TY - JOUR
T1 - The potential for upscaling kelp (Saccharina latissima) cultivation in salmon-driven integrated multi-trophic aquaculture (IMTA)
AU - Fossberg, Julia
AU - Forbord, Silje
AU - Broch, Ole Jacob
AU - Malzahn, Arne M.
AU - Jansen, Henrice
AU - Handå, Aleksander
AU - Førde, Henny
AU - Bergvik, Maria
AU - Fleddum, Anne Lise
AU - Skjermo, Jorunn
AU - Olsen, Yngvar
N1 - Publisher Copyright:
© 2018 Fossberg, Forbord, Broch, Malzahn, Jansen, Handå, Førde, Bergvik, Fleddum, Skjermo and Olsen.
PY - 2018/11/9
Y1 - 2018/11/9
N2 - Integrated multi-trophic aquaculture (IMTA) has the potential of reducing open-cage fish farming impacts on the environment while also introducing new value chains. The aim of this study was to investigate the growth and composition of the kelp Saccharina latissima in salmon-driven IMTA, and to assess the spatial extent of the influence of salmon derived nitrogen in order to evaluate the upscaling potential for IMTA. S. latissima was cultivated 100, 200, and 1,000 m east and 1,000 m west of a 5,000 tons salmon farm in Western Norway from February to September 2013. The proportion of salmon derived nitrogen available for the kelp showed a clear decline with distance from the farm. Accordingly, the kelp cultivated near the salmon cages grew faster during the spring season, and growth rate decreased with increasing distance from the farm. A spatially explicit numerical model system (SINMOD), including compartments for dissolved nutrients and kelp growth, was tuned to the field data and used to investigate the potential for upscaling IMTA production. The model was used to introduce a new metric-the impacted area IA-for the areal effects of IMTA in terms of the increase in production by IMTA. The model showed that a 25 hectare kelp farm in the vicinity of the studied salmon farm could take up 1.6 of the 13.5 tons of dissolved inorganic nitrogen released during kelp cultivation, amounting to almost 12% of the ammonia released during the cultivation period from February to June. The 25 hectare kelp farm would have a production yield of 1,125 tons fresh weight (FW), being 60% more than that of a non-IMTA kelp farm, while a 20% increase of kelp FW could be obtained over a 110 hectar area in salmon-driven IMTA. To achieve an even mass balance, an area of approximately 220 ha-1 would be needed to cultivate enough kelp to fix an equivalent of the nitrogen released by the fish.
AB - Integrated multi-trophic aquaculture (IMTA) has the potential of reducing open-cage fish farming impacts on the environment while also introducing new value chains. The aim of this study was to investigate the growth and composition of the kelp Saccharina latissima in salmon-driven IMTA, and to assess the spatial extent of the influence of salmon derived nitrogen in order to evaluate the upscaling potential for IMTA. S. latissima was cultivated 100, 200, and 1,000 m east and 1,000 m west of a 5,000 tons salmon farm in Western Norway from February to September 2013. The proportion of salmon derived nitrogen available for the kelp showed a clear decline with distance from the farm. Accordingly, the kelp cultivated near the salmon cages grew faster during the spring season, and growth rate decreased with increasing distance from the farm. A spatially explicit numerical model system (SINMOD), including compartments for dissolved nutrients and kelp growth, was tuned to the field data and used to investigate the potential for upscaling IMTA production. The model was used to introduce a new metric-the impacted area IA-for the areal effects of IMTA in terms of the increase in production by IMTA. The model showed that a 25 hectare kelp farm in the vicinity of the studied salmon farm could take up 1.6 of the 13.5 tons of dissolved inorganic nitrogen released during kelp cultivation, amounting to almost 12% of the ammonia released during the cultivation period from February to June. The 25 hectare kelp farm would have a production yield of 1,125 tons fresh weight (FW), being 60% more than that of a non-IMTA kelp farm, while a 20% increase of kelp FW could be obtained over a 110 hectar area in salmon-driven IMTA. To achieve an even mass balance, an area of approximately 220 ha-1 would be needed to cultivate enough kelp to fix an equivalent of the nitrogen released by the fish.
KW - Bioremediation
KW - Nitrogen
KW - Norway
KW - Numerical modeling
KW - Stable isotope
UR - http://www.scopus.com/inward/record.url?scp=85056092535&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85056092535&partnerID=8YFLogxK
U2 - 10.3389/fmars.2018.00418
DO - 10.3389/fmars.2018.00418
M3 - Article
AN - SCOPUS:85056092535
SN - 2296-7745
VL - 9
JO - Frontiers in Marine Science
JF - Frontiers in Marine Science
IS - NOV
M1 - 418
ER -