Automation Concepts for Industrial-Scale Production of Seaweed

In order to industrialize macroalgal cultivation in Norway, new automated methods and solutions for seeding, deployment and harvesting need to be developed. Today's solutions are time and resource demanding, still yielding volumes nationally in the range of 100–200 tons per year in total (not including wild harvest), while the potential is in the megaton range. Standardization of equipment and automation can be one way to upscale production. Here we present results from a design study of a module-based solution for industrial cultivation, with specific solutions for spinning of thin seedling strings onto longlines, and a robotic module for interaction with the submerged farm at deployment and harvest. A reduced-scale physical prototype of the farm concept with the robot has been built for testing of deployment and harvesting techniques. The concept has been named SPOKe: Standardized Production of Kelp.

Simulating the Trajectory and Biomass Growth of Free-Floating Macroalgal Cultivation Platforms along the U.S. West Coast

Trajectory tracking and macroalgal growth models were coupled to support a novel macroalgae-harvesting concept known as the Nautical Off-shore Macroalgal Autonomous Device (NOMAD). The NOMAD consists of 5 km long carbon-fiber longlines that are seeded and free float southward along the U.S. West Coast for approximately 3 months before harvesting off the California coast, taking advantage of favorable environmental conditions. The trajectory and macroalgal growth models were applied to answer planning questions pertinent to the techno-economic analysis such as identifying the preferred release location, approximate pathway, timing until harvest, and estimated growth. Trajectories were determined with the General NOAA Operational Modeling Environment (GNOME) model, using 11 years of current and wind data, determining probabilities by running nearly 40,000 Monte Carlo simulations varying the start time and location. An accompanying macroalgal growth model was used to estimate the growth of macroalgae based on the trajectory tracks and environmental forcing products, including light, temperature and nutrients. Model results show that NOMAD lines transit south in the months of April to September due to seasonal currents, taking approximately 3 months to reach Southern California. During transit, NOMAD lines are dispersed but typically avoid beaching or passing through marine sanctuaries. NOMAD lines can yield up to 30 kg wet weight per meter of cultivation line.

Challenges for marine macroalgal biomass production in Indian coastal waters

Due to its large, exclusive economic zone, India has considerable potential for implementing large-scale cultivation of macroalgae. However, such cultivation requires the availability of, and access to, sites where technical, legal, governmental, and environmental factors are favorable. This review discusses the challenges that have held back the development of seaweed cultivation in India. The review is based on a literature survey and informal discussions with industry-related personnel. It cites the strong need for clear and definitive policies related to access to and use of coastal waters to enable the Indian seaweed industry to reach its full potential. The main challenges that the expansion of macroalgal cultivation in India face are related to legal and regulatory aspects that can be resolved by focusing the policy issues on providing planning tools toward success. In addition, there is a strong need for an adequate bioeconomy that clearly defines the need for marine macroalgal biomass for food, chemicals, and biofuels. Furthermore, the Indian government needs to allocate sufficient funds for accelerating seaweed R&D in areas of seaweed cultivation, harvesting, processing technologies, and their implementation in the local industry.