The Kelp Cultivation Potential in Coastal and Offshore Regions of Norway

Abstract

We have evaluated the cultivation potential of sugar kelp (Saccharina latissima) as a function of latitude and position (near-and offshore) along the Norwegian coast using a coupled 3D hydrodynamic-biogeochemical-kelp model system (SINMOD) run for four growth seasons (2012-2016). The results are spatially explicit and may be used to compare the suitability of different regions for kelp cultivation, both inshore and offshore.The simulation results were compared with growth data from kelp cultivation experiments and in situ observations on coverage of naturally growing kelp. The model demonstrated a higher production potential offshore than in inshore regions, which is mainly due to the limitations in nutrient availability caused by the stratification found along the coast. However, suitable locations for kelp cultivation were also identified in areas with high vertical mixing close to the shore. The results indicate a latitudinal effect on the timing of the optimal period of growth, with the prime growth period being up to 2 months earlier in the south (58 • N) than in the north (71 • N). Although the maximum cultivation potential was similar in the six marine ecoregions in Norway (150-200 tons per hectare per year), the deployment time of the cultures seems to matter significantly in the south, but less so in the north. The results are discussed, focusing on their potential significance for optimized cultivation and to support decision making toward sustainable management.

Latitudinal, seasonal and depth-dependent variation in growth, chemical composition and biofouling of cultivated Saccharina latissima (Phaeophyceae) along the Norwegian coast

“…Cultivation locations should not exhibit seasonal or sporadic reductions in salinity much below 30-35 psu as low salinity can severely suppress kelp growth (Spurkland and Iken 2011; Kerrison et al 2015). Frond length and biomass measured at the southern locations (1-58°N to 5-61°N) did not reach those at central and northern locations (6-63°N, 9-69°N), probably because of more severe and long-lasting nutrient limitation in these regions during large parts of the cultivation period (Young et al 2007;Kerrison et al 2015;Broch et al 2019).…”

“…Seeded lines of S. latissima were deployed in February 2017 because at that time: (i) there were naturally occurring sori at all locations eliminating the need to establish cultures of gametophytes or to artificially induce sori (Forbord et al 2012), (ii) light conditions were adequate at all locations to allow seedlings to grow immediately upon deployment (Handå et al 2013), and (iii) ambient nutrient levels were high (Broch et al 2013(Broch et al , 2019. It is likely advantageous for most farmers in southern Norway and temperate Europe to deploy their seed lines before February.…”

“…Light intensity and day length are more variable seasonally at high than at low latitudes. In temperate regions, increasing temperature at the sea surface during spring causes stratification of the water column, varying in timing and strength along a latitudinal gradient, resulting in substantial seasonal differences in nutrient availability along the coast (Rey et al 2007;Ibrahim et al 2014;Broch et al 2019). This seasonal variation in the abiotic environment (light, temperature and nutrients) will likely cause phenology differences in developmental stages and biochemical composition along the latitudinal gradient which in turn will affect the cultivated biomass and eventually the endproducts (Hurd 2000;Handå et al 2013;Peteiro and Freire 2013;Marinho et al 2015a;Schiener et al 2015).…”

Production of Value-Added Chemicals by Bacillus methanolicus Strains Cultivated on Mannitol and Extracts of Seaweed Saccharina latissima at 50°C

“…Brown seaweeds are rich in structural (alginate and cellulose) and storage (laminaran and mannitol) carbohydrates (Schiener et al, 2015). The big brown algae are abundant in the North Atlantic Ocean, and technology for large-scale ocean farming is under development (Fossberg et al, 2018;Broch et al, 2019). So far, Saccharina latissima is the dominating cultivated species, and the free mannitol and laminaran comprise the easily extractable fraction of S. latissima (Horn et al, 2000a,b).…”

Temperature Modulates Sex-Biased Gene Expression in the Gametophytes of the Kelp Saccharina latissima

“…In the present study we provide the first data on transcriptomic responses of male and female gametophytes of the sugar kelp, S. latissima, to temperature. S. latissima is a relevant foundation species in temperate to Arctic coasts (Steneck et al, 2002;Teagle et al, 2017) and it is the selected species in several aquaculture facilities in Europe and North America (Forbord et al, 2012;Kim et al, 2015;Broch et al, 2018).…”