8 Seaweed Startups Riding the $18.4B Green Wave

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Back in 2020, the Trends team discovered a type of seaweed that was trending like crazy — Irish Moss.

“This superfood trend has gathered steam alongside the COVID-19 pandemic and will likely remain popular moving forward, as an age-old remedy for many ailments.”

Boy, were we right on the money. Interest in Irish Moss (aka “sea moss”) has remained high since then, with 448k global searches/month, per Ahrefs.

Called it. Source: Google Trends, six-month rolling average

But there’s so much more to seaweed, the versatile marine plant that has taken the business (and tech) world by storm in recent years.

• Startups that work with seaweed got generous funding
• The US Department of Energy is granting ~$19m to algae-related projects
• The global commercial seaweed market reached $18.4B in 2024

So why the obsession? Let’s get into it.

First, The Basics

Seaweed. Algae. Kelp. Sea moss… I don’t know about you, but I was thrown for a loop by these names.

So with some basic research and a little help from AI, I whipped up a highly simplified explainer of the relationship among these organisms:

I’m only including the common names here. In reality, algae is a broad term that contains thousands of organisms, including seaweed, our protagonist today.

Seaweed refers to the kinds of algae (roughly 12k of them) that live in the ocean, and are large enough to be seen with the naked eye, aka “macroscopic.”

…and that’s all the science talk for today! 😮‍💨

So why do businesses find algae, or seaweed, so valuable?

• Versatile: They can be used in a variety of industries, like food, biofuels, bioplastics, cosmetics, and even fashion.  
• Easy: They grow fast, and require minimal resources to cultivate compared to land plants
• New: They’re not widely adopted in the US yet, so there’s a ton of untapped potential for innovation

Now let’s look at some cool businesses that are making millions by working seaweed’s magic.

Eight Companies Making Waves In The Seaweed Business

1. Food

Seaweed is a popular ingredient in Asian food culture, but its potential application in food goes beyond crunchy snacks (like nori) and fibrous supplements (like Irish moss) — it’s actually a rising star in the alternative protein space.

Umaro Foods

I’ve never tried seaweed bacon, but I imagine it’ll be extra crispy. That’s what Umaro Foods is working on — they raised $3.8m in March to turn seaweed into imitation bacon that preserves the fatty flavor and texture.

They previously went on Shark Tank and won a $1m deal for 7% equity from Mark Cuban.

Poseidona

Poseidona is a Barcelona-based startup that turns invasive algae into protein. It raised €1.1m (~$1.2m) of pre-seed funding in March. Their solution promises to protect the ocean from harmful invasive seaweeds, and provide a sustainable source of alt protein for consumers.

2. Packaging

The packaging sector generates 36% of all single-use plastics (SUP) in the world, and almost all SUP products are made from fossil fuel, which emits tons of greenhouse gas.

Enter seaweed, a biodegradable material with the potential to replace plastic packaging. Quite a few startups are working on this:

Sway

California-based Sway raised a $5m seed round in February. Its proprietary technology, called “TPSea™️, is a resin made from seaweed. It can be used in packaging for food, home goods, and clothing. Companies like J.Crew are already testing it out.

Notpla

Sway’s competitor, Notpla, put its own spin on seaweed packaging and developed an eye-catching water bubble called “Ooho,” among other things. They raised $14.4m in funding, and received a $1.1m grant last October.

But what really caught my eye was their team bio. I mean… cute.

The seaweed love is strong with this one. Source: Notpla 

Other startups in this space include Uluu and Kelpy (not to be confused with Kelpi, which raised $5.5m this month to do the same thing, basically).

3. Carbon sink

Global carbon emissions have increased steadily each decade since the 1960s, and hit 36.8B metric tons in 2023.

Guess what – that’s a problem seaweed can help with, too.

Carbonwave

Carbonwave collects sargassum – a type of brown seaweed that washes up on beaches with a foul smell – and refine it into useful materials like fertilizers, cosmetic emulsifiers, and bioplastics.

The Puerto Rico-based startup was one of Fast Company’s “most innovative companies of 2024,” with a total of $17.3m raised.

Seaweed Generation

Another company that tackles the problematic sargassum…but with robots.

Using AlgaRay and AlgaVator, two Transformers-sounding robots, Seaweed Generation sinks invasive sargassum into the deep ocean (along with the carbon dioxide it absorbs), and increases automation to lower the cost of growing seaweed.

Source: Seaweed Generation

4. Biofeed

Did you know cow burps are bad for the environment? 

Turns out, ruminants (mammals including cows, sheep, and their relatives) account for 27% of annual methane emissions in the US. And 32% of global human-induced methane emissions also come from livestock.

Companies are mixing up the diet for these creatures so they don’t burp out so much methane, which accelerates global warming.

Once again, seaweed to the rescue.

Sea Forest

This Tasmania-based startup developed a feed supplement that reduces livestock’s methane production by up to 90%, using a type of red seaweed called asparagopsis. (It also made Fast Company’s most innovative list this year.)

Alga Biosciences

This YC-backed startup has a similar mission to Sea Forest – helping reduce methane emissions from cow burps. Their solution promises a higher ROI for farmers as well as good for the environment.

Other Areas of Opportunities

Seaweeds are so damn cool — these companies are only a small slice of the vast opportunities they present.

We can keep going, but we know you want in on the action. So here are some ideas you could look into:

Source: World Bank

🐶 Pet food: Forget gassy cows – your own pet could use some seaweed feed. Studies show that seaweed-derived food and supplements can improve the digestive or skin health of 88% of dogs. The seaweed-based pet food industry is worth $1B+, per a World Bank report.

🌈 Dye: You could extract color pigments from seaweed and turn it into a natural dye. Partner with eco-conscious fashion brands (SeaDyes, an up-and-coming Scottish startup, does this), or create your own seaweed dyed clothing line and market on social media with eye-catching content.

👭 Community: 40% of seaweed startups are led by women, a much higher rate than other categories. You can build a community for female founders in the seaweed sector (or the blue economy in general), and offer them resources, education, and networking opportunities.

Finally, don’t overlook the more traditional, low-tech ways to make money from seaweed, such as selling white-labeled supplements, smoothie mixes, curated snack/culinary kits, or even monetize info products (like a seaweed research database or blog) through selling reports, ads, or affiliate income.