interpret This Requirement?

  • The following characteristics should be used to define the Waterbody Unit of Management (WUM):

    • The WUM reflects a logical geographic scope, for example, a lake and its catchment area.

    • The boundaries of the waterbody reflect the ability to realistically manage eutrophication risk within it.

    • Boundary setting should consider hydro-morphology, bathymetry, water movement and stratification characteristics.

      • Areas with high risk of adverse impacts due to cumulative effects, for example HIEs in larger waterbodies, should be a separate WUM.

      • Areas established for water quality monitoring at a national or regional level.

    • The Water Quality Advisory Committee (WQAC) can resolve issues with defining the WUM where the WUM boundaries are not clear.

Evidence of Implementation

  • A map of the WUM which includes the components outlined in Appendix 8 (8.6).

    • The map should be updated on an annual basis where required.

  • The results of measurements to confirm if the WUM is a HIE (if applicable).

Auditors Should Confirm

  • A map of the WUM has been developed and presented by the UoC, according to the method outlined in Appendix 8 (8.6).

Indicator 2.6.5

Requirement

The UoC shall ensure that the Receiving Waterbody (RW) has been classified per site as Type A, B or C, following the method outlined in Appendix 8 (8.5).

How Do I Interpret This Requirement?

  • The UoC should initially define the boundaries of the Receiving Waterbody (RW) based on hydrological characteristics, which determines its sensitivity to nutrient enrichment.

    • Hydrodynamically isolated embayments (HIEs) should be treated as separate waterbodies during the classification process.

  • Marine waterbodies include:

    • Off-shore and inshore coastal systems.

    • More enclosed waterbodies susceptible to seawater intrusion through tidal exchange or storm surges.

    • Exposed near-shore waterbodies (i.e. not in a bay or channelised system) and offshore waterbodies will be classified as Type C.

    • Once the boundaries of the RW are defined, HRT should be calculated unless the RW is an exposed near-shore or offshore waterbody.

      • The area and average depth of the waterbody need to be determined.

    • The cross-sectional area of the waterbody outflow or channel is required to calculate flow rate.

    • A transect should be determined from one side of the outflow/channel to the other side.

      • The length (in metres) of the transect is multiplied by the average depth of the transect to determine the cross-sectional area.

      • The cross-sectional area in then multiplied by the flow velocity (V). The result of this calculation is the flow rate (Q).

      • If a marine waterbody has HRT ≥5 days, it is a Type A, if it is ≤ 5 days, it is Type C.

    • Determining flow rate and levels of Total Suspended Solids (TSS) will distinguish between Type B and C freshwater bodies.

    • Flow rate can be obtained from regulatory bodies. Low flow then needs to be calculated by plotting the cumulative distribution of the data and calculating the 25^th^ percentile of the cumulative distribution.

    • This can be calculated in Microsoft Excel using the cumulative distribution function. The 25^th^ percentile (or quartile) can then be calculated.

  • Waterbody types designated under national legislation should be used only if the following are met:

    • The classification includes area-based water quality monitoring.

      • Targets are used to determine good ecological status. An example is the Water Framework Directive.

Evidence of Implementation

  • A map of the Receiving Waterbody, which outlines:

    • The area and average depth of the waterbody; and,

      • The location where flow rate (Q) was determined; or,

    • That the site is in a RW which is an exposed near-shore or off-shore marine RW (Type C only).

    • The waterbody classification, which includes outputs from HRT, flow rate and TSS calculations.

      • The methods used to measure flow rate and TSS, in accordance with Appendix 8 (8.5 and 8.12).

      • If applicable, evidence that demonstrates alternative methodologies to calculate TSS or flow rate are equivalent to the ones in Appendix 8 (8.5).

Auditors Should Confirm

  • A map has been presented by the UoC which outlines the RW, and which supports the classification of the RW.

  • The results of the HRT calculation and flow rate/TSS measurements conducted by the UoC.

    • These results will support the RW classification determined by the UoC.

  • Evidence presented by the UoC, demonstrating the methods used to measure flow rate and TSS, in accordance with Appendix 8 (8.5 and 8.12).

Useful Resources

[Steps to determine whether the RW is a HIE are as follows:]

1. If the site is in a waterbody that has been identified as a HIE by a regulatory body, this will form the boundaries of the RW.

2. Review the characteristics of the RW and determine if at least one of the following is identified:

  • The RW has poor connectivity to deep offshore waters, and/or;

  • The RW is sheltered from energetic conditions e.g., inflows, currents, exposure to onshore or monsoonal winds, and/or;

  • The hypolimnion is periodically or permanently poorly flushed.

