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AI-Light Spectrum Replicator (LSR): A Novel Simulated In Situ Lab/On-Deck Incubator
Full text linkIn this communication, we present the prototype of a new simulated in situ lab/on-deck incubator, the light spectrum replicator (LSR), and a method for simulating the measured in situ HOCR light spectrum curves in incubation chambers. We developed this system using AI and genetic algorithms in an iterative fashion to find the best-fitting light spectrum in situ irradiance at different depths. The HOCR light spectrum measured at the depth and time of sampling was processed immediately, so the incubator is in a stable and ready condition by the time the samples inoculated with 14C were placed in sample holders (10 min after sampling). This incubator is intended to provide a reliable, fast, and easy-to-use tool for studying primary production based on the evaluation of the photosynthetic uptake of 14C. This system enables short incubation periods for small samples: we tested incubations of 5 mL samples during 15 min incubation periods. Our initial measurements taken using the prototype revealed a sufficiently good correlation between the on-deck measurements and in situ incubations. This prototype can be improved, as discussed in this text.publishedVersio
Enriched local convenience foods with two different small pelagic fish species increases the nutritional value without compromising taste
Full text linkCereals and their derived products are important dietary sources for humans but are mostly deficient in protein and several micronutrients. To increase the nutrient content of rice and wheat flour-based recipes, nutrient-dense powders of the small pelagic fish species Anchovy (Engraulis encrasicolus) and Atlantic bumper (Chloroscombrus chrysurus) were used to enrich the high carbohydrate content mostly found in cereals. Sensory evaluation by 60 panelists showed that the enrichment of recipes with fish powder was acceptable. Recipes with dried anchovy showed higher sensory acceptance than recipes fortified with dried Atlantic bumper. Nutritional analyses showed that several of the tested recipes can be regarded as significant sources of micronutrients (vitamin A, D and B12, iodine and calcium) and the omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid. The actual analysed nutrient content of the test diets differed from the estimated nutrient content of the recipes by using values from the West-African food composition table. For vitamin A, analysed values were generally higher than the estimated values, indicating that the values in the food composition table are not sufficient to estimate the nutritional fortification with powdered small fish. In conclusion, the fortified foods prepared according to the tested recipes were accepted by sensory panelists and can be regarded as significant source of several essential nutrients. Food composition tables should be revised to enable a better estimation of the nutritional value of fortified diets for the combat of malnutrition.publishedVersio
Snøkrabbe på norsk sokkel i Barentshavet - Status og rådgivning for 2025
Full text linkBasert på en MSY-tilnærming anbefaler Havforskningsinstituttet at totalfangsten av snøkrabbe på norsk sokkel i 2025 ikke bør overstige 12 724 tonn. Kvoterådet gjelder for den høstbare delen av bestanden, som er snøkrabbe over minstemålet på 95 mm skallbredde.Snøkrabbe på norsk sokkel i Barentshavet - Status og rådgivning for 2025publishedVersio
Possible transport routes of IgM to the gut of teleost fish
Full text linkFish rely on mucosal surfaces as their first defence barrier against pathogens. Maintaining mucosal homeostasis is therefore crucial for their overall well-being, and it is likely that secreted immunoglobulins (sIg) play a pivotal role in sustaining this balance. In mammals, the poly-Ig receptor (pIgR) is an essential component responsible for transporting polymeric Igs across mucosal epithelia. In teleost fish, a counterpart of pIgR has been identified and characterized, exhibiting structural differences and broader mRNA expression patterns compared to mammals. Despite supporting evidence for the binding of Igs to recombinant pIgR proteins, the absence of a joining chain (J-chain) in teleosts challenges the conventional understanding of Ig transport mechanisms. The transport of IgM to the intestine via the hepatobiliary route is observed in vertebrates and has been proposed in a few teleosts. Investigations on the stomachless fish, ballan wrasse, revealed a significant role of the hepatobiliary route and interesting possibilities for alternative IgM transport routes that might include pancreatic tissue. These findings highlight the importance of gaining a thorough understanding of the mechanisms behind Ig transport to the gut in various teleosts. This review aims to gather existing information on pIgR-mediated transport across epithelial cells and immunoglobulin transport pathways to the gut lumen in teleost fish. It provides comparative insights into the hepatobiliary transport of Igs to the gut, emphasizing the current understanding in teleost fish while exploring potential alternative pathways for Ig transport to the gut lumen. Despite significant progress in understanding various aspects, there is still much to uncover, especially concerning the diversity of mechanisms across different teleost species.publishedVersio
Ocean climate and hydrodynamics drive decadal shifts in Northeast Atlantic dinoflagellates
Full text linkThe abundance of large marine dinoflagellates has declined in the North Sea since 1958. Although hypotheses have been proposed to explain this diminution (increasing temperature and wind), the mechanisms behind this pattern have thus far remained elusive. In this article, we study the long-term changes in dinoflagellate biomass and biodiversity in relation to hydro-climatic conditions and circulation within the North Atlantic. Our results show that the decline in biomass has paralleled an increase in biodiversity caused by a temperature-induced northward movement of subtropical taxa along the European shelf-edge, and facilitated by changes in oceanic circulation (subpolar gyre contraction). However, major changes in North Atlantic hydrodynamics in the 2010s (subpolar gyre expansion and low-salinity anomaly) stopped this movement, which triggered a biodiversity collapse in the North Sea. Further, North Sea dinoflagellate biomass remained low because of warming. Our results, therefore, reveal that regional climate warming and changes in oceanic circulation strongly influenced shifts in dinoflagellate biomass and biodiversity.publishedVersio
Borealization impacts shelf ecosystems across the Arctic
Full text linkClimate change is rapidly modifying biodiversity across the Arctic, driving a shift from Arctic to more boreal ecosystem characteristics. This phenomenon, known as borealization, is mainly described for certain functional groups along sub-Arctic inflow shelves (Barents and Chukchi Seas). In this review, we evaluate the spatial extent of such alterations across the Arctic, as well as their effects on ecosystem-level processes and risks. Along the inflow shelves, borealization is driven by long-term strengthened inflow of increasingly warm waters from the south and punctuated by advection and low sea ice extreme events. A growing body of literature also points to an emerging borealization of the other Arctic shelf ecosystems, through a “spillover” effect, as local changes in environmental conditions enable movement or transport of new species from inflow shelves. These modifications are leading to changes across functional groups, although many uncertainties remain regarding under-sampled groups, such as microbes, and technical challenges of consistent, regular monitoring across regions. There is also clear consensus that borealization is affecting phenology, species composition, community traits, population structure and essential habitats, species interactions, and ecosystem resilience. Non-dynamic environmental factors, such as depth and photoperiod, are thought to limit the complete borealization of the system, and may lead to intermediate, “hybrid” ecosystems in the future. We expect current borders of Arctic and boreal ecosystems to progress further northward and ultimately reach an equilibrium state with seasonal borealization. Risks to the system are difficult to estimate, as adaptive capacities of species are poorly understood. However, ice-associated species are clearly most at risk, although some might find temporary refuge in areas with a slower rate of change. We discuss the likely character of future Arctic ecosystems and highlight the uncertainties. Those changes have implications for local communities and the potential to support Blue Growth in the Arctic. Addressing these issues is necessary to assess the full scale of Arctic climate impacts and support human mitigation and adaptation strategies.publishedVersio
Barents Sea Capelin - Report of the Joint Russian-Norwegian Working Group on Arctic Fisheries (JRN-AFWG) 2024
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Broadband backscattering by Atlantic herring (Clupea harengus L.) differs when measured from a research vessel vs. a silent uncrewed surface vehicle
