Adjustable Depth Seaweed Growth System
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 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:
The University of Southern Mississippi (USM) will lead a MARINER Category 1 project to design and develop a novel, robust seaweed growth system capable of deployment across the U.S. Exclusive Economic Zone. The technology will enable precise positioning of large farm structures to maximize productivity and actively avoid surface hazards such as weather or marine traffic. The seaweed will grow while affixed to support ropes strung between concentric rings. The structure will have automated buoyancy compensation devices to optimize depth minute-by-minute for maximum light intensity and minimum wave impact, as well as automatically lowering during storms or to allow large ships to pass over it. Automated adjustments can include “dives” into deeper, nutrient-rich, zones to access nutrients at depth during the night. If successful, the system will minimize structure cost per dry metric ton and risk by sinking to avoid storm forces, while leaving nothing on the ocean surface to interfere with shipping traffic or other ocean stakeholders. The project team will also investigate autonomous systems capable of returning to its home port for harvesting when not roaming thousands of miles offshore.
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 and bioenergy from domestically produced marine biomass could ensure that the U.S. has at its disposal a scalable, domestic source of low-carbon energy supplies.
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.