Survey report (Part 2) from the joint Norwegian/Russian Ecosystem Survey in the Barents Sea and the adjacent waters August-October 2023 — Marine environment, Mesozooplankton, Commercial Demersal Fish, Fish Biodiversity, Commercial Shellfish, Benthic Invertebrate Community, Marine Mammals and Seabirds

The aim of the joint Norwegian/Russian ecosystem survey in the Barents Sea and adjacent waters, August-October (BESS) is to monitor the status and changes of in the Barents Sea ecosystem. The survey has since 2004 been conducted annually in the autumn, as a collaboration between the IMR in Norway and the Polar Branch of VNIRO (PINRO) in Russia. The general survey plan, tasks, and sailings routes are usually agreed at the annual PINRO-IMR Meeting in March, but in 2023, due to external factors making physical meetings between Norwegian and Russian researchers difficult, they were agreed by correspondence. Survey coordinators in 2023 was Dmitry Prozorkevich (PINRO) and Geir Odd Johansen (IMR). No exchange of Russian and Norwegian experts between their respective vessels in 2023. The 21th BESS was carried out during the period from 10th August to 7th October by the Norwegian research vessels “Kronprins Haakon”, “G.O. Sars” and “Johan Hjort”, and the Russian vessels “Vilnyus”. The scientists and technicians taking part in the survey onboard the research vessels are listed in Table 1. As always, we would like to express our sincere gratitude to all the crew and scientific personnel onboard RVs “Vilnyus”, “G.O. Sars”, “Kronprins Haakon” and “Johan Hjort” and for their dedicated work, as well as all the people involved in planning and reporting of BESS 2023. This is a first part of the survey report summarising the observations and status assessments based on the survey data. The information obtained in BESS 2023 will be further used for the implementation of various international and national projects, assessment of fish and invertebrate stocks, environmental monitoring, etc.Survey report (Part 2) from the joint Norwegian/Russian Ecosystem Survey in the Barents Sea and the adjacent waters August-October 2023 — Marine environment, Mesozooplankton, Commercial Demersal Fish, Fish Biodiversity, Commercial Shellfish, Benthic Invertebrate Community, Marine Mammals and SeabirdspublishedVersio

Diversification of marine aquaculture in Norway under climate change

Recently there has been increased interest in species diversification in aquaculture as a strategy to adapt to climate change. Since species diversification is a long-term strategy, climate change and future farming conditions must be considered. The aim of this study was to evaluate how changing temperatures under different IPCC climate scenarios may affect marine aquaculture species diversification in Norway. Since farm conditions vary between locations, this study focused on four geographic areas (South, West, North and Arctic) and three farms within each area. Using a climate model downscaling of three climate scenarios (Shared Socioeconomic Pathways; SSP1–2.6, SSP2–4.5, and SSP5–8.5), daily temperatures from the years 2020–2099 were evaluated at each farm location to identify challenging conditions for 34 species. A Challenging Conditions Index (CCI) was developed based on species thermal tolerances to compare the 34 potential aquaculture species. The results showed differences in the number of challenging days (hot and cold) between areas, and even within areas, highlighting the need to consider site-specific conditions. For warm-water species more commonly farmed in the Mediterranean (e.g. European seabass, gilthead seabream), the calibrated model projections at the investigated Norwegian farm sites suggest that cold temperatures would still be challenging. Differences in the number of challenging days between the climate scenarios become more apparent towards the mid and end of century, though all scenarios show interannual variation rather than a constant change in conditions over time. Hence, any species selected for diversification purposes will have to be able to tolerate a range of temperature conditions, and species with narrower tolerance ranges could be a risk. These findings underline the importance of considering the interannually varying conditions that species will be exposed to rather than focusing solely on long-term averages. Establishing a new large-scale commercial aquaculture species takes a considerable amount of time and resources. Therefore, to support interpretation of the results and further studies on diversification under climate change, this study also introduces Aquaculture Readiness Level (ARL®) as a consistent evaluation of the research and development status, progress towards commercialisation and climate action orientated production. As species will have to be able to tolerate a range of temperature conditions over different years, the level of knowledge, resources, and innovation will have to be continually enhanced to improve adaptive capacity.publishedVersio

