Ethereum Foundation public sector home
All case studies

Enaleia Hub

Enaleia Hub helps fishers, port coordinators, recyclers, and manufacturers trace marine plastic through the supply chain. It publishes records on Optimism, an Ethereum layer 2 network, allowing others to review the reported movement of materials.

Public records for marine-plastic collection, recycling, and manufacturing

Environmental provenance · Greece · Mediterranean

Institutional context

Marine plastic can pass through fishers, ports, recyclers, and manufacturers before becoming a new product. When records remain in separate spreadsheets and reports, institutions, funders, and other stakeholders may have difficulty tracing materials across the full supply chain. Enaleia works with fishing communities across Greece and the wider Mediterranean to collect marine plastic and used fishing gear and connect suitable materials with recycling and manufacturing partners.

Through Lefteris Arapakis’s 2024 Next Billion Fellowship, Enaleia worked with Pollen Labs to develop a shared tracking system, now called Enaleia Hub.

System design

At a participating port, a coordinator weighs a fisher’s collection, scans their identification card, and records the materials using a mobile app. The coordinator submits the record on behalf of the collection point, so individual fishers do not need to interact directly with the blockchain. QR labels identify batches as they move between organizations.

Recyclers record incoming weights, sorting, and processing steps such as washing, shredding, and turning plastic into pellets. New batch records link the materials going into a process with those coming out. Manufacturers can then record production batches associated with finished goods. The app supports offline data entry and submits records when connectivity returns.

The mobile application is open source, allowing others to inspect, adapt, and reuse the software. A public dashboard presents the submitted records as a traceable journey, while a separate backend and administrative tools support day-to-day operations. The longer-term aim is for other organizations to adopt common tools and data standards, supporting interoperability beyond Enaleia’s own network.

Ethereum’s role

Enaleia Hub uses Ethereum Attestation Service on Optimism to publish verifiable records of reported supply-chain events, such as a batch’s material type, weight, and processing stage. These records are known as attestations: digitally signed statements that can be checked independently. Optimism is an Ethereum layer 2 network that processes transactions separately while relying on Ethereum for security.

Each published record identifies the account that submitted it and can be reviewed through publicly accessible tools. Institutions, partners, and outside observers can examine the same records without relying only on Enaleia’s private reporting system. The network preserves what was submitted; checking that materials were actually collected, weighed correctly, and handled as reported still requires checks of the physical process.

Status and milestones

  1. 8 September 2026

    A public supply-chain record was created on Optimism using Enaleia Hub’s record format, showing recorded activity beyond the initial deployment announcement.

  2. May 2026

    The Enaleia Hub Android app received an update addressing port selection and other interface controls, providing evidence of continued application maintenance.

  3. May 2025

    Enaleia Hub is deployed on Optimism’s public network and linked directly to its supply-chain records.

Implementation considerations

Effective traceability requires consistent batch identifiers, shared data standards, reliable weighing procedures, and clear responsibility for the information submitted at each stage. Records should account for materials being combined or transformed, with checks between collection, transport, recycling, and production.

Privacy and correction procedures also matter. The published record format includes fields for collector names and coordinates, so institutions should decide which details genuinely need to be public. A record can be marked as revoked, but that does not erase previously published information. Operational continuity also depends on maintaining the devices, application, connectivity, and supporting services used throughout the system.

Sources