44 SEP TEMBER 2022 • WORLD AQUACULTURE • WWW.WA S .ORG The areas near our farm sites were closely monitored per ruling of ICES by scientists from a consortia of five universities fromMaine, New Hampshire, Massachusetts and New Brunswick, Canada; if any escapees were found, the farm would be shut down. Growing Nori inMaine To learn the process of nori culture and nori sheetmaking, I spent three weeks in January of 1993, 1994 and 1995 on a nori farm in the Inland Sea with Yugi Urano, one of the most progressive nori farmers in Japan. He also came with his son to visit CPI in Eastport, Maine. Nori Goyami, the national nori farmers’ cooperative, was of great assistance, making available nori researchers and farmers to share the technology. The cooperative felt that the more the West knew about nori, the faster the market would grow, and what little CPI could produce would not be competitive. They also knew the challenges of producing a good sheet and the general perception was that there was little likelihood CPI could do it. I grew the conchocelis, the summer phase, in shallow tanks artificially lit with fluorescent lights at 16-h daylength inside a converted sardine factory in Eastport during the winter (Fig. 2). Temperature and pH were monitored daily and the shells cleaned once every ten days to remove benthic diatoms. This was rather labor-intensive as there were approximately 10,000 shells in the facility. I induced spawning by lowering the temperature of the tank 7 F, and seeded the culture nets. We had about 53 ha of leased sites, with space for 1,100 saku, or 1,000 m × 1.5 m nori nets. The nets were seeded with spores released from the conchocelis. Thirty-six nori nets, 1.5 m × 18 m, tied in six bundles of six nets each, were then tied to a 183 cm diameter wheel turned at 12 rpm in a shallow tank with several hundred conchocelis shells Finding large quantities of nori Porphyra spp. along the shores of Cobscook and Assamaquoddy Bay, Maine, I decided it might be lucrative to culture the nori on nets, as done in the Far East. In 1991, I founded Coastal Plantations Inc. (CPI), a nori seaweed culture company (Fig. 1). The challenges were great; initially, the five local species of nori were two cells thick. Good candidates for nori sheet-making had to be only one cell thick, otherwise the sheet is too tough, rough, full of holes and hard to chew. Porphyra linearis, found in surf zones in the Gulf of Maine, is the only species that is a single cell thick, but it is more difficult to culture as it frequents turbulent areas. The need to look for non-native species was clear. After two years of bureaucratic wrangling, the International Council for the Exploration of the Sea (ICES) of the United Nations gave me permission to import the Japanese species P. yezoensis strain U-51 to use on the farm. As with any imported species, its level of invasiveness had to be considered, but we were able to successfully illustrate that there was no associated risk using the nori’s natural reproduction triggers. Porphyra has two life stages – a conchocelis stage where it exists in scallop or oyster shells, and the winter phase where it exists as blades that can be eaten. The Japanese nori conchocelis stage requires four months of 80 F or greater water temperatures. It releases spores when the temperature drops precipitously 5-7 F over 24 h to the low 70s F after a cold front as winter in Japan approaches. These spores grow into the nori plants that are used for making sheets and can survive in water temperatures in the 50s F. The water temperature never rises above 55 F in Cobscook Bay, except for a few minutes at low tide over intertidal flats, where the sun can temporarily heat the incoming water. Maintaining a temperature of 80 F for four months was not possible in this bay, meaning the nori wasn’t an invasive risk. Growing Japanese Seaweed in Maine: Challenges and Insights Steve Crawford FIGURE 1. Coastal Plantations, Inc.: A nori growing site. FIGURE 2. Shells with conchocelis.
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