Comparative study of fatty acid composition of muscles of Atlantic cod (Gadus morhua Linnaeus, 1758) with natural diet and feeding near salmon farms

Coastal aquaculture and local fisheries interact in shared marine environments, influencing each other synergistically and/or antagonistically. Salmon farming, notably with open-net sea cages along the Norwegian coast, attracts wild fish due to increased food availability from uneaten feed, but it also exposes wild fish to farm emissions like waste and toxic chemicals (de-lice treatments, antifouling and medical agents). The attraction behaviour of wild fish can impact fatty acid composition in fish tissues, influenced by the high terrestrial fat content in salmon aquafeed. We study how the Atlantic cod, aggregating around salmon farms in a subarctic fjord in Northern Norway, can be affected, potentially altering their natural diet and fatty acid profiles. Our study compares the muscle-tissue fatty acid compositions of cod caught near aquaculture facilities (impact) versus fish caught in neighbouring fjords (control), and we hypothesise decreased omega-3 fatty acids near farms. The analysis revealed no significant differences in the fatty acid concentrations or categories between the impacted and control fish, challenging our initial expectations. However, differences were found for C18:1(n9)t (elaidic acid), with a higher value in the impacted fish. These findings suggest that salmon farming’s influence on cod’s fatty acid profiles in the flesh (i.e., relevant for the nutritional quality of the fillets that consumers eat) may be limited or minimal despite their aggregative behaviours around farms. The threshold levels of salmon feed consumed by wild cod before it affects the quality and survival of, e.g., sperm or other life stages, are not known and require new investigations. This study underscores the complexity of interactions between aquaculture and wild fisheries, impacting both ecological dynamics and consumer perspectives on seafood quality and health benefits.Comparative study of fatty acid composition of muscles of Atlantic cod (Gadus morhua Linnaeus, 1758) with natural diet and feeding near salmon farmspublishedVersio

Sluttrapport for Frisk Oslofjord - 2018-2024

Det overordnede målet for «Frisk Oslofjord» prosjektene har vært å skape varig miljøbevissthet og engasjement for Oslofjorden gjennom undervisning og formidling bygget på kunnskap fra forskning, overvåkning og miljøkartlegging, samt legget et grunnlag for nye prosjekt og permanente løsninger.Sluttrapport for Frisk Oslofjord - 2018-2024publishedVersio

Rømt og vill fisk i Etneelva 2023 - Resultat fra Fjord- og Elvelaboratoriet i Etne