> Where the RW shares these characteristics, it is possible to demonstrate the RW is not a HIE. The steps to demonstrate that the RW is not a HIE are as follows:

1. Identify the narrowest point in the embayment opening (red line in Figure 1).

2. Establish two transects of length, which start at the narrowest point and extend in and out of the embayment (red dashed line in Figure 1).

3. Collect water samples at 0.5m depth from an equal number of equally spaces sites in each transect.

4. Analyse water samples for concentrations of chloride, conductivity, salinity, TN or TP. Analytical methods for TN and TP can be found in Appendix 8 (8.12).

5. Plot the concentrations of the parameter analysed in step 4 against their position on the transects.

6. Based on the results from step 5, determine whether there is a statistically significant increasing or decreasing trend in concentrations moving from the furthest offshore to the most enclosed site.

7. An embayment is hydrologically isolated when a statistically significant increasing or decreasing trend in concentrations has been determined.

Figure 1. Tracer sampling points along a transect for HIE determination.

Indicator 2.6.3

Requirement

Indicator scope: cage-fed systems with feed of a diameter ≥3mm. The UoC shall ensure that feed used contains <1% fines, following the method outlined in Appendix 8 (8.3).

How Do I Interpret This Requirement?

  • Indicator 2.6.3 complements the other water quality indicators by addressing the direct release of uneaten feed in the form of fines into the environment.

  • Setting a maximum percentage of fines in the feed addresses the efficient and proper transport, storage and physical delivery of feed pellets to the site.

  • Poor performance in any of the above phases of feed handling will result in a higher percentage of fines (fine particles of feed) and potentially greater impacts on water quality, due to an increase in suspended organic particles and nutrients released into the environment.

  • Sampling of feed lots includes feed delivered as material in bulk, big bags and small bags to the site.

  • Testing by the feed manufacturer to the UoC is permissible where there is no significant risk of feed deterioration during subsequent handling, storage or application.

    • The UoC should demonstrate that deterioration in feed does not take place during the processes outlined above.

    • The UoC should report the schedule and location of testing of feed if it is not conducted on-site.

  • Rationale for not testing on site should also be reported.

Evidence of Implementation

  • The method used to determine the percentage of fines in feed, in accordance with Appendix 8 (8.3).

  • The determination and documentation of a schedule and location for the testing of feed.

  • If testing takes place prior to delivery to the site, the rationale should be documented for not testing on site.

  • Calibration of sieving machines (if used) in accordance with the manufacturer’s recommendations.

Auditors Should Confirm

  • The rationale for the timing and location of feed sampling.

  • The UoC has appropriate testing technology on site and that, if applicable, it is calibrated as required.

  • The method used to determine the percentage of fines in feed, in accordance with Appendix 8 (8.3).

  • Review testing results and confirm that results demonstrate feed contains <1% of fines.

Indicator 2.6.1

Requirement

Indicator scope: fed systems The UoC shall adhere to species-specific limits on Total Nitrogen (TN) and Total Phosphorus (TP) release, according to Appendix 2(2.1). 2.6.2 Indicator scope: fed systems Reporting The UoC shall annually report to ASC TN and TP release (Indicator 2.6.1), according to ASC data submission procedure.

How Do I Interpret This Requirement?

  • TN and TP in the feed are required for the calculations. TN and TP content in the feed should be obtained from the feed supplier.

  • The suitability of the TN and TP limits per tonne of production should be reviewed if the UoC is in a Type A waterbody and needs to implement corrective actions, in accordance with Indicator 2.6.13.

  • The annual limits may need to be reduced to prevent shifts in trophic status or correct increases in limiting nutrients.

  • Equipment used to measure TN and TP per tonne of production should be calibrated according to the technical specifications. The equipment used will be based on the formula used in Appendix 8 (8.2):

    • Equipment is required for Formula 2 to measure TN and TP concentration in the influent and effluent water and the volume of the effluent water.

    • Equipment is required for Formula 3 to measure TN and TP concentration in the influent and effluent water.

Evidence of Implementation

  • The formula (outlined in Appendix 8 (8.1)) used to determine the TN and TP load per tonne of production.

  • Results of the TN and TP load per tonne of production based on the relevant calculation.

  • Equipment to measure TN and TP load per tonne of production has been calibrated according to the manufacturer’s instructions, based on the formula used in Appendix 8 (8.2).

Auditors Should Confirm

  • TN and TP load per tonne of production has been determined.

  • Species-specific limits have been adhered to (where applicable) over the previous 24-month period.

    • TN and TP have been determined and reported where species-specific limits are not available.

  • The UoC has calibrated the equipment used to determine the TN and TP load per tonne of production, based on the formula used in Appendix 8 (8.2).