Seaweed Aquaculture by the Numbers

Booming Demand Seen in Food, Pharmaceutical, Textile Industries

Traditional seaweed farming in Bali, Indonesia. istock

Seaweed aquaculture—the farming of marine macroalgae such as kelp, nori, and wakame—is increasingly viewed as one of the most environmentally sustainable forms of food production, according to government and market analysts.

Seaweed grows entirely in seawater and relies on sunlight and naturally dissolved nutrients, meaning it requires no freshwater irrigation, fertilizers, or pesticides. As seaweed grows, it absorbs carbon dioxide and excess nutrients from the surrounding ocean, helping improve water quality and support marine ecosystems.

Meanwhile, global demand for seaweed products—from food and animal feed to fertilizers, cosmetics, pharmaceuticals, textiles, and biomaterials—is expanding rapidly, says the US National Oceanic and Atmospheric Administration (NOAA). Market analyses from Cognitive Market Research and The Business Research Company suggest the seaweed sector could become a major component of the emerging “blue economy,” combining environmental benefits with significant economic growth potential.

Key Environmental and Market Data Points

• Every year, about 35 million metric tons of seaweed are produced globally, making seaweed one of the largest sectors of aquaculture worldwide.

• The global seaweed cultivation market was valued at approximately $19.29 billion in 2024. The sector is projected to expand at a 10.34% compound annual growth rate (CAGR) between 2024 and 2031.

• North America accounted for a tiny slice—about 4.05%—of the global seaweed cultivation market in 2024. This indicates significant room for expansion of seaweed farming along US and Canadian coastlines.

• The global commercial seaweed market reached approximately $24.47 billion in 2025, It is expected to grow to reach $43.1 billion by 2030, reflecting strong growth across food, agriculture, and industrial uses.

• The commercial seaweed sector is projected to grow at roughly 12% compound annual growth annually through the decade.

• Seaweed aquaculture requires no freshwater because seaweed grows directly in seawater. It also requires no pesticides or synthetic fertilizers since macroalgae absorb nutrients already dissolved in seawater.

• Seaweed absorbs two major nutrient pollutants—nitrogen and phosphorus—from coastal waters, helping reduce eutrophication and harmful algal blooms.

• Growing seaweed absorbs carbon dioxide and releases oxygen through photosynthesis, helping support marine ecosystem health.

• Seaweed can be grown alongside shellfish or finfish in integrated multitrophic aquaculture systems, where it absorbs excess nutrients produced by other farmed species.

Aerial view of a contemporary South Korean seaweed farm. istock

Sources:

• NOAA Fisheries – Seaweed Aquaculture (https://www.fisheries.noaa.gov/national/aquaculture/seaweed-aquaculture)

• The Business Research Company – Commercial Seaweed Global Market Report (https://www.thebusinessresearchcompany.com/report/commercial-seaweed-global-market-report)

• Cognitive Market Research – Seaweed Cultivation Market Report (https://www.cognitivemarketresearch.com/seaweed-cultivation-market-report