Nori aquaculture

The marine red alga Porphyra ("laver", "nori") is the most valuable sea vegetable in the world, with the Japanese product alone representing over $2 billion (US) a year. Welsh laver bread is one of several traditional uses of Porphyra in Celtic cooking; nori is used in sushi and soups in Asian cooking. More recently, sale of fluorescent pigments (e.g., phycoerythrin) from Porphyra began; these pigments can be used to tag antibodies and other molecules used in biomedical research. Porphyra has a life history in which the commerically important blade alternates with a small microscopic stage called the conchocelis-stage. Understanding that these two phases were connected was a major research advance made in the late 1940s in Britain. The Japanese used this discovery to transform their mariculture industry, and, today, major mariculture industries based upon Porphyra (principally of the Pacific species P. yezoensis) exist in Japan, China, and South Korea, among others. Asian mariculturalists typically practice "integrated mariculture" in which algae and finfish are raised adjacent to each other. This provides nutrients to the algae from animal excretions, while lowering point-source pollution from fish culture. Wild harvest of Porphyra occurs in some areas of Maine now, but none of our native species has been domesticated. Maine has at least 7 native species of Porphyra. The goal of our research at CCAR is to develop some of these as new mariculture crops in Maine. We are studying environmental cues that trigger reproduction in our native species, in order to be able to control these for net-seeding of Porphyra. We plan to work with local aquaculturalists to test these in the sea.