This Swiss startup is rebuilding the ocean's reefs, and investors are diving in

On the day of this article's publication, it was June 8th, World Ocean Day. In a sobering twist, half of the world's coral reefs have already disappeared, and scientists project that over 95% of reef area could be gone by 2050. With it, roughly a third of all marine life, the coastlines reefs protect, and the livelihoods of more than a billion people will be at risk of collapse.

Against a problem of that scale, responses have been lethargic, manual, and difficult to scale. rrreefs, an ETH Zurich spin-off founded by four women, has spent the past six years building an alternative, and this week it reached a milestone that suggests investors are beginning to take notice.

The launch of their seed round, running from now until June 16th, comes about as rrreefs approaches six years since its founding. Having started life as an association, rrreefs has since developed into an impact-driven business that counts Accor Group, Lufthansa subsidiary Edelweiss, and Zurich Insurance among its clients. It has now been selected as one among 1000 Ocean startups in the global ocean innovation ecosystem hosted by the World Economic Forum. Following a brief period of fundraising from early registrants, the company has since passed its threshold during the pre-sale period.

rrreefs has been deploying its system in the ocean since 2019. Whereas conventional reef restoration tends to rely on coral gardening, replanting corals one by one, which is slow and hard to scale. rrreefs instead installs interlocking, 3D-printed clay modules that recreate the physical structure of a healthy reef, giving corals somewhere to settle and fish somewhere to return to, after which the ecosystem regenerates without further intervention. Its first experiment, 98 clay tiles installed in the Maldives, supported around 30 surviving coral recruits per square metre after fifteen months, against the 7.4 recorded on bleached natural reefs nearby.

The projects have grown considerably since. In the Philippines, the company laid 820 modules in Pujada Bay alongside some 9,000 newly planted mangroves; a later reef in Siquijor followed; and a deployment off Ecuador took the system into the Pacific for the first time, giving rrreefs field data across three oceans. 

rrreefs partners with organisations already established in coral conservation, and with universities, so that each reef can double as a site for research. Deployment and monitoring are carried out together with the local coastal communities who live alongside these reefs. In the Philippines, rrreefs crew members are now training local partners and community members in their installation methods, certifying them as Reef Builders who can go on to build reefs themselves.

Since 2023, it has generated over CHF 1.3 million in revenue and doubled its gross margin in 2025, with a pipeline now standing at around CHF 2.4 million. A production hub in the Philippines has cut implementation costs by more than half, and the company is targeting break-even in 2027 and CHF 11 million in revenue by 2030. Rather than selling a one-off installation, it offers reef regeneration as a continuing service, bundling monitoring, biodiversity data for ESG reporting, and community engagement, which gives it recurring revenue and keeps cash-flow risk relatively low.

The CHF 800,000 the company is now raising is intended to fund international expansion and further development of the technology. rrreefs has been open about why it opted for crowdinvesting rather than venture capital. "We learnt that the classic VC path was not right for us," says Marie Griesmar, COO and co-founder. "The expected timelines, return perspectives, and pressure towards a short-term exit don't align with how we want to build rrreefs." A round open to their community, in the company's view, suits a business with a longer horizon better than funding tied to a near-term exit.

rrreefs now opens its doors to investors to become co-owner with small share packages starting at CHF 500. The campaign runs until June 16th, and can be found on OOMNIUM here.