26 Development of the cultivation of Laminaria Saccharina as the extractive inorganic component of an integrated aquaculture system and monitoring of therapeutants and phycotoxins

Abstract

The development of sustainable integrated aquaculture systems requires combining fed aquaculture (finfish) with extractive inorganic aquaculture (seaweed) and extractive organic aquaculture (shellfish). With the support of AquaNet, the Network of Centers of Excellence in Aquaculture in Canada, we are developing such a system at an industrial pilot scale by co‐cultivating salmon (Salmo salar), kelp (Laminaria saccharina) and blue mussel (Mytilus edulis) at aquaculture sites in the Bay of Fundy, Canada. This presentation will focus on the development of the extractive inorganic component. The entire cycle of rearing Laminaria saccharina has been completed and improved, both in the laboratory and at the integrated sites: release in the laboratory of spores from mature macroscopic sporophytes, seeding of ropes, germination of microscopic gametophytes, sexual maturation of male and female gametophytes, development of zygotes into juvenile sporophytes, which are then transplanted to the sites for rapid grow‐out. Another aspect of the project, food safety monitoring of chemical therapeutants and phycotoxins in mussel and kelp cultured in proximity to salmon, will also be described. The productivity, nutrient absorption capacity, and role of the seaweed component are being analyzed so that its appropriate scale to the other components can be defined in order to develop responsible aquaculture practices in which metabolic/physiological processes of the different co‐cultured organisms counter‐balance each other within acceptable operational limits. Adopting polytrophic strategies will be key to the aquaculture industry to develop its environmentally and economically‐balanced diversification and increase its social acceptability within a broader coastal management framework.