Multi-decadal environmental change in the Barents Sea recorded by seal teeth

This work resulted from the ARISE project (NE/P006035/1, NE/P006000/1), part of the Changing Arctic Ocean programme, jointly funded by the UKRI Natural Environment Research Council (NERC). We thank Jim Ball for his help in the isotopic lab in Liverpool University. This work resulted from the ARISE project, part of the Changing Arctic Ocean programme.Multiple environmental forcings, such as warming and changes in ocean circulation and nutrient supply, are affecting the base of Arctic marine ecosystems, with cascading effects on the entire food web through bottom-up control. Stable nitrogen isotopes (δ15N) can be used to detect and unravel the impact of these forcings on this unique ecosystem, if the many processes that affect the δ15N values are constrained. Combining unique 60-year records from compound specific δ15N biomarkers on harp seal teeth alongside state-of-the-art ocean modelling, we observed a significant decline in the δ15N values at the base of the Barents Sea food web from 1951 to 2012. This strong and persistent decadal trend emerges due to the combination of anthropogenic atmospheric nitrogen deposition in the Atlantic, increased northward transport of Atlantic water through Arctic gateways and local feedbacks from increasing Arctic primary production. Our results suggest that the Arctic ecosystem has been responding to anthropogenically induced local and remote drivers, linked to changing ocean biology, chemistry and physics, for at least 60 years. Accounting for these trends in δ15N values at the base of the food web is essential to accurately detect ecosystem restructuring in this rapidly changing environment.Publisher PDFPeer reviewe

Report of the NAMMCO-ICES Workshop on Seal Modelling (WKSEALS 2020)

To support sustainable management of apex predator populations, it is important to estimate population size and understand the drivers of population trends to anticipate the consequences of human decisions. Robust population models are needed, which must be based on realistic biological principles and validated with the best available data. A team of international experts reviewed age-structured models of North Atlantic pinniped populations, including Grey seal (Halichoerus grypus), Harp seal (Pagophilus groenlandicus), and Hooded seal (Cystophora cristata). Statistical methods used to fit such models to data were compared and contrasted. Differences in biological assumptions and model equations were driven by the data available from separate studies, including observation methodology and pre-processing. Counts of pups during the breeding season were used in all models, with additional counts of adults and juveniles available in some. The regularity and frequency of data collection, including survey counts and vital rate estimates, varied. Important differences between the models concerned the nature and causes of variation in vital rates (age-dependent survival and fecundity). Parameterisation of age at maturity was detailed and time-dependent in some models and simplified in others. Methods for estimation of model parameters were reviewed and compared. They included Bayesian and maximum likelihood (ML) approaches, implemented via bespoke coding in C, C++, TMB or JAGS. Comparative model runs suggested that as expected, ML-based implementations were rapid and computationally efficient, while Bayesian approaches, which used MCMC or sequential importance sampling, required longer for inference. For grey seal populations in the Netherlands, where preliminary ML-based TMB results were compared with the outputs of a Bayesian JAGS implementation, some differences in parameter estimates were apparent. For these seal populations, further investigations are recommended to explore differences that might result from the modelling framework and model-fitting methodology, and their importance for inference and management advice. The group recommended building on the success of this workshop via continued collaboration with ICES and NAMMCO assessment groups, as well as other experts in the marine mammal modelling community. Specifically, for Northeast Atlantic harp and hooded seal populations, the workshop represents the initial step towards a full ICES benchmark process aimed at revising and evaluating new assessment models.Publisher PDFPeer reviewe

Pelagiske økosystem i De nordiske hav - grunnlagsstudie knyttet til åpningsprosess for utforskning og utvinning av havbunnsmineraler på norsk kontinentalsokkel

Denne rapporten er en leveranse til bestillingen «Grunnlagsstudie: Pelagisk økosystem» fra Oljedirektoratet til Havforskningsinstituttet. Studien er bestilt i forbindelse med at regjeringen har igangsatt en prosess for åpning av norsk sokkel for havbunnsmineralvirksomhet. Rapporten sammenstiller vår nåværende kunnskap om de pelagiske økosystemenes struktur og funksjon og belyser viktige kunnskapshull. Det er lagt særlig vekt på å beskrive økosystemkomponenter og prosesser som er essensielle for arbeidet med planprogram for konsekvensutredning av havbunnsmineralvirksomhet i norske havområder, og fokus vil derfor tidvis være litt annerledes enn det man vil finne i en generell beskrivelse av Norskehavet, Islandshavet og Grønlandshavet. Vi har lagt mer vekt på eksisterende kunnskapshull, og fokusert mer på utredningsområdet og på økologi og prosesser i pelagisk sone i dyphavet, enn det som kan forventes i for eksempel en lærebok om plankton-, fisk eller sjøpattedyrøkologi. Selv om formålet dermed har farget fokuset for beskrivelsene, beskriver kapitlene generell fordeling og økologi i de pelagiske systemene i Norskehavet, Islandshavet og Grønlandshavet.publishedVersio

