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Introduction
I'm a specialist in Ecological Genetics and my work focuses on the application of genetic tools to fisheries management and conservation. I'm also interested in the impact of fisheries and resources utilization on population genetic diversity and their consequence on the evolutionary potential of species.
Current institution
Additional affiliations
September 2002 - August 2021
January 2000 - September 2002
January 1997 - December 1999
Tour du Valat - Université Montpellier II
Position
- PhD Student
Education
January 1997 - November 1999
Univeristy of Montpellier II
Field of study
- Evolutionary Ecology
Publications
Publications (233)
Capelin in the Iceland-East Greenland-Jan Mayen region has experienced a range shift over the last two decades potentially driven by climate change. The population now inhabits the east Greenland shelf during the late feeding season, instead of the north Iceland shelf as in the past. Spatial and temporal variation in phenotypic and life history tra...
Myctophids play an essential role in the marine ecosystem, linking the surface to the mesopelagic layer through diel vertical migration, and contributing to carbon sequestration. However, basic knowledge of their biology and distribution is still limited. Here, we described the length and age distribution, growth and otolith morphometrics for one o...
Sustainable fisheries management is important for the continued harvest of the world's marine resources, especially as they are increasingly challenged by a range of climatic and anthropogenic factors. One of the pillars of sustainable fisheries management is the accurate identification of the biological units, i.e., populations. Here, we developed...
Myctophids are one of the most diverse and abundant fish families in the mesopelagic zone, making them a key component in the marine pelagic community. In the North Atlantic, Benthosema glaciale (glacier lantern fish) is considered the most abundant myctophid north of 35° N, yet some regions within its extensive range lack information on its basic...
Capelin in the Iceland-East Greenland-Jan Mayen region has experienced a range shift over the last two decades potentially driven by climate change. The population now inhabits the east Greenland shelf during the late feeding season, instead of the north Iceland shelf as in the past. Spatial and temporal variation in phenotypic and life history tra...
The Greenland-Scotland Ridge is a submarine mountain that rises up to 500 m below the sea surface and extends from the east coast of Greenland to the continental shelf of Iceland and across the Faroe Islands to Scotland. The ridge not only separates deeper ocean basins on either side, that is, the North Atlantic and Arctic oceans, but also forms a...
Atlantic herring (Clupea harengus) feeding in the Norwegian Sea are assumed to consist of Norwegian spring spawners (NSSH), Icelandic summer spawners (ISSH) and North Sea autumn spawners (NSAH). Putative Norwegian autumn spawners (NASH), Faroese autumn (FASH) and spring (FSSH) spawners also feed in the area. Still, until there is a method to discri...
Genomic rearrangements have in recent years gained attention due to their evolutionary role in processes related to adaptation to local environmental conditions as well as diversification and speciation. In this study, we report on genomic rearrangements in the cold-water adapted polar cod (Boreogadus saida), a keystone Arctic fish species. By taki...
Capelin (Mallotus villosus) is both an important commercial and ecological resource of the North Atlantic subpolar region. Two decades ago, the stock distribution around Iceland drastically changed. During autumn, which corresponds to the main feeding period, the capelin stock was previously located between the North of Iceland and the Jan Mayen ar...
Í byrjun árs 2022 hófst átak í þorskrannsóknum og áætlað er að verkefnið taki fimm ár. Í verkefninu er lögð áhersla á þrjú megin viðfangsefni með það að markmiði að bæta ráðgjöf um veiðar á íslenska þorskstofninum. Rannsóknaefnin þrjú eru stofngerð þorsks, útbreiðsla ungviðis og fæðuvistfræði þorsks. Helstu verkefnin árið 2023 voru að safna erfðasý...
The stomach of a spotted wolffish (Anarhichas minor) caught in Icelandic waters was found to contain ~727 greater eelpout larvae (Lycodes esmarkii). All the larvae were of similar size and at a similar state of digestion, indicating they were all consumed together. The likely explanation for this observation is that greater eelpout lay their eggs i...
The harbour porpoise (Phocoena phocoena), a highly mobile cetacean species of the Northern Hemisphere, inhabits basins that vary broadly in salinity, temperature, and food availability; such variation can drive divergent adaptation among local populations. To shed light on range-wide population structure and local adaptation, we generated ddRAD seq...
Black ruff (Centrolophus niger) is a rare and poorly studied species found in both the Atlantic and Pacific Oceans and also in the Mediterranean Sea. It is sporadically caught south of Iceland during the annual International Ecosystem Summer Survey of the Nordic Seas. In total, 43 specimens were caught from 2009 to 2021, of which 41 specimens were...
In Icelandic waters, the diet of the harbour porpoise, a small marine mammal, has been studied using stomach content analysis of more than 1,000 bycaught individuals collected in 1991-1997. This analysis suggested that capelin was the predominant prey both in late winter and spring, while sandeel was dominant in the summer. However, this study was...
Black ruff (Centrolophus niger) is a rare and poorly studied species found in both the Atlantic and Pacific Oceans and also in the Mediterranean Sea. It is sporadically caught south of Iceland during the annual International Ecosystem Summer Survey of the Nordic Seas. In total, 43 specimens were caught from 2009 to 2021, of which 41 specimens were...
The Risso’s dolphin Grampus griseus (Cuvier 1812) is widely distributed in tropical and temperate waters of both the north and south hemispheres. In the North Atlantic Ocean, Risso’s dolphins have been observed from the equator to as far north as 64°N, and in recent years observations at 69°N latitude in coastal northern Norway has been reported (A...
Juveniles of Arctic Rockling (Gaidropsarus argentatus) occupy a different niche than their adult counterparts and have a distinct morphology, with silvery sides and dark backs. It is unknown how long the juveniles occupy the pelagic zone before descending to the benthic environment they inhabit as adults. Data on the species’ distribution and biolo...
The world oceans support diverse ecosystems in the mesopelagic zone (200-1000m), which are adapted to their physical environment. Around Iceland, cold Polar waters dominate the water masses north and east of the island, while warmer Atlantic waters dominate the south and west. This study aims to describe the mesopelagic layer (ML) around Iceland an...
In July 2022, two Risso's dolphins were reported stranded in Hrútafjörður (N65°
09,503; W21° 05,529), a fjord in northern Iceland. These events represent the first
confirmed observations and strandings of Risso's dolphins in Icelandic waters. Given
the uniqueness of these events, a decision was made to conduct full necropsies on
these individuals....
The harbour porpoise ( Phocoena phocoena ), a highly mobile cetacean species of the Northern hemisphere, inhabits basins that vary broadly in salinity, temperature, and food availability, and can drive divergent adaptation among local populations. To shed light on range-wide population structure and local adaptation, we generated ddRAD sequencing d...
During recent decades