Hovudfokus ved feltstasjonen i Etne er miljøeffektar av havbruk, som genetisk påverknad frå rømt oppdrettslaks, lakselus og virussmitte. I 2023 vart fiskefella i Etneelva sett i drift 11. april og registreringa pågjekk til 8. november. Det var noko redusert fangseffektivitet i løpet av sesongen pga høg vassføring. I tilsaman 9 driftsdøgn (4% av driftstida) var fangsten i fella redusert pga høg vassføring. Tilsvarande reduksjon i fangsteffektivitet har vi også hatt i tidlegare år med 12 driftsdøgn (6% av driftstida) i 2022 og 9% i 2021. Fyrste villaks blei registrert i veke 19 og fyrste rømling i veke 29. I alt vart 2684 fiskar handtert på fella i 2023, mot 4063 i 2022, 3746 i 2021, 5093 i 2020 og 2693 i 2019. Av dei registrerte fiskane var 1095 villaks,1543 sjøaure, 23 pukkellaks og 23 rømte laks. I 2023 hadde 50% av villaksen vandra opp pr. veke 29, ni veker tidlegare enn rømlingane. Som tidlegare år dominerte storlaksen tidleg i oppvandringa medan terten dominerte i slutten av oppvandringsforløpet. For rømlingane registrert på fella varierte storleiken frå 0,59 kg til 6,31 kg, med ei overvekt av individ på 1,0 til 3,0 kg. Skjellkontrollen stadfesta oppdrettsbakgrunn til alle dei registrerte oppdrettslaksane. Av dei 23 registrerte rømlingane på fella, var 39% kjønnsmodne og 61% umodne. Gjennom uttaksfisket om hausten nedstraums fella i sone 1 og 2, vart det fanga 15 oppdrettslaksar. Av dei vart 2 (13%) klassifisert som modne, 13 (87%) vart klassifisert som umodne. Frå sportsfisket blei det rapportert inn 3 oppdrettslaksar nedstraums fella. Av dei 3 rapporterte rømlingane nedstraums, vart to verifisert ved skjellkontroll, og ein vart vurdera som villaks. I dei resterande skjellprøvane frå sportsfisket nedstraums fella, blei det ikkje oppdaga flerie rømlingar. I skjellmaterialet av villaks teke i fiskefella er det heller ikkje funne flerie rømlingar. Basert på registreringane i fiskefella og rapporteringar av sportsfisket i Elveguiden, er andel rømt fisk i 2023 redusert frå 2,1 % til omlag 0 %. Rundt 10 personar var i større eller mindre grad engasjert på fella og Havforskingsinstituttet sitt budsjett for drifta var ca 4 mill kroner med tillegg på 0,5 mill kroner frå OURO. Feltstasjonen i Etneelva framstår no som eit av dei mest nøyaktige målepunkta i Europa for rømt oppdrettsfisk, villaks og sjøaure. Med utgangspunkt i merksemda som feltstasjonen i Etneelva har fått i forskings- og forvaltingsmiljøa, er det etablert ei referansegruppe for Fjord- og elvelaboratoriet for å bidra til kunnskapsdeling og -utvikling og sikra best muleg utnytting av data, materiale og ressursar.Rømt og vill fisk i Etneelva 2023 - Resultat fra Fjord- og Elvelaboratoriet i EtnepublishedVersio

Risikorapport norsk fiskeoppdrett 2024 - Produksjonsdødelighet hos oppdrettsfisk og miljøeffekter av norsk fiskeoppdrett

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Blue mussel (Mytilus edulis) silage, a possible low trophic marine protein source for Atlantic salmon (Salmo salar L.)

Blue mussel (Mytilus edulis) could be a promising marine protein source in fish feeds and is of great interest since it can be cultivated along the Norwegian coastline. However, the use of blue mussels in feeds is dependent on developing suitable preservation and processing methods to produce a feed grade raw material. The present studies were conducted to investigate whether blue mussel silage could be used in the feed for Atlantic salmon post-smolt. Two feeding experiments were conducted using the same reference diet with FM inclusion of 25%, giving a mix of ∼59–63% plant-based ingredients vs ∼34–36% marine ingredients to simulate a standard grower feed for salmon post-smolts in SW. In experiment 1, fish were fed diets containing three different inclusion levels of blue mussel silage (BMS 3, 7, and 11%), a diet containing blue mussel meal (BMM) (12%) as well as the reference feed. In this experiment, the fish that were fed a diet containing BMS had a decline in both weight gain and condition factor when compared to the fish given the reference and BMM. The daily feed intake was similar in all groups, but the feed conversion ratio (FCR) increased in the fish fed BMS. The inclusion of BMS and BMM did not affect the digestibility of nutrients, but reduced retention of whole-body lipid and protein retention was observed. Salmon given BMS in the diet also had lower iron (Fe) concentrations in liver and whole body, indicating lower Fe uptake, irrespective of inclusion level. These findings were followed up in a second feeding experiment aiming to investigate whether different processing methods of blue mussel silage could influence the bioavailability of iron, as well as feed utilization and growth. The reference feed was formulated similar to the feed in exp. 1. Additionally, fish were fed diets containing BMM (9%) and the same batch of BMS (9%) used in exp. 1 as well as two diets containing new productions of BMS (9%) using either a lower acid level or only formic acid at the same level. In experiment 2, no differences were seen in weight gain, feed intake, FCR, nutrient retention or body composition between fish given BMS and reference diet. The lower Fe status observed in experiment 1 was not seen in the second study. In both experiments, there were no differences in fish welfare indicators between the group of fish fed with BMS, BMM and the reference group. The present results show that blue mussel silage can be used in the diet for Atlantic salmon, however, the different processing and preservation methods to produce BMS influence the nutritional properties and consequently growth performance and feed utilization of Atlantic salmon post-smolts.publishedVersio

