This Appendix details the methods to calculate the metrics on feed efficiency required by Indicator 2.12.5: economic Feed Conversion Ratio (eFCR), Forage Fish Dependency Ratio (FFDR), and EPA and DHA content in feed and as percentage of fish oil in feed.

Calculations can be made using the calculation templates provided by ASC.

15.1 – economic Feed Conversion Ratio (eFCR)

The economic Feed Conversion Ratio (eFCR) is the ratio between the amount of feed used and the weight of animals produced, taking into account uneaten feed and loss of animals during production, such as mortality or escapes. The eFCR is calculated according to Aas et al. (2019) 159159Aas, T.S., Ytrestøl, T. & Åsgård, T. (2019). Utilization of feed resources in the production of Atlantic salmon (Salmo salar) in Norway: An update for 2016. Aquaculture Reports 15. https://doi.org/10.1016/j.aqrep.2019.100216 as follows:

$\mathrm{eFCR}=\frac{\text{total feed use}\left(\mathrm{tonnes}\right)}{\text{net production}\left(\mathrm{tonnes}\right)}$

$\text{net production}\left(\mathrm{tonnes}\right)=\mathrm{harvested}\mathrm{production}\left(\mathrm{tonnes}\right)-\mathrm{stocked}\mathrm{production}\left(\mathrm{tonnes}\right)$

15.2 – Forage Fish Dependency Ratio (FFDR)

The Forage Fish Dependency Ratio (FFDR) measures the amount of forage fish in fishmeal (FFDRm) and fish oil (FFDRo) used to produce one kg of farmed animal.

The ratio considers the differences in content and yield between the feed types used. FFDRm and FFDRo are calculated according to Aas et al. (2019)159159Aas, T.S., Ytrestøl, T. & Åsgård, T. (2019). Utilization of feed resources in the production of Atlantic salmon (Salmo salar) in Norway: An update for 2016. Aquaculture Reports 15. https://doi.org/10.1016/j.aqrep.2019.100216:

$\mathrm{FFD}{R}_m=\frac{(\frac{f{\text{m content}}_{\mathrm{type}1}(\%)}{{\text{fm yield}}_{\mathrm{type}1}(\%)}*{\text{feed use}}_{\mathrm{type}1}(\mathrm{tonnes}\left)\right)+(\frac{f{\text{m content}}_{\mathrm{type}2}(\%)}{{\text{fm yield}}_{\mathrm{type}2}(\%)}*{\text{feed use}}_{\mathrm{type}2}(\mathrm{tonnes}\left)\right)+\mathrm{etc}}{\text{total feed use}\left(\mathrm{tonnes}\right)}*\mathrm{eFCR}$

$\mathrm{FFD}{R}_o=\frac{(\frac{f{\text{o content}}_{\mathrm{type}1}(\%)}{{\text{fo yield}}_{\mathrm{type}1}(\%)}*{\text{feed use}}_{\mathrm{type}1}(\mathrm{tonnes}\left)\right)+(\frac{{\text{fo content}}_{\mathrm{type}2}(\%)}{{\text{fo yield}}_{\mathrm{type}2}(\%)}*{\text{feed use}}_{\mathrm{type}2}(\mathrm{tonnes}\left)\right)+\mathrm{etc}}{\text{total feed use}\left(\mathrm{tonnes}\right)}*\mathrm{eFCR}$

fm content (%) and fo content (%) are the fishmeal or fish oil content of each feed type respectivelyfo yield (%) and fm yield (%) are the efficiencies at which fish oil or meal are derived for each feed type a (note that yield is equal to fishmeal production (tonnes)/fish landings (tonnes) * 100). ASC-certified farms receive this information from the ASC-certified feed mill.

Only fishmeal and fish oil derived directly from forage fisheries (e.g. anchoveta) is to be included in the calculation of FFDR.

Fishmeal and fish oil derived from fisheries’ by-products, such as trimmings and offal, shall not be included in the calculation of FFDR. Trimmings are defined as by-products when fish are processed for human consumption or if whole fish is rejected for use in human consumption.

15.3 – EPA and DHA content in feed (marine salmonids)

The EPA and DHA content in feed is calculated per site as follows:

$\text{EPA and DHA in feed}(g/\mathrm{kg})=\frac{\text{fo content}(\%)*\text{EPA and DHA content}(\%)}{10}$

$\text{weighted EPA and DHA in feed}(g/\mathrm{kg})=\frac{\text{total EPA and DHA in feed}\left(g\right)}{\text{total feed use}\left(\mathrm{tonnes}\right)*1000}$

Total EPA and DHA in feed are calculated as follows:

$\text{total EPA and DHA in feed}\left(g\right)=\left({\text{EPA and DHA content}}_{\mathrm{type}1}\right(\%)*{\text{fo content}}_{\mathrm{type}1}(\%)*{\text{feed use}}_{\mathrm{type}1}(\mathrm{tonnes})*100)+\left({\text{EPA and DHA content}}_{\mathrm{type}2}\right(\%)*{\text{fo content}}_{\mathrm{type}2}(\%)*{\text{feed use}}_{\mathrm{type}2}(\mathrm{tonnes})*100)+\mathrm{etc}.$

Only fish oil derived directly from a forage fishery (e.g. anchoveta) is to be included in the calculation of EPA and DHA.

Fish oil derived from fisheries’ by-products, such as trimmings and offal, shall not be included in the calculation of EPA and DHA. Trimmings are defined as by-products when fish are processed for human consumption or if whole fish is rejected for use in human consumption.

15.4 – EPA and DHA Content as percentage of fish oil in feed (freshwater salmonids)

The EPA and DHA content as percentage of fish oil in feed is calculated per site as follows:

$\text{weighted EPA and DHA in fish oil}(\%)=$

$\frac{\left({\text{EPA and DHA content}}_{\mathrm{type}1}\right(\%)*{\text{feed use}}_{\mathrm{type}1}(\mathrm{tonnes}\left)\right)+\left({\text{EPA and DHA content}}_{\mathrm{type}2}\right(\%)*{\text{feed use}}_{\mathrm{type}2}(\mathrm{tonnes}\left)\right)+\mathrm{etc}.}{\text{total feed use}\left(\mathrm{tonnes}\right)}$

Where EPA and DHA content (%) is the feed-specific percentage of EPA and DHA content of the fish oil.

Only fish oil derived directly from a forage fishery (e.g. anchoveta) is to be included in the calculation of EPA and DHA.

Fish oil derived from fisheries’ by-products, such as trimmings and offal, shall not be included in the calculation of EPA and DHA. Trimmings are defined as by-products when fish are processed for human consumption or if whole fish is rejected for use in human consumption.

Introduction

The impacts of aquaculture extend beyond the UoC, as many species rely on upstream supply chain stages (such as hatchery and nursery production) occurring across different sites. This Appendix sets out the requirements for fish supplier sites in the UoC’s upstream supply chain, in accordance with the species defined in the scope of Indicator 1.5.2. These requirements are based on the Principles of the ASC Farm Standard and focus on the impacts most relevant to these sites.

The UoC shall maintain documentation from the supplier sites within the upstream supply chain as evidence that these sites conform with the requirements of this Appendix.

This Appendix details:

13.1 Introduction

Effective sea lice management is essential to protect the health of both farmed and native salmonid populations. An element of management includes setting limits to the number of on-site sea lice to ensure the health and welfare of farmed fish and minimise the risk of sea lice from farmed fish origin affecting native populations, especially during sensitive periods such as the out-migration.

