NINA Brage (Norsk institutt for naturforskning)
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Detection of Non-Native Pink Salmon (Oncorhynchus gorbuscha) in Swedish Rivers Using eDNA
Full text linkBiological invasions are increasing on a worldwide scale and can have severe ecological and economic consequences. Pink salmon (Oncorhynchus gorbuscha) have a native range in the Pacific Ocean but have been introduced and are now spreading in the Arctic and North Atlantic Oceans, including Sweden. A comprehensive eDNA sampling scheme was conducted in 27 river systems in south-western Sweden in 2023, with the aim to detect adult spawning pink salmon. We applied qPCR and dPCR analysis on aquatic eDNA samples. Results indicated the presence of pink salmon at 24 sites across 11 river systems. Pink salmon were not detected in any of the sampled rivers that drain into the Baltic Sea. However, pink salmon were present in a river only 35 km from the entrance to the Baltic Sea, which means there is a high risk pink salmon will spread into the Baltic Sea in the coming years. Catch reporting is generally low and camera fish counters are few across these systems; therefore, the strength of incorporating eDNA methods is beneficial for the development of pink salmon monitoring programs and aquatic invasive species management. alien invasive species | Baltic Sea | fish | North Sea | salmonid | watercoursepublishedVersio
Population and habitat assessments for conservation: Comparing national strategies for Canadian boreal caribou and Norwegian wild reindeer
No full textHabitat loss and fragmentation are major threats to biodiversity. While essential, demographic data alone may be insufficient to rapidly detect habitat-driven population declines and identify efficient management actions. This study explores how conservation strategies can use and integrate demographic and environmental information to detect, monitor and counter population declines. By comparing two extensive conservation strategies for Rangifer tarandus in Canada and Norway, we draw key insights for more comprehensive and actionable strategies. Conservation strategies often use multicriteria approaches combining population and habitat metrics, but seldom succeed in formally integrating these through a causal understanding of habitat-population relationships. The Canadian strategy probabilistically assesses the viability of boreal caribou populations both through direct population modeling, and by statistically linking habitat disturbance to recruitment - thus indirectly capturing habitat-mediated changes in predator-prey dynamics and their consequences on caribou vital rates. The Norwegian strategy develops an expert-based approach to score the quality of wild reindeer populations by combining assessments of habitat quality, connectivity, demography, genetics and health. While the Norwegian assessment is more locally anchored and explores a wider range of drivers, the Canadian one is more targeted and provides a statistical conversion rate between habitat and population metrics. Both assessments serve as a basis for follow-up management actions. This study highlights the need to intensify research to quantify cumulative anthropogenic impacts on the loss of functionally connected habitat, and their consequences on population viability. This would enable early-warning systems for assessing population declines, and help shape more targeted prevention, mitigation and restoration actionspublishedVersio
Complex relationships between marine growth and age at maturity in Atlantic salmon
Full text linkDrastic declines in abundance of Atlantic salmon have been attributed to ecosystem change at sea reducing growth in body size, which in turn could impact survival because mortality at sea may be size-selective. A less scrutinized hypothesis proposes that poor growth conditions at sea may also increase mortality if slow growing individuals need more time at sea to become sexually mature with a longer marine residence period also increasing mortality risk. However, published analyses of the relationship or reaction norm between marine growth and age at maturity in salmon suggest that poor growth is linked with both earlier and later maturation. Hence, understanding why these opposing norms of reaction for age at maturity arise may be critical for elucidating the effects of maturation timing on the dynamics of Atlantic salmon populations. As a step toward this goal, we explain how developmental threshold theory can account for the contrasting norms of reaction that have been observed between marine growth and age at maturity in salmon. To aid our explanation, we construct and interpret a growth in body length at sea vs. age at maturity reaction norm from nearly 4000 individuals returning to the River Namsen in Norway, showing that rapid marine growth can be linked with later maturation and that maturation age can be influenced by shifts in growth occurring during the marine migration. We discuss possibilities for future studies that might yield a better understanding of the relationship between growth at sea and age at maturity in Atlantic salmonpublishedVersio
Bridging the gap between science, policy and stakeholders: Towards sustainable wolf–livestock coexistence in human-dominated landscapes
Full text link1. While the return of wolves (Canis lupus) to many European countries is a conservation milestone, the negative impacts are unevenly distributed across society, placing high pressure on livestock grazing systems. 2. For this perspective, scientists from diverse disciplines and geographical backgrounds reflect on the state of livestock–wolf interactions in Europe and formulate recommendations for enabling wolf–livestock coexistence. 3. We argue that co-designing, co-implementing and co-disseminating research with key stakeholders, such as livestock farmers, is a productive approach to developing and implementing locally appropriate coexistence strategies. 4. Decision-making should be informed by scientific evidence. We recommend that ecological data on wolves and livestock are collected and shared across borders. Evidence from the social sciences is important for understanding the human dimension of wolf–livestock interactions. 5. We suggest bridging the gaps within multidisciplinary wolf–livestock research to strengthen interdisciplinary insights, comprehensively evaluate management approaches and guide governance and policy decisions that properly account for inherent complexities. 6. Policy implications: As wolf populations and their impacts continue to grow in Europe, policymakers at all levels must make decisions that adequately safeguard wolf populations while simultaneously protecting livestock and livelihoods. This requires access to reliable scientific evidence. adaptive management, Canis lupus, co-implementation, grazing systems, human–wildlife coexistence, interdisciplinary research, science communication, stakeholder engagementpublishedVersio
Uncertainties in ecosystem services assessments and their implications for decision support – A semi-systematic literature review
No full textEcosystem services (ES) assessments are rarely integrated into decision-making processes, with uncertainties often cited as a major barrier. While various uncertainties, such as modelling and data uncertainties, are inherent in ES assessments, their role in uptake of ES assessment results in decision-making remains unclear. We conducted a semi-systematic literature review of scientific papers assessing ES to reveal how uncertainties in ES assessments relate to ES uptake, i.e., the potential use of ES assessment results by decision makers. We performed logistic regressions to analyse the influence of three main sources of uncertainty on ES uptake, i.e., (i) modelling uncertainties, (ii) uncertainties related to qualitative and quantitative descriptions of scenarios, and (iii) uncertainties related to the transfer of ES assessment results into decision-making. Furthermore, we investigated if stakeholder involvement plays a role in ES uptake. First, and most importantly, the results indicate that clarifying the policy context can decrease decision uncertainty and thus improve ES uptake. Referring to a specific policy, following a decisive study purpose and documenting the intended policy entry point are factors that significantly enhance ES uptake. Second, the way how ES are modelled is related to ES uptake. Our results show that using multiple models to assess ES significantly promotes ES uptake. Third, involving stakeholders in ES assessments is significantly associated with increased documented uptake. We discuss that explicitly anchoring the assessment in a policy context increases the salience and timeliness of an ES study, assessing model uncertainties can lead to more credible results, and involving stakeholders can provide more legitimacy, which together increase the potential for ES assessments and their results to be used in decision-making. This study encourages future ES assessments to integrate uncertainties in order to support informed decision-making and promote the conservation and sustainable management of ecosystems and their services. ES, Uncertainty, Decision-making, Uptake, Stakeholders, Science-policypublishedVersio
Påvisning av infeksjoner hos pukkellaks Oncorhynchus gorbuscha ved bruk av HT-qPCR
Full text linkMo, T.A., Karlsson, S. & Fossøy, F. 2025. Påvisning av infeksjoner hos pukkellaks Oncorhynchus gorbuscha ved bruk av HT-qPCR. NINA Rapport 2532. Norsk institutt for naturforskning.
I juli 2023, ble 20 pukkellaks fanget i en fiskefelle i munningen av Syltefjordelva på nordsiden av Varangerhalvøya i Finnmark, mens 20 laks og 10 pukkellaks ble fanget i to kilenøter i Varangerfjorden. Ulike vevsprøver fra hver fisk ble analysert for forekomst av 47 ulike infektive organismer ved hjelp en spesiell PCR-maskin som kan analysere opptil 9.216 qPCR- reaksjoner (96 x 96) per kjøring. Totalt ble det påvist 14 ulike infektive organismer hos pukkellaks og laks. Seks infektive organismer ble påvist hos begge fiskearter, mens fire bare ble påvist i pukkellaks og fire bare ble påvist i laks. Store antall pukkellaks kan bidra til å øke smittepresset av ulike infektive organismer til villaks, sjøørret og sjørøye i havet og i elvene, men også til regnbueørret og oppdrettslaks i merder langs norskekysten.Mo, T.A., Karlsson, S. & Fossøy, F. 2025. Detection of infective organisms in pink salmon Oncorhynchus gorbuscha using HT-qPCR. NINA Report 2532. Norwegian Institute for Nature Research.
