Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2026
Authors
Celayir, IremAbstract
--- Abstract and files will be published: 2027-05-15
Authors
Daniel Henn Carmen Girón Domínguez Andrés Martínez-Arce George Bishop Colm Duffy Vibeke Lind David StylesAbstract
No abstract has been registered
Abstract
Introduction In echinoculture, commercial success is often measured by gonad yield and gross biomass. However, these parameters may overlook the critical physiological transitions occurring during nutritional recovery. Green sea urchins (Strongylocentrotus droebachiensis) frequently face long periods of food scarcity in the wild, which leads to major metabolic shifts. This study explores the “quality of recovery” by investigating how starved individuals allocate resources from a macroalgal diet (Saccharina latissima). The hypothesis was tested that sea urchins prioritize structural stabilization and biochemical “priming” over immediate biomass accumulation. Materials and Methods Green sea urchins harvested by hand from Tromsø, Norway, were shipped to Bodø, Norway, and maintained under controlled conditions (7±1 °C) in the laboratory. The animals were divided into two groups: one subjected to long-term starvation and the other fed to satiation with S. latissima. Morphological indices, including fresh weight (FW), test diameter, and gonad index (GI), were recorded (n=10). Biochemical analyses of minerals using ICP-OES focused on the tests (shells) and a combined visceral fraction (intestines and coelomic fluid). “True protein” content was determined by summing proteinogenic amino acid residues using HPLC, excluding the non-proteinogenic amino acid taurine to ensure analytical precision. Statistical differences were assessed using independent samples t-tests or Wilcoxon rank-sum tests at a 5% significance level (P = 0.05) in the statistical software package R (v 4.5.1). Results and Discussion This study revealed a sophisticated hierarchy in resource allocation. While the starved group demonstrated remarkable structural resilience by maintaining basic body dimensions without significant skeletal degradation, the kelp-fed group exhibited a profound “biochemical reset”. The fed urchins showed a highly significant increase in the Gonad Index (10.75 ± 2.33% vs. 5.70 ± 2.68%; P < 0.001; Figure 1A). Interestingly, although the total fresh weight did not differ significantly between groups, the internal quality of the tissues underwent a dramatic transformation. In the tests, ash content increased significantly in fed individuals (82.21 ± 3.87 g vs. 79.04 ± 2.70 g; P < 0.05), indicating a strategic investment in skeletal mineralization (Figure 1B). This was accompanied by higher concentrations of matrix-stabilizing amino acids such as glycine and arginine. In the visceral fraction, a “priming” effect was observed. While the increase in total protein content (141.18 ± 27.50 mg g-1 DW vs. 118.23 ± 23.66 mg g-1 DW) narrowly missed the significance threshold (P = 0.061), specific essential amino acids like phenylalanine, leucine, and methionine increased significantly. This suggests that before significant gross growth occurs, the organism optimizes its metabolic machinery and amino acid pools to support future physiological demands. Conclusion Our findings demonstrated that green sea urchins employ a strategic rebuilding process during nutritional recovery. Investment is prioritized toward reinforcing the structural integrity of the test and priming the biochemical capacity of the viscera. For the aquaculture industry, these results suggest that traditional morphological indices should be supplemented with biochemical profiling to fully evaluate the efficacy of “roe enhancement” diets and the physiological health of the animals.
Authors
Jakob GeipelAbstract
This report evaluates the practical guidance accuracy of a John Deere 6130R tractor equipped with a John Deere AutoTrac autosteering system and a StarFire 6000 GNSS receiver. The experiment was conducted at NIBIO Apelsvoll, Norway, using a Trimble S3 robotic total station as an independent reference measurement system. Tractor trajectories were measured while driving along predefined guidance lines at travel speeds of 7, 10 and 13 km h-1. A total of 1097 position measurements were analysed. Mean cross-track deviations ranged from 4.2 to 5.2 cm, while standard deviations ranged from 3.3 to 4.0 cm. 95% of all observations remained within approximately 10 to 13 cm of the intended trajectory. Pass-to-pass deviations ranged from 0.7 to 2.9 cm, indicating good consistency between neighbouring guidance passes. The results indicate stable centimetre-level guidance performance throughout the tested operating range. Differences between travel speeds were small and are unlikely to be operationally important for most agricultural field operations. The measured guidance performance is compatible with the requirements of modern precision-agriculture applications such as tillage, sowing, fertiliser spreading and crop protection.