Effective management also includes the cooperation of multiple sites within a specific area to manage sea lice collectively. This Area-Based Management approach helps reduce the overall sea lice burden and mitigate the risk of infestation spreading between sites. Key elements of this cooperation include the coordination of activities, such as stocking, treatment and fallowing, and information sharing.

Parasiticide treatments are used to reduce the number of sea lice on farmed fish. However, relying heavily on these chemical treatments is not a sustainable long-term solution, as they pose challenges related to environmental impact, the development of resistance, and the health and welfare of the farmed fish. Addressing these challenges requires alternatives to chemical parasiticide treatments aiming to reduce their use and ultimately eliminate reliance on them.

13.2 Area-Based Management – ABM (Indicators 4.1.1.11.1, 4.5.1 and 4.5.2)

13.2.1 Attributes of the ABM (Indicator 4.1.1.11.1 and 4.5.1)

The purpose of the ABM scheme is to improve health and biosecurity management at the site, ultimately aiming to reduce potential negative impacts on native fish populations.

A. Definition of the ‘area’

The area covered by the ABM shall reflect a logical geographic scope, such as a fjord or a group of ecologically-connected fjords.

The boundaries of the area shall be defined considering:

If an ABM is a regulatory requirement and its definition of ‘area’ aligns with these considerations, sites may use that definition for the requirements in Criterion 4.5.

B. Participation in the ABM

At least 80% of farmed salmonid production in the area, by weight, shall participate in the ABM.

Participation shall include all sites owned by ASC Certificate Holders, including those that are not ASC-certified, and ASC applicants.

C. Documentation

The ABM shall document the following:

The objectives shall be reviewed and revised as necessary based on new information, including substantiated concerns raised by communities or local native fish interest groups as part of engagement with stakeholders required by Indicator 3.13.4.

D. Information and Data Sharing

The ABM shall ensure the sharing of information and data amongst sites to facilitate effective coordination, including at least the following:

E. Coordination

The ABM shall include coordination amongst sites regarding:

13.2.2 Establishment, review and revision of ABM sea lice load and on-site sea lice levels (Indicator 4.5.2)

In areas with native salmonids, Indicator 4.5.2 requires the ABM to establish, review and potentially revise the maximum sea lice load. The purpose is to assess the potential cumulative infection pressure from on-site sea lice, expressed as the number of sea lice on all sites in the ABM. This maximum sea lice load provides accurate information on the potential risks to native salmonid populations.

13.3 Method for collecting sea lice data on native salmonids (Indicator 4.5.4)

The purpose is to clarify the correlation between sea lice occurrence in native and farmed salmonids through objective data. The collected data provides meaningful information for the ABM review of the maximum sea lice load (see Indicator 4.5.2 and Section 13.2.2).

Data collection shall conform with the following:

An exception applies where:

13.4 Method for on-site sea lice sampling (Indicator 4.5.6)

The on-site sea lice sampling shall conform with the following:

13.5 On-site sea lice thresholds for sensitive periods (Indicator 4.5.9)

Indicator 4.5.9 requires that on-site sea lice levels remain below the thresholds outlined in Table 1 during sensitive periods.

Table 1 Sea lice thresholds and sensitive period per region

* In regions where a threshold is not established, 0.2 adult females apply.

**In regions where a sensitive period is not established, the length and timing should be specified according to a defined criterion (e.g. when juveniles are in proximity to cages) and using the latest knowledge.

***Motile includes adult L. salmonis females (with or without egg strings) and other motile L. salmonis (including adult males and preadults). Mobile is considered a synonym of motile.

13.6 Method for calculating the Weighted Number of Medicinal Treatments (WNMT) (Indicator 4.5.12)

The Weighted Number of Medicinal Treatments (WNMT) is the total number of medicinal parasiticide treatments applied on a site over the production cycle157157Hydrogen peroxide (H₂O₂) is considered a medicinal parasiticide treatment.. Indicator 4.5.12 requires sites to meet an Entry Level (EL) that expresses an initial WNMT to conform with, after which a 25% reduction needs to be achieved until the WNMT meets a defined Global Level (GL) (see Indicator 4.5.13). Table 2 shows the EL and GL per region.

Table 2 Entry Level and Global Level per region

*In regions not listed, an EL of 6 and GL of 3 shall apply.

**Partial treatments (i.e. treatments applied to some cages from the total number of cages in use) should be counted as a proportion of the cages treated.

*** An exception applies where two times a ‘coupled treatment158158A “coupled treatment” is defined as a bath treatment applied in two treatment events (i.e., one treatment at t1 and a follow-up treatment at t2). Each treatment (t1 and t2) shall be included in the calculation of the WNMT.’ is given (counted as 2+2 = 4 WNMT), in which case a GL of 4 applies. Additional treatments applied will result in an exceedance of GL=4.

This Appendix details the requirements for Health and Welfare training, monitoring, ablation-free sourcing and permitted stunning method usage, and methodologies to calculate the metrics on mortalities, antibiotic load and stocking density under Principle 4.

12.1 Introduction

Aquatic animal health and welfare is highly context-specific, given the diversity of species and culture systems. This variability highlights the importance of adjusted approaches within the ASC Farm Standard, as maintaining health and welfare is key to ensuring sustainable and ethical aquaculture practices. To address this complexity, the tables below and methodologies outline requirements that must be implemented according to the specific scenarios and needs of different species and systems.

12.2 Training requirements

Table 1 below outlines the requirements for basic and advanced aquatic animal health and welfare training.

Table 1. Aquatic animal Health and Welfare Training Requirements

12.3 Water Quality Monitoring Requirements

Table 2 below outlines the water quality monitoring requirements for fish culture (including cleaner fish) in the various culture systems, water types and during live transport. Table 3 below outlines the water quality monitoring requirements for crustacean culture in the various culture systems and water types.

Table 2. Water quality monitoring requirements for fish culture and live transport (including cleaner fish) as required by Indicators 4.1.1.10.1, 4.1.1.26.1, 4.1.2.10, 4.1.2.24.

Table 3. Water quality monitoring requirements for crustacean culture as required by Indicator 4.2.1.8.1

12.4 Ablation-free requirements

Table 4 below outlines the requirements for UoCs culturing Penaeus vannamei and Penaeus monodon to progress towards sourcing entirely from ablation-free female broodstock.

Table 4. Sourcing requirements for UoCs culturing Penaeus vannamei and Penaeus monodon, as required by Indicator 4.2.1.13.

12.5 Permitted stunning methods

Table 5 below outlines the permitted stunning methods and usage requirements for UoCs for the various fish species.

Table 5. Species-specific permitted stunning methods and usage requirements for UoCs, as required by Indicators 4.1.3.4 and 4.1.3.12

12.6 Methodologies

The methodologies below outline the formulae to calculate the metrics on mortalities, survival rates, antibiotic load and stocking density under Principle 4.

12.6.1

The mortality rate and real percentage mortality is calculated for each species in production at each site, as required by Indicator 4.1.1.6.

