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Evaluating the fillet quality and sensory characteristics of Atlantic salmon (Salmo salar) fed black soldier fly larvae meal for whole production cycle in sea cages
Full text linkThere is scarce research on the use of black soldier fly larvae (BSFL) meal in the diets of Atlantic salmon (Salmo salar) reared in a real farm. Thus, the current study aimed to evaluate the effect of feeding BSFL meal to salmon in terms of fillet quality and sensory analysis at farm level conditions. Fish were fed a total of three diets (pellet size; 4.5 mm and 9 mm); a control diet (Control: 0% BSFL meal) formulated using a standard commercial recipe, containing FM (10%) and plant-based proteins. Two experimental diets were formulated using partially defatted BSFL meal (53% crude protein), in which plant-based proteins at 37% inclusion level from the control diet (4.5 mm pellets) were replaced by BSFL meal at 5% (BSFL 5%) and 10% (BSFL 10%). While for the 9.0 mm pellets, plant-based proteins at 35% were replaced by the BSFL meal at 5% and 10% inclusion level. All the three diets were formulated to be iso-nitrogenous and iso-lipidic diets. Diets were assigned to the sea-cages in triplicate (12 ×12 m; 1900 m3); housing ∼6000 fish per cage from 173 ± 2.7 g to harvest size 3.45 ± 74 kg for a period of 13 months. Feeding salmon with BSFL meal had no negative impact on the general fillet physical, chemical, and nutritional parameters. The fillet sensory evaluation showed that the control samples were associated with the typical attributes such as fresh salmon taste, while BSLF 10% to rancid taste but these attributes were not significantly different among the dietary groups. Overall, the current study showed that diet containing BSFL meal did not affect the general fillet parameters compared to salmon fed a commercial diet and thus validate the inclusion of BSFL meal up to 10% reared for a whole production cycle in sea cages.publishedVersio
Kongekrabbe i norsk sone - Status og rådgivning for 2025
Full text linkBestandsvurderingen viser en økning i den høstbare kongekrabbebestanden, og det ser ut til at en redusert kvote i 2024 har resultert i en betydelig lavere fiskeridødelighet. Havforskningsinstituttet (HI) anbefaler at den totale fangsten av hannkrabbe for 2025 i kvoteregulert område ikke overstiger 1510 tonn. Dette korresponderer med forvaltningsmål på maksimalt 35% sannsynlighet for at fiskeridødeligheten overskrider Flim samt en mindre enn 10% sannsynlighet for at bestanden faller under Blim. HI anbefaler at det frie fisket utenfor det kvoteregulerte området opprettholdes for å redusere spredningshastigheten og sikre forvaltningsmålet om lav tetthet av kongekrabbe i dette området. HI anbefaler at bruk av fredningsperiode som forvaltningsverktøy videreføres og utvides til å gå fra april til mai. Ytterligere forlengelse av fredningen vil sikre stabilitet og god økonomi i fisket, med tanke på kvalitet på krabben. En utvidet fredningsperiode kan også bidra til å redusere andelen skadet kongekrabbe i bestanden. Om det ønskes reduksjon i andelen skadet krabbe, anbefaler derfor at det i tillegg til utvidet fredningsperiode, allokeres en økt kvoteandel til skadet krabbe. Andelen skadet krabbe i bestanden har i de siste fem årene variert mellom 15 og 30%.Kongekrabbe i norsk sone - Status og rådgivning for 2025publishedVersio
Coastal alterations influence deep water renewal in Norwegian sill fjords
Full text linkRecent observations have heightened concerns that the reduced density of coastal water is leading to a decrease in the frequency of basin water renewal in Norwegian sill fjords. There are indications that coastal water is becoming lighter due to climate change. The renewal of fjord basin water constitutes the primary source of oxygenation in these fjords, and many sill fjords naturally undergo stagnation periods lasting up to several years. In this paper, we have mapped alterations in coastal water using time series data from hydrographic measurements along the coastline, utilizing them as input for a simplified two-layer fjord model. We demonstrate that the temperature has risen, salinity has decreased, and consequently, the density of coastal water has declined since approximately 1990. At a depth of 10 m, the rise in temperature and the reduction in salinity made similar contributions to the decrease in density. However, at depths of 50 and 100 m, the increasing temperature emerged as the primary factor. The density exhibited a more substantial decrease in the upper layers compared to the lower layers. Consequently, not only was the water less dense, but the stability of the water column had also increased. The estimated temperature in the fjord basins increased after 1990 in 98 out of 101 evaluated fjords, with an average increase of 0.6 °C. The altered coastal stratification had an impact on the estimated work against the buoyant forces in the fjord basins. In 78 out of the 101 fjords, the work against buoyant forces by diapycnal mixing increased. In most of the fjord basins where the work against buoyant forces increased, the rise was insufficient to compensate for the decreasing density at the coast. Consequently, basin water renewal occurred less frequently in 65 out of the 101 fjord basins along the Norwegian coast.publishedVersio
The long-lived deep-sea bivalve Acesta excavata is sensitive to the dual stressors of sediment and warming
Full text linkHuman influence in the deep-sea is increasing as mining and drilling operations expand, and waters warm because of climate change. Here, we investigate how the long-lived deep-sea bivalve, Acesta excavata responds to sediment pollution and/or acute elevated temperatures. A. excavata were exposed to suspended sediment, acute warming, and a combination of the two treatments for 40 days. We measured O2 consumption, NH4+ release, Total Organic Carbon (TOC), and lysosomal membrane stability (LMS). We found suspended sediment and warming interacted to decrease O:N ratios, while sediment as a single stressor increased the release of TOC and warming increased NH4+ release in A. excavata. Warming also increased levels of LMS. We found A. excavata used protein catabolism to meet elevated energetic demands indicating a low tolerance to stress. A. excavata has limited capacity for physiological responses to the stressors of warming and sediment which may lead to decreased fitness of A. excavata.publishedVersio
Spatial distribution of small microplastics in the Norwegian Coastal Current
Full text linkHigh concentrations of microplastic (MP) particles have been reported in the Arctic Ocean. However, studies on the high-resolution lateral and vertical transport of MPs from the European waters to the Arctic are still scarce. Here, we provide information about the concentrations and compositions of MPs in surface, subsurface, and deeper waters (300 μm), and overall, SMPs 80 % of all detected MPs. However, no statistically significant geographical patterns were observed in SMP concentrations in surface/subsurface seawaters between the six sampling transects, suggesting a relatively homogeneous horizontal distribution of SMPs in the upper ocean within the NCC/Norwegian Atlantic Current (NwAC) interface. The Lagrangian particle dispersal simulation model further enabled us to assess the large-scale transport of MPs from the Northern European waters to the Arctic.publishedVersio
A gap analysis on modelling of sea lice infection pressure from salmonid farms. I. A structured knowledge review
Full text linkSustainability of aquaculture, an important component of the blue economy, relies in part on ensuring assessment of environmental impact and interactions relating to sea lice dispersing from open pen salmon and trout farms. We review research underpinning the key stages in the sea lice infection process to support modelling of lice on wild salmon in relation to those on farms. The review is split into 5 stages: larval production; larval transport and survival; exposure and infestation of new hosts; development and survival of the attached stages; and impact on host populations. This modular structure allows the existing published data to be reviewed and assessed to identify data gaps in modelling sea lice impacts in a systematic way. Model parameterisation and parameter variation is discussed for each stage, providing an overview of knowledge strength and gaps. We conclude that a combination of literature review, empirical data collection and modelling studies are required on an iterative basis to ensure best practice is applied for sustainable aquaculture. The knowledge gained can then be optimised and applied at regional scales, with the most suitable modelling frameworks applied for the system, given regional limitations.publishedVersio
Community composition and distribution of epi- and suprabenthic macrofauna in the bathyal, abyssal, and hadal zones of the northern North Pacific
Full text linkThe deep sea, Earth’s largest biome, harbors numerous unknown species. Prior to the AleutBio (Aleutian Trench Biodiversity Studies) expedition from July to September 2022, the Northeast (NE) Pacific at abyssal and hadal depths was virtually unexplored. Our study presents new findings from the AleutBio project on the macrofaunal composition of the Bering Sea (BS) and Aleutian Trench (AT) collected by means of an epibenthic sledge (EBS), comparing these results with data from the Kuril-Kamchatka Trench (KKT) and the Northwest (NW) Pacific. Additionally, we examine variations in macrofaunal composition and abundance across different regions and depths. A biogeographic gap analysis using data from the Ocean Biodiversity Information System (OBIS) and the Global Biodiversity Information Facility (GBIF) found that, out of 170,627 occurrence records from the North Pacific and Bering Sea, only 153 were from depths below 3,500 m. The AleutBio project addressed this gap by significantly expanding the dataset with 36,499 new records collected during the expedition using an EBS. Nearly 98% of the specimens were from five phyla: Arthropoda, Annelida, Mollusca, Echinodermata, and Nematoda, with Polychaeta, Copepoda, and Nematoda being the most abundant taxa. Although the number of individuals varied