In July 2023, 20 pink salmon were caught in a fish trap at the mouth of the River Syltefjord on the north side of the Varanger Peninsula in Finnmark, while 20 Atlantic salmon and 10 pink salmon were caught in two bag-nets in the Varanger Fjord. Different tissue samples from each fish were analysed for the presence of 47 different infective organisms using a special PCR machine that can analyse up to 9,216 qPCR (96 x 96) reactions per run. In total, 14 different infective organisms were detected in pink salmon and Atlantic salmon. Six organisms were detected in both fish species, while four were only detected in pink salmon and four were only detected in Atlantic salmon. Large numbers of pink salmon can contribute to increased infection pressure of various infectious organisms to wild salmon, sea trout and sea char in the ocean and in rivers, but also to rainbow trout and farmed salmon in cages along the Norwegian coast.publishedVersio
Norsk insektovervåking. Rapport fra feltsesong 2024
Full text linkÅström, J., Gohli, J., Birkemoe, T., Brealey, J., Dahle, S., Davey, M., Ekrem, T., Fossøy, F., Laugsand, A., Opsahl, N., A., Solvang Klokke, V., Staverløkk, A. & Sverdrup‐Thygeson, A. 2025. Norsk insektovervåking. Rapport fra feltsesongen 2024. NINA Rapport 2526. Norsk institutt for naturforskning. http://hdl.handle.net/11250/3167288
Denne rapporten dokumenterer virksomheten i Norsk insektovervåking (NorIns) i 2024 og presenterer noen hovedfunn. Til denne rapporten har referansebasen for DNA‐strekkoder og rutinene for artsidentifisering fått en stor oppdatering, noe som har forbedret evnen til å identifisere det innsamlede materialet. Hele dataserien er kjørt igjennom på nytt, noe som betyr at resultater fra tidligere år også er oppdatert. Det totale artsantallet, og antallet rødlistede og fremmede arter, har derfor økt betydelig. Vi estimerer nå at overvåkingsprogrammet har fanget nesten 27 000 arter insekter siden starten i 2020 (sammenlignet med litt over 20 000 som ble rapportert i fjorårets rapport). I tillegg er det funnet et par hundre andre arter leddyr. De fleste av artene kan fortsatt ikke kobles til kjente referansestrekkoder og dermed få et artsnavn, men drøyt 6 200 arter har i denne versjon et artsnavn med tilstrekkelig konfidanse for å rapporteres. For hele Norge er det kjent ca. 20 000 arter insekter fra tidligere, altså betydelig færre enn hva bare dette overvåkingsprogrammet har registrert. Det er imidlertid velkjent at det mangler en fullstendig artsliste for alle insektarter i landet. Faktisk utgjøres en betydelig del av insektmangfoldet i Norge og den øvrige verden av såkalte «dark taxa», der artene enten er ukjente for vitenskapen eller svært vanskelige å skille. DNA‐metodikk er den eneste praktiske måten å håndtere et så stort og rikt materiale som dette i en løpende overvåking, og teknikken muliggjør også storskala overvåking av insekter som ennå ikke er navngitt.
I 2024 ble overvåkingen utvidet til å inkludere også semi‐naturlig mark på Vestlandet, og programmet er dermed landsdekkende for semi‐naturlig mark. Skog overvåkes foreløpig kun på Østlandet, men overvåkingsprogrammet ville hatt stor nytte av å inkludere denne habitattypen i flere regioner. Sammenlignet med andre land har Norge kommet langt med insektovervåking basert på malaisefeller og metastrekkoding, men det er planer på å implementere lignende overvåkingsmetodikk i øvrige deler av Europa.
Etter fire år med enhetlig nedgang snudde tallene for insektbiomasse opp på Østlandet og Sørlandet. Den tilsynelatende kraftige nedgangen er dermed brutt, selv om utviklingen varierer mellom regioner. Det kreves lengre tidsserier før man kan si noe om vedvarende trender i biomassen. Værvariabler fortsetter å forklare en stor del av variasjonen i fangstmengder, men dette dreier seg først og fremst om variasjoner innenfor sesongene eller mellom områder. Vi har fortsatt ikke en god kvantifisert forståelse av variasjoner mellom år, hvilket realistisk sett krever lengre tidsserier.
Det første omdrevet på Østlandet ble fullført i 2024 og vi kan nå oppsummere noe av insektfunnene i regionen. Vi ser tydelige mønstre i biomangfoldets fordeling, der høyde over havet er en kraftig prediktor og der det største mangfoldet finnes i dalførene og lavlandet omkring Oslo. Litt uventet viser ikke biomassen like tydelige mønstre. En foreløpig analyse antyder at temperatursummen er en viktig prediktor for insektaktiviteten, og datasettet kan brukes til å analysere trender og forskjeller i fenologi mellom ulike insektgrupper. Vi har også sett på hvordan sammensetningen av artssamfunnet – som kan betraktes som et fingeravtrykk av hvilke insekter du finner på et spesifikt sted – varierer over hele landet. Dette viser det unike ved hver nasjonale region, ved at forskjellen eller avstanden mellom individuelle artsfellesskap i stor grad samsvarer med deres geografiske plassering, og dermed ligner et nasjonalt kart.
Vi har i 2024 undersøkt resultatene av å knuse fangstene i vindusfeller før metastrekkoding, i håp om å forbedre identifiseringen av biller i skogslokalitetene. Dette ble såpass vellykket at vi anbefaler å fortsette med denne metodikken for vindusfeller. Gevinsten i mengden artsfunn vurderes som tilstrekkelig høy til å motivere tapet av muligheten til å etterprøve funnene. Det vurderes fortsatt som viktig å oppbevare det hovedsakelige fellematerialet fra malaisefellene, for verifisering av arer og for å muliggjøre videre analyser som ennå ikke er praktisk gjennomførbare.Åström, J., Gohli, J., Birkemoe,T., Brealey, J., Dahle, S., Davey, M., Ekrem, T., Fossøy, F., Laugsand, A., Opsahl, N., A., Solvang Klokke, V., Staverløkk, A. & Sverdrup‐Thygeson, A. 2025. Norwegian insect monitoring program. Report from the field season of 2024. NINA Report 2526. Norwegian Institute for Nature Research. http://hdl.handle.net/11250/3167288
This report documents the activities of Norwegian Insect Monitoring (NorIns) in 2024 and presents some key findings. For this report, the reference database for DNA barcodes and the routines for species identification have received a major update, which has improved the ability to identify the collected material. The entire data series has been re‐processed, meaning that results from previous years are also updated. The total number of species, and the number of red‐listed and alien species, has therefore increased significantly. We now estimate that the monitoring program has captured almost 27,000 insect species since its start in 2020 (compared to just over 20,000 reported in last year’s report). In addition, a couple of hundred other arthropod species have been found. Most of these species still cannot be linked to known reference barcodes and thus be given a species name. However, a little over 6 200 species of insects are now identified to species with enough confidence to be reported. For all of Norway, approximately 20,000 insect species are known from before, which is significantly fewer than what this monitoring program alone has recorded. However, it is well‐known that a complete species list for all insect species in the country is lacking. In fact, a significant part of the insect diversity in Norway and the rest of the world consists of so‐called “dark taxa,” where the species are either unknown to science or very difficult to distinguish. DNA methodology is the only practical way to handle such a large and rich material in ongoing monitoring, and it also enables large‐scale monitoring of insects that have not yet been identified.
In 2024, the monitoring was expanded to include semi‐natural land also in Western Norway, making the program nationwide for semi‐natural land. Forests are currently only monitored in Eastern Norway, but the monitoring program would benefit greatly by including this habitat type in the more regions. Compared to other countries, Norway has come far in insect monitoring based on malaise traps and metabarcoding, and there are aims to implement comparable monitoring programs in other parts of Europe.
After four years of a uniform decline, the figures for insect biomass turned upwards in Eastern and Southern Norway. The seemingly sharp decline has thus been broken, although the development varies between regions. Longer time series are required before anything can be said about sustained trends in biomass. Weather variables continue to explain a large part of the variation in catch quantities, but this primarily concerns within‐season or between‐locality variations. We still do not have a good quantified understanding of inter‐annual variations. Realistically, this also requires longer time series.
The first five‐year cycle in Eastern Norway was completed in 2024. We can now summarize some of the finds in the region and observe clear patterns in the distribution of biodiversity. Altitude is a powerful predictor, and the greatest diversity is found in the valleys and lowlands around Oslo. Somewhat unexpectedly, biomass does not show equally clear patterns. A preliminary analysis suggests that the temperature sum is an important predictor for insect activity, and the dataset can be used to analyze trends and differences in phenology among various insect groups. We have also looked at how the composition of the species community – which can be considered a fingerprint of which insects you find in a specific location – varies across the country. This highlights the uniqueness of each national region, in that the difference or distance between individual species communities largely corresponds to their geographical location, thus resembling a national map.
In 2024, we investigated the results of crushing window trap catches before metabarcoding, hoping to improve the identification of beetles in forest localities. This proved so successful that we recommend continuing with this methodology for window traps. The gain in the number of species findings is considered sufficiently high to outweigh the loss of the ability to verify the findings. It is still considered important to store the malaise trap material for species verification and to enable further analyses that are not yet practically feasible
Developing methodology for setting Favourable Reference Values for large carnivores in Europe. Report to the European Comission under contract N° 09.0201/2023/907799/SER/ENV.D.3 “Support for Coexistence with Large Carnivores. Task B.3 – Assessment of large carnivores’ conservation status”
Full text linkThis report aims to develop new guidelines for the setting of Favourable Reference Values (FRVs), which areneeded to assess Favourable Conservation Status (FCS), for the specific context of large carnivores (brown bear, Eurasian lynx, wolf, wolverine, golden jackal) in Europe. The work builds on the Guidelines for Population Level Management of Large Carnivores in Europe report that was published in 2008, but takes into account new developments in conservation science, new case law, experience with their
implementation, and the rapid development of the conservation status of large carnivores.
The need for these guidelines is underlined by the fact that until now relatively few member states have set quantitative values for their FRVs, and there is a massive degree in variation in the scientific basis for those that have. The need for specific guidance on large carnivores stems from both their specific ecology, with wide ranging movements and transboundary populations, and from their complex and often conflictful
relationship with humans.
In the report we explore the conceptual basis for setting FRVs. This involves trying to align best-practice and current scientific concepts with the legal / administrative language of the Habitat Directives and associated
guidance documents. In recent years conservation science has made important developments in multiple
relevant areas, including a shift away from the science of avoiding extinction to a science of planning for
species recovery and long term persistence. This involves a focus on building representation of ecological
conditions and building resiliency to changing environments, at least in part by ensuring redundancy. It also involves a greater focus on the long term genetics of populations in addition to shorter term demographic aspects. It is also important to recognise that conservation science has made important steps in mapping and understanding the diverse conflicts that are often associated with large carnivore populations in humanmodified landscapes.
