Evidence type
Field observation, controlled experiment, natural analogue, model, synthesis or authoritative framework?
Ocean setting
The source reports physical setting, season, nutrient and iron conditions, circulation and community context.
Sources and methods
Ocean iron fertilisation: Evidence selection and interpretation.
Field studies, natural analogues, assessments and legal sources retain their stated location, season, method and observation window.
Evidence interpretation
Observed settings and evidence boundaries.
Documented field experiments, observatory records and natural analogues connect specific HNLC regions to carbon-fate questions.
- 01
- 02
Evidence class
Field observation, intervention experiment, natural analogue, model result and assessment have distinct evidentiary roles.
- 03
Carbon question
Biological response, air–sea exchange, particle export, carbon transfer to depth and atmospheric return pathways are distinct components.
- 04
Place-specific context
Protected-area, coastal-state, high-seas or disputed-context information can change interpretation of a result.
- 05
Unresolved questions
A study’s inference is limited by its measured time, depth, comparator and geography.
Reading a result
Six dimensions of an inference boundary.
Setting and time
Region, coordinates, depth, season, dose, duration and follow-up window.
Measured variable
Direct observation, proxy, derived variable, inferred flux or modelled outcome.
Comparator
Untreated patch, historical baseline, climatology, model counterfactual or no comparator.
Inference boundary
Response, export, atmospheric attribution, durability, ecology, scalability and permission are distinct questions.
Additional evidence
Longer observation, a matched reference, deeper measurements, ecological monitoring or replication in another study.
Primary sources
Fourteen scientific and legal sources.
Primary papers, official datasets and institutional legal texts.
Source group
Regional experiments and models
Primary field studies and scenario evidence used in the three regional pathways.
IronEx II
- Publication / date
- 1996
- Scientific relevance
- Equatorial Pacific response and patch tracking
- Access
- Publisher access
- Limit
- Short observation window
SERIES
- Publication / date
- 2004
- Scientific relevance
- Subarctic particle-export evidence
- Access
- Publisher access
- Limit
- Export is not atmospheric removal
EIFEX
Smetacek et al. (2012), Nature ↗
- Publication / date
- 2012
- Scientific relevance
- Southern Ocean deep particle observations
- Access
- Publisher access
- Limit
- One eddy and bloom
Regional trade-offs
- Publication / date
- 2026
- Scientific relevance
- Scenario comparison and return pathways
- Access
- Publisher access
- Limit
- Model results are not field validation
Source group
Risk, carbon and measurement evidence
Primary hazard evidence, independent assessments and research-observatory guidance.
Ocean-based CDR
- Publication / date
- 2022
- Scientific relevance
- Carbon durability, MRV and impacts
- Access
- Open access
- Limit
- Not a project assessment
OIF observatory
- Publication / date
- 2024
- Scientific relevance
- Measurement architecture
- Access
- Open access
- Limit
- Not a crediting protocol
Source group
Scientific and geographic context
Scientific context products used to explain the three ocean systems.
HNLC overview
- Publication / date
- 2024
- Scientific relevance
- Broad HNLC context
- Access
- Open access
- Limit
- Broad synthesis
Cartographic base
Natural Earth 1:50m raster and physical vectors ↗
- Publication / date
- Accessed 2026
- Scientific relevance
- Coastline and shaded-relief geographic context
- Access
- Public domain
- Limit
- Cartographic base; not HNLC boundary data
GEOTRACES
- Publication / date
- Accessed 2026
- Scientific relevance
- Trace-element context
- Access
- Programme access
- Limit
- Coverage and methods vary
Source group
Legal and governance sources
Treaty texts, resolutions, depositary records and governance context sources.
London Protocol
International Maritime Organization ↗
- Publication / date
- Accessed 2026
- Scientific relevance
- Marine geoengineering context
- Access
- Official source
- Limit
- Exact application is fact-specific
LP.4(8) acceptance status
IMO Status of IMO Treaties, pp. 597–598 ↗
- Publication / date
- Official IMO status certificate dated 9 December 2025
- Scientific relevance
- Nine acceptances recorded in that certificate; amendment not in force
- Access
- Official source
- Limit
- The acceptance count and territorial application can change; the IMO depositary is the current official record.
BBNJ Agreement
- Publication / date
- Accessed 2026
- Scientific relevance
- Areas beyond national jurisdiction
- Access
- Official source
- Limit
- Layered obligations
Antarctic Protocol
Antarctic Treaty Secretariat ↗
- Publication / date
- Accessed 2026
- Scientific relevance
- Antarctic environmental context
- Access
- Official source
- Limit
- Exact geography matters
CCAMLR measures
- Publication / date
- Accessed 2026
- Scientific relevance
- Southern Ocean management context
- Access
- Official source
- Limit
- Measures change
Evidence boundary
Evidence boundaries.
Research findings, treaty status and local governance change over time.
Glossary
Terms with distinct scientific meanings.
- Observation
- A measurement tied to a stated method, location and time. It does not automatically generalise.
- Model output
- A result conditional on model structure, parameters, forcing and scenario; not a field measurement.
- Natural analogue
- A naturally occurring system that helps examine a mechanism but is not identical to a deliberate intervention.
- HNLC
- High-nutrient, low-chlorophyll ocean context. It is not synonymous with iron limitation at every place or time.
- Carbon transfer to depth
- Movement of carbon below a stated depth horizon; its storage duration depends on remineralisation, circulation and ventilation.
- Permission
- A legally effective authorisation or consent from the relevant actor under applicable law; not inferred from a map, treaty table or evidence page.