The Pacific Northwest National Laboratory (PNNL) will lead a MARINER Category 1 project to design, build, and field-test a Nautical Off-shore Macroalgal Autonomous Device (NOMAD), which is a free-floating, sensor-equipped, carbon-fiber longline (5 km) to which macroalgae can be attached for cultivation. The PNNL concept eliminates the significant costs associated with mooring, or anchoring, farms at a precise, invariable location in the ocean. Rather, PNNL proposes to release the NOMADs from a seeding vessel far offshore the United States West Coast and use harvesting boats to collect the free-floating systems after a six month, 1500 km southbound journey along nutrient-rich ocean currents. The NOMADs will be equipped with buoys and GPS sensors to track their positions as well as accelerometers and underwater light sensors to estimate, in real time, the biomass yield to optimize harvesting time. The project will employ state-of-the-art hydrodynamic modeling to identify offshore locations for release and harvest that result in optimum biomass yields as the NOMAD travels in nutrient-rich currents. Fully automated, high-speed seeding and harvesting machines will be designed and deployed to minimize labor costs. The team will also use polyculture farming where two species of kelp will be grown to improved light utilization and potentially achieve higher biomass yields than a single species could achieve alone.
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.