between stations, there was no significant decrease in abundance with increasing depth, and some hadal stations had similar numbers of invertebrates as abyssal stations. Regional differences were observed, with Polychaeta and Nematoda being dominant in the BS, and Copepoda more prevalent at western abyssal stations. Depth emerged as the key factor influencing macrofaunal distribution, with distinct patterns across bathyal, abyssal, and hadal depths. Comparisons with other NW Pacific regions, like the Sea of Japan and the Sea of Okhotsk, show that depth and water body isolation play crucial roles in shaping faunal communities. AleutBio’s extensive sampling below 3,500 m has vastly increased available data, aiding in the understanding and conservation of deep-sea biodiversity. While certain taxa showed patchy distributions, no significant differences in faunal composition were found between geographic areas or depth zones. These findings underscore the dynamic nature of deep-sea ecosystems and highlight the importance of depth in shaping macrofaunal communities, emphasizing the need for continued research in these fascinating environments.publishedVersio
Marine protected areas can be useful but are not a silver bullet for kelp conservation
Full text linkKelp forests are among the most valuable ecosystems on Earth, but they are increasingly being degraded and lost due to a range of human-related stressors, leading to recent calls for their improved management and conservation. One of the primary tools to conserve marine species and biodiversity is the establishment of marine protected areas (MPAs). International commitments to protect 30% of the world's ecosystems are gaining momentum, offering a promising avenue to secure kelp forests into the Anthropocene. However, a clear understanding of the efficacy of MPAs for conserving kelp forests in a changing ocean is lacking. In this perspective, we question whether strengthened global protection will create meaningful conservation outcomes for kelp forests. We explore the benefits of MPAs for kelp conservation under a suite of different stressors, focusing on empirical evidence from protected kelp forests. We show that MPAs can be effective against some drivers of kelp loss (e.g., overgrazing, kelp harvesting), particularly when they are maintained in the long-term and enforced as no-take areas. There is also some evidence that MPAs can reduce impacts of climate change through building resilience in multi-stressor situations. However, MPAs also often fail to provide protection against ocean warming, marine heatwaves, coastal darkening, and pollution, which have emerged as dominant drivers of kelp forest loss globally. Although well-enforced MPAs should remain an important tool to protect kelp forests, successful kelp conservation will require implementing an additional suite of management solutions that target these accelerating threats.publishedVersio
A unique warm–water oasis in the Siberian Arctic’s Chaun Bay sustained by hydrothermal groundwater discharge
Full text linkChaun Bay, located on the fringe of the East Siberian Sea, has been described since the mid-20th century to support a unique marine ecosystem that is atypical for the local Siberian Arctic. Here we use ship-board physical, biogeochemical and geological measurements taken in October 2020, along with hydrographic observations taken from land-fast ice in April 2023, to demonstrate that these warm-water biological communities are supported by hydrothermal submarine groundwater discharge that delivers heat, salinity, nutrients, and trace elements to the bay. We identify a cyclonic eddy that mixes the warm nutrient-rich groundwater with oxygen-rich surface water, resulting in a water mass within Chaun Bay that has similar physical and chemical properties to the highly productive waters of the North Pacific and Southern Chukchi Sea. The bay showed elevated concentrations of chlorophyll-a and zooplankton, and the abundance and species diversity of epibenthos significantly exceeded values observed elsewhere in the East Siberian Sea. The benthic communities contained a number of boreal species that are not typically found in the Arctic Ocean. We also observed Thysanoessa krill populations, a pelagic species generally considered an expatriate in Arctic waters.publishedVersio
Scenarios for offshore wind co-existence opportunities and trade-offs
Full text linkThis paper introduces the MARCO (MARine CO-existence scenario building) concept for using scenario exploration in stakeholder engagement processes in offshore wind. MARCO builds on spatial analyses using geographic information systems (GIS), and projections over time using system dynamics simulation models. We position the concept within the existing literature on tools for decision support and stakeholder participation, and provide a preliminary status on the spatial baselines, as well as example scenarios for area usage in offshore wind and implications, including risks and co-existence opportunities, on other sectors and nature.Scenarios for offshore wind co-existence opportunities and trade-offspublishedVersio