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Fremmedstoffer i villfisk 2023 - Bestemmelse av uorganisk arsen, metylkvikksølv og PFAS i utvalgte sjømatprøver
Get PDFI dette prosjektet er det gjennomført analyser for uorganisk arsen, metylkvikksølv og perfluorerte alkylstoffer (PFAS) i ti ulike fiskearter samt reker fra norske havområder. Prøvematerialet var samlet inn gjennom ulike tidligere undersøkelser og hentet fra Havforskningsinstituttets lager av backup-prøver. Vi analyserte filetprøver av snabeluer (Sebastes mentella), breiflabb (Lophius piscatorius), lyr (Pollachius pollachius), rødspette (Pleuronectes platessa), blåkveite (Reinhardtius hippoglossoides), brosme (Brosme brosme), sei (Pollachius virens), torsk (Gadus morhua), lysing (Merluccius merluccius), hyse (Melanogrammus aeglefinus) og atlantisk kveite (Hippoglossus hippoglossus) samt hele og pillede dypvannsreker (Pandalus borealis), og prøvene hadde opprinnelse fra ulike deler av norske havområder.Fremmedstoffer i villfisk 2023 - Bestemmelse av uorganisk arsen, metylkvikksølv og PFAS i utvalgte sjømatprøverpublishedVersio
Per- and polyfluoroalkyl substances (PFAS) in surface sediments of the North-east Atlantic Ocean: A non-natural PFAS background
Get PDFThe extreme persistence and environmental mobility of per- and polyfluoroalkyl substances (PFAS) make their presence ubiquitous in the marine environment. Target analysis of 20 most common PFAS revealed the presence of nine perfluoroalkyl acids at low levels in surface sediments from five Norwegian marine areas covering the vast region from the eastern North Sea in the south to the Arctic Ocean north of Svalbard in the north. After correcting for sediment characteristics, no substantial difference in the sum of the nine PFAS (Σ9PFAS) between the five areas was found. Among separate compounds, PFOS, PFOA and PFNA dominate sample composition. Only two compounds, PFOS and PFUnDA, showed a statistically significant difference for one of the areas, the levels of these compounds being somewhat higher in the southernmost area than in the other areas. This may be due to local inputs in the fjords in this area. Open-sea and coastal sediments of the North-east Atlantic outside of locations with significant local sources seem to share a common, anthropogenic “PFAS background”, which may be part of a larger, global pattern.Per- and polyfluoroalkyl substances (PFAS) in surface sediments of the North-east Atlantic Ocean: A non-natural PFAS backgroundpublishedVersio
Are rigid sorting devices necessary to control size selectivity in demersal trawl fisheries?
Get PDFDiamond mesh codends are the most common size selectivity devices in trawls for releasing bycatch and undersized individuals. However, codend selectivity can vary due to the flexibility of the netting meshes, making discrimination by size between retained and released fish difficult to control. In some trawl fisheries, rigid sorting devices have been introduced to make size selection more controlled with sharper discrimination by size. However, the resulting size selectivity often does not show a sharp size selection. In the present study, we tested and compared the size selectivity performance of two “diamond-mesh codend designs” in the Barents Sea gadoid-trawl fishery: a four-panel codend, which was more rigid than a traditional two-panel codend design due to the additional selvedges, and a fully rigid codend design, that included a metal frame. The aim was to investigate the effect of added codend rigidness on the size selectivity of cod (Gadus morhua), haddock (Melanogrammus aeglefinus) and redfish (Sebastes spp.). In addition, the obtained results were compared to earlier research on size selectivity in this fishery including codends with different levels of rigidness and sorting grids. The results demonstrated that using a fully rigid codend did not result in a sharper size selectivity compared to a four-panel codend. Further, there was no indication that a rigid sorting grid makes size selectivity sharper than what can be obtained with a four-panel diamond mesh codend alone. There was also no proof that other codend stabilizing mechanisms such as shortened lastridge ropes could make the size selection sharper compared to the four-panel codend.publishedVersio