As a result of this alignment between science and law / policy we developed a number of conceptual
recommendations that are important for developing functional FRVs. These include;
- Recognising FRVs as realistic and achievable targets for population recovery that represent the degree of member state contribution which is required for the collective conservation effort.
- Defining FRVs in terms of genetically effective population sizes aligned with the 50:500 heuristic. The 50
and 500 values refer to the effective population sizes required to minimise short term inbreeding and to
enable long-term adaptive capability respectively. Effective population size is a genetical concept, where the effective population size is typically between one third and one tenth of the total population size depending on species ecology.
- Recognising that FRVs, and FCS, are not necessarily absolute values. To be achievable they must be scaled to member state preconditions (size, area of habitat, landuse).
- Accordingly we propose a separation between population level FRVs that are pegged on absolute values
associated with genetically effective population sizes (often involving transboundary populations), and
member state level FRVs that are scaled to their preconditions as long as the contributions of all member
states sharing a population sum to a level that satisfies the population level FRV. In other words, FRVs and FCS are both absolute and relative concepts depending on the scale being considered.
- The need for large population sizes (FRP) requires a renewed focus on range (FRR) at national and
international levels and ensuring that there are widely dispersed populations with high degrees of
connectivity. Mapping and safeguarding this connectivity are important components of FRR.
- We also propose an additional focus on ensuring that range spans all Natura 2000 sites designated for the species, all relevant biogeographic regions, and all relevant ecosystem types. This helps address aspects related to the ecological functionality of large carnivores which have remained a neglected component of the definition of FCS.
- This approach requires a high degree of coordination in monitoring across borders, and with a strong focus on monitoring both demographic and genetical properties.
- These efforts would be enhanced by transboundary cooperation and the setting of joint management
plans, although we also propose post hoc mechanisms for larger scale assessment based on reports
submitted by member states.
We integrate these concepts into simple checklists that can guide the setting of the FRVs that are necessary to reach FCS at both population and member state levels. In addition, we provide illustrative scenarios of how current distributions relate to Natura 2000 sites and biogeographic regions, as well as illustrating how different degrees of connectivity and different parameter choices would influence the size of populations required to reach the recommended effective population sizes for the different species.
If these concepts are followed it should secure the long term conservation of large carnivores in Europe. The requirements can be jointly met through transboundary cooperation which shares the effort across member states, and for most populations can be realistically achieved.publishedVersio
Overvåking av insekter i hule eiker. Innsamling i region Vest i 2024
Full text linkJacobsen, R. M., Endrestøl, A., Hamre, Ø., Hanssen, O., Laugsand A. E., Tvete, K. O., Åström, J. 2025. Overvåking av insekter i hule eiker. Innsamling i region Vest i 2024. NINA Rapport 2561. Norsk institutt for naturforskning.
Hule eiker er en utvalgt naturtype i henhold til naturmangfoldloven på grunn av det store mangfoldet av arter som lever i hule eiker. Et stort antall arter av sopp, mose, lav og ikke minst insekter, har spesialisert seg på unike mikrohabitat som ofte finnes i hule eiker, som død ved i kronen eller på stammen, grov sprekkebark og vedmuld i hulrom. Svært mange av disse artene er sjeldne og flere er truet med utryddelse, fordi hule eiker dessverre er i nedgang.
I 2023 ble det på oppdrag fra Miljødirektoratet igangsatt en overvåking av insekter tilknyttet hule eiker (der hul eik er definert i henhold til naturmangfoldloven og dermed også inkluderer spesielt store eiketrær), med fokus på den svært artsrike gruppen biller. I tillegg til å informere om truede arters nåværende utbredelse, vil en flerårig overvåking kunne informere om trender og påvirkningsfaktorer for arter tilknyttet hule eiker.
Overvåkingen ble designet som en innsamling på to sett med 50 overvåkingstrær, med innsamling fra trær i region Øst (Østfold, Akershus, Vestfold og Telemark) i 2023, og innsamling fra trær i region Vest (Agder, Rogaland og Vestland) i 2024. Insekter ble samlet inn med to vindusfeller i hver eik, en i kronen og en ved hulrommet eller på stammen, og innsamlede biller ble identifisert morfologisk. Denne rapporten resultater fra innsamlingen i region Vest i 2024.
De 50 overvåkingstrærne i region Vest var fordelt på 31 lokaliteter (500 x 500 meters ruter), der to av lokalitetene lå i Vestland, to i Rogaland, og resten i Agder. Det ble registrert informasjon om eikene, blant annet forekomst av synlige hulrom (31 av overvåkingstrærne) og omkrets (gjennomsnitt 195 cm). Det ble hengt opp totalt 100 vindusfeller, som ble tømt fire ganger i perioden medio juni til medio september.
