Seaweed aquaculture is a nature-based climate solution. Macroalgae contribute roughly 1.5 petagrams of carbon (PgC) to global annual net primary production, and farm sediments can bury about 1.87 ± 0.73 tons of carbon dioxide equivalent (CO2e) per hectare per year - about twice the rate of adjacent non-farmed areas.
Yet open-ocean expansion is limited by strong currents that prevent stable attachment and destroy the low-velocity conditions needed for growth. Nutrients such as nitrogen, phosphorus, and dissolved iron are too dilute for large-scale cultivation. Existing platforms either depend on scarce offshore infrastructure or cannot regulate local flow. Based on these challenges, in-depth research is needed to develop scalable, low-cost structures that regulate flow, supply nutrients, and support attachment.
Researchers at Zhejiang University, with collaborators at Guizhou University and the Ningbo Innovation Center, published (DOI: 10.1016/j.ese.2026.100769) the study online on 28 September 2026 in Environmental Science and Ecotechnology. The team designed the Seaweed Origami-inspired Aquaculture System (Seaweed OAS), assembled from 12 variant pentagonal units into a dodecahedron-like shell. Each module combines an origami-inspired shell, an internal nutrient space, a central buoyancy ball, and connection seats. Using computational fluid dynamics (CFD), laboratory and lake tests, and an open-ocean trial in the Philippine Trench region, the researchers evaluated flow regulation, stability, and global deployment potential.
The geometry is the breakthrough. Inspired by the traditional Chinese huiwen (fret) pattern, the researchers folded flat panels into a 25-sided variant pentagonal unit. Twelve units assemble into a dodecahedron-like shell. The dimensionless scaling ratio φ = a/R, where a is the auxiliary-circle radius and R is the base-circle radius, controls folding. Simulations tested φ values from 0.28 to 0.56; optimal single-unit design was φ = 0.36. At 2.0 m s-¹ inflow, it produced 2,607.7 cm³ of suitable growth volume, and the best single-unit result reached 2,791.6 cm³ - 17 times a spherical reference. Suitable growth was defined as streamwise velocity ≤0.5 m s-¹.
In a six-unit Hexagon 2 layout with 0.35 m spacing, total suitable volume reached 33,210.3 cm³ at 2.0 m s-¹, or 5,535.1 cm³ per unit, 2.1 times an isolated unit. The modules were 3D-printed with polylactic acid (PLA) and water-soluble polyvinyl alcohol (PVA) supports. Compression tests gave a minimum peak load of 11,693 N versus a predicted peak drag of 39.9 N, a safety factor of 293. In lake and Philippine Trench trials, the system stayed afloat and stable, including during wave impacts. Global mapping estimated 10,335 million hectares - 28.5% of the global ocean - as potentially suitable.
The authors said the design turns an ancient folding idea into a practical marine tool. "By reshaping flow around each module, the system creates quiet microhabitats where seaweed can attach and grow, while the same module stores slow-release nutrients," they said. They added that cooperative wake interactions can amplify performance: the optimized hexagonal array lets upstream units shield downstream units, increasing suitable growth volume per unit. Still, they cautioned that long-term cultivation outcomes, deep-ocean carbon storage, and the ecological effects of material degradation remain unverified and require field study.
If validated over longer deployments, the Seaweed OAS could support open-ocean seaweed cultivation for food, feed, biomaterials, and carbon sequestration. Its modular shell-core design may be deployed without existing offshore infrastructure, and connection modules with controllable degradation could eventually let the system break apart so carbon-rich biomass sinks to the deep ocean for long-term storage. Global suitability mapping suggests vast potential across marine areas, though shipping lanes, ice cover, temperature, nutrient ratios, flow speed, and marine protected areas (MPAs) must guide siting. The authors call for long-term offshore trials to quantify seaweed growth, structural durability, material ecotoxicity, and the fate and persistence of sequestered carbon.