Genomics and breeding of giant kelp

Why Kelp?

Macroalgae, or seaweed, refers to a set of exceptionally diverse multicellular, non-vascular photosynthetic organisms that can be harvested for the production of fuels, chemicals, feed, and food. In 2014, the world produced approximately 25 million wet metric tons of seaweed through a combination of wild harvesting and 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 macroalgae farming systems and components. The recent developments in genomics analysis enable a "Blue Revolution" parallel to land crops while removing the costly and limiting need for land and freshwater.

Project Innovation and Advantages

Funded by Arpa-E MARINER program, our University of Wisconsin-Milwaukee team, partnered with the University of Southern California and UC Santa Barbara, to develop a genomics breeding program focused on the ideal traits for farmed giant kelp, Macrocystis pyrifera. Controlled genetic improvements require establishing a bank of genetically homogeneous lines that are examined for markers and traits important for domestication and production. We begin our strain collection by sampling from three groups of different genetic co-ancestry found in the Southern California Bight, an area of high genetic diversity. Our test farm location, at Catalina Island, has oceanographic conditions that resemble the warm, offshore waters suitable for macroalgae farming at scale. The team will measure traits such as survival, growth rate, temperature tolerance and photosynthetic efficiency at different stages. We plan to use a combination of genome sequencing, optical mapping, and capture sequencing to create a genotyped strain collection - enabling the selection of the best performing farming traits from 50,000 possible crosses. If successful, these germplasm lines will constitute a ‘seed stock’ similar to that established for agricultural crops that can be used by breeders to stage model-based, efficient, cost-effective, and environmentally sound targeted genome-based selection.

Potential Impact

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.

  • ECONOMY: 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 the Maine to the Gulf, to Alaska, and the Pacific Islands.

  • SECURITY: Production of biofuels from domestically produced marine biomass could lessen U.S. dependence on foreign oil, bolstering energy security.

  • ENVIRONMENT: 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 of many coastal ocean regions.