Design of Large Scale Macroalgae Systems
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 Catalina Sea Ranch team will lead a MARINER Category 1 project to design an advanced giant kelp cultivation system for deployment on open ocean sites to assess their ability to produce economical and sustainable biomass for a future biofuels industry. The team plans to develop solutions to the main challenges facing macroalgae cultivation: scalability of seeding, cultivation, and harvest; survivability of the offshore installations; energy use and ecosystem impact; predictability of yield and quality of harvested biomass; and cost effectiveness. The effort will begin by optimizing macroalgae cultivation in the open ocean through site-specific adaption and techno-economic modeling of a proven offshore cultivation system. In collaboration with its commercial partners, the team will then use a direct seeding method, which deposits young plants onto specially designed substrates to save money and time during the hatchery and deployment phase. Additionally, the team’s mechanical partial harvest technology, which allows the same plant to be cut multiple times, is expected to further reduce annual seeding costs compared to the state of the art systems.
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.