Mathematical model ofLaminaria production near a British Columbian salmon sea cage farm

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.

Section: Simulation Experiments and Implications For Imtamentioning

confidence: 99%

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

Broch¹,

Ellingsen²,

Forbord³

et al. 2013

“…A depth of 0.2 m was set for Z. The temperature parameters T e and T opt were obtained from Petrell et al (1993), Duarte et al (2003) and Wu et al (2009). Chapman et al (1978) reported the growth rate of the congeneric S. latissima (as Laminaria saccharina) to be 0.18 d , based on our own data (J.…”

Section: Model Parametersmentioning

confidence: 99%

A model for the growth of mariculture kelp Saccharina japonica in Sanggou Bay, China

Zhang¹,

Wu²,

Ren³

et al. 2016

“…Spatial gradients obviously provide a greater ability to assess spatial resolution of nutrient spread than simple comparisons between farm and reference sites. Furthermore, Sanderson et al (2008) and Petrell et al (1993) have reported that inorganic nitrogen transit from fish cages is commonly non-linear; this may be reflected in the occasionally higher concentrations measured further from the farm compared to measurements directly beside net pens. The authors suggest this relates to complex near-field hydrodynamics in the proximity of fish cages.…”

Section: Physical Processesmentioning

confidence: 99%

“…The authors suggest this relates to complex near-field hydrodynamics in the proximity of fish cages. As detailed in the Canadian case study, a range of factors may affect flow patterns, resulting in variable and fluctuating current directions (Petrell et al 1993, Huang et al 2008, Reid et al 2010, consequently leading to complex nutrient plume dynamics in the near-field or close to structures . In addition to hydrodynamic influences from cages (Løland 1993, Helsley & Kim 2005, Lader et al 2007, Le Bris et al 2007), near-cage currents can be affected by the swimming behavior of fish (Gansel et al 2011(Gansel et al , 2014 as postulated in the Norwegian case study.…”

Section: Physical Processesmentioning

confidence: 99%

Discrete water quality sampling at open-water aquaculture sites: limitations and strategies

Jansen¹,

Reid²,

Bannister³

et al. 2016

While environmental performance of cage-based aquaculture is most often monitored through benthic conditions, there may also be requirements that necessitate discrete, pelagic sampling. In the pelagic realm, adequately capturing the spatial and temporal dynamics of interest and attributing causality to aquaculture processes can be extremely challenging. Conditions are seldom ideal, and data adequacy concerns of discrete samples collected at open-water aquaculture sites are not uncommon. Further exploration of these challenges is needed. Herein, we aim to explore considerations for study design, analysis, and data interpretation of discrete pelagic sampling. As examples, we present 2 case studies where limited sampling occurred under conditions of complex pelagic dynamics. A Norwegian case study quantified particle abundance around salmon farms, and aimed to highlight the effects of spatial−temporal variation on sampling design, the need for inclusion of companion parameters, and the benefits of a priori and a posteriori data interpretation strategies. A Canadian case study collected discrete samples to measure ammonium concentrations with continuous current measurements at an Integrated Multi-Trophic Aquaculture (IMTA) farm, to explore issues of complex hydrodynamics, reference site suitability, sampling resolution, data pooling, and post hoc power tests. We further discuss lessons learned and the implications of study design, ambient conditions, physical processes, farm management, statistical analysis, companion parameters, and the potential for confounding effects. Pragmatic consideration of these aspects will ultimately serve to better frame the costs and benefits of discrete pelagic sampling at open-water aquaculture sites.