Advice on fishing opportunities for beaked redfish in 2025 and 2026 in ICES subareas 1 and 2
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Survey report for testing a sparker sound source on cod behavior (SpawnSeis Sparker) - Cruise report 2023200035
No full textThe SpawnSeis project aims at studying the behaviour of free-living cod to different sources of antropogenic sound, and previous experiments have been conducted with seismic air guns and a marine vibrator. This study test the effect of a sparker source, a sound source used to investigate the sea bottom e.g. before installations of wind farms. During 3 days in May 2023, tagged cod were exposed to 3 different source levels from the sparker source while their movement and vertical behaviour was monitored using acoustic telemetry. Sound from the sparker was recorded by hydrophones placed at two different distances from the source. A total of 6 exposure blocks were conducted. The maximum measured sound exposure level (SEL) in the area inhabited by the tagged cod was 125 dB re 1µPa2s. No appaerent movement away from the area by the cod could be detected from a first screening of the data, but more in depth analyses will be conducted.Survey report for testing a sparker sound source on cod behavior (SpawnSeis Sparker) - Cruise report 2023200035publishedVersio
Krabbespredning i nord - Toktrapport 2023200030
Get PDFTaskekrabbe (Cancer pagurus) har spredd seg nordover i Troms, men utbredelse og bestandstetthet i Nord-Norge har så langt ikke blitt kartlagt. Det er ukjent om taskekrabbens utbredelsesområder overlapper med kongekrabbens (Paralithodes camtschaticus). Forvaltningen av kongekrabbe utenfor det kvoteregulerte området (vest av Nordkapp) skal begrense spredningen, men arten har sannsynligvis etablert lokale bestander i deler av Troms. Toktet i 2023, sammen med planlagte tokt i 2024 og 2026, har til formål å kartlegge utbredelse og tetthet av taskekrabbebestanden og sammenligne resultatene med tilgjengelig data fra kystområder fra Vestlandet til Trøndelag. I løpet av perioden skal vi undersøke lokale forekomster av kongekrabbe i sørvestlige deler av Troms, samt bestemme mulig overlapp mellom de to artene. I tillegg skal observasjonsdata av krabbeartene i kombinasjon med miljødata brukes i artsutbredelsesmodellering. Data fra toktet er viktig for å etablere et datagrunnlag for å lage bestandsindikatorer for krabber i et viktig område for fiskeri- og havbruksnæringen.Krabbespredning i nord - Toktrapport 2023200030publishedVersio
Protokoll for vurdering av modningsgrad hos oppdrettstorsk
Get PDFDen gjeldende protokollen for vurdering av modningsnivået hos oppdrettstorsk skisserer distinkte modenhetsstadier hos både hann- og hunntorsk (Gadus morhua). Denne protokollen hjelper til med å evaluere graden av modenhet hos torsk i oppdrettsanlegg. Hvert stadium involverer en makroskopisk vurdering, som inkluderer bilder av gonadene både inne og utenfor fisken, detaljerte bilder, en generell beskrivelse av gonadene og fiskemålinger. I tillegg inkluderer det en mikroskopisk vurdering, med histologiske bilder og beskrivelser. Protokollen gir også retningslinjer for riktig innsamling av gonadeprøver fra hann- og hunntorsk for videre histologiske analyser.Protokoll for vurdering av modningsgrad hos oppdrettstorskpublishedVersio
Vurdering av kunnskapsgrunnlaget for bestemmelse av vandringsruter for vill postsmolt av atlantisk laks i Norge - Potensielle interaksjoner med planlagte områder for oppdrett til havs
