Porphyra dioica J.Brodie et L.M.Irvine; a first look to a mass cultivation of a European species

The use of macroalgae for human nutrition is in constantly expanding, particularly in Europe. In particular, the Porphyra/Pyropia species which have an important economic relevance. In this study was focused on Porphyra dioica, present in all of Northern Europe and considered a species suitable for aquaculture. The present research aimed to study the influence of different environmental parameters on thalli growth to improve the knowledge on mass cultivation methods for P. dioica. For this study thalli of P. dioica were collected along the coasts of Galicia. The blades were cultured at 14°C. The main target was to test the effects on biomass yield of photoperiod (12L: 12D, 16L: 8D and 8L: 16D) and irradiance (250, 140 and 70 μE m-2 s-1). Furthermore, we tested the "free-living" growth conditions on the conchocelis phase, traditionally cultivated on a calcareous substrate. To support the obtained data, the health status of the gametophytes was evaluated by the Fv/Fm index. The highest growth of thalli was obtained at the photoperiod 16:8 and the light intensity of 140 μE m-2 s-1. The further increase of light intensity caused a reduction in the growth due to high light stress, as shown by the Fv/Fm index. The cultivation of the conchocelis stage in free-living conditions present excellent results.