Mangrove Credits Are the Scarcest Thing in the Carbon Market

In 2024 the average voluntary carbon credit changed hands at $6.34 a tonne. The average blue carbon credit changed hands at $29.72, up 257% on the year before and nearly five times the market. In August 2025, S&P Global Platts assessed the benchmark mangrove credit, from the Delta Blue Carbon project in Pakistan’s Indus Delta, at a record $29.30, with a trade printed at $30.50. Traders told Platts that demand for nature-based credits had improved “significantly.” One added that available supply “seems a little tight.”

That is a polite way of saying there is almost none.

The demand is real

Buyers want removals, and mangroves are the densest removal there is. Removal credits traded at a 381% premium over reductions in 2024, and Ecosystem Marketplace groups mangrove restoration with reforestation and agroforestry as the largest category of removal credit available today. A mangrove stores on average 1,023 tonnes of carbon per hectare, among the highest of any forest in the tropics. One credit carries a removal label, a biodiversity story and a coastal-protection story at once.

The money is lining up behind them. The Mangrove Breakthrough targets $4 billion to protect and restore 15 million hectares by 2030; by the end of 2025, eleven endorsing governments had written mangroves into their national climate pledges. Buyers of blue carbon credits are 42% American and 40% European, the two markets where claims rules are tightening fastest.

The supply is not

Blue carbon is less than 1% of the voluntary market. Fewer than 7 million blue carbon credits had ever been issued by March 2025, against roughly 180 million tonnes the whole market retires in a single year. Of the 81 blue carbon projects on the registries in October 2025, ten were issuing credits. One of them, Delta Blue Carbon, accounts for 73% of every blue carbon credit ever issued. And in 2024, transacted volume fell, from 0.4 million tonnes to 0.2 million. Price up 257%. Volume down by half. The premium is a scarcity signal, not a quality signal.

Why supply is stuck in the mud

The carbon is where a satellite photo cannot see it. In the study that made mangroves famous, organic-rich soils half a metre to more than three metres deep held 49–98% of the carbon. Crediting that stock means coring it, modelling how tides and sediment move it, and defending a baseline for what would have happened without the project. Calyx Global’s assessment is blunt: measuring carbon in muddy, underwater soil is technically complex and expensive, and monitoring is far harder than for a forest on dry land.

The rulebook is only now catching up. Gold Standard published a mangrove methodology built around remote-sensing monitoring in August 2024. On 11 May 2026, the Integrity Council approved Isometric’s Mangrove Restoration Protocol, the first blue carbon methodology eligible for the Core Carbon Principles label. It arrives with three signed projects and a potential 2 million removal credits by 2030. That is what “first CCP-eligible blue carbon” amounts to. Against a $4 billion ambition and 818,000 hectares the Global Mangrove Alliance rates as restorable, it is a rounding error.

The honest caveat: this is a thin market. The entire 2024 blue carbon trade was worth $5.2 million, and a single large buyer can move the price. One trader told Platts that “people won’t buy DBC at $30+.” A premium built on a handful of projects can deflate as fast as it inflated.

What it means

For buyers: you are paying for scarcity. Before paying $30 for a mangrove tonne, ask how the soil carbon was measured, to what depth, with what uncertainty, and whether the methodology carries or is seeking a CCP label. The premium over a $20 reforestation credit should buy better evidence, not a better story.

For project developers: the constraint on this market is not demand and it is not hectares. It is the ability to produce a number for belowground carbon that a verifier, a rating agency and a buyer’s lawyer will all accept. The project that can show its soil carbon, with an uncertainty range, sells at $30. The project that cannot does not get to market at all.

This is the measurement Akrov exists to make: the tonne in the mud, with an uncertainty a buyer can hold you to.