UMaine Researcher Opens New Doors for Sea Vegetable Aquaculture

Maine’s potential as a provider of sea vegetables has remained largely untapped, due at least in part to the average American’s lack of familiarity with the ocean garden.

“Sea vegetable aquaculture is a $6 billion industry worldwide. Nori alone is nearly $2 billion of that, and that comes entirely from Asia. Nori and other algae are high in protein. They’re also a good source of omega-3 fatty acids. They’re a very healthful food; we’re just not used to eating them. Because there are so few people working on this in the U.S., and because there is so little known about its basic biology, you have to spread yourself around a little bit,” said Blouin, whose lab and field schedules combine to create a very demanding schedule. “I have projects going on both sides – in basic research and in economic development.”

As part of his master’s thesis, Blouin worked to develop reliable techniques that could be used for cultivating P. umbilicalis commercially. With funding from Maine Sea Grant, Maine Technology Institute and the Environmental Protection Agency, Blouin gathered the initial data that could provide the foundation for large-scale cultivation of native nori in Maine waters.

“A lot of what we are doing with P. umbilicalis involves adaptations of other technologies - bringing them together in one uniform way,” said Blouin.

“The idea is to streamline the process so that we can transfer that technology to future sea vegetable farmers.”

A native of the North Atlantic, P. umbilicalis has a potential advantage over Pacific species of nori such as P. yezoensis that are currently used in Asia’s large-scale aquaculture operations: it reproduces exclusively asexually along the northeast coast. Currently, commercial nori farmers spend more than half of the yearlong growing season coddling the tiny, inedible filamentous phase of the alga’s complicated life cycle. In China, Japan and South Korea, gigantic warehouses shelter shallow tanks filled with billions of clamshells, each one tinted with the pink stain of nori in its filamentous state. P. umbilicalis produces asexual spores that begin their lives as tiny versions of adult blade, effectively pressing fast-forward on the algae’s life cycle.

By utilizing the asexual spores of P. umbilicalis, Maine nori farmers could bypass the expensive filamentous phase, speeding production, eliminating seasonality and reducing overhead costs.

The cultivation of nori and other marine algae could prove to be the perfect compliment for other forms of aquacultural enterprise. Preliminary studies conducted by Blouin near salmon pens in Cobscook Bay suggest that net-grown nori could be incorporated into multicrop aquaculture. Dubbed Integrated Multi-Trophic Aquaculture (ITMA), this approach to ocean farming is critical to the development of stable and sustainable food production in the Earth’s oceans.

Blouin’s doctoral research is now focused on unraveling the mysteries of reproduction in this red alga at the genetic level. Identifying the genetic triggers for asexual reproduction in P. umbilicalis may offer important insights into similar mechanisms in other species, providing researchers with a better understanding of the evolution of sex and greater control over the cultivation of sea vegetable varieties chosen for size, speed of growth, flavor or other traits.