Det ble totalt fanget 1688 individer av biller, hvorav 1617 individer ble bestemt til 236 arter. Arter med død ved som levested (saproxyle) utgjorde 73,5% av individene og 66% av artene. I tillegg hadde 48 arter (496 individer) en kjent preferanse for eik eller andre løvtrær, hvorav 16 arter (147 individer) var kjent som eikespesialister. De dominerende billefamiliene var smellere (Elateridae), snutebiller (Curculionidae) og nebbiller (Salpingidae).
Det ble funnet 15 rødlista arter (54 individer), hvorav 11 arter (48 individer) var i kategorien nær truet, tre arter (3 individer) var i kategorien sårbar og en art (3 individer) var i kategorien sterkt truet i henhold til norsk rødliste (Artsdatabanken 2021). De rødlista artene ble samlet fra 20 forskjellige overvåkingstrær, de fleste trærne kun med en rødlisteart, mens eika «Støylen_12» hadde fire rødlistearter og naboeika «Støylen_8» på samme lokalitet i Åmli hadde to rødlistearter.
Den rødlista arten med flest individer var praktgullbasse (Gnorimus nobilis, 27 individer), mens de andre rødlista artene var representert med fem eller færre individer. De tre sårbare artene, som var representert med ett individ hver, var bløtbillen Malthinus facialis, vedboreren Melandrya caraboides og vedsoppbillen Mycetophagus decempunctatus, som alle er arter tilknyttet død ved av løvtrær. Den sterkt truede arten lindråtevedbille (Dromaeolus barnabita) ble påvist med ett individ fra en eik i Grimstad og to individer fra en eik i Risør.
Det var ingen tydelige forskjeller i gjennomsnittlig artsrikhet mellom fylkene Agder, Rogaland og Vestland. Derimot ble det samlet inn flere individer og arter fra region Øst i 2023, til tross for en kortere innsamlingsperiode (medio juni til og med juli i 2023), enn i region Vest. Gjennomsnittlig kostnad per feltrunde økte derimot for region Vest, grunnet større avstander til lokalitetene i Vestland og Rogaland. En grundigere analyse av datasettene fra region Øst og Vest kan gi bedre svar på hvor forskjellige artssamfunnene i de hule eikene er avhengig av geografisk område, og dermed hvorvidt overvåking må foregå i hele eikas utbredelse for å omfatte alle assosierte arter.Jacobsen, R. M., Endrestøl, A., Hamre, Ø., Hanssen, O., Laugsand A. E., Tvete, K. O., Åström, J. 2025. Monitoring of insects in veteran oaks. Sampling in region West in 2024. NINA Report 2561. Norwegian Institute for Nature Research.
Veteran oaks are defined as a selected nature type protected by the Norwegian Nature Diversity Act due to the high diversity of associated species. Very many species of fungi, lichen, moss and insects have specialised on unique microhabitats occurring in veteran oaks, such as dead wood in the canopy and on the trunk, coarse bark crevices and wood mould in hollows. Many of these species are rare and threatened with extinction, as veteran oaks are in decline.
The Norwegian Environmental Agency commissioned a survey of insects in veteran oaks in 2023, focusing on the very species rich group beetles. This survey will improve our knowledge of the current distribution of threatened species, and if it is repeated several years, it can inform about trends and stressors for species associated with veteran oaks.
The survey was designed with two sets of 50 trees, one set in region East (Østfold, Akershus, Vestfold and Telemark) and one set in region West (Agder, Rogaland and Vestland). Insects were sampled with two window traps in each oak, one in the canopy and one near a hollow or on the trunk, and beetles were identified morphologically. Insects were sampled in region East in 2023, while this report presents results from the insect sampling from region West in 2024.
The 50 monitored oaks in region West were distributed among 31 localities (500 x 500-meter squares), with two localities in Vestland, two in Rogaland and the rest in Agder. Characteristics of the oaks were registered, such as occurrence of visible hollows (31 of the monitored oaks) and circumference (average 195 cm). A total of 100 window traps were installed and emptied four times during the period mid-June until mid-September.
In total, 1688 beetle individuals were sampled, of which 1617 individuals were identified to 236 species. Species living in dead wood comprised 73,5% of the individuals and 66% of the species. Furthermore, 48 species (496 individuals) were known to prefer oak or other deciduous trees, while 16 species (147 individuals) were known to be oak specialists.
Fifteen red listed species (54 individuals) were collected, of which 11 species (48 individuals) were in the category near threatened, three species (three individuals) were in the category vulnerable and one species (three individuals) was in the category endangered, according to the Norwegian red list (Artsdatabanken 2021). The red listed species were sampled from 20 different oaks, with just one species from most trees, but four red listed species were collected from the oak «Støylen_12» and two from its neighbouring oak «Støylen_8» on the same locality in Åmli.
