Sorry, you need to enable JavaScript to visit this website.

Continuous, High-Yield Kelp Production


Continuous, High-Yield Kelp Production

ARPA-E Award: 
Albany, CA
Project Term: 
03/16/2018 to 04/15/2020
Project Status: 
Technical Categories: 
Critical Need: 

Marine macroalgae, also referred to as seaweeds or kelp, are a group of exceptionally diverse aquatic plants. Macroalgae can be found along nearly all coastlines around the globe and in some cases also in the open ocean. They have traditionally been used for food and feed, as well as fertilizer. In 2016, the world produced approximately 26 million wet metric tons of seaweed, primarily through highly labor-intensive farming techniques. While macroalgae production has increased six-fold over the past quarter-century, the current state of macroalgae "mariculture" is not capable of achieving the scale, efficiency and production costs necessary to support a seaweed-to-fuels industry. Dramatically increasing productivity will require significant advancements in the domestication of macroalgae and new farming technologies. To accelerate the development of critical tools and technologies, the MARINER program is supporting projects in five technical areas: 1) Integrated Cultivation & Harvest System Design, 2) Critical Enabling Components, 3) Computational Modeling, 4) Monitoring Tools, and 5) Breeding & Genomic Tools.

Project Innovation + Advantages: 

Trophic will lead a MARINER Category 1 project to design and develop a seaweed cultivation system anticipated to maximize biomass yield while reducing costs. Trophic's system will rely on development of a number of innovations to increase the production of seaweed-based biomass. First, they will implement a variable-row spacing cultivation system to maximize the capital efficiency of the farm. Seaweed is traditionally grown on multiple parallel long culture ropes. Trophic's concept will explore the capability to dynamically vary the distance between each line to maximize the sustainable yield over the entire farm area across all stages of seaweed growth -- the culture ropes are kept closer together when the plants are small, while expanding as the plants grow. This reduces crowding and shading that could lead to slower growth rates. The second innovation is to design a passively tethered hydrofoil powered by solar energy. Higher concentrations of nutrients exist in deeper ocean depths. The hydrofoil, positioned deep below the surface and tethered to a buoy, lifts nutrients from deeper water to fertilize crops at the surface. A third innovation is their wave-diving system. Large waves pose a consistent danger in unprotected offshore environments. The wave-diving system acts as a brake against the upward movement of the culture ropes, capping the maximum structural loads from waves, thus allowing the system to survive much heavier sea states than otherwise possible. The team plans to combine these innovations with computer modeling to develop a system for seaweed farming that, if successful, will produce high yields at a cost of less than $60 per dry metric ton.

Potential Impact: 

If successful, MARINER projects strive to develop the tools needed to allow the United States to become a world leader in marine biomass production for multiple important applications, including the production of biofuels.


Production of biofuels from domestically produced marine biomass could lessen U.S. dependence on foreign oil, bolstering energy security.


Growing large amounts of macroalgae would not compete with land-based food crops, requires no fresh water and can be grown without the addition of energy-intensive, synthetic nitrogen fertilizer. Large-scale macroalgae cultivation may help reduce the negative effects of nutrient overload and ocean acidification in many coastal ocean regions.


A domestic macroalgae industry would not only create a valuable new source of domestic energy, but also create significant new economic and employment opportunities in many waterfront communities along the U.S. coasts from Maine to the Gulf of Mexico, Alaska, and the Pacific Islands.

ARPA-E Program Director: 
Dr. Marc von Keitz
Project Contact: 
Beth Zotter
Otherlab, Inc.
University of New Hampshire
Release Date: