Techniques for Tropical Seaweed Cultivation
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 Marine Biological Laboratory (MBL), located at Woods Hole Oceanographic Institution, will lead a MARINER Category 1 project to design and develop a cultivation system for the tropical seaweed Eucheuma isiforme to produce biomass for biofuels. Eucheuma is a commercially valuable species of “red” macroalgae, primarily cultivated in Asia, which has been difficult to propagate in a cost-effective manner. Cultivation of Eucheuma is labor intensive — making up almost 70% of the production costs — and is limited to easily accessible areas near shore. The MBL team will design and development a farm system that will mechanize the seeding and harvesting process to drastically reduce labor costs, and allow farms to be deployed in offshore areas to greatly expand large-scale production and increase biomass yield per dollar of capital. The ultimate goal of the project is to cost-effectively produce biomass in underutilized areas of the Gulf of Mexico and tropical U.S. Exclusive Economic Zones where year-round production is possible. MBL will investigate opportunities to deploy an experimental farm in Puerto Rico where a wide range of exposure to prevailing winds and waves creates an ideal testbed to understand the influence of environmental conditions on biological, physiological, and chemical properties of cultivated macroalgae. If successful, the project can disrupt the current practices in the red macroalgae market and reduce reliance on imports from foreign sources, and ultimately scale to production levels relevant for bioenergy production.
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.