The red listed species with the most individuals was the noble chafer (Gnorimus nobilis, 27 individuals), while the other red listed species were represented with five or fewer individuals each. The three vulnerable species, each represented by only one individual in total, were the soldier beetle Malthinus facialis, the false darkling beetle Melandrya caraboides og the hairy fungus beetle Mycetophagus decempunctatus, all species associated with deciduous dead wood. The endangered species Dromaeolus barnabita occured with one individual sampled from an oak in Grimstad and two individuals from an oak in Risør.
There were no clear differences in average species numbers between the counties Agder, Rogaland and Vestland. However, more individuals and species were sampled in 2023 in region East, despite a shorter sampling period (mid-June until the end of July), than in region West. The average cost for each field trip to the oaks was higher in region West, due to greater distances to localities in Vestland and Rogaland. A more thorough analysis of the beetle data from both regions can indicate more clearly to what degree the species composition in veteran oaks differs due to geographic location, and whether monitoring should continue in the entire distribution area of oaks in order to include all species associated with veteran oaks
Bruk av genbank for ville laksefisk. Strategier for bevaring av anadrom laksefisk ved hjelp av levende og frossen genbank
Full text linkHagen, I.J., Bjøru, B., Bolstad, G.H., Holthe, E., Karlsson, S., Laikre, L., Lo, H., Skoglund, H. & Wacker, S. 2025. Bruk av genbank for ville laksefisk. Strategier for bevaring av anadrom laksefisk ved hjelp av levende og frossen genbank. NINA Rapport 2503. Norsk institutt for naturforskning.
De norske genbankene for anadrom laksefisk har vært avgjørende for å bevare bestander av laks og sjøørret i vassdrag infisert med lakseparasitten Gyrodactylus salaris. Etter hvert som bestander har blitt reetablert etter utryddelse av G. salaris har påvirkning fra blant annet lakselus og rømt oppdrettslaks ført til at nye bestander av laks og sjøørret er tatt inn i levende og frossen genbank.
I dette prosjektet har en ekspertgruppe, på oppdrag fra Miljødirektoratet, benyttet informasjon fra genbankene, data fra reetablerte bestander og eksisterende kunnskap for å vurdere strategier i norske genbanker for anadrome laksefisk. Ut fra hvordan strategiene i genbankene har vært, og det endrede trusselbildet, gir vi råd om hvilke strategier som vil være mest hensiktsmessig for fremtidig drift.
Det empiriske grunnlaget hadde utgangspunkt i laksebestandene i Røssåga, Rauma, Vefsna og Fusta, som alle nå er reetablerte etter utryddelse av G. salaris. For disse bestandene gjorde vi teoretiske analyser av effektiv bestandsstørrelse for å beregne tap av genetisk variasjon ved generasjonsskifter. Videre sammenliknet vi allelfrekvenser fra prøver av voksen laks i perioden da opphavsfisk ble innsamlet til genbank med stikkprøver av naturlig produsert og utsatt voksen laks og ungfisk i senere år. Dette har gitt informasjon om hvordan genetisk variasjon og integritet har blitt ivaretatt, både i innsamling til genbankene og i reetableringsfasen.
Undersøkelsene av Røssåga, Rauma, Vefsna og Fusta viste at krysningsregimet som har vært brukt i genbankene, der familier slåes sammen og antall familier halveres i hver generasjon fører til tap av genetisk variasjon i form av sjeldne alleler ettersom effektiv bestandsstørrelse reduseres. Videre viser prøvematerialet som er samlet inn under og etter reetablering, at det er betydelig innslag av genmateriale som ikke har opphav i genbanken blant naturlig produserte individer. Tilbakeføring av det genetiske materialet i genbanken har vært svært viktig for å reetablere bestandene, men har i begrenset grad klart å dominere genmaterialet i bestandene.
For fremtidig drift av genbankene anbefaler vi at frossen melke med opphav i så mange individer som mulig – med et mål om 200 ubeslektede individer – bør være grunnsteinen i genbankene. Innsamling av frossen melke bør skje på et tidlig tidspunkt mens genetisk variasjon og integritet fortsatt er god.
Ved langtidsbevaring over mange generasjoner uten at det gjøres utsettinger fra genbanken foreslår vi følgende strategi for fremtidig drift av genbankene:
● Under forutsetning av at det meste av den genetiske variasjonen er ivaretatt i frossen genbank behøver ikke den levende genbanken ha som mål å bevare all genetisk variasjon i bestandene, men i stedet ha som funksjon å videreføre mitokondriell variasjon og friske morlinjer til reetablering.
● Krysninger ved generasjonsskifter bør basere seg på 1x1 krysninger, innavl bør holdes så lav som mulig ved hjelp av optimale krysninger mellom individer hvis slektskap og foreldre er kjent og bestandsstørrelsen i genbankbestanden bør holdes konstant.
