Farmed clams, cockles and ark shells, live, fresh or chilled

1. Scope and Applicability

This PCR guides the production of foreground life cycle inventory datasets for farmed clams, cockles and ark shells supplied live, fresh or chilled. It covers grow-out aquaculture of in-shell bivalves of the clam, cockle and ark shell groups, their harvesting, and landing-site handling up to the point where the product leaves the landing-site gate. The reference product state is live, fresh or chilled; the product is not frozen, dried, salted, smoked, brined or otherwise processed.

This PCR applies to foreground data packages produced by farm operators or by practitioners using farm records. It does not cover wild-caught clams, cockles and ark shells, seed or spat production inside a hatchery or nursery as a foreground product, processed or preserved clam products, or downstream distribution, retail and consumption.

2. Product Category Identity

Field	Value
canonical_pcr_id	pcr.agriculture-forestry-and-fishery-products.fish-crustaceans-molluscs-and-other-aquatic-invertebrates-products.farmed-clams-cockles-and-ark-shells-live-fresh-or-chilled
classification_refs	CPC 3.0 code 04452 (exact)
covered_products	Farmed clams, cockles and ark shells, in shell, supplied live, fresh or chilled; typical species include Manila clam (Ruditapes philippinarum), blood cockle (Tegillarca granosa) and hard clam (Mercenaria mercenaria)
excluded_products	Wild-caught clams, cockles and ark shells (CPC 04451); frozen, smoked, dried, salted or in-brine clam products; canned or otherwise processed clam meat; live clams supplied as seed, bait or for ornamental use
representative_product	Manila clam (Ruditapes philippinarum), live in shell, farmed on intertidal flats and supplied fresh at a landing site
production_route	Clam seed (spat) supply as an upstream starting condition, grow-out culture on intertidal flats, in ponds or in suspended systems, harvesting, then landing-site washing, depuration, grading and chilling where declared
market_state	Production mix at landing site; large-scale commercial bivalve aquaculture dominated by Asian producers, with China the largest producer

3. Reference Flow

Field	Value
What	Farmed clams, cockles and ark shells, live, fresh or chilled, in shell, at the landing-site gate
How much	1 kg drained live weight in shell
How well	Marketable size grade; live, fresh or chilled state as declared; mortality and reject share within declared limits
How long or cycle	One grow-out production cycle from stocking to dispatch, including landing-site handling
reference_flow_link	Process landing_site_handling, Outputs, Product flows, row reference_product_output

Field	Value
Reference amount	1
Reference product flow	Farmed clams, cockles and ark shells, live, fresh or chilled 4a6625c6-2c26-4618-aaab-4ea8949e5635
Reference flow property	Mass 93a60a56-a3c8-11da-a746-0800200b9a66
Reference unit group	Units of mass 93a60a57-a4c8-11da-a746-0800200c9a66
Reference unit	kg
Required qualifiers	species; culture system (intertidal flat, pond, or suspended); product state (live, fresh, or chilled); in-shell drained live weight; production region and site; grow-out cycle period

When constructing a foreground data package, the items listed in Required qualifiers must be declared in dataset metadata, process notes, reference flow comment, product description, or an equivalent data package field. Missing required qualifiers make the reference flow definition incomplete for that data package.

4. Measurement and Unit Rules

rule_id	Applies to	Required property	Required unit	Rule
reference_mass	reference product flow	Mass 93a60a56-a3c8-11da-a746-0800200b9a66	kg	The reference flow is measured as drained live weight in shell in kg; counts or crate numbers must be converted with declared, calibrated mass conversion records.
live_weight_state	clam product and biomass amounts	Mass 93a60a56-a3c8-11da-a746-0800200b9a66	kg	All clam biomass amounts (seed, harvested, dispatched, rejected, dead stock) are recorded as in-shell drained live weight in kg; shell-free meat yields may not be substituted.
electricity_energy	electricity inputs	Net calorific value 93a60a56-a3c8-11da-a746-0800200c9a66	kWh	Electricity is collected in kWh from meters or utility bills; when the host dataset stores electricity on an energy basis, 1 kWh is converted to 3.6 MJ.
water_volume	process water inputs	Volume 93a60a56-a3c8-22da-a746-0800200c9a66	m3	Washing and depuration water is recorded in m3; a screening conversion of 1,000 kg per m3 applies where a mass property is required.
seed_dual_record	clam seed input	Mass 93a60a56-a3c8-11da-a746-0800200b9a66	kg	Clam seed is recorded both as stocked mass in kg and as seed count with size grade, so that survival and growth can be reconciled.