Abstract
Total DNA quantification in seaweeds is paramount important and it enables selective breeding and physiological understanding. Measuring DNA content identifies genetic quality and potential in candidate organisms for aquaculture development, supporting the selection of strains with faster growth, higher nutrient profiles, or enhanced stress tolerance. Since DNA content reflects cell ploidy levels the number of chromosome sets quantification reveals how ploidy influences seaweed growth rates, stress responses, metabolic efficiency, and environmental adaptation. Seaweed of the genus Ulva widely known as sea lettuce, is a high protein content and fast-growing plant and can grow in wide range of climate. Ulva fenestrata stands out as a premier candidate for sustainable aquaculture, notable for offering exceptionally high levels of bioactive vitamin B12, balanced essential amino acids, and efficient nutrient bioremediation and serves as a versatile feedstock for functional foods, animal feed additives, and eco-friendly biomaterials.
Abstract
The sugar kelp Saccharina latissima has received intense scientific attention over the last decade due to their great potential to be utilized as human food, biomolecules, feed, and feed additives. In Norway as well as in other coastal European countries, the commercial-scale farming of the sister species S. latissima has been widely successfully demonstrated within the past decade. Norway has nutrient-rich seawaters, diverse seaweed biodiversity, and conducive geographical structure which can favor aquaculture of this species at commercial scale. Development of Karyotyping and systematic analysis of an organism’s chromosome composition is crucial for seaweed breeding programs because it provides essential genetic information that directly impacts crop improvement, selection efficiency, and biotechnological applications. Therefore, breeders can identify distinct cytotypes (organisms with different chromosome numbers) and use this knowledge to select genetically diverse parents for crosses, which increases the likelihood of producing plantlets with desirable agronomic traits including accelerated maturation, structural robustness, stress resilience, vigorous growth, and elevated nutrient accumulation.
Abstract
Palmaria palmata is a protein-rich red seaweed containing essential amino acids and bioactive compounds with potential applications in aquaculture nutrition and fish health. In this study, liquid extracts enriched in soluble compounds were obtained through mechanical fractionation of P. palmata. The recovered fractions were characterized for their lipid and amino acid composition and evaluated for cytotoxic and immunomodulatory response in salmon head kidney-derived SHK-1 cell line (Salmo salar) cell lines as a first step towards assessing their suitability as functional ingredients for aquaculture feed applications.
Abstract
There is growing interest in simple and resource-efficient recovery strategies that maximize pigment yield while minimizing chemical inputs and processing intensity. Mechanical fractionation using twin-screw press offers a promising approach by releasing soluble intracellular compounds into a liquid fraction while simultaneously generating a solid fraction that can be further valorized. In this study, freshly harvested P. palmata biomass was mechanically fractionated prior to ammonium sulfate precipitation, dialysis, and freeze-drying to produce a phycoerythrin. This approach aims to maximize R-PE recovery through low-input processing while reducing chemical consumption and energy requirements compared with conventional extraction methods. The distribution and recovery of R-PE within the generated process streams were evaluated to assess the potential of mechanical fractionation as a primary recovery step in phycoerythrin extraction.
Abstract
Brown seaweeds are rich in sulphated polysaccharides, minerals, proteins, and other bioactive compounds suitable for cascading biorefinery. Ascophyllum nodosum, an abundant North Atlantic species, contains fucoidan, laminarin, and mannitol with potential food and feed applications. Efficient utilisation requires fractionation strategies that recover target compounds while enabling further valorisation of the remaining biomass. Here, a food-compatible process using water and citric acid was applied to recover fucoidan- and alginate-rich fractions and retain residual biomass for further use. Material distribution, concentration efficiency, and recovery were evaluated across the process, which recovered 57.3% of the initial dry biomass as value-added products.
Abstract
Mechanical dewatering using a twin-screw press not only reduces biomass moisture content but also facilitates the partitioning of valuable biochemical components between liquid and solid fractions. While mechanical dewatering is commonly applied as a low-energy pre-treatment step, its potential as a fractionation strategy for brown seaweed biorefinery remains largely unexplored. Pressure-driven separation generates a liquid fraction containing soluble compounds and a solid fraction enriched in structural biomass components. In this study, different pre-treatments were combined with twin-screw pressing to evaluate their influence on the distribution of protein-bound amino acids, fucose, and uronic acids in Alaria esculenta. The results demonstrated distinct partitioning patterns, with higher concentrations of all three component groups generally retained in the solid fraction, highlighting the potential of mechanical dewatering as an initial fractionation step in cascading seaweed biorefinery. This approach aims to establish mechanical dewatering as a scalable, low-energy entry point for downstream processing, supporting efficient valorization and zero-waste processing.