Dersom det skal gjøres fortløpende utsettinger fra genbanken, eller det er kort tid til reetablering (2-3 generasjoner), må genbankbeholdningen og krysningsregimet skaleres i forhold til produk-sjonsbehovet.
Teoretiske simuleringer, og erfaringer fra bestander som har blitt reetablert etter behandling med rotenon, tilsier at det kan være utfordrende å dominere bestanden med genbankmaterialet. Reetablering med genbankmateriale i bestander som er naturlig reetablerte eller har beholdt en betydelig bestandsstørrelse, vil kreve store utsettinger over lang tid for å tilbakeføre det opprinnelige genbankmaterialet i den ville bestanden. Under forutsetning om en forventet reduksjon i trusler innen et gitt tidsrom anbefaler vi derfor at utsettinger fra genbanken gjøres før truslene er fjernet for å opprettholde genetisk integritet og variasjon i den ville bestanden. Når trusler er fjernet og miljøsituasjonen er god bør en vurdere om utsettingene skal oppskaleres. Vi anbefaler at utsettinger fra genbank bør baseres på tidlige livshistoriestadier som rogn og yngel. Utsettinger fra genbank må evalueres og balanseres mot den ville gytebestanden slik at negative genetiske effekter unngås.Hagen, I.J., Bjøru, B., Bolstad, G.H., Holthe, E., Karlsson, S., Laikre, L., Lo, H., Skoglund, H. & Wacker, S. 2024. The use of gene banks for wild salmonids. Strategies for the preservation of anadromous salmonids using live and frozen gene banks. NINA Report 2503. Norwegian Institute for Nature Research.
The Norwegian gene banks for anadromous salmonids have been important for the preservation of Atlantic salmon and sea trout in catchments infected with the salmon parasite Gyrodactylus salaris. As populations have been reestablished after eradication of G. salaris, negative impacts from sea lice and escaped farmed salmon (among other threats) have led to new populations of salmon and sea trout being included in the live and frozen gene bank program.
The Norwegian Environment Agency appointed a group of experts to evaluate the Norwegian gene bank program using information from the gene banks, data from reestablished populations and current knowledge. Based on an evaluation of historic gene bank strategies, the expert group provides advice on which strategies that will be most appropriate considering the current threats to Norwegian anadromous salmonids.
Data from reestablished populations encompassed the salmon populations in the rivers Røssåga, Rauma, Vefsna and Fusta, now all reestablished after the successful eradication of G. salaris. We used theoretical analyses of effective population size to estimate the loss of genetic variation over generations. Furthermore, allele frequencies in samples from adult salmon collected during the time periods when founders were collected to the gene bank were compared to allele frequencies in adult and juvenile salmon of wild and stocked (from gene bank) origin. This analysis provided information on how genetic variation and integrity have been preserved among founders in the gene bank populations and during reestablishment of populations in their river of origin.
Evaluation of the populations in Røssåga, Rauma, Vefsna and Fusta showed that the current strategy for broodfish crossings, where families are fused and the number of families are halved in the making of each new generation, leads to a considerable loss of rare alleles due to an inherent reduction in effective population size. Moreover, samples collected during and after reestablishment show that in all four populations there was a considerable presence of naturally produced individuals that did not originate from gene bank releases. The releases of genetic material from the gene banks into the populations have been important for reestablishment but have only partially succeeded in dominating the gene pool in the reestablished populations.
For future processes in the gene banks we recommend that frozen milt originating from as many unrelated individuals as possible – ideally 200 individuals – should constitute the foundation for genetic variation in the gene banks. Collection of individuals for the preservation of milt should occur early in a population’s trajectory.
For preservation over many generations without releases from the gene banks to the wild populations we propose the following strategy for future processes:
● Under the prerequisite that (all) genetic variation is preserved in the frozen gene banks, the live gene banks need not aim to preserve all genetic variation in a population but rather preserve mitochondrial genetic variation and provide healthy females for use during reestablishment.
● In the making of new generations, broodfish should be crossed 1x1, inbreeding should be kept as low as possible, and the population size should be constant.
If the gene banks produce individuals for releases, or time to reestablishment is short (2-3 generations), then the number of brood fish and protocols for crossings must be adapted to the production needs.
Theoretical simulations and experience from reestablished populations suggest that reestablishing the genetic material preserved in the gene banks into the wild populations can be challenging, also where there are few naturally occurring spawners in the populations. Reestablishing the gene pool preserved in the gene banks into populations that are naturally reestablished or have kept a considerable population size will require large releases over a long period. Under the prerequisite that threats will be eliminated or sufficiently resolved within a given time frame, we therefore recommend that small-scale releases from the gene banks are done before threats are mitigated to increase genetic integrity and variation in the wild population. When threats are mitigated, and the environmental state is satisfactory, large-scale releases should be considered. Releases from the gene banks should be based on early life-history stages such as eyed eggs and alevins. Releases from the gene banks must be evaluated and balanced such that negative genetic effects do not occur.Miljødirektoratet: M-2882|202