5. System Boundary

Boundary Abstraction

Field	Value
declared_starting_condition	Clam seed (spat) at the grow-out farm gate, ready for stocking; hatchery, nursery or natural seed collection that produced the seed is upstream of the foreground boundary
starting_condition_role	boundary_start
product_classification_scope	CPC 3.0 code 04452, farmed clams, cockles and ark shells, live, fresh or chilled
recursive_input_rule	Clam seed or live clams of the same product category received from another farm are recorded as product inputs carrying an upstream dataset produced under this PCR; the receiving data package does not recurse into the earlier production cycle
upstream_dataset_requirement	Seed supply, fertilizers, lime, electricity, diesel, gear materials, process water and ice are supplied by supplier-specific foreground datasets or by secondary background datasets
disclosure	The data package declares culture system, site and water body, stocking density and cycle length, fertilization and pond preparation practice, harvesting method, depuration practice, survival rate, allocation keys and cut-off choices

Boundary Rules

rule_id	Applies to	Rule	source_ids
sb_starting_condition	foreground system boundary	The foreground boundary starts at clam seed delivered to the grow-out farm; seed production burdens enter only through the upstream dataset of the seed input flow.	fao-cultured-aquatic-species-ruditapes-philippinarum
sb_recursive_input	same-category inputs	Live clams or seed of this category moved between farms are modelled as product inputs with an upstream dataset under this PCR, never as a recursive expansion of the receiving dataset.
sb_cut_off	foreground inputs	An input may be cut off only when its mass share is below 1% of total product inputs and the cumulative cut-off stays below 5%; capital gear with multi-cycle service life is annualized instead of cut off, and every cut-off is disclosed.

6. Process Inventory Structure

Process Map

process_id	process_name	inclusion	inclusion_condition	role	quantitative_reference
grow_out_culture	Grow-out culture on intertidal flats, in ponds or in suspended systems	required		foreground core	kg marketable live clams transferred to harvest per cycle
harvesting	Harvesting of market-size clams	required		foreground	kg harvested live clams landed per cycle
landing_site_handling	Landing-site washing, depuration, grading and chilling	conditional	Included when the declared route washes, depurates, grades or chills the product at a landing facility; required when the product is declared chilled or depurated	foreground	1 kg live, fresh or chilled clams at the landing-site gate

Process: Grow-out culture on intertidal flats, in ponds or in suspended systems (grow_out_culture)

Inputs

Product flows

Clam seed (spat) stocked in the culture system (clam_seed)

Clam seed from a hatchery, nursery or natural collection crosses the foreground boundary at stocking and starts the grow-out cycle. The quantity is obtained from stocking logs and supplier delivery notes.

• Selected flow: Clam seed (spat), live, at farm gate

• Flow property / unit: Mass / kg

• Amount rule: stocked seed mass per production cycle, with seed count and size grade recorded alongside

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg marketable live clams transferred to harvest

• Basis kind: Process output (process_output)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_seed_stocking_records

• Range: Seed stocking intensity guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 0.02
  • Upper: 0.6
  • Unit: kg
  • Basis: kg stocked seed per kg marketable live clams transferred to harvest
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Nitrogen fertilizer applied for pond fertilization (nitrogen_fertilizer)

Nitrogen fertilizer such as urea is recorded when pond fertilization is practised to sustain phytoplankton. The quantity is obtained from purchase invoices and field application logs.

• Selected flow: Nitrogen fertilizer (urea or equivalent)

• Flow property / unit: Mass / kg

• Amount rule: applied fertilizer mass per production cycle

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg marketable live clams transferred to harvest

• Basis kind: Process output (process_output)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_fertilizer_records

• Range: Fertilizer nitrogen intensity guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 0
  • Upper: 0.05
  • Unit: kg
  • Basis: kg nitrogen fertilizer per kg marketable live clams transferred to harvest
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Phosphate fertilizer applied for pond fertilization (phosphate_fertilizer)

Phosphate fertilizer is recorded when pond fertilization is practised. The quantity is obtained from purchase invoices and field application logs.

• Selected flow: Superphosphate 8c9749b5-e19f-4480-a575-3058aff804b3

• Flow property / unit: Mass / kg

• Amount rule: applied fertilizer mass per production cycle

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg marketable live clams transferred to harvest

• Basis kind: Process output (process_output)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_fertilizer_records

• Range: Fertilizer phosphate intensity guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 0
  • Upper: 0.05
  • Unit: kg
  • Basis: kg phosphate fertilizer per kg marketable live clams transferred to harvest
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Lime applied for pond or bottom preparation (lime)

Lime is recorded when ponds or culture bottoms are disinfected or conditioned before stocking. The quantity is obtained from pond preparation logs and purchase invoices.

