The gaps in this subsection reflect the lack of knowledge of whether seaweed can accumulate target minerals (lithium, cobalt, rare earth elements) at concentrations sufficient to make bio-extraction cost-competitive with conventional mining, and whether the variability in mineral concentration across species and geographies can be characterized well enough to underpin a viable supply chain for clean energy transition minerals

Species Selection and Cultivation 

Optimization of seaweed strains for mining is at an early stage:

While there have been some initial positive results, there still exists a need to select the ideal seaweed strains conducive to mining different minerals in key geographies across the world as well as to understand the fundamental processes governing the variability in absorption of critical minerals in seaweeds.

There are not enough fast-growing seaweed strains for responsibly scaled cultivation

Commercially cultivated seaweed is dominated by a small number of genera whose production has suffered from climate stress and genetic mis-management (Rimmer et al., 2021). Scaling requires diverse strains that are disease-resistant, heat-tolerant and safe for local environments (e.g., University of Connecticut’s National Seaweed Nursery Directory, University of Wisconsin-Milwaukee, Woods Hole Oceanographic Institution; Rahmadi et al., 2025).

Few environmental impact assessments  of seaweed cultivation farms exist, especially at scale

More research is needed to understand how cultivation impacts adjacent and underlying ecosystems. This includes negative (e.g., nutrient competition, adjacent habitat degradation, species invasions, chemical use) and positive (e.g., net climate benefits, marine life interactions) impacts. Developing low-cost methods to track biological and ecological impacts alongside mixed-methods carbon accounting  can support responsible scaling practices (Hurd et al., 2022; Fakhraee and Planavsky, 2026; Kelp Forest Foundation, 2025).

Nearshore cultivation systems have come under stress due to climate change and disease, impacting productivity.

While offshore cultivation, if successful will enable scale with minimized conflict, nearshore cultivation can be further developed as well. Nearshore cultivation systems have come under pressure due to disease, presence of fouling organisms (e.g. epiphytes) and impacts of climate change (Kim et al., 2017). Development of thermo-tolerant strains as well as those with disease resistance and the capability for fast growth are needed.

The gaps in this subsection reflect the need for development of extraction methods to improve the cost and carbon intensity of seaweed-derived minerals to compete credibly against the conventional mining supply chains they aim to displace.

Processing and Conversion Technologies

Processes are still not optimized because they are at lab scale

Extracting critical minerals from seaweed biomass involves a sequence of steps — cultivation, harvesting, drying, biomass digestion, and chemical separation of target elements — each of which has only been demonstrated at small scale. Optimization of these processes will play a role in developing cost-competive minerals from seaweeds.

Conversion techniques have environmental challenges that need to be addressed

mineral extraction methods often use dilute acids called lixiviants, raising environmental concerns. Greener extraction technologies need to be developed to reduce environmental impact.

Final Use

Seaweed-derived minerals have not been tested for end-use applications

While a purified mineral is chemically identical regardless of its source, extraction from organic biomass introduces potential impurities and processing residues that could affect product purity profiles. Until seaweed-derived minerals have been tested against the tight specifications required by battery manufacturers and magnet producers, their functional equivalence to conventionally sourced feedstocks remains an assumption rather than a demonstrated fact.

The gaps in this subsection reflect the challenges in attracting the mainstream capital needed for commercial-scale cultivation and processing needed for climate impact.

The current cost of seaweed biomass is too high to produce price-competitive critical mineral feedstock

Currently, the modeled minimum selling price for the “Alg-Ore” feedstock exceeds the value of the minerals contained within it, even before purification costs are included. Achieving profitability depends heavily on reducing operational costs and maximizing co-product value.

The early stage of technological development and high market risk reduce appeal to investors

Investments in seaweed-based technologies are currently limited to a narrow set of specialty investors. More mainstream investors will be needed to address the high capital costs of setting up seaweed cultivation and processing facilities.

Seaweed cultivation infrastructure needs to be scaled up significantly to become relevant to the global critical mineral value market

Current production volumes, especially outside Asia, are low, and existing supply is largely destined for traditional, higher-value markets like food and hydrocolloids (The World Bank Group, Global Seaweed New and Emerging Markets Report, 2023). Generating the large supply needed for production requires substantial scaling of volumes and a significant reduction of production costs.

The gaps in this subsection reflects on the challenges that prevent seaweed farms from scaling fast enough to develop a meaningful supply of critical minerals in time to support clean energy transition timeline.

Regulatory uncertainty and permitting barriers limit the ability for new seaweed farms to develop and existing seaweed farms to scale
Without streamlined, growth-supportive policies, scaling efforts will remain constrained. For example, burdensome and lengthy permitting can create unnecessary farming requirements and discourage investment, particularly in Europe and North America (Camarena Gómez and Lähteenmäki-Uutela, 2024).