Developing a laboratory cultivation protocol for local species of Porphyra spp.
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- Institutt for biologi 
The cultivation of Porphyra for use in food has a long tradition in Asian countries, and with recent food trends and nutritional awareness, macroalgae has become a popular ingredient throughout the rest of the world as well. The Norwegian coast has several species of Porphyra suited for use in many ways, but harvesting wild material is time consuming and limited by few occurrences in the wild. Cultivation is thus the preferred option for future exploitation of the genus. This study is aimed at adapting existing cultivation techniques to local species and environmental factors, for indoor cultivation. A field search was performed to map local occurrences of the genus in the Trondheimsfjord, and a laboratory protocol was established for cultivation of collected material. Several variables were applied at different stages of the life cycle; stress for induction of spore release, treatment with germanium dioxide for decontamination, variations in light intensities and application of scallop shell as a substrate for growth. Also a method for quantification of conchochelis (sporophyte stage) growth were developed and applied.The field search found that the genus is scarcely represented in local waters, with few and far between occurrences. The laboratory experiment proved that contaminants like diatoms is a challenge, but manageable with correct treatment. Tolerance levels for germanium dioxide were also established, and the experiment showed that the local species of Porphyra are well suited for indoor cultivation under the given conditions. The experiment was concluded when the life cycle was fulfilled, from wild collected gametophytes, through the conchochelis sporophyte stage, to growing gametophytes in the laboratory.