• Selected flow: hydrated lime dry slaked 88c10493-a480-431e-9ea2-372d3a99318d

• Flow property / unit: Mass / kg

• Amount rule: applied lime mass per production cycle

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg marketable live clams transferred to harvest

• Basis kind: Process output (process_output)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_pond_preparation_records

• Range: Lime application intensity guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 0
  • Upper: 0.15
  • Unit: kg
  • Basis: kg lime per kg marketable live clams transferred to harvest
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Electricity for aeration and water pumping (growout_electricity)

Electricity powers aerators and water exchange pumps during grow-out. The quantity is obtained from meter readings or utility bills allocated to the grow-out process.

• Selected flow: Electricity, medium voltage 2eb3b2fd-6511-4a22-9018-768024a5b5a6

• Flow property / unit: Net calorific value / kWh

• Amount rule: metered electricity allocated to grow-out per production cycle

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg marketable live clams transferred to harvest

• Basis kind: Process output (process_output)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_electricity_records

• Range: Grow-out electricity intensity guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 0
  • Upper: 0.5
  • Unit: kWh
  • Basis: kWh per kg marketable live clams transferred to harvest
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Diesel for culture boats and machinery (growout_diesel)

Diesel fuels culture boats and machinery used for inspection, maintenance and in-situ work during grow-out. The quantity is obtained from fuel purchase records and equipment logs.

• Selected flow: Diesel 9fc9d30c-0229-459c-a7f5-8f55d6533225

• Flow property / unit: Mass / kg

• Amount rule: diesel consumed by grow-out operations per production cycle

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg marketable live clams transferred to harvest

• Basis kind: Process output (process_output)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_fuel_records

• Range: Grow-out diesel intensity guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 0
  • Upper: 0.1
  • Unit: kg
  • Basis: kg diesel per kg marketable live clams transferred to harvest
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Plastic gear materials consumed (gear_plastics)

Nets, mesh bags, ropes and other plastic culture gear are consumed over their service life. The quantity is obtained from stock records and replacement logs annualized per cycle.

• Selected flow: polyethylene low density granulate (PE-LD) 4f19f116-7b3b-11dd-ad8b-0800200c9a66

• Flow property / unit: Mass / kg

• Amount rule: annualized consumption of plastic gear per production cycle

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg marketable live clams transferred to harvest

• Basis kind: Process output (process_output)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_material_consumption_records

• Range: Plastic gear consumption guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 0
  • Upper: 0.05
  • Unit: kg
  • Basis: kg plastic gear per kg marketable live clams transferred to harvest
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Bamboo stakes and supports consumed (bamboo_stakes)

Bamboo stakes and supports are recorded when intertidal or pond culture uses bamboo structures. The quantity is obtained from stock records annualized per cycle.

• Selected flow: Bamboo Wood b5a65214-5930-42b6-994f-02fbcf42798b

• Flow property / unit: Volume / m3

• Amount rule: annualized bamboo consumption per production cycle

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg marketable live clams transferred to harvest

• Basis kind: Process output (process_output)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_material_consumption_records

• Range: Bamboo consumption guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 0
  • Upper: 0.005
  • Unit: m3
  • Basis: m3 bamboo per kg marketable live clams transferred to harvest
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Waste flows

Elementary flows

Outputs

Product flows

Market-size live clams transferred to harvesting (marketable_clams_growout)

Market-size live clams standing in the culture system at the end of grow-out transfer to harvesting. The quantity equals the harvested yield reconciled with harvest records.

• Selected flow: Farmed clams, cockles and ark shells, live, fresh or chilled 4a6625c6-2c26-4618-aaab-4ea8949e5635

• Flow property / unit: Mass / kg

• Amount rule: marketable live weight per production cycle reconciled with harvest yield records

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: per production cycle output

• Basis kind: Process output (process_output)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_harvest_yield_records

• Range: Harvest multiple over stocked seed guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 2
  • Upper: 20
  • Unit: kg
  • Basis: kg marketable live clams per kg stocked seed
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Waste flows

End-of-life plastic culture gear (culture_gear_waste)

Worn-out nets, ropes and other plastic gear leave the process as waste at replacement. The quantity is obtained from waste transfer notes or weighed disposal records.

• Selected flow: Plastic Waste 3fd9ff2b-455a-4ed6-a52d-e2cb5a1484f3

• Flow property / unit: Mass / kg

• Amount rule: disposed plastic gear mass per production cycle

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg marketable live clams transferred to harvest

• Basis kind: Process output (process_output)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_waste_records

• Range: Plastic gear waste guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 0
  • Upper: 0.05
  • Unit: kg
  • Basis: kg plastic waste per kg marketable live clams transferred to harvest
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Dead stock and shell residues (mortality_shell_residue)

Clams that die during grow-out and their shell residues are collected or returned to the culture bottom. The quantity is estimated from periodic mortality inspections.

• Selected flow: Dead stock and shell residues from bivalve culture

• Flow property / unit: Mass / kg

• Amount rule: estimated dead stock mass per production cycle

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg marketable live clams transferred to harvest

• Basis kind: Process output (process_output)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_mortality_records

• Range: Mortality residue guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 0
  • Upper: 0.5
  • Unit: kg
  • Basis: kg dead stock per kg marketable live clams transferred to harvest
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Elementary flows

Net nitrogen exchange with coastal water (nutrient_n_exchange)

Net nitrogen exchange between the culture system and coastal water combines fertilizer input, influent water nitrogen, harvested biomass removal and sediment retention; negative values denote net removal by the clams. The quantity is calculated by rule cr_nutrient_balance.

• Selected flow: nitrogen, total (excluding N2) e1716164-e906-48e4-ad77-8f2ec4a9a4c5

• Flow property / unit: Mass / kg

• Amount rule: net nitrogen exchange per production cycle from the nutrient balance calculation

• Value mode: Calculated value (calculated_value)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg marketable live clams transferred to harvest

• Basis kind: Process output (process_output)

• Evidence kind: Calculated from collection (calculated_from_collection)

• Collection protocol: cp_nutrient_balance_records

• Range: Net nitrogen exchange guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: -0.05
  • Upper: 0.02
  • Unit: kg
  • Basis: kg N per kg marketable live clams transferred to harvest; negative values denote net removal
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Net phosphorus exchange with coastal water (nutrient_p_exchange)

Net phosphorus exchange between the culture system and coastal water follows the same balance as nitrogen; negative values denote net removal. The quantity is calculated by rule cr_nutrient_balance.

• Selected flow: phosphorus, total f9df3107-6b59-4067-b920-3c61cf3630c7

• Flow property / unit: Mass / kg

• Amount rule: net phosphorus exchange per production cycle from the nutrient balance calculation

• Value mode: Calculated value (calculated_value)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg marketable live clams transferred to harvest

• Basis kind: Process output (process_output)

• Evidence kind: Calculated from collection (calculated_from_collection)

• Collection protocol: cp_nutrient_balance_records

• Range: Net phosphorus exchange guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: -0.01
  • Upper: 0.005
  • Unit: kg
  • Basis: kg P per kg marketable live clams transferred to harvest; negative values denote net removal
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Suspended solids from biodeposition and resuspension (growout_suspended_solids)

Biodeposits and maintenance activities change suspended solids exchange with the surrounding water. The quantity is modelled when direct measurement is unavailable.

• Selected flow: Suspended solids, unspecified 618d3d9a-9f85-417d-b0c4-e87942a9e345

• Flow property / unit: Mass / kg

• Amount rule: modelled net suspended solids per production cycle

• Value mode: Modelled estimate (modelled_estimate)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg marketable live clams transferred to harvest

• Basis kind: Process output (process_output)

• Evidence kind: Reasoned estimate (reasoned_estimate)

• Range: Suspended solids screening estimate

  • Range role: Default estimate (default_estimate)
  • Lower: 0
  • Upper: 2
  • Unit: kg
  • Basis: kg suspended solids per kg marketable live clams transferred to harvest
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Process: Harvesting of market-size clams (harvesting)

Inputs

Product flows

Diesel for harvest boats and dredging or pumping machinery (harvest_diesel)

Diesel fuels harvest boats, dredges and pump systems during harvesting. The quantity is obtained from fuel purchase records and equipment logs allocated to harvesting.

• Selected flow: Diesel 9fc9d30c-0229-459c-a7f5-8f55d6533225

• Flow property / unit: Mass / kg

• Amount rule: diesel consumed by harvesting per production cycle

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg harvested live clams landed

• Basis kind: Process output (process_output)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_fuel_records_harvest

• Range: Harvest diesel intensity guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 0
  • Upper: 0.15
  • Unit: kg
  • Basis: kg diesel per kg harvested live clams landed
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Electricity for hydraulic harvesting pumps (harvest_electricity)

Electricity powers hydraulic harvesting pumps and winches where used. The quantity is obtained from meter readings allocated to harvesting.

• Selected flow: Electricity, medium voltage 2eb3b2fd-6511-4a22-9018-768024a5b5a6

• Flow property / unit: Net calorific value / kWh

• Amount rule: metered electricity allocated to harvesting per production cycle

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg harvested live clams landed

• Basis kind: Process output (process_output)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_electricity_records_harvest

• Range: Harvest electricity intensity guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 0
  • Upper: 0.3
  • Unit: kWh
  • Basis: kWh per kg harvested live clams landed
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Waste flows

Elementary flows

Outputs

Product flows

Harvested live clams landed (harvested_clams)

Harvested live clams are landed and transferred to landing-site handling. The quantity is obtained from landing weighing records.

• Selected flow: Farmed clams, cockles and ark shells, live, fresh or chilled 4a6625c6-2c26-4618-aaab-4ea8949e5635

• Flow property / unit: Mass / kg

• Amount rule: landed live weight per production cycle from calibrated weighing

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: per production cycle output

• Basis kind: Process output (process_output)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_harvest_yield_records_harvest

• Range: Harvest recovery over marketable stock guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 0.8
  • Upper: 1
  • Unit: kg
  • Basis: kg harvested live clams landed per kg marketable live clams transferred from grow-out
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Waste flows

Undersized clams and incidental by-catch returned to the water (undersized_bycatch_return)

Undersized clams and incidental by-catch sorted at harvest are returned to the culture water. The quantity is estimated from sorting records at landing.

• Selected flow: Undersized clams and incidental by-catch returned alive

• Flow property / unit: Mass / kg

• Amount rule: estimated returned mass per production cycle

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg harvested live clams landed

• Basis kind: Process output (process_output)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_harvest_yield_records_harvest

• Range: Returned undersized and by-catch guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 0
  • Upper: 0.3
  • Unit: kg
  • Basis: kg returned per kg harvested live clams landed
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Elementary flows

Suspended solids from sediment disturbance at harvest (harvest_suspended_solids)

Dredging, raking or hydraulic harvesting disturbs sediment and releases suspended solids. The quantity is modelled when direct measurement is unavailable.

• Selected flow: Suspended solids, unspecified 618d3d9a-9f85-417d-b0c4-e87942a9e345

• Flow property / unit: Mass / kg

• Amount rule: modelled suspended solids release per production cycle

• Value mode: Modelled estimate (modelled_estimate)

• Specificity: Technology-specific (technology_specific)

• Normalization basis: per kg harvested live clams landed

• Basis kind: Process output (process_output)

• Evidence kind: Reasoned estimate (reasoned_estimate)

• Range: Harvest sediment disturbance screening estimate

  • Range role: Default estimate (default_estimate)
  • Lower: 0
  • Upper: 5
  • Unit: kg
  • Basis: kg suspended solids per kg harvested live clams landed
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Process: Landing-site washing, depuration, grading and chilling (landing_site_handling)

Inputs

Product flows

Process water for washing and depuration (process_water)

Clean water for washing and depuration crosses the boundary at the landing facility; seawater may substitute tap water and is recorded as water volume with the source declared. The quantity is obtained from water meters or pumping records.

• Selected flow: Tap water 3a8411b6-e476-4f98-9d77-0d492661a07f

• Flow property / unit: Volume / m3

• Amount rule: metered water volume per handling season

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg dispatched live, fresh or chilled clams

• Basis kind: Process output (process_output)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_water_records

• Range: Process water intensity guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 0
  • Upper: 0.05
  • Unit: m3
  • Basis: m3 per kg dispatched live, fresh or chilled clams
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Electricity for depuration, aeration and refrigeration (handling_electricity)

Electricity powers depuration pumps, aeration, ice making and cold storage at the landing facility. The quantity is obtained from meter readings allocated to handling.

• Selected flow: Electricity, medium voltage 2eb3b2fd-6511-4a22-9018-768024a5b5a6

• Flow property / unit: Net calorific value / kWh

• Amount rule: metered electricity allocated to handling per season

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg dispatched live, fresh or chilled clams

• Basis kind: Process output (process_output)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_electricity_records

• Range: Handling electricity intensity guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 0
  • Upper: 0.5
  • Unit: kWh
  • Basis: kWh per kg dispatched live, fresh or chilled clams
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Ice used for chilling (ice)

Ice is recorded when the product is chilled for dispatch. The quantity is obtained from purchase invoices or ice-maker records.

• Selected flow: Ice and snow 1ff2c05e-4b5d-4971-9883-65f2a6b0007f

• Flow property / unit: Mass / kg

• Amount rule: ice consumed per handling season

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg dispatched live, fresh or chilled clams

• Basis kind: Process output (process_output)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_ice_records

• Range: Ice consumption guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 0
  • Upper: 0.5
  • Unit: kg
  • Basis: kg ice per kg dispatched live, fresh or chilled clams
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Waste flows

Elementary flows

Outputs

Product flows

Live, fresh or chilled farmed clams at the landing-site gate (reference_product_output)

The reference product leaves the landing-site gate live, fresh or chilled for first sale. The quantity is obtained from dispatch weighing records and equals the reference flow amount of 1 kg in the normalized data package.

• Selected flow: Farmed clams, cockles and ark shells, live, fresh or chilled 4a6625c6-2c26-4618-aaab-4ea8949e5635

• Flow property / unit: Mass / kg

• Amount rule: dispatched live weight per handling season; normalized to 1 kg reference flow

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: reference flow of 1 kg dispatched product

• Basis kind: Reference flow (reference_flow)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_product_dispatch_records

• Range: Dispatch share of landed mass guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 0.8
  • Upper: 1
  • Unit: kg
  • Basis: kg dispatched live, fresh or chilled clams per kg harvested live clams landed
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Waste flows

Dead or broken clams rejected at grading (grading_rejects)

Dead or broken clams rejected during grading leave the process as organic waste. The quantity is obtained from grading line records.

• Selected flow: Rejected dead or broken clams from grading

• Flow property / unit: Mass / kg

• Amount rule: rejected mass per handling season

• Value mode: Foreground record (foreground_record)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg dispatched live, fresh or chilled clams

• Basis kind: Process output (process_output)

• Evidence kind: Collected record (collected_record)

• Collection protocol: cp_reject_records

• Range: Grading reject guardrail

  • Range role: QA guardrail (qa_guardrail)
  • Lower: 0
  • Upper: 0.15
  • Unit: kg
  • Basis: kg rejects per kg dispatched live, fresh or chilled clams
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Elementary flows

Chemical oxygen demand in depuration and washing effluent (effluent_cod)

Depuration and washing effluent carries organic matter measured as chemical oxygen demand. The quantity is modelled from effluent volume and declared effluent quality or measured directly.

• Selected flow: Chemical Oxygen Demand e57fc631-2c77-457a-aa30-be79e357792b

• Flow property / unit: Mass / kg

• Amount rule: modelled or measured COD load per handling season

• Value mode: Modelled estimate (modelled_estimate)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg dispatched live, fresh or chilled clams

• Basis kind: Process output (process_output)

• Evidence kind: Reasoned estimate (reasoned_estimate)

• Range: Effluent COD screening estimate

  • Range role: Default estimate (default_estimate)
  • Lower: 0
  • Upper: 0.02
  • Unit: kg
  • Basis: kg COD per kg dispatched live, fresh or chilled clams
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

Suspended solids in washing effluent (effluent_suspended_solids)

Washing effluent carries sand, silt and shell debris as suspended solids. The quantity is modelled from effluent volume and declared effluent quality or measured directly.

• Selected flow: Suspended solids, unspecified 618d3d9a-9f85-417d-b0c4-e87942a9e345

• Flow property / unit: Mass / kg

• Amount rule: modelled or measured suspended solids load per handling season

• Value mode: Modelled estimate (modelled_estimate)

• Specificity: Site-specific (site_specific)

• Normalization basis: per kg dispatched live, fresh or chilled clams

• Basis kind: Process output (process_output)

• Evidence kind: Reasoned estimate (reasoned_estimate)

• Range: Effluent suspended solids screening estimate

  • Range role: Default estimate (default_estimate)
  • Lower: 0
  • Upper: 0.05
  • Unit: kg
  • Basis: kg suspended solids per kg dispatched live, fresh or chilled clams
  • Basis kind: Process output (process_output)
  • Evidence kind: Reasoned estimate (reasoned_estimate)

7. Allocation and Co-product Handling

rule_id	Applies to	Rule	source_ids
al_shell_part_of_product	reference product	Shells are part of the live in-shell reference product; no allocation between meat and shell is performed.
al_polyculture_shared_inputs	shared pond or flat inputs in multi-species culture	Where clams share ponds, flats or equipment with other species, shared inputs are allocated to the clam output by economic value of the harvested outputs over the cycle; physical mass allocation is used only when value data are unavailable, and the applied key is disclosed.	iso-14044-2006
al_mortality_no_coproduct	dead stock, rejects and returned undersized clams	Mortalities, grading rejects and returned undersized clams carry no economic value and receive no allocated burden; all foreground burdens remain with the dispatched reference product.

8. Foreground Data Collection, Calculation, and Quality Rules

Data Collection Protocols

protocol_id	process_id	flow_role	record_type	raw_fields	collection_method	unit	frequency	temporal_coverage	site_scope	aggregation_rule	quality_evidence
cp_seed_stocking_records	grow_out_culture	clam seed input	stocking log	seed batch id; stocked mass; seed count; size grade; stocking date	farm stocking records with supplier delivery notes	kg	per stocking event	full grow-out cycle	each pond or culture parcel	sum of stocked seed mass per cycle	supplier invoices; signed stocking log
cp_fertilizer_records	grow_out_culture	fertilizer inputs	purchase and application log	product name; nutrient content; applied mass; application date	purchase invoices and field application log	kg	per application	full grow-out cycle	each pond	sum per cycle by fertilizer product	invoices; fertilizer label or specification
cp_pond_preparation_records	grow_out_culture	lime input	preparation record	lime product; applied mass; date; pond area	pond preparation log with purchase invoices	kg	per pond preparation	one preparation per production cycle	each pond	sum per cycle	preparation log; purchase invoices
cp_electricity_records	grow_out_culture	electricity input	metered consumption record	meter reading; period; allocated equipment	meter readings or utility bills, allocated by equipment hours where shared	kWh	monthly	at least one full production cycle	whole farm allocated to processes	sum per period allocated to each process	utility bills; meter reading records
cp_fuel_records	grow_out_culture	diesel input	fuel log	fuel type; mass or volume; date; equipment	fuel purchase records and equipment logs	kg	per purchase or monthly	full production cycle	farm fleet allocated to processes	sum per cycle allocated to each process	fuel invoices; equipment hour logs
cp_material_consumption_records	grow_out_culture	gear material inputs	consumption record	material type; mass or volume; service life; replaced share	stock records and replacement logs annualized over service life	kg or m3	per replacement event	full production cycle	each culture parcel	annualized consumption summed per cycle	purchase invoices; inventory counts
cp_harvest_yield_records	grow_out_culture	harvested output	harvest log	harvest date; parcel; landed live weight	landing weighing with calibrated scales	kg	per harvest event	harvest season of the cycle	each harvested parcel	sum per cycle	weighing records; sales slips
cp_mortality_records	grow_out_culture	dead stock output	mortality log	event date; estimated mass; cause; disposal route	periodic mortality estimates during culture inspection	kg	monthly or per event	full production cycle	each culture parcel	sum per cycle	inspection notes; disposal records
cp_waste_records	grow_out_culture	waste gear output	waste transfer log	waste type; mass; disposal route	waste transfer notes or weighed disposal records	kg	per disposal event	full production cycle	whole farm	sum per cycle	waste contractor receipts
cp_nutrient_balance_records	grow_out_culture	nutrient balance inputs	water and biomass test record	fertilizer nutrient input; influent water nutrient concentration; harvested biomass nutrient content	laboratory analysis of water and biomass samples with fertilizer specifications	kg	water sampled at stocking, mid-cycle and harvest; biomass at harvest	full production cycle	each pond or water exchange zone	cycle nutrient balance normalized per kg output	laboratory reports; sampling records
cp_water_records	landing_site_handling	process water input	water meter log	source type; volume; period	water meter readings or pumping records	m3	monthly	handling season of the cycle	landing facility	sum per season	meter readings; utility bills
cp_ice_records	landing_site_handling	ice input	ice consumption log	ice mass; date; source	purchase invoices or ice-maker records	kg	per dispatch day	handling season of the cycle	landing facility	sum per season	invoices; ice-maker logs
cp_product_dispatch_records	landing_site_handling	reference product output	dispatch log	dispatch date; product state; mass; grade	calibrated scale weighing at dispatch	kg	per dispatch	handling season of the cycle	landing facility	sum per season	dispatch notes; sales records
cp_reject_records	landing_site_handling	grading rejects output	grading log	reject mass; cause; disposal route	grading line records	kg	per grading batch	handling season of the cycle	landing facility	sum per season	grading logs; disposal records
cp_electricity_records_harvest	harvesting	electricity input	metered consumption record	meter reading; period; allocated equipment	meter readings or utility bills allocated to harvesting equipment	kWh	monthly	harvest season of the cycle	farm allocated to harvesting	sum per harvest season allocated to the process	utility bills; meter reading records
cp_fuel_records_harvest	harvesting	diesel input	fuel log	fuel type; mass or volume; date; equipment	fuel purchase records and equipment logs allocated to harvesting	kg	per purchase or monthly	harvest season of the cycle	farm fleet allocated to harvesting	sum per harvest season allocated to the process	fuel invoices; equipment hour logs
cp_harvest_yield_records_harvest	harvesting	harvested output and returned undersized	harvest and sorting log	harvest date; parcel; landed live weight; returned undersized and by-catch estimate	landing weighing with calibrated scales and sorting estimates	kg	per harvest event	harvest season of the cycle	each harvested parcel	sum per cycle	weighing records; sorting notes

Calculation Rules

rule_id	Applies to	Formula or rule	Inputs	Output	source_ids
cr_output_normalization	all foreground inventory rows	amount_per_kg = recorded_cycle_amount / dispatched_reference_product_kg	recorded cycle amounts; dispatched reference product mass	inventory amount normalized to 1 kg reference product
cr_electricity_unit_conversion	electricity rows	electricity_MJ = electricity_kWh x 3.6	metered electricity in kWh	electricity amount on an energy basis where the dataset requires it
cr_nutrient_balance	nutrient_n_exchange; nutrient_p_exchange	net_nutrient_exchange = fertilizer_nutrient_input + influent_water_nutrient - harvested_biomass_nutrient - declared_sediment_retention; a negative result denotes net removal from the water and must be disclosed with its calculation inputs	fertilizer records; influent water nutrient tests; harvested biomass nutrient tests	net nitrogen or phosphorus exchange per kg reference product
cr_harvest_mass_closure	harvesting; landing_site_handling	harvested_mass = dispatched_mass + grading_reject_mass + handling_mortality_mass; deviations beyond 10 percent must be explained in the data package	harvest yield records; dispatch records; reject records	reconciled harvest-to-dispatch mass closure

Data Quality Requirements

requirement_id	Applies to	Requirement	Evidence
dq_identity	reference flow and UUID-bearing rows	Selected Tiangong flow, flow property and unit group UUIDs match the names declared in this PCR and are confirmed by lookup before publication.	lookup confirmation record retained outside PCR content
dq_measurement	collected foreground amounts	Amounts derive from calibrated meters, scales, invoices or laboratory analyses; any estimation method is declared.	calibration records; invoices; laboratory certificates
dq_temporal_coverage	foreground dataset	Records cover at least one full grow-out production cycle including its harvest and handling season.	stocking, harvest and dispatch logs spanning the cycle
dq_completeness	process inventory	Every required process and flow row is populated or explicitly justified as not applicable to the declared route.	completeness checklist against the process map
dq_disclosure	dataset metadata	Culture system, site, fertilization practice, depuration practice, survival rate, allocation keys and cut-off choices are disclosed.	dataset metadata fields

9. Validation Rules

rule_id	Applies to	Rule	source_ids
vr_reference_flow_identity	reference flow definition	The data package reference flow carries the product flow, flow property and unit group UUIDs declared in section 3, with reference amount 1 and unit kg.
vr_required_qualifiers	dataset metadata and reference flow comment	Every required qualifier in section 3 is declared; a data package with a missing qualifier fails validation.
vr_mass_closure	harvest and handling mass balance	Harvested mass reconciles with dispatched mass plus rejects and handling mortality within 10 percent, and the closure calculation is documented.
vr_unit_consistency	inventory rows	Amounts use the units declared in the flow rows and section 4; electricity is stored consistently in kWh or MJ with the conversion documented.
vr_range_conformance	collected foreground amounts	Collected amounts outside a QA guardrail range are flagged with an explanation or corrected before the data package is treated as conforming.

10. Published Dataset Profile

Field	Value
dataset_role	foreground_product_dataset
downstream_use	secondary_dataset; background_dataset
allowed_use	Life cycle modelling of farmed clams, cockles and ark shells supplied live, fresh or chilled; upstream dataset for same-category transfers between farms under this PCR
excluded_use	Representing wild-caught products; representing processed, frozen or preserved clam products; use outside the declared culture system, region and cycle without remodelling
required_metadata	required qualifiers of section 3; data quality disclosures of section 8; allocation keys; cut-off disclosures
required_quality_disclosure	measurement basis, temporal coverage, completeness against the process map, and guardrail range flags
update_trigger	new production cycle data; change of culture system, fertilization or depuration practice; correction of a referenced Tiangong UUID; methodological update of this PCR

11. Data Sources

Source id	Type	Reference	Used for
un-cpc-ver-3-0	Standard (standard)	United Nations Central Product Classification Version 3.0, code 04452	product category identity and classification scope
fao-cultured-aquatic-species-ruditapes-philippinarum	Official guidance (official_guidance)	FAO Cultured Aquatic Species Information Programme, Ruditapes philippinarum fact sheet	process decomposition, culture systems, representative product and boundary starting condition
fao-fishstat-aquaculture-production	Dataset (dataset)	FAO FishStat global aquaculture production statistics	market state and production scale
iso-14044-2006	Standard (standard)	ISO 14044:2006 Environmental management - Life cycle assessment - Requirements and guidelines	allocation hierarchy for shared inputs