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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.

Colored Dissolved Organic Matter (CDOM) is an important optical constituent in seawater, which significantly attenuates the violet to blue portion of visible light. Thus, CDOM reduces the radiation energy available to phytoplankton and affects remote-sensing signals. We present data from two cruises transecting the Polar Front from Atlantic to Arctic waters in the Barents Sea, in 2007 and 2008. The latter took place during the spring bloom of phytoplankton in May (0.2 b [Chl a] b 13 mg m −3) and the former during August (max. [Chl a] b 2 mg m −3). Absorption by CDOM at 443 nm ranged from 0.004 to 0.080 m −1 during May and from 0.006 to 0.162 m −1 during August. Surprisingly, CDOM absorption differed little across the Polar Front, but was higher during August than during May (P b 0.05). The slope coefficient of the absorption spectra (S) ranged from 0.008 to 0.036 nm −1 (mean = 0.015 nm − 1) including both cruises, and varied little across the Front (P > 0.05). The CDOM remote sensing product from GlobColour correlated well with sampled data (R 2 = 0.73) during May. However, during August the satellite product performed poorly (R 2 = 0.02) due to extensive scattering caused by coccolithophorids in the Atlantic Water. The CDOM pool was of autochthonous (marine) origin as characterized from its S vs. absorption relationship. Modeling showed that CDOM, on average, contributed equally to the light absorption as did phytoplankton (at 1 mg Chl a m −3), and thereby reduces the amount of light available for primary production.

To study the use of nuclear magnetic resonance (NMR) spectroscopy as a method of classification, we performed high-resolution magic angle spinning proton (HR MAS 1 H) NMR spectroscopy analysis of whole-cell samples of Dunaliella sp. (Chlorophyceae), Amphidinium carterae (Dinophyceae), Phaeodactylum tricornutum and Thalassiosira pseudonana (Bacillariophyceae). Emphasising the potential use of NMR spectroscopy as a routine analysis of microalgae we chose a straightforward procedure for culturing and harvesting, without extraction or radioactive labelling. We obtained well-resolved HR MAS 1 H NMR spectra from the 4 algae, despite the fact that our samples contained whole cells and some residual sea water. Selected parts of 5 replicate spectra from each microalga were used as input in 2 multivariate pattern-recognition strategies (principal component analysis and fuzzy clustering), both analyses showing clear grouping of the different species. Two spectra from a previous sample run (cultures grown under the same conditions) were also included, and both were correctly classified. We therefore consider HR MAS 1 H NMR spectroscopy to be a potential method of classification for microalgae, with statistical data processing indicating replicability and robustness of the method.

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