The mortality rate is calculated as the observed mortality count as a percentage of the stocking count:

$\text{Mortality rate}(\%)=\frac{\text{observed mortality count}(\#\mathrm{animals})}{\text{stocking count}(\#\mathrm{animals})}*100$

The real percentage mortality is calculated as the difference between stocked and harvested animals divided by the stocked animals:

$\text{Real percentage mortality}(\%)=\frac{\left(\text{stocking count}\right(\#\mathrm{animals})-\text{harvest count}(\#\mathrm{animals}\left)\right)}{\text{stocking count}(\#\mathrm{animals})}*100$

The survival rate for crustaceans is calculated for each species in production at each site, as required by Indicator 4.2.1.4.

The survival rate is calculated as the harvest count as a percentage of the stocking count:

$\text{Survival rate}(\%)=\frac{\text{harvest count}(\#\mathrm{animals})}{\text{stocking count}(\#\mathrm{animals})}*100$

12.6.2 The formula below outlines the methodology for antibiotic load calculation, as required by Indicator 4.4.16.

The antibiotic load is calculated for each species in production at each site and is the total amount of active component used from all applied antibiotics used divided by the net production volume.

$\text{Antibiotic load}\left({\text{kg tonne}}^{-1}\right)=\frac{\text{total mass of active component}\left(\mathrm{kg}\right)}{\text{net production}\left(\mathrm{tonnes}\right)}$

12.6.3 The formulae below outline the methodologies for stocking density calculation, as required by Indicators 4.1.1.12, 4.1.1.27, and 4.2.1.11.

The UoC shall calculate stocking densities at the highest stocked volume or highest stocking count.

Depending on the species in production, the stocking density is reported as biomass per surface area (kg/m²), biomass per water volume (kg/m³) or number of aquatic animals per surface area (# aquatic animals/m²):

$\text{stocking density}\left(\frac{\mathrm{kg}}{m^2}\right)=\frac{\text{stocked production}\left(\mathrm{kg}\right)}{\text{water surface area}\left(m^2\right)}$

$\text{stocking density}\left(\frac{\mathrm{kg}}{m^3}\right)=\frac{\text{stocked production}\left(\mathrm{kg}\right)}{\text{water volume}\left(m^3\right)}$

$\text{stocking density}\left(\frac{\#\mathrm{animals}}{m^2}\right)=\frac{\text{stocking count}(\#\mathrm{animals})}{\text{water surface area}\left(m^2\right)}$

The water surface area of circular production units can be calculated as follows:

$\text{surface area}\left(m^2\right)=\pi \times {\mathrm{radius}}^2\left(m\right)\times \#\text{production units}$

Where radius is calculated as:

$\mathrm{radius}\left(m\right)=\frac{\mathrm{diameter}\left(m\right)}{2}$

The water surface area for rectangular production units can be calculated as follows:

$\text{surface area}\left(m^2\right)=\mathrm{length}\left(m\right)\times \mathrm{width}\left(m\right)\times \#\text{production units}$

The water volume can be calculated by multiplying the surface area with the height of the production units for circular and rectangular production units, respectively:

$\text{water volume}\left(m^3\right)=\pi \times {\mathrm{radius}}^2\left(m\right)\times \mathrm{height}\left(m\right)\times \#\text{production units}$

$\text{water volume}\left(m^3\right)=\mathrm{length}\left(m\right)\times \mathrm{width}\left(m\right)\times \mathrm{height}\left(m\right)\times \#\text{production units}$

This Appendix details the methods for calculating comparable employee remuneration and assessing it against the Living Wage estimate to determine a living wage gap, as required in Criterion 3.8 (Indicator 3.8.2).

11.1 Step 1: Select the living wage estimate

Select the relevant living wage estimate for the UoC’s location and reference year. The UoC shall use an ASC-approved living wage estimate, following the ‘Living Wage Benchmarks’ guidance document available via the ASC Programme Centre.

11.2 Step 2: Identify employees to include in the calculation

The employees included in the living wage gap calculation shall be determined using the ASC definition of ‘employee’.

The UoC shall include data on employee remuneration following one of two options:

For UoCs under multi-site or group certification, employees from all sites may be combined into a single living wage gap calculation. In such cases, the UoC shall ensure that the data collected is representative of all sites included in the certification scope.

Grouping employees into categories

Grouping employees into categories can make the calculation process easier, particularly for UoCs with many employees. Employees can be grouped into a category where:

Where these conditions are not met, employees shall be assessed separately.

11.3 Step 3: Choose the calculation tool

The UoC can calculate a living wage gap using several different tools. All calculations shall follow the approach described below, which is based on the Anker Research Institute’s methodology144144https://www.ankerresearchinstitute.org/anker-methodology. The key difference between the options is how the calculation is performed. The following options may be used:

ASC strongly recommends the use of the IDH Salary Matrix. The IDH Salary Matrix automates key steps in the calculation including the capping of in-kind benefits, conversion of remuneration to full-time equivalent (FTE) values, and comparison against the living wage estimate. The tool automatically generates a report for verification and data needed for reporting (See Indicator 3.8.3). This saves time, prevents calculation errors, and ensures accurate results.

Manual calculation requires the same steps to be performed explicitly, including the proration of remuneration to FTE values and comparison with the living wage estimate. The tool is easy to use, available in multiple languages, and guidance is embedded. Further training on living wage concepts and the IDH Salary Matrix is available via the ASC Programme Centre.

11.4 Step 4: Calculate allowable wages and bonuses

Table 1 below lists the annual wages and bonuses that are allowed to be included in the calculation. All payroll information must be gross figures (no tax deducted) taken from the previous calendar year.

To ensure accuracy, four conditions shall be met for a payment to be counted towards the employee remuneration calculation146146From Living Wages Around the World by Martha and Richard Anker, Chapter 15 Measuring Prevailing Wages to Compare to a Living Wage, page 271.:

Table 1. Description of the Wages and Bonuses included in the living wage gap calculation

11.5 Step 5: Calculate in-kind benefits

In-kind benefits are considered in the living wage gap calculation, as they reduce the amount of cash wage that employees require to cover living expenses. The UoC shall calculate allowable in-kind benefits according to the following three-part process147147From Living Wages Around the World by Martha and Richard Anker, Chapter 15 Measuring Prevailing Wages to Compare to a Living Wage, page 299.: Part A: Identify allowable in-kind benefits

In-kind benefits marked with a check in Table 2 below can be included in the living wage gap calculation.

Part B: Value the in-kind benefits

To value in-kind benefits, the UoC shall calculate the total cost to the employer and divide this by the number of employees receiving the benefit. The value of each in-kind benefit shall not exceed any of the following:

If an in-kind benefit requires that the employee share some of the cost, the employee’s cost should be subtracted from the total value.

Part C: Ensure in-kind benefits fall within the maximum limits

To ensure that employees have a sufficient income they can spend as they choose, and in line with applicable legal requirements in many countries, the percentage of total income that is provided to employees in-kind is limited. Employees shall not receive more than:

If valuation of in-kind benefits exceeds any of the above percentages, the amount included in the calculation shall be reduced to comply with limits. The IDH Salary Matrix tool automatically limits in-kind benefits.

Table 2. In-Kind Benefits

11.6 Step 6: Calculate total comparable remuneration

To enable comparison with the living wage estimate and determine the gap, the UoC shall calculate total comparable remuneration for each employee category. All remuneration components (wages, bonuses, and in-kind benefits) identified in Steps 4 and 5 shall be converted into full-time equivalent (FTE) values for comparison with the living wage estimate, which is based on FTE.

