The People's Posidonia

Passive conservation runs 38 to 58 euros per hectare per year (ARTEMIS 2025 page 11, from recent Balearic data), against active restoration at 516,000 to 942,000 per hectare (Bayraktarov et al. 2016, at 2010 prices) and 2.5 million for a 2024 Balearic project. The comparison sets an annual cost against a one-off cost, so it is stated that way rather than as a like-for-like multiple. ARTEMIS names passive conservation the most impactful and efficient approach for seagrass, and lists its mechanisms as eco-moorings, ending illegal anchoring, verified pollution reduction, and surveillance and enforcement, which is what the survey protocol produces. Posidonia grows about a centimetre a year, so a meadow lost is lost on a timescale of centuries.

And the knowledge arrives on a five-year cycle. Producing one extent survey takes a local community, a local company, Rome and several universities. Patrol, anchoring decisions and any avoided-loss claim turn over inside a season.

The thirty euros was stated by the fishermen of Acciaroli during the People's Posidonia week in July 2026, as the typical profit left after fuel and the broker's cut. It is a reported figure from the people who earn it rather than a survey.

Vittorio already earns more from taking people out than from fishing. Nothing has to create the transition from extraction to stewardship: the decline of the fishery and the arrival of ecotourism have already begun it. The survey is not a vessel hire, it is a marginal addition to a day that is already funded, which is why the network can plausibly sustain itself. The capital item is the instrument rather than the labour: side-scan sonar is about 8,000 euros per boat.

The pairing is the interface. These are people who barely use phones, so an interface complex enough to be useful would be complex enough to be abandoned. The fisherman never touches a complex screen; the student does. The fisherman brings forty years of knowing where the meadow is, the student brings the phone, and neither works alone. That is why the school partnership is load-bearing rather than decorative.

The split is deliberate: Island Lab supplies the method, the tooling and the quality control, and the community owns the data. That is what makes the monitoring independent of the parties being monitored.

The kit: side-scan sonar, temperature and salinity sensors, GPS tracks, photogrammetry and drop cameras. The four screens: route, here is today's water; monitor, capture as the boat goes; protect, flag an anchor over meadow and route it to authority the same afternoon; predict, the whole area and what a level of protection buys.

The software behind each step, for anyone who wants to open it. Planning and running the line is Periplus. Telemetry and provenance is Triton. The living extent and condition is the ecosystem map. The comparison against what was expected is Meadow Futures. The names matter to whoever maintains them and to nobody else; what matters here is that each one opens and runs today.

One fleet, three consumers. Scientists and labs get where to dive next and ground truth to compare models against, so limited dive days go where the meadow is actually changing. Restoration investors get a provenance-grade baseline and the stretches that do not need replanting, which for millions deployed is worth more than the map. Verification gets continuous measurement instead of periodic survey, with every point carrying a vessel, a route, a timestamp and a named operator, which is the audit trail a verifier asks for.

The extent this works against is 5,310 hectares across the Cilento coast, or 1,075 within Pollica's own bounds, both computed from the ISPRA features and both re-runnable. Which footprint the programme covers is an open scope decision. The return edge of the loop, carrying returns through to the map that sets tomorrow's route, is what the first phase closes.

The credit lines. Carbon at 24 euros per tonne of CO2e (band 11 to 27) gives 9.84 per hectare per year at 0.41 tonnes durable. Biodiversity adds 150 per hectare per year (band 50 to 500). Stacked at 159.84, that is a ceiling near 172,000 a year across 1,075 hectares or 849,000 across 5,310. Ceilings gated on verification being funded, not forecasts, and the honest band is roughly tenfold. Carbon was carried at 40 until it was sourced properly; the sourced central is 24, and that correction is stated here because a number revised downward with its band showing is worth more than one that survives until someone checks it.

Verification and MRV carries no figure. No Posidonia credit has issued on any registry, so there is no verifier fee to derive one from and inventing one would undo the point of the rest. The headroom instead: below about 147,000 a year at the Pollica footprint the central case still covers its operating cost.

The separate figure of 86,000 euros per hectare per year is a 2024 French court ruling reported via WWF MMI 2025 in ARTEMIS 2025. It is a judicial valuation of harm rather than capturable revenue, and it is not a credit price.

The strategic payoff is local advocates acting on their own behalf instead of waiting for a regulator. When a coastal group can see its own water and trust the numbers, that is the difference between compliance and stewardship, and it is what a funder is actually buying.

Already made: a youth-led short documentary linking the hidden seagrass to local heritage, slow food and the Mediterranean diet. In development with the community: the key messages, deliberately shaped there so the language belongs to the coast rather than to us. The Living Museum of the Mediterranean Diet at Pioppi, the Castello at Pollica and the BLUERA centre at Acciaroli are the standing venues; Viviamo Cilento is the moment.

A record owned by a project ends when the project does. A record held by the comune is one a community can act on and a verifier can audit, and it is what makes the monitoring independent of the parties being monitored.

The closest working example is Torre Guaceto, where two municipalities and a conservation organisation manage the reserve jointly through a consortium and the fishermen sit on a standing co-management roundtable alongside scientists and authorities rather than being consulted by it.

Built and running: the ecosystem map integrating ISPRA extent with open ocean models, the survey planner, the scenario tool, the investment board, and the trust layer that attaches provenance and uncertainty to every reading. All of them open at their own addresses.

Not yet run: a survey on real returns, end to end, on this coast. Two outings have been made and the protocol has been demonstrated on generated data. Closing that is what the first phase is for.

Still open, and better said than discovered: the receiving entity for an Italian programme; the cost of verification, which is uncosted because no Posidonia credit has issued to derive a fee from; and four cost lines derived from comparables until local figures replace them.