Get PDFI denne rapporten vurderes kunnskapsgrunnlaget for å kunne estimere vandringsruter for vill postsmolt av atlantisk laks, og om disse overlapper med tre planlagte områder for oppdrett til havs. Kunnskapen om vandringsveier til postsmolt ut i havet og hva som kan påvirker postsmoltens vandringsvalg kommer i hovedsak fra forsøk med merking og gjenfangst av smolt. Det foreligger data både fra gjenfangst av fisk merket med ytre merker, og telemetriforsøk med akustisk merking og registrering på lyttebøyer. Fra pelagisk tråling i havet foreligger det data fra over 9 000 fangster av postsmolt gjennom årene, som kan gi et bilde på hvordan postsmolten fordeler seg i havet i ulike tidsperioder. Slike data er brukt til å utvikle en individuell vandringsmodell for norsk postmolt som presenteres i denne rapporten. Modellen estimerer sannsynlig vandringsrute for postsmolt fra ulike deler av Sør- og Midt-Norge og kvantifiserer sannsynlig overlapp mellom de planlagte havbruksområdene og postsmoltens vandring.Vurdering av kunnskapsgrunnlaget for bestemmelse av vandringsruter for vill postsmolt av atlantisk laks i Norge - Potensielle interaksjoner med planlagte områder for oppdrett til havspublishedVersio
Monitoring marine alien species in Norway - A pilot study for implementing a national program
Get PDFIn this pilot study we tested the efficiency of different methods to detect alien marine species in three different ports in Rogaland County. The methods used followed by far the recommendations in the HELCOM protocol, which is developed for the Baltic Sea, but also included beach survey, video survey, dredging and extensive use of DNA-methods. Material from zooplankton samples, scrapings from settlement panels as well as e-DNA samples from filtrated water and sediments were subject to meta-barcoding. A total of 33 alien species were recorded in this study, of which seven were door knockers to the Norwegian coast. The conventional methods recorded 19 alien species, and the methods RCS in marinas, settlement panels and beach surveys had the highest detection rate. DNA-methods detected 26 alien species, and scrapings from settlement panels and water samples were the most efficient methods. We recommend a combination of conventional and DNA-methods to be used in a national monitoring program. Although sampling of mobile fauna yielded no alien species in the pilot area we still recommend to use this method, being the best method for catching alien crabs and fishes.Monitoring marine alien species in Norway - A pilot study for implementing a national programpublishedVersio
Ecotoxicological assessment of Cu-rich acid mine drainage of Sulitjelma mine using zebrafish larvae as an animal model
Get PDFAcid mine drainage (AMD) is widely acknowledged as a substantial threat to the biodiversity of aquatic ecosystems. The present study aimed to study the toxicological effects of Cu-rich AMD from the Sulitjelma mine in zebrafish larvae. The AMD from this mine was found to contain elevated levels of dissolved metals including Mg (46.7 mg/L), Al (20.2 mg/L), Cu (18.3 mg/L), Fe (19.8 mg/L) and Zn (10.6 mg/L). To investigate the toxicological effects, the study commenced by exposing zebrafish embryos to various concentrations of AMD (ranging from 0.75% to 9%) to determine the median lethal concentration (LC50). Results showed that 96 h LC50 for zebrafish larvae following AMD exposure was 2.86% (95% CI: 2.32–3.52%). Based on acute toxicity results, zebrafish embryos (<2 hpf) were exposed to 0.1% AMD (Cu: 21.7 µg/L) and 0.45% AMD (Cu: 85.7 µg/L) for 96 h to assess development, swimming behaviour, heart rate, respiration and transcriptional responses at 116 hpf. Light microscopy results showed that both 0.1% and 0.45% AMD reduced the body length, eye size and swim bladder area of zebrafish larvae and caused phenotypic abnormalities. Swimming behaviour results showed that 0.45% AMD significantly decreased the locomotion of zebrafish larvae. Heart rate was not affected by AMD exposure. Furthermore, exposure caused a significant increase in oxygen consumption indicating vascular stress in developing larvae. Taken altogether, the study shows that even heavily diluted AMD with environmentally relevant levels of Cu caused toxicity in zebrafish larvae.acceptedVersio