Using the IDH Salary Matrix:

When using the IDH Salary Matrix, total comparable remuneration is calculated automatically. The tool:

Manual calculation:

When calculating manually, the UoC shall:

The UoC shall maintain records of all calculations to enable effective verification.

11.7 Step 7: Calculate the living wage gap

Monthly comparable remuneration for each employee category shall be compared to the applicable living wage estimate for the same reference year. For example, for an audit taking place in 2026, employee remuneration data from January-December 2025 shall be compared against the 2025 living wage estimate.

Using the IDH Salary Matrix:

The IDH Salary Matrix will automatically calculate living wage gaps for each employee category, the employees below living wage (as % of workforce), and an average living wage gap.

Manual calculation:

For manual calculation, the following calculations need to be performed:

1. Living wage gap for each employee category

$\text{Employee category living wage gap}(\%)=\frac{\text{Living wage estimate}-\text{Comparable remuneration}}{\text{Living wage estimate}}X100$

Where comparable remuneration equals or exceeds the living wage estimate, the living wage gap shall be 0% for that employee category.

2. Employees below living wage (% of workforce)

The percentage of employees below living wage shall be calculated as the proportion of employees with a living wage gap.

$\text{Employees below living wage}(\%)=\frac{\text{Number of employees in categories with a living wage gap}}{\text{Total number of employees}}X100$

3. Average living wage gap

The average living wage gap shall be calculated for all employees with a living wage gap. This shall be calculated as the sum of each employee category’s living wage gap multiplied by the number of employees in that category, divided by the total number of employees with a living wage gap.

$\text{Average living wage gap}(\%)=\frac{\mathrm{SUM}\left(\text{Category living wage gap x Number of employees in category}\right)}{\text{Total number of employees with living wage gap}}X100$

This Appendix details the process, timeline, and implementation of remediation actions and plans in response to instances of forced labour as required in Criterion 3.2 (Indicator 3.2.2) and child labour as required in Criterion 3.3 (Indicator 3.3.2).

10.1 Introduction

Remediation is the process of restoring an individual after a human rights violation has been discovered, reported and verified. The issue can be discovered in several ways, including through the grievance process, internally at a site or during a third-party audit. The United Nations Guiding Principles for Business and Human Rights (UNGPs) 143143https://www.business-humanrights.org/en/big-issues/governing-business-human-rights/un-guiding-principles/ require that both states and businesses take steps to ensure that when there are human rights violations, employees have access to effective remedy.

The UoC can work in partnership with employee representation and external partners but is always responsible for ensuring that the remediation process is carried out and that it prioritises the best interest of the person. The remediation process includes the following steps, which are outlined in this document and shown in Figure 1:

Figure 1 Remediation process timeline

10.2 Step 1: Immediate response and safeguarding (within 24 hours of detection)

Once a case has been detected, the first step in remediation is for the site to ensure the person’s safety, and make sure that the person does not feel threatened. Not all situations require immediate safeguarding. However, child labour and forced labour often require immediate actions to protect the person and remove them from an unsafe situation until the remediation plan is developed and enacted.

When a person working in forced labour is found to be working on a site:

When a child below the allowed working age is found to be working on a site:

When a child of legal working age is found to be working in a hazardous situation:

10.3 Step 2: Remediation plan development

The next step is to develop and agree upon a remediation plan for the person, seeking input from the affected person, as well as external experts when appropriate. When it is a case of child labour, the child’s family or guardian shall also be involved in the process. When the family is not available, local child protection authorities shall be engaged.

Remediation will take different forms depending on the situation and the needs of the person in question but always considers the best interest of the person. The development and implementation of most plans shall involve working with an NGO or other partner organisation and/or government agencies who are experts in the issue. The criminal justice system is contacted when criminal actions have occurred. How quickly the plan is finalised is dependent on the complexity of actions that need to occur and the urgency of the case, but in any case, within 28 calendar days of an abuse finding.

Elements to consider in the development of a remediation plan for child labour:

Where a child of legal working age is found working in a hazardous situation, the goal is to ensure the child’s health and safety and preserve their income with safe work. Remediation actions may include the following:

When a child below the allowed working age is found to be working, the goal is to protect the child and assure access to adequate resources and long-term support for the child and their education. Remediation actions may include the following:

Elements to consider in the development of a remediation plan for forced labour:

For forced and bonded labour, the goal is usually to provide safe and fairly compensated work where possible, and return any trafficked persons employed against their will to their home when they wish. Remediation actions may include the following:

Whether the issue is discovered through a third-party audit, self-detected by the UoC, or reported through the grievance mechanism, employee representation is involved in the

development of any remediation plan. They are made aware of external resources available for remediation and the development of any remediation plan. This supports mutual learning and accountability.

10.4 Step 3: Implementation and monitoring of remediation plan

Once the plan has been agreed on by all parties, it is implemented and monitored. Major remediation actions shall be completed within three months of finding the abuse. However, in some cases of child labour, implementation of the child’s remediation plan can take up to several years until a child has finished schooling and is eligible for legal employment. In this case, the plan shall be underway (e.g. the child is enrolled in school and the family is supported) at the end of the 90 days, with a clear plan of continued action.

Regular monitoring of the plan is important to confirm that the plan is implemented, that the implementation is effective, and that necessary adjustments are made when circumstances change – for example when a child needs to change school enrolment due to a move.

10.5 Step 4: Corrective action plan to prevent reoccurrence

An effective remediation process includes the development of a corrective action plan to ensure that root causes are understood, and to prevent the abuse from happening again to someone else. To develop this, the UoC shall perform a root cause analysis of what went wrong in their system and shall implement and monitor appropriate corrective actions to prevent recurrence.

This Appendix details the methods for calculating energy use and greenhouse gas (GHG) emissions as required by Criterion 2.10. It also provides GHG targets to guide development of GHG management plans.

9.1 Introduction

Measurement, reporting, and management of on-site energy use and GHG emissions are data and calculation-intensive processes. ASC strongly recommends the use of the ASC Greenhouse Gas Calculator (https://ghg.asc-aqua.org) to assist in undertaking calculations; it ensures correct methods and provides results consistent with the required reporting format. Other tools or frameworks may be used if it can be demonstrated that they follow the methodological requirements outlined in this Appendix.

9.2 Scope and timeframe for calculating energy use and GHG emissions

Both energy use and GHG emissions are calculated relative to a quantity of production. This requires that production data and input data (feeds, energy inputs, etc.) relate to a consistent timeframe. Given the differences between production cycles of different culture systems and species, two timeframe options may be used for calculations:

Option A. Calculate values for the most recently completed production cycle.

Option B. Calculate values for the three most recent consecutive years of production.

If insufficient data are available for initial audits, the UoC shall demonstrate how they will collect and calculate values once production data are available (after first production cycle if using Option A or, on an interim basis, after one year of continuous production if using Option B).

All energy use and GHG data calculations may be undertaken at a site-specific or multi-site scale. If calculating values for multiple sites together, all sites included shall farm the same species, use the same production method, and be located in the same country.

9.3 On-site energy use (Indicator 2.10.1)

Energy use of production is calculated as megajoules of energy per tonne of net live weight production (MJ/t). The required scope of activities and inputs to include in energy use calculations is provided in Table 1.

Table 1 Energy inputs required in energy consumption calculations for Indicator 2.10.1.

On-site energy use shall be calculated using the following formula:

$E=\frac{(Q_i\times D_i)}{P}$

Where:

To facilitate calculations, energy densities are automatically calculated when submitting energy use data to ASC.