Full text linkBroadband frequency-modulated signals are believed to improve acoustic spectral-based target classification. Efficient use of uncrewed surface vehicles (USV) for fisheries science applications, with no possibility for biological sampling, is believed to be facilitated by use of broadband signals with methods for target classification. If the broadband frequency response used to train automated target classifiers are obtained from conventional research vessels (RVs), due to potential vessel avoidance, the swimming angle distribution may be different than for USVs. This may have consequences for target classification if the model is trained with RV data. The aim of this study was to assess whether the frequency response differs between platforms due to avoidance. Broadband acoustic data were collected with a conventional RV and a small USV. The broadband frequency response of Norwegian spring spawning herring obtained with the USV and RV was found to be significantly different for shallow herring layers in the 200 kHz band. This indicates that broadband frequency response has potential as a tool for real-time monitoring of behaviour reactions to vessels and to provide insight into fish behaviour in general. When using broadband frequency response for target classification, the potential platform-dependent broadband frequency response should be considered.Broadband backscattering by Atlantic herring (Clupea harengus L.) differs when measured from a research vessel vs. a silent uncrewed surface vehiclepublishedVersio
Novel large-scale mapping highlights poor state of sea trout populations
Full text link1. The state of sea trout in 1251 Norwegian watercourses was assessed based on a scoring system for human pressures, abundance data, and local knowledge. 2. Over 16,000 km of rivers and lakes were available to sea trout in these watercourses, spanning from the temperate to Arctic regions. 3. Sea trout were classified to be in a good or very good state in fewer than 25% of the watercourses and in a poor or very poor state in almost 40%. Twenty-nine watercourses had lost their sea trout populations. 4. Salmon lice from aquaculture salmon farms had by far the largest adverse effect on sea trout among the human impact factors, both in the number of watercourses (83%) and river area affected (60%), and the total effect on sea trout abundance. 5. Agriculture and hydropower production also had strong adverse impacts (35% and 19% of watercourses), but substantially lower than that caused by salmon lice. Culverts related to road crossings and other habitat alterations also had impacts on sea trout in many watercourses (27%). 6. Exploitation of sea trout has been reduced in Norway in recent years, both in the marine and freshwater fisheries. Yet, the exploitation pressure was moderate or high in almost 14% of the watercourses where the state of sea trout was poor or very poor, suggesting a high potential for overexploitation in these. 7. The state of sea trout was best in the northern sparsely populated areas. However, distribution of watercourses with sea trout in a poor or very poor state was more linked to aquaculture, agriculture, and hydropower production than human population density. 8. The developed approach for large-scale mapping of state and pressures, which is vital for prioritizing management measures, may inspire other nations in their conservation effort for this important species. acidification, anthropogenic pressures, brown trout (Salmo trutta), culverts, exploitation, hazardous substances, salmon lice (Lepeophtheirus salmonis), sewagepublishedVersio
Overview of the MOSAiC expedition: Ecosystem
Full text linkThe international and interdisciplinary sea-ice drift expedition “The Multidisciplinary drifting Observatory for the Study of Arctic Climate” (MOSAiC) was conducted from October 2019 to September 2020. The aim of MOSAiC was to study the interconnected physical, chemical, and biological characteristics and processes from the atmosphere to the deep sea of the central Arctic system. The ecosystem team addressed current knowledge gaps and explored unknown biological properties over a complete seasonal cycle focusing on three major research areas: biodiversity, biogeochemical cycles, and linkages to the environment. In addition to the measurements of core properties along a complete seasonal cycle, dedicated projects covered specific processes and habitats, or organisms on higher taxonomic or temporal resolution in specific time windows. A wide range of sampling instruments and approaches, including sea-ice coring, lead sampling with pumps, rosette-based water sampling, plankton nets, remotely operated vehicles, and acoustic buoys, was applied to address the science objectives. Further, a broad range of process-related measurements to address, for example, productivity patterns, seasonal migrations, and diversity shifts, were made both in situ and onboard RV Polarstern. This article provides a detailed overview of the sampling approaches used to address the three main science objectives. It highlights the core sampling program and provides examples of habitat- or process-specific sampling. The initial results presented include high biological activities in wintertime and the discovery of biological hotspots in underexplored habitats. The unique interconnectivity of the coordinated sampling efforts also revealed insights into cross-disciplinary interactions like the impact of biota on Arctic cloud formation. This overview further presents both lessons learned from conducting such a demanding field campaign and an outlook on spin-off projects to be conducted over the next years.Overview of the MOSAiC expedition: EcosystempublishedVersio