Seaweed outbreaks are clogging up waters from the Caribbean to the Baltic. Algae are now harvested alongside farmed crops to make ingredients for cosmetics and food products.

Mari Granström says her love of scuba diving first made her aware of the ongoing problem of toxic algae blooms in the Baltic Sea.

The outbreaks occur when tiny cyanobacteria, also known as blue-green algae, multiply rapidly and spread across the surface of the water for kilometers.

It is a type of marine suffocation, also known as eutrophication, and it is a major environmental concern in the Baltic Sea. According to official figures, it can occur in 97% of the total area of the sea.

The blooms have an impact on other marine life by reducing water quality, causing oxygen deficiency, and blocking out light.

The problem is caused by an excess of nutrients entering the water, most notably nitrogen and phosphorus from synthetic fertilizers. These are carried into the sea by rivers from Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, and Sweden.

While the use of such fertilisers has reduced in recent years, the Baltic Marine Environment Protection Commission, the intergovernmental organisation that aims to improve water quality in the sea, says "the effect of these measures has not yet been detected"..

Ms Granström, a Finnish biochemist, decided to take on the problem herself six years ago. She'd harvest the algae and turn it into ingredients for a variety of products. Algae extracts can be used in detergents, animal feed, and even packaging materials, in addition to cosmetics and human food.

This comes as seaweed is increasingly being harvested for such purposes as a replacement for oil-based ingredients.

"I saw - or perhaps couldn't see - how it was affecting the marine ecosystem and decided to do something about it," she says. "There was far too much finger pointing and far too little action."

Ms Granström says she worked on the project as a "hobby for a long time" before launching Origin by Ocean in 2019. (ObO). She is the president and CEO.

The company, which has received both commercial investment and European Union funds, is now pursuing a pilot production scheme with the goal of becoming fully operational by 2025-26.

ObO collects algae off the coast of Finland by sucking it onto boats and then separating it from the water. In addition, the company is importing invasive sargassum seaweed from the Dominican Republic in the Caribbean.

For several years, that region has been plagued by massive blooms of that algae. "Every year, 25 million tonnes of sargassum bloom in the Caribbean," says Ms Granström.

"It discourages people from fishing and harms tourism. We are currently purchasing several tonnes of sargassum from the Dominican Republic, and this quantity will grow."

Unwanted seaweed is also sourced from Portuguese and Spanish waters.

ObO's pilot processing is carried out in a facility in northern Sweden. It uses a patented biorefinery technology it calls "Nauvu" to separate the algae into numerous useable materials.

These are then sold to companies involved in the food, cosmetics, textiles, packaging, and agriculture industries.

ObO is collaborating with one of its investors, the Finnish chemicals and industrial group Kiilto, to help grow the business. "If this can be successfully scaled up here, ObO will be able to replicate similar processes all over the world," says Ville Solja, Kiilto's chief business development officer.

ObO has already announced plans to build a refinery in the Dominican Republic.

In Sweden, a separate company called Nordic Seafarm is demonstrating how versatile seaweed can be.

"We make algae-based gin and beer, both of which are produced locally," director Fredrik Gröndahl explains.

Nordic Seafarm is a commercial spin-off of Seafarm, a Swedish government-funded project that helps commercialize aquaculture research.

"If this market [for seaweed] becomes large, which we believe it will," says Prof Gröndahl, who is also the project leader of Seafarm and the head of the department of sustainable development, environmental science, and engineering at the Royal Institute of Technology in Stockholm.

"Imagine if Ikea asked for algae-based meatballs all over the world, which could happen."

Prof. Gröndahl also hopes that algae will become a key ingredient in animal feed in the future, replacing an environmentally damaging fish meal, which is commonly found in pig and poultry diets. "Algae is also less expensive than existing ingredients because it does not require feeding or irrigation."

Back at ObO, Ms Granström says the goal is for shoppers all over the world to "help clean up the Baltic Sea" by purchasing a variety of consumer goods.

"We wanted to help at both ends of the process, upstream and downstream, as it were - cleaning the seas while also monetising a shift in consumer behavior."