Categorical data analysis using discretization of continuous variables to investigate associations in marine ecosystems

Understanding and predicting interactions between predators and prey and their environment are fundamental for understanding food web structure, dynamics, and ecosystem function in both terrestrial and marine ecosystems. Thus, estimating the conditional associations between species and their environments is important for exploring connections or cooperative links in the ecosystem, which in turn can help to clarify such directional relationships. For this purpose, a relevant and practical statistical method is required to link presence/absence observations with biomass, abundance, and physical quantities obtained as continuous real values. These data are sometimes sparse in oceanic space and too short as time series data. To meet this challenge, we provide an approach based on applying categorical data analysis to present/absent observations and real-number data. The real-number data used as explanatory variables for the present/absent response variable are discretized based on the optimal detection of thresholds without any prior biological/ecological information. These discretized data express two different levels, such as large/small or high/low, which give experts a simple interpretation for investigating complicated associations in marine ecosystems. This approach is implemented in the previous statistical method called CATDAP developed by Sakamoto and Akaike in 1979. Our proposed approach consists of a two-step procedure for categorical data analysis: (1) finding the appropriate threshold to discretize the real-number data for applying an independent test; and (2) identifying the best conditional probability model to investigate the possible associations among the data based on a statistical information criterion. We perform a simulation study to validate our proposed approach and investigate whether the method's observation includes many zeros (zero-inflated data), which can often occur in practical situations. Furthermore, the approach is applied to two datasets: (1) one collected during an international synoptic krill survey in the Scotia Sea west of the Antarctic Peninsula to investigate associations among krill, fin whale (Balaenoptera physalus), surface temperature, depth, slope in depth (flatter or steeper terrain), and temperature gradient (slope in temperature); (2) the other collected by ecosystem surveys conducted during August–September in 2014–2017 to investigate associations among common minke whales, the predatory fish Atlantic cod, and their main prey groups (zooplankton, 0-group fish) in Arctic Ocean waters to the west and north of Svalbard, Norway. The R code summarizing our proposed numerical procedure is presented in S4S1.publishedVersio

Assessment of genetically modified maize DP915635 for food and feed uses, import and processing under Regulation (EC) No 1829/2003 (application EFSA-GMO-NL-2020-172)

