Modelling the cultivation and bioremediation potential of the kelp Saccharina latissima in close proximity to an exposed salmon farm in Norway

Abstract

A 3-dimensional hydrodynamic−ecological model system (SINMOD) was used to estimate the full-scale cultivation potential of the brown alga Saccharina latissima in integrated multi-trophic aquaculture (IMTA) with Atlantic salmon Salmo salar. A previously developed model for the frond size and composition (carbon and nitrogen content) of S. latissima sporophytes was adjusted to data from an outdoor mesocosm growth experiment and then coupled and run online with the 3-dimensional model system. Results from simulations were compared with data from an IMTA field experiment, providing partial validation of the hydrodynamic-ecologicalkelp model system. The model system was applied to study the large-scale cultivation potential of S. latissima in IMTA with salmon and to quantify its seasonal bioremediation potential. The results suggest a possible yield of 75 t fresh weight S. latissima ha −1 in 4 mo (February to June) and about 170 t fresh weight ha −1 in 10 mo (August to June). The results further suggest that the net nitrogen consumption of a 1 ha S. latissima installation in the vicinity of a fish farm producing approximately 5000 t salmon in a production cycle is about 0.36 (0.15) t NH 4 + -N, or a removal of 0.34% (0.41%) of the dissolved inorganic nitrogen effluent with a cultivation period from August (February) to June. Due to the differing seasonal growth patterns of fish and kelp, there was a mismatch between the maximum effluent of NH 4 + -N from the fish farm and the maximum uptake rates in S. latissima.

Spatiotemporal Dispersal and Deposition of Fish Farm Wastes: A Model Study from Central Norway

“…The 20,000 and 4,000 m model domains encompass the Arctic Ocean and Nordic seas (Ellingsen et al, 2009), while the 800 m model domain covers the Norwegian coast from 61 Broch et al, 2013). SINMOD has been shown to successfully resolve the circulation dynamics of the Norwegian shelf off Northern Norway (Slagstad et al, 1999;SkarDhamar and Svendsen, 2005;Anon, 2011) and has previously been applied to studying e.g., dispersal patterns of cod eggs and larvae in fjord environments (Uglem et al, 2012) and the dispersal of dissolved nutrients from salmon farming (Broch et al, 2013). Two 160 m resolution model domains were used to generate boundary conditions for the 3 model domains of 32 m resolution (Figure 2).…”

“…The system is applicable to other fish or aquaculture species with appropriate re-parametrization. SINMOD's ecosystem module (Wassmann et al, 2006;Broch et al, 2013) has a number of biogeochemical variables that may be coupled with the dispersal model. For example, SINMOD may simulate oxygen concentrations and hence the potential for deteriorating water quality in situations with a high influx of particulate matter and high temperatures.…”

Performance measures and models for open‐water integrated multi‐trophic aquaculture

“…; Broch et al . ). Therefore, we will focus here exclusively on models for seaweeds, in particular models in a marine environment.…”

Offshore and Multi-Use Aquaculture with Extractive Species: Seaweeds and Bivalves

“…Considering a 10:1 DW:FW ratio and average values of nitrogen (Pyropia/Porphyra: 5.5%, Gracilaria: 3.0%, Kappaphycus/Eucheuma: 1.7%, kelp: 2.0% and Sargassum: 4.1%) and carbon (Pyropia/Porphyra: 38%, Gracilaria: 28%, Kappaphycus/Eucheuma: 29%, kelp: 30% and Sargassum: 34%), the total nitrogen and carbon removal by these five major aquaculture groups is approximately 54 million t of nitrogen per year and 700 million t of carbon per year (equivalent to 2600 million t of CO 2 ), respectively (Asare and Harlin 1983;Gerard 1997;Schaffelke and Klumpp 1998;Gevaert et al 2001;Schaffelke 2001;Chung et al 2002;Rawson et al 2002;Sahoo and Ohno 2003;Dean and Hurd 2007;Kim et al 2007Kim et al , 2014aKim et al , 2015aBuschmann et al 2008;Abreu et al 2009;Robertson-Andersson et al 2009;Levine and Sahoo 2010;Broch et al 2013). This is, in fact, a significant amount of carbon and nitrogen removal.…”

“…USA, Canada, Norway, Scotland, Ireland, Sweden and Germany; Buchholz 2004a, 2005;Chopin et al 2004;Barrington et al 2009;Broch et al 2013;Marinho et al 2015;Kraemer et al 2014;Kim et al 2015a) and Macrocystis in the eastern Pacific Ocean (e.g. Chile; Buschmann et al 2008).…”