Innspill til høring - Forslag til program for konsekvensutredning for mineralvirksomhet på norsk sokkel

Rapporten er et høringssvar sendt til Olje- og Energidepartementet i forbindelse med et forslag til konsekvensutredningsprogram for mineralvirksomhet på norsk kontinentalsokkel. I høringssvaret påpeker Havforskningsinstituttet at det er stor mangel på kunnskap, både med hensyn til biomangfold og økologiske forhold, men også når det gjelder teknologien som vil anvendes for utvinning av mineraler og metaller på havbunnen. Denne kunnskapsmangelen representerer en usikkerhet som bør synliggjøres i konsekvensutredningen, blant annet gjennom en risikoanalyse. Havforskningsinstituttet påpeker også at ulike initiativ når det gjelder kunnskapsinnhenting burde vært ferdigstilt før gjennomføringen av høringen. En grundigere oppsummering av rapportens innhold er gitt i første kapittel.publishedVersio

First results from the L3+C experiment at CERN

The L3+C experiment combines the high-precision spectrometer of the L3 detector at LEP, CERN, with a small air shower array. The momenta of cosmic ray induced muons can be measured from 20 to 2000 GeV/c. During the 1999 data taking period 5 billion muon events were recorded in the spectrometer. From April until mid Summer 2000 an additional 3 billion muon events have been recorded as well as 25 million air shower events. Here the first results on the muon momentum spectrum and charge ratio will be presented

Status for miljøet i norske havområder - Rapport fra Overvåkingsgruppen 2023

I denne rapporten gir Overvåkingsgruppen, for første gang, en felles vurdering av miljøtilstanden i Barentshavet og havområdene utenfor Lofoten, Norskehavet og Nordsjøen med Skagerrak. Det er også første rapport som bruker resultater fra det nylig utviklede fagsystemet for vurdering av økologisk tilstand. I denne rapporten dekkes to hovedtemaer: (1) Dominerende trekk i status og utvikling i økosystemet i alle tre havområdene, basert på vurderingene av økologisk tilstand, Overvåkingsgruppens rapport om forurensning fra 2022, indikatorer fra Overvåkingsgruppen som ikke er dekket under vurdering av økologisk tilstand, samt rapporter og annen relevant informasjon fra forskning, og (2) en vurdering av karbonbinding i marint plankton, marine vegetasjonstyper og marine sedimenter. I tillegg er det gitt en oppsummering for endringer i ytre påvirkning, vurdering av kunnskapsbehov samt en vurdering av indikatorverdier i forhold til referanseverdier og tiltaksgrenser. Vurderingen av dominerende trekk i utvikling og tilstand av miljøet som er gitt i kapittel 2, utgjør Overvåkingsgruppens bidrag til Faglig forums samlerapport om det faglige grunnlaget for revisjon og oppdatering av de helhetlige forvaltningsplanene for norske havområder.Status for miljøet i norske havområder - Rapport fra Overvåkingsgruppen 2023publishedVersio

Building time series of female reproductive parameters for Northeast Atlantic harp (Pagohilus groenlandicus) and hooded seals (Cystophora cristata)

Long term bilateral Russian/Norwegian scientific co-operation as a basis for sustainable management of living marine resources in the Barents Sea. Proceeding of the 12th Norwegian/Russian Symposium Tromsø, 21-22 August 200

Population genetic structure of grey seals (Halichoerus grypus) : Diversity, differentiation and prospects for genetic population assignment with special reference to Norwegian waters

Population structure of grey seal breeding colonies in Norway (n=300), Northwest Russia (n=40) and Scotland (n=100) is currently being investigated based on Mt-DNA control region sequencing and fragment analysis (8 microsatellite primers) applied to biopsies from live sampled pups. In addition, mixed adult/pup samples from Iceland (n=80), the Baltic Sea (n=50) and Canada (n=50) are included in the study, which thus spans the distributional limits of the main grey seal concentrations worldwide. In line with previous observations of a high degree of female philopatry in grey seals, preliminary results from Mt-DNA analyses show highly significant differentiation of 3 breeding populations along the Norwegian coastline. Both juvenile and adult grey seals are, however, capable of undertaking long distance migrations and mixing of non breeding animals from different populations has been documented by tagging studies. We analyse the grey seal sequence and microsatellite data with respect to genetic diversity and population differentiation and evaluate the potential for genetic assignment of native population to grey seals sampled out of the breeding season with particular focus on Norwegian waters. Depending on geographical resolution, assignment tests may be a valuable tool for assessing degrees of population intermixing in grey seals and for estimating population specific parameters such as huntig and bycatch mortality