The Norwegian Scientific Committee for Food and Environment (VKM) has assessed an application for approval of the genetically modified maize DP915635 for food and feed uses, import and processing in the EU. In accordance with an assignment specified by the Norwegian Food Safety Authority (NFSA) and the Norwegian Environment Agency (NEA), VKM assesses whether genetically modified organisms (GMOs) intended for the European market can pose risks to human or animal health, or the environment in Norway. VKM assesses the scientific documentation regarding GMO applications seeking approval for use of GMOs as food and feed, processing, or cultivation. The EU Regulation 1829/2003/EC (Regulation) covers living GMOs that fall under the Norwegian Gene Technology Act, as well as processed food and feed from GMOs (dead material) that fall under the Norwegian Food Act. The regulation is currently not part of the EEA agreement or implemented in Norwegian law. Norway conducts its own assessments of GMO applications in preparation for the possible implementation of the Regulation. In accordance with the assignment by NFSA and NEA, VKM assesses GMO applications during scientific hearings initiated by the European Food Safety Authority (EFSA), as well as after EFSA has published its own risk assessment of a GMO, up until EU member countries vote for or against approval in the EU Commission. The assignment is divided into three stages. (link) Maize DP915635 DP915635 is a genetically modified maize that expresses the insecticidal protein IPD079Ea for control of corn rootworm pests, the enzyme phosphinothricin acetyltransferase (PAT) for tolerance to glufosinate-ammonium herbicides, and the enzyme phosphomannose isomerase (PMI) that was used as a selectable marker during development. The scientific documentation provided in the application for DP915635 maize is adequate for risk assessment, and in accordance with EFSA guidance on risk assessment of genetically modified plants for use in food or feed. The VKM GMO panel does not consider the introduced modifications in DP915635 maize to imply potential specific health or environmental risks in Norway, compared to EU-countries. The EFSA scientific Opinion is adequate also for Norwegian conditions. Therefore, a full risk assessment of DP915635 maize was not performed by the VKM GMO Panel. About the assignment: In stage 1, VKM shall assess the health and environmental risks of the genetically modified organism and derived products in connection with the EFSA scientific hearing of GMO applications. VKM shall review the scientific documentation that the applicant has submitted and possibly provide comments to EFSA. VKM must also consider: i) whether there are specific Norwegian conditions that could give other risks in Norway than those mentioned in the application, ii) whether the Norwegian diet presents a different health risk for the Norwegian population should the GMO be approved, compared to the European population, and iii) risks associated with co-existence with conventional and/or ecologic production of plants for GMOs seeking approval for cultivation. Relevant measures to ensure co-existence must also be considered. In stage 2, VKM shall assess whether comments from Norway have been satisfactorily answered by EFSA. In addition, VKM shall assess whether comments from other countries imply need for further follow-up. If EFSAs response to Norwegian comments is not satisfactory, or comments by other countries imply the need for further follow-up, VKM shall in stage 3 perform a risk assessment of these conditions, including conditions specific to Norway.Assessment of genetically modified maize DP915635 for food and feed uses, import and processing under Regulation (EC) No 1829/2003 (application EFSA-GMO-NL-2020-172)publishedVersio

Zinc nutrition at first feeding imprints a programming effect on growth and hepatic lipid metabolism in juvenile rainbow trout

The objective of this study was to determine whether supplementation with deficient zinc (Zn) or/and excess copper (Cu) in the first-feeding diet of rainbow trout fry influenced the growth and physiological regulation of juvenile fish subjected to similar challenge feeds again. The feeding trial lasted for 24 weeks and had three phases. In phase I, rainbow trout fry was treated with one of four different plant-based feeds containing or exempting Zn or Cu supplementation (coded Zn-Cu-, Zn+Cu-, Zn-Cu+, Zn+Cu+) for 6 weeks. Thereafter, all groups were fed a common commercial feed for the next 12 weeks (phase II). In phase III, all groups were fed with the “challenge diet” for another 6 weeks which was the basal diet (Zn-Cu-) except that the vegetable oils were replaced by fish oil. The results demonstrated that fish fed a Zn+ diet at first feeding increased larval growth (phase-I), but it had no effect on growth at the end of phase II when fed commercial feeds. In phase III, when re-introduced to a Zn- challenge diet, the feed intake and growth of juveniles with Zn+ history significantly increased, with reduced feed efficiency. Fish growth was neither influenced by dietary Cu levels or by the dietary Cu history in any of the growth phases, but dietary Cu excess (Cu+) reduced body lipid and energy content in fry. In phase I, lower whole-body Zn concentration was observed in the fry of Zn- group compared to Zn+, while the contrary was observed in the juvenile fish as affected by dietary Zn history (phase III). In addition, Zn- dietary history showed increased levels of PUFA and higher mRNA expression of fatty acid biosynthesis genes in the liver. To conclude, early-stage dietary Zn+ history improved growth of juvenile rainbow trout, while dietary Zn- history exhibited signs of improved fatty acid biosynthesis capacity in the liver.publishedVersio