US researchers investigate seeding technologies for sea vegetables
By John Mosig
By John Mosig
Sarah Redmond, Maine Sea Grant Extension Associate at the University of Maine’s Center for Cooperative Aquaculture (CCAR), is working with Susan Brawley, professor of marine sciences at the University of Maine, to complete R&D on laver (Porphyra umbilicalis) as a Maine aquaculture crop and develop strains and line-seeding techniques for dulse (Palmaria palmata) and alaria (Alaria esculenta).
The two-year project, funded by Maine Sea Grant and conducted at CCAR, aims to determine the current phenology of the three strains on the Maine shore and to isolate and control strains that show rapid growth and high spore production, indicating they will be the most productive for aquaculture farmers along the Maine shore.
Due to increasing demand for these types of seaweed, wild supplies are insufficient and there is a strong market for local aquacultured product. To support Maine seaweed aquaculture, both by individual farmers and large aquaculture companies, the project aims to develop the most efficient seeding techniques of these species for nets and long lines and make them available for growers for field trials at first, and ultimately for commercial use. Because some Maine wild seaweeds are “Certified Organic,” the project will also explore using organic fertilizers to support this market.
With funding from Maine Technology Institute, Redmond and Brawley have expanded their nursery at CCAR. They have two 20-foot by 10-foot walk-in environmental chambers that contain refrigeration units, filtered sterilized seawater and filtered air and lighting. Redmond says the researchers will use the chambers to seed lines, conduct research and develop and hold seedstock. They also have two additional Percival incubators for conducting research and holding seedstock, and they have purchased a custom-made Porphyra seeding wheel to seed nets.
Brawley, Redmond and two graduate students at the University of Maine have begun working on several projects. They include collecting seed from different sites, completing work on the raceway that will be used for the nursery stage of the seeded Porphyra nets and looking at the combined effects of temperature and day length on the reproductive development of dulse fronds that are currently vegetative. To begin the phenology survey, they are running transects at three different places on the coast.
“At this point, we’re the only people in the US investigating hatchery and seeding techniques for these species,” she says, “but there is a related project beginning at University of New Hampshire that is looking into another type of nori.” She and Brawley will report on their progress at Maine Seaweed Scene 2014 to be held on August 30th at Southern Maine Community College in S. Portland, preceding the first Maine Seaweed Festival at the same venue, a public event that will include a kelp farming workshop.
— Muriel L. Hendrix
Photos: Sarah Redmond