Table 2 Energy density values for calculation of energy consumption.

Source: DESNZ (2022)140140DESNZ (2022). Greenhouse gas reporting: Conversion factors 2022. United Kingdom Department for Energy Security and Net Zero. Available at https://www.gov.uk/government/publications/greenhouse-gas-reporting-conversion-factors-2022

9.4 GHG emissions (Indicator 2.10.2)

GHG emissions are calculated following an attributional life cycle assessment approach (Figure 1). Emissions are calculated and reported in units of kg carbon dioxide-equivalent (CO₂e) per tonne of live weight production and then converted to kg CO₂e per kg of edible product to inform target-setting and tracking the GHG Management Plan.

Figure 1 System boundaries for calculating GHG emissions of aquaculture products, showing included processes for feed (shaded) and farm stages.

Calculation of GHG emissions for ASC is categorised following the emission scopes defined by the Greenhouse Gas Protocol (WRI, 2004141141World Resources Institute (WRI). (2004). The Greenhouse Gas Protocol: A Corporate Accounting and Reporting Standard. Washington, D. C.: World Resources Institute.). To ensure comparability of GHG data between ASC-certified sites, a consistent application of these scopes is used, including activities and inputs listed for each in Table 3.

Table 3 Included inputs and activities for GHG emissions calculations according to Greenhouse Gas Protocol scope.

ASC accepts two methods of handling co-product allocation in GHG accounting: mass allocation and economic allocation. This methodological choice affects GHG emission factors for feed ingredients as well as processing of fish products, if applicable. Farms may follow one or both allocation methods. Feed mills are required to provide farms GHG data specific to the allocation method requested. If farms are using the ASC GHG Calculator or another tool that supports both methods, and have data from their feed suppliers reflecting both methods, they shall subsequently report GHG values following both methods.

UoCs are highly encouraged to use the ASC GHG Calculator or another tool to support GHG calculations. If undertaking calculations manually, the following equations shall be used to calculate Scope 1 (Appendix 9 (9.4.1)), Scope 2 (Appendix 9 (9.4.2)) and Scope 3 (Appendix 9 (9.4.3)) emissions. Each calculation requires a combination of input quantities and their corresponding emission factors, which must be documented alongside calculations.

9.4.1 Scope 1 GHG Emissions

Scope 1 GHG emissions shall be calculated using the following formula:

$S_1=\frac{(Q_i\times G_i)}{P}$

Where:

Table 4 Greenhouse gas intensity (kg CO₂e/unit), according to Greenhouse Gas Protocol scope, for calculation of Scope 1 and Scope 3 emissions from on-site energy use.

Source: DESNZ (2022)140140DESNZ (2022). Greenhouse gas reporting: Conversion factors 2022. United Kingdom Department for Energy Security and Net Zero. Available at https://www.gov.uk/government/publications/greenhouse-gas-reporting-conversion-factors-2022

9.4.2 Scope 2 GHG Emissions

Scope 2 GHG emissions shall be calculated using the following formula:

$S_2=\frac{(Q_i\times G_i)}{P}$

Where:

9.4.3 Scope 3 GHG Emissions

Scope 3 emissions associated with feed ingredients and milling shall be calculated using the following formula:

$S_{3\left(\mathrm{Feed}\right)}=\frac{(Q_f\times G_{f,a})}{P}$

Where:

Scope 3 emissions from feed transportation to sites shall be calculated using the following formula:

$S_{3\left(\text{Feed transport}\right)}=\frac{(Q_f\times T_{f,m}\times G_m)}{P}$

Where:

Scope 3 emissions associated with (production of) fuels and other inputs (e.g., liquid oxygen) shall be calculated using the following formula:

$S_{3\left(\mathrm{Other}\right)}=\frac{(Q_i\times G_i)}{P}$

Where:

9.5 Target-setting for GHG management plans (Indicator 2.10.3)

Species-specific targets serve as a basis for understanding the relative emissions of aquaculture production and guiding reduction efforts in GHG management plans (Table 5). These are based on average species-specific estimates of GHG intensity from Gephart et al. (2021)142142Gephart, J. A., Henriksson, P. J., Parker, R. W., Shepon, A., Gorospe, K. D., Bergman, K., … & Troell, M. (2021). Environmental performance of blue foods. Nature, 597(7876), 360-365.. They will be regularly updated based on data submitted to ASC to support target-setting and tracking relevant to different species and production systems. Farms are not required to meet these targets but they serve as guidance to inform reduction efforts in the GHG management plans.

Table 5 Species-specific GHG targets to incorporate into GHG management plans.

This Appendix details the methods for all water quality measurements and calculations as required in Criterion 2.6. Some calculations are only required for certain waterbody types as classified in Indicator 2.6.4, while others are applicable across all waterbodies.

8.1 Introduction

The water quality monitoring methods are based on the type of waterbody in which a site is situated and the type of effluent discharge from the culture system.

The first sections of the Appendix, sections 8.2 to 8.4, apply to all waterbody types and culture systems. They include methods to calculate nutrient releases, fines in feed and how to classify the type of receiving waterbody.

The methods in sections 8.5 to 8.7 outline the steps to determine the Waterbody Unit of Management, form a collaborative network with other aquaculture sites, how to conduct a 24-month water quality monitoring survey and characterise the baseline of the waterbody. These sections apply to sites located in waterbodies that are the most sensitive to nutrient loading, based on the classification outlined in section 8.4.

Calculations can be made using the ASC Water Quality Calculator provided by ASC.

For culture systems with point source discharges, methods outlined in sections 8.8 to 8.10 determine the steps to measure nutrients in effluent waters, calculate the effluent flow contribution to the receiving waterbody and monitor dissolved oxygen.

ASC has benchmarked the ASC Farm Standard methods for water quality against applicable regulatory requirements. Outcomes of the benchmark are available via the ASC Programme Centre.

8.2 Total Nitrogen and Total Phosphorous load (Indicators 2.6.1 and 2.6.2)

To calculate Total Nitrogen (TN) and Total Phosphorous (TP) load per tonne of production, one of the four following formulas shall be used per site:

Unless otherwise stated, all values shall apply over the previous 12-month period. Net production volume shall be calculated using the following formula:

$\text{Net production volume}\left(\mathrm{tonnes}\right)=\left(\text{harvested volume}\right(\mathrm{tonnes})+\text{other removed volume}(\mathrm{tonnes}\left)\right)-\text{stocked volume}\left(\mathrm{tonnes}\right))$

Formula 1:

TN load shall be calculated using the following formula:

$\text{TN load}\left(\mathrm{kg}{\mathrm{tonne}}^{-1}\right)=\frac{\text{TN release}\left(\mathrm{kg}\right)}{\text{net production volume}\left(\mathrm{tonnes}\right)}$

$\text{TN release}\left(\mathrm{kg}\right)=\text{TN in feed}\left(\mathrm{kg}\right)-\text{TN in animals}\left(\mathrm{kg}\right)$

$\text{TN in feed}\left(\mathrm{kg}\right)=\text{Feed use}(\mathrm{tonnes}/\mathrm{year})\times \text{TN content feed}(\%)\times 10$

$\mathrm{TN}\text{in animals}\left(\mathrm{kg}\right)=\text{net production volume}(\mathrm{tonnes}/\mathrm{year})\times \text{TN in animals}(\%)\times 10$

$\text{TP load}\left(\mathrm{kg}{\mathrm{tonne}}^{-1}\right)=\frac{\text{TP release}\left(\mathrm{kg}\right)}{\text{net production volume}\left(\mathrm{tonnes}\right)}$

$\text{TP release}\left(\mathrm{kg}\right)=\text{TP in feed}\left(\mathrm{kg}\right)-\text{TP in animals}\left(\mathrm{kg}\right)$

TP in feed shall be equal to the mass of feed used (tonnes, dry weight) multiplied by the feed TP content:

$\text{TP in feed}\left(\mathrm{kg}\right)=\text{Feed use}(\mathrm{tonnes}/\mathrm{year})\times \text{TP content feed}(\%)\times 10$

$\text{TP in animals}\left(\mathrm{kg}\right)=\text{net production volume}(\mathrm{tonnes}/\mathrm{year})\times \text{TP in animals}(\%)\times 10$

Formula 2:

TN load shall be calculated using the following formula:

$\text{TN load}\left(\mathrm{kg}{\mathrm{tonne}}^{-1}\right)=\frac{{\mathrm{TN}}_{\mathrm{out}}\left(\mathrm{kg}\right)-{\mathrm{TN}}_{\mathrm{in}}\left(\mathrm{kg}\right)}{\text{net production volume}\left(\mathrm{tonnes}\right)}$

${\mathrm{TN}}_{\mathrm{out}}\left(\mathrm{kg}\right)=[\mathrm{TN}{]}_{\mathrm{effluent}}\left(\frac{\mathrm{mg}}{L}\right)\times 0.001\times {\mathrm{volume}}_{\mathrm{effluent}}(m^3)$

${\mathrm{TN}}_{\mathrm{in}}\left(\mathrm{kg}\right)=[\mathrm{TN}{]}_{\mathrm{influent}}\left(\frac{\mathrm{mg}}{L}\right)\times 0.001\times {\mathrm{volume}}_{\mathrm{influent}}(m^3)$

$\text{TP load}\left(\mathrm{kg}{\mathrm{tonne}}^{-1}\right)=\frac{{\mathrm{TP}}_{\mathrm{out}}\left(\mathrm{kg}\right)-{\mathrm{TP}}_{\mathrm{in}}\left(\mathrm{kg}\right)}{\text{net production volume}\left(\mathrm{tonnes}\right)}$

${\mathrm{TP}}_{\mathrm{out}}\left(\mathrm{kg}\right)=[\mathrm{TP}{]}_{\mathrm{effluent}}\left(\frac{\mathrm{\mu g}}{L}\right)\times 0.000001\times {\mathrm{volume}}_{\mathrm{effluent}}(m^3)$

${\mathrm{TP}}_{\mathrm{in}}\left(\mathrm{kg}\right)=[\mathrm{TP}{]}_{\mathrm{influent}}\left(\frac{\mathrm{\mu g}}{L}\right)\times 0.000001\times {\mathrm{volume}}_{\mathrm{influent}}(m^3)$

Formula 3:

The average daily water exchange rate (%/day x 0.01), multiplied by the total pond volume, multiplied by the numbers of days in a year shall give a proxy for the daily effluent volume and influent volume respectively. This formula assumes the influent volume equals the effluent volume.

Annual TN load shall be calculated using the following formula:

$\text{TN load}\left(\mathrm{kg}{\mathrm{tonne}}^{-1}\right)=\frac{{\left(\right[\mathrm{TN}]}_{\mathrm{effluent}}(\mathrm{mg}/L)-\left[\mathrm{TN}{]}_{\mathrm{influent}}\left(\frac{\mathrm{mg}}{L}\right)\right)\times {\mathrm{volume}}_{\mathrm{pond}}\left(m^3\right))\times \text{daily water exchange}(\%/\mathrm{day}\times 0.01)\times \mathrm{days}(n)}{\text{net production volume}\left(\mathrm{tonnes}\right)}\times 0.001$

Daily Total P load shall be calculated using the following formula:

$\text{TP load}\left(\mathrm{kg}{\mathrm{tonne}}^{-1}\right)=\frac{{\left(\right[\mathrm{TP}]}_{\mathrm{effluent}}(\mathrm{\mu g}/L)-\left[\mathrm{TP}{]}_{\mathrm{influent}}\left(\mu \frac{g}{L}\right)\right)\times {\mathrm{volume}}_{\mathrm{pond}}\left(m^3\right))\times \text{daily water exchange}(\%/\mathrm{day}\times 0.01)\times \mathrm{days}(n)}{\text{net production volume}\left(\mathrm{tonnes}\right)}\times 0.000001$

Formula 4:

Nutrient loads shall be calculated using the following formula:

$\text{TN load}\left(\mathrm{kg}{\mathrm{tonne}}^{-1}\right)=\frac{\text{TN input}\left(\mathrm{kg}\right)\times 0.3}{\text{net production volume}\left(\mathrm{tonnes}\right)}$

$\text{TP load}\left(\mathrm{kg}{\mathrm{tonne}}^{-1}\right)=\frac{\text{TP input}\left(\mathrm{kg}\right)\times 0.2}{\text{net production volume}\left(\mathrm{tonnes}\right)}$

8.3 Percentage of fines in feed (Indicator 2.6.3)

The site shall determine the percentage of fines in feed using one of the two methods outlined below. Testing shall take place either on-site (Appendix 8 (8.3.1)) after feed has been delivered to the site, or by the feed manufacturer prior to the feed arriving on-site (Appendix 8 (8.3.2)).

8.3.1 On-site testing

This method shall be used when the percentage of fines is determined on-site. The method encompasses the sampling and testing of feed and the calculation of fines. The determination of fines shall be conducted when the feed is delivered to site.

Feed sampling

The steps to conduct the sampling of feed lots per site are as follows:

Feed testing

Feed testing can be conducted by either a manual test or by using a sifting machine. The sample of fines shall be sieved with a sieve of a maximum sieve opening of:

Manual feed testing

The steps to conduct the testing are as follows:

Sifting machine feed testing

The steps to conduct testing with a sifting machine are as follows:

Calculations – both methods:

The following equation shall be used to calculate the percentage of fines in the feed sampled: fines percentage (%) = (md/m0) x 100.

8.3.2 Feed manufacturer testing

If fines testing is conducted by the feed manufacturer, results shall demonstrate a <0.25% difference between manufacturer-tested fines content and on-site tested fines content. Either the manual feed testing or sifting machine feed testing method shall be used to determine on-site fines content.

The requirements for feed manufacturer testing are as follows:

8.4 Receiving Waterbody classification (Indicator 2.6.4)

The site shall classify the Receiving Waterbody (RW) according to Table 1 based on:

Table 1. Overview of the Receiving Waterbody types and thresholds for the classification parameters.

8.4.1 Hydraulic Retention Time (HRT)

HRT shall be calculated using the following formula, where HRT is used to classify the RW (according to Table 1):

$\text{Mean Hydraulic Retention Time}\left(\mathrm{days}\right)=\left(\frac{1,000,000*A*z}{(86,400*Q)}\right)$

8.4.1.1 Flow rate calculation

Flow rate data is required to calculate the HRT of the RW. The method to calculate flow rate is based on the characteristics of the waterbody:

Marine waterbodies:

Freshwater and brackish waterbodies:

8.4.1.2 Determination of total suspended solids (TSS) at low flow

Flow rate and TSS calculations are used to distinguish between Type B and C freshwater and brackish waterbodies only (TSS is >20mg/L at low flow, according to Table 1). The following method shall be used to determine TSS:

8.5 Waterbody Unit of Management (WUM) (Indicator 2.6.5)

A Waterbody Unit of Management (WUM) is the geographic or spatial scope of the waterbody. The WUM shall be defined per site and include information on aquaculture sites discharging effluents in the waterbody.

