Calculate Greenhouse Gas Emissions Under ASC Feed Standard

Greenhouse gas reporting rules under ASC Feed Standard

The Aquaculture Stewardship Council updated greenhouse gas emission reporting rules under Indicator 1.21.4, Indicator 1.21.5 and Indicator 3.4.5 in version 1.2 of the ASC Feed Standard. This affects quality managers, compliance leads and sustainability personnel at certified feed manufacturing facilities. Certified feed mills must calculate product climate footprints in kilogram carbon dioxide equivalents per tonne of species-specific product produced each year. Conformity Assessment Body auditors verify these emission calculations and data sources during initial and annual surveillance audits.

Feed production accounts for the majority of greenhouse gas emissions in an aquaculture product supply chain. Understanding emission drivers across aquafeed formulations helps feed mills and fish farms improve climate performance. Unlike general operational energy monitoring that evaluates total facility output, greenhouse gas calculations apply to ASC-conforming feeds and require species-specific data. Failing to document emission factors, exclude micro-ingredients incorrectly or omit land use change calculations indicates a non-conformity.

Auditors examine raw material formulations, energy records and emission factor databases to verify calculation accuracy. Where feed mills supply certified aquaculture farms, transparent product carbon disclosures allow farm clients to calculate their farm-gate environmental footprint. Demonstrating rigorous life cycle accounting supports market transparency across global seafood supply chains.

Three scopes of greenhouse gas accounting

Feed manufacturers must evaluate greenhouse gas emissions across three distinct scopes defined by the Greenhouse Gas Protocol:

• Scope 1 emissions: Direct emissions occurring on site from burning fuel carriers such as diesel in litres, petrol in litres and natural gas in cubic metres during feed milling operations.
• Scope 2 emissions: Indirect emissions occurring off site from generating purchased grid electricity, off-grid power, district heating or cooling consumed at the mill.
• Scope 3 emissions: Upstream supply chain emissions associated with producing, processing and transporting raw feed ingredients from agricultural crops, fisheries, poultry and livestock sources.

Calculating species-specific feed emissions

Indicator 1.21.4 and Appendix 2, Section B establish a six-step calculation procedure for estimating feed product carbon footprints across species groups:

• Input identification: Identify species-specific ASC-conforming feed formulations and list all energy inputs alongside ingredients making up at least one percent of raw material composition.
• Quantity determination: Calculate the quantity of each energy input and ingredient required to produce one tonne of species-specific feed during the previous calendar year.
• Emission factor recording: Select and record verified emission factors expressed in kilogram carbon dioxide equivalents for each identified input, noting whether factors derive from databases such as Agri-footprint or ecoinvent, direct modelling or the ASC GHG calculator.
• Input impact multiplication: Multiply the quantity of each input by its corresponding emission factor to calculate individual input emissions per tonne of feed.
• Total footprint summation: Sum total greenhouse gas emissions across all inputs to establish the overall carbon footprint per tonne of ASC-conforming feed in kilogram carbon dioxide equivalents.
• Data submission reporting: Submit quantities, emission factors, individual input impacts and total calculated footprints per species group to the Aquaculture Stewardship Council using official data templates.

Modeling requirements and co-product allocation

Appendix 2, Section B specifies strict methodological rules when selecting emission factors and allocating environmental burdens among co-products:

• Included emissions: Emission factors for ingredients must incorporate upstream production, processing, transportation, biogenic emissions such as paddy rice methane and land use change occurring within the previous twenty years.
• Excluded carbon: Carbon sequestered in plant and animal raw materials must not be subtracted from ingredient emission factors, as sequestered carbon returns to the atmosphere upon consumption.
• Cut-off thresholds: Ingredients comprising at least one percent of species-specific feed mix must be included, while micro-ingredients such as vitamins and minerals are grouped together before applying the one percent threshold.
• Mass and economic allocation: When processing multi-output co-products such as fishmeal, fish oil or feather meal, feed mills must apply both relative mass allocation and economic allocation methods for calculations and data sharing with farms.

What to do now

• Map species formulations: Group ASC-conforming feed formulations by species and isolate ingredients representing at least one percent of total diet composition.
• Gather Scope 1 and 2 inputs: Aggregate on-site fuel usage and purchased electricity data from the previous calendar year following Appendix 2, Section A3.
• Select verified emission factors: Obtain emission factors in kilogram carbon dioxide equivalents from recognized databases, direct supplier disclosures or the online ASC GHG calculator.
• Calculate mass and economic allocations: Compute product emission footprints using both relative mass and economic allocation methods for annual reporting to ASC and disclosure to farm clients.

Reference documents

• ASC Feed Standard, V1.2, Criterion 1.21, Indicators 1.21.4, 1.21.5, Criterion 3.4, Indicators 3.4.5, Appendix 2, Section B
• ASC Feed Standard Interpretation Manual, V1.2, Criterion 1.21, Criterion 3.4