Abyssal Claims: an open map placing EMODnet data beside deep-sea mining claims

Organisation 

Abyssal Claims is an independent, non-commercial project built and maintained by one person: Michal Mazurowski, a solution architect based in Poland. It is not a company, an institute or a funded programme. It began in April 2026 as a personal project, it has no revenue model, and it carries no advertising.

The platform brings public datasets from 49 institutions together on one interactive 3D globe with 59 toggleable layers: seabed mining concessions issued by the International Seabed Authority, offshore human activities and infrastructure, biodiversity records, ocean chemistry and physics, and terrestrial mining impacts.

Everything it serves is public, openly licensed data, displayed with its original provenance, license and citation attached. The platform deliberately adds no editorial judgement to the values it shows: where a source is sparse, biased or uncertain, the layer says so in its own legend rather than smoothing it over.

All records can be downloaded through an open Area Export tool and a documented public API. The work is archived on Zenodo (concept DOI 10.5281/zenodo.19745884) and registered on Wikidata (Q140184639).

Challenges Faced 

The question the platform tries to make answerable is simple to ask and hard to answer: what else is already happening where seabed extraction is proposed? Answering it means putting concessions, infrastructure, biology and physical conditions on one map — which needs harmonised, cross-border data.

In European waters, that is exactly the gap EMODnet fills. National registries publish license polygons in a dozen different schemas, coordinate systems and languages; some publish nothing machine-readable at all. Instead of collecting and reconciling marine infrastructure data separately from national authorities across Europe, Abyssal Claims can access harmonised EMODnet data through a single service, under a clear license. For a project maintained by one person, that turns months of integration work into a process that can be automated and updated regularly.

Concretely, EMODnet supplies:

• Offshore oil & gas licences and wind-farm polygons, which sit inside a 6,845-row multi-regulator Offshore Activities layer built from more than two dozen national registries covering 40 coastal states;
• ~1,255 submarine cable features aggregated from seven national contributor layers (NVE, Rijkswaterstaat, BSH, UK fibre, IGN) — the European backbone of a six-source global cable layer, including named interconnectors such as NORNED and Baltic Cable;
• EU EEZ and maritime-boundary reference geometry;
• EMODnet physical data helps the platform place underwater noise alongside marine wildlife observations and other human activities. 

The challenge that EMODnet addressed was not volume, but harmonisation. Without institutional backing, integrating Norwegian, Dutch, German, UK and Spanish marine infrastructure data sources would have been extremely difficult. EMODnet transformed what could have required months of separate negotiations into a weekly automated synchronisation process.

EMODnet Services Used 

All access is machine-to-machine; nothing is downloaded by hand.

1. EMODnet Human Activities — WFS: 
   • emodnet:activelicenses — active oil & gas licences
   • emodnet:windfarmspoly — offshore wind-farm polygons
   • Cable layers (7): pcablesnve (Norway NVE, 918) · rijkscables (NL, 93) · pcablesbshcontis (DE power, 89) · sigcables (ES/IGN, 60) · pcablesrijks (NL, 37) · ukfibrecables (UK, 30) · bshcontiscables (DE telecom, 28)
   • EU EEZ / maritime boundaries
2. EMODnet Physics — ERDDAP
   • EP_ERD_INT_UWN_NAT — continuous underwater noise (TotalSPL)
   • EP_UWN_INER — impulsive noise / INER (pulse days per ICES sub-square)

See the results live:

• Submarine cables
• Offshore activities
• Underwater-noise impact
• EU EEZs 
• Combined layers
   

Each layer's full documentation (source, frequency of updates, how to read it, and known limitations) is in the platform's Legend panel, and every record is downloadable via the Area Export Tool. 

Impact of EMODnet 

The honest answer is about scale, not possibility: EMODnet had already harmonised the European half of what was extended worldwide at a later stage.

This is a one-person, unfunded project. Integrating European offshore infrastructure source by source would have meant contacting five to seven national authorities, reading five to seven schemas in four languages, and negotiating redistribution terms with each — realistically months of work, with a fair chance of ending in a refusal or a paper chart. EMODnet compressed that into one endpoint, one licence, and an ingest module of a few hundred lines that now re-syncs weekly with no human involvement. The cable layer took days instead of a season.

The clarity of the licence matters as much as the data. The CC BY 4.0 licence, combined with a published acknowledgement statement, enables integration, redistribution and exposure of the data through public APIs and export tools without legal uncertainty, while allowing the same freedoms to be passed on to end users. Several other sources permit access and use but restrict downstream downloading and redistribution. EMODnet data can be integrated and shared without those barriers.

The societal side is the reason the project exists. Deep-sea mining is decided in rooms most people cannot enter, using data most people never see. Putting an ISA concession polygon next to the cables, wind farms, licences and noise fields already occupying that water — all from authoritative sources, all attributed, all downloadable — lets a journalist, a student or a citizen check a claim for themselves instead of taking someone's word for it. EMODnet supplies the European half of that picture.

Concretely: EMODnet contributes to 4 of the platform's 59 layers, drawn from 49 institutions, is downloadable through the open Area Export tool, and is documented in the public API used by external institutions.

“As one person with no institutional standing, I could not have negotiated marine infrastructure data out of five national authorities in four languages. EMODnet had already done it — one endpoint, one schema, one licence. Layers that would have taken a season took days.” — Michal Mazurowski, Abyssal Claims (something-rare.com)

“The licence matters as much as the data. CC BY 4.0 meant I could pass EMODnet data straight through to my users — visible on the map, downloadable, and available through the public API. Not every source lets me do that.” — Michal Mazurowski, Abyssal Claims (something-rare.com)