Using one of the following methods, the site shall demonstrate that a WUM has been created per site:

A map shall be created or presented for the WUM which indicates the following characteristics:

8.6 Components of a Water Quality Monitoring Network (Indicator 2.6.7)

The intent of the Water Quality Monitoring Network (WQMN) is to establish a mechanism for collaboration and the sharing of information between aquaculture sites in Type A waterbodies. This will provide the foundation for an Area Management Agreement (AMA) in a future version of the ASC Farm Standard.

Based on the WUM characterised according to the method outlined in Appendix 8 (8.5), the site shall establish, join a WQMN or present evidence of an area-based approach to manage water quality at a national level.

The steps to establish a WQMN per site are as follows:

If water quality is managed using an area-based approach by the national or regional regulatory body in which a site is located, the site shall present evidence demonstrating that the area-based approach meets the requirements of the WQMN, as outlined in Appendix 8 (8.6.1).

8.6.1 WQMN Requirements

The requirements of the WQMN are as follows:

8.7 Site level monitoring survey and baseline characterisation(Indicators 2.6.8 to 2.6.12)

The site level monitoring survey outlines a method to collect data to establish the trophic status and baseline characterisation of Type A waterbodies.

8.7.1 Site level monitoring survey

The steps to conduct the monitoring survey per site are as follows:

8.7.2 Trophic status

The steps to determine trophic status are as follows:

Table 2. The Trophic Status Index (TSI) for four classification parameters: Secchi depth (SD), total phosphorous (TP) concentration, total nitrogen (TN) concentration and Chlorophyll-a (Chl-a).

8.7.3 Biological oxygen demand (BOD) calculation

BOD shall be calculated per site per closed calendar year, based on:

BOD shall be calculated according to the following formula:

$\mathrm{BOD}\left(\text{kg O}2\right)=\left(\right(\left(\text{TN in feed}\right(\mathrm{kg})+\text{TN in fertiliser}(\mathrm{kg}\left)\right)-\text{TN in animals}\left(\mathrm{kg}\right))\times 4.57)+\left(\right(\left(\text{TC in feed}\right(\mathrm{kg})+\text{TC in fertiliser}(\mathrm{kg}\left)\right)-\text{TC in animals}\left(\mathrm{kg}\right))\times 2.67)$

8.7.4 Baseline characterisation

The results of the site level monitoring survey shall be used to characterise the baseline of the RW per site. The steps to characterise the baseline are as follows:

8.8 Point source effluent measurement (Indicators 2.6.15 to 2.6.17)

The steps to conduct sampling of point source effluents are as follows:

8.9 Effluent flow contribution (Indicator 2.6.16)

The steps to determine the effluent flow contribution to the RW for sites discharging point-source effluents are as follows:

Alternative methods to determine flow rate shall be permitted if data is available from the point-source discharge or culture treatment system.

8.10 Dissolved oxygen measurement (Indicators 2.6.18 to 2.6.21)

Measurements of DO are used to determine whether limits on DO concentration (mg/L) and percent saturation (%) are met.

8.10.1 Diffuse-source effluent release measurements

One of the following methods shall be used to conduct sampling of DO at 5m depth per site:

Method 1

Method 2

DO shall be measured by conducting continuous monitoring using an electronic probe and recorder, with a 15-minute sampling frequency for at least one week.

Method 3

DO shall be measured at a ‘downstream, near-field’ impacted location immediately downstream of the site, and at an ‘upstream, far-field’ non-impacted reference location at a minimum 500m upstream from the site.

8.10.2 Point-source effluent release DO measurements

One of the following methods shall be used to conduct sampling of DO at 0.5m depth per site:

Method 1

DO concentration (mg/L) shall be recorded at sampling locations immediately downstream from the outflow point where mixing is complete. The steps to conduct sampling of DO per site are as follows:

Method 2

DO shall be measured by conducting continuous monitoring using an electronic probe and recorder, with a 15-minute sampling frequency for at least one week.

Method 3

DO shall be measured at a ‘downstream, near-field’ impacted location: immediately downstream of the site, and at an ‘upstream, far-field’ non-impacted reference location at a minimum 500m upstream from the site.

8.10.3 Daily diurnal dissolved oxygen fluctuation

Daily diurnal dissolved oxygen (DDDO) fluctuation shall be calculated according to the following formula:

$\mathrm{DDDO}=[\frac{\text{maximum dissolved oxygen}(\mathrm{mg}/L)}{{\text{tabulated dissolved oxygen at saturation}}_{\max }(\mathrm{mg}/L)}\times 100]-[\frac{\text{minimum dissolved oxygen}(\mathrm{mg}/L)}{{\text{tabulated dissolved oxygen at saturation}}_{\min }(\mathrm{mg}/L)}\times 100]$

8.11 Water quality analytical methods (Indicators 2.6.8 to 2.6.11, 2.6.16 and 2.6.18)

Total Phosphorus (TP):

TP shall be measured in unfiltered 500ml samples collected in clear plastic bottles. These shall be placed on ice in a cooler and analysed within 48 hours.

A VanDorn, Kemmerer or Ruttner type sampler shall be used to collect water for field or laboratory analysis. Samples of TP shall be collected using one of the following methods:

Total Nitrogen (TN):

TN shall be measured in unfiltered 500ml samples collected in clear plastic bottles. These shall be placed on ice in a cooler and analysed within 48 hours.

A VanDorn, Kemmerer or Ruttner type sampler shall be used to collect water for field or laboratory analysis. Samples of TN shall be collected using one of the following methods:

Total Suspended Solids (TSS):

TSS shall be measured in unfiltered 500ml samples collected in clear plastic bottles. These shall be placed on ice in a cooler and analysed within 48 hours.

A VanDorn, Kemmerer or Ruttner type sampler shall be used to collect water for field or laboratory analysis. Samples of TSS shall be analysed using one of the following methods:

Chlorophyll-a (chl-a) sensor:

Chl-a shall be measured in-situ using an electronic sensor and calibrated to manufacturer’s instructions according to the following method:

Dissolved Oxygen (DO) sensor:

DO shall be measured in-situ using an electronic sensor and calibrated to manufacturer’s instructions. The sensor shall record both percentage saturation and temperature corrected/compensated concentrations. The sensor shall be calibrated according to the following method:

Appendix 7 – Methods for Benthic Monitoring

This Appendix details the methods for benthic monitoring required in Criterion 2.5. It also details the method for determining the distance between the site and seagrass habitats (required in Criterion 2.2), and copper monitoring (required in Criterion 2.11) for sites using copper nets or copper-treated nets.

7.1 Introduction

For cage culture and suspended marine mollusc culture systems (Indicators 2.5.1 and 2.5.2), the ASC method for benthic monitoring requires sampling at predefined zones to determine benthic status. The method is based on a three-level approach in which a site conducts increasingly more detailed benthic monitoring if the results of Level 1 or Level 2 monitoring do not demonstrate an ‘Acceptable’ benthic status. Conversely, a site that demonstrates an ‘Acceptable’ benthic status in Level 1 or Level 2 does not need to conduct a higher level of monitoring. Sites may decide to start monitoring at any of the three levels. The method uses five benthic Ecological Quality Status (EQS) categories that are numerically defined using a range of abiotic and biotic Indicator thresholds (see Table 1 and Table 2). An EQS Category is assigned to the monitoring results of each sampling zone which determines the benthic status of a site.

In the case of cage culture in marine/brackish waters using copper nets or copper-treated nets (Indicator 2.11.11), the method requires additional benthic monitoring to determine the copper level in sediments.

Sites producing Seabass, seabream and meagre are required to determine the distance to seagrass habitat from the zone 1 boundary (Indicator 2.2.5) outlined in Figure 1.

For freshwater systems discharging into rivers (Indicator 2.5.4), the ASC method for benthic monitoring requires sampling upstream and downstream from the site outflow point to determine the presence, composition, abundance and diversity of invertebrate fauna, and to categorise the benthic status upstream and downstream.

ASC has benchmarked the ASC Farm Standard methods for benthic monitoring against applicable regulatory requirements. Outcomes of the benchmark are available via the ASC Programme Centre.

Table 1. Abiotic Indicator thresholds for the EQS categories used by the methods for cage culture and suspended marine mollusc systems.

Table 2. Biotic Indicator thresholds for the EQS categories used by the methods for cage culture and suspended marine mollusc systems.

7.2 Method for Cage Culture in Marine/Brackish Waters (Indicators 2.5.1 and 2.5.2) 

7.2.1 Sampling Method

Level 1: This monitoring level provides a rapid assessment of benthic impacts in the direction of greatest risk (i.e. the direction of the predominant current) and employs practical abiotic Indicators.

If the EQS Category results in:

Level 2: This monitoring level provides a two-dimensional spatial analysis of benthic conditions using abiotic Indicators.

If the EQS Category results in:

Level 3: This monitoring level provides direct information on the impact of the site on the benthic macrofauna community.

If the EQS Category results in:

Zone 1

Zone 2

Zone 3

30 m

100 m

150 m

500 m Reference Zone

Predominant Current

Figure 1. Cage Systems in Marine/Brackish – Sampling zones (shaded areas) and sampling locations (dots) required for Level 1 (●), 2 (● and ○) and 3 (● and ○) monitoring. Sampling locations are established on transects within the boundaries of sampling zones 1, 2 and 3 and at the 500 metres reference zone. Sample stations in zones 1, 2 and 3 can be located at any distance within the zone (from the cage array). For example, the zone 2 sample station can be located anywhere within 30 m and 100 m from the cage array. Figure 1 presents an example of the sampling locations inside the boundaries of zones 1, 2 and 3.

Sampling Timing

Sampling shall be conducted during the period when the benthic impact is expected to be highest. Sites shall provide information on when the maximum impact on the benthos is predicted to occur. Based on this information:

After three years of demonstrating conformance with Indicator 2.5.2, sites with multiple peaks in feeding/biomass occurring in any year may reduce sampling to once per certification cycle (i.e. every three years) as long as there have been no significant changes to farming practices and thus that previously determined benthic status provides a credible proxy for future performance.

7.2.2 Conformance Framework

A numerical scoring method is used to combine all Indicator data collected within each sampling zone, which allows for determining the EQS Category and benthic status of the site as required by Indicator 2.5.2.

The steps to calculate the EQS Category for each sampling zone are as follows:

Table 5. EQS Categories for ‘Acceptable’ benthic status.

7.3 Method for Cage Culture in Freshwater Lakes/Reservoirs (Indicators 2.5.1 and 2.5.2)

7.3.1 Sampling Method

Level 1: This monitoring level provides a rapid assessment of benthic impacts in the direction of greatest risk (i.e. the direction of the predominant current) and employs practical abiotic Indicators.

If the EQS Category results in:

Level 2: This monitoring level provides a two-dimensional spatial analysis of benthic conditions using abiotic Indicators.

If the EQS Category results in:

Level 3: This monitoring level provides direct information on the impact of the site on the benthic macrofauna community.

If the EQS Category results in:

Zone 1

Zone 2

30 m

100 m

150 m Reference Zone

Predominant Current

Figure 2. Cage Systems in Freshwater Lakes/Reservoirs – Sampling zones (shaded areas) and sampling locations (dots) required for Level 1 (●), 2 (● and ○) and 3 (● and ○) monitoring. Sampling locations are established on transects within the boundaries of sampling zones 1 and 2 and at the 150 metre reference zone. Sample stations in zones 1 and 2 can be located at any distance within the zone (from the cage array). The reference station shall be located 150 m from the cage array. For example, the zone 2 sample station can be located anywhere within 30 m and 100 m from the cage array. Figure 2 presents an example of the sampling locations inside the boundaries of zones 1 and 2.

Sampling Timing

Sampling shall be conducted during the period when the benthic impact is expected to be highest. Sites shall provide information on when the maximum impact on the benthos is predicted to occur. Based on this information:

After three years of demonstrating conformance with Indicator 2.5.2, sites with multiple peaks in feeding/biomass occurring in any year may reduce sampling to once per certification cycle (i.e. every three years) as long as there have been no significant changes to farming practices and thus that previously determined benthic status provides a credible proxy for future performance.

7.3.2 Conformance Framework

A numerical scoring method is used to combine all Indicator data collected within each sampling zone, which allows for determining the EQS Category and benthic status of the site as required by Indicator 2.5.2.

The steps to calculate the EQS Category for each sampling zone are as follows:

Table 8 EQS Categories for ‘Acceptable’ benthic status

7.4 Method for Suspended Marine Molluscs Systems (Indicators 2.5.1 and 2.5.2)

7.4.1 Sampling Method

Level 1: This monitoring level provides a rapid assessment of benthic impacts in the direction of greatest risk (i.e. the direction of the predominant current) and uses practical abiotic Indicators.

If the EQS Category results in:

Level 2: This monitoring level provides a two-dimensional spatial analysis of benthic conditions using abiotic Indicators.

If the EQS Category results in:

Level 3: This monitoring level provides direct information on the impact of the site on the benthic macrofauna community.

If the EQS Category results in:

Predominant Current

Site Boundary

Inside Site Boundary

Outside Site Boundary

Figure 3. Suspended Marine Molluscs Systems – Sampling locations (dots) per zone (inside and outside site boundary) required for Level 1 (●), 2 (● and ○) and 3 (● and ○). Sampling locations on each transect are 10m apart, with the third sampling location (i.e. the middle of the five locations) being situated inside the edge of the site boundary.

Sampling Timing

Sites may reduce the sampling frequency to once per certification cycle (i.e. every three years) if the EQS Category for Benthic Status inside the site boundary is ‘Good’ or High’ and the EQS Category for Benthic Status outside the site boundary is at least ‘Moderate’.

The reduction in sampling frequency shall be permitted as long as there have been no significant changes to farming practices and therefore the previously determined benthic status provides a credible proxy for future performance.

7.4.2 Conformance Framework

A numerical scoring method is used to combine all Indicator data collected within each sampling zone, which allows for determining the EQS Category and benthic status of the sampling zones surrounding the site as required by Indicator 2.5.2.

The steps to calculate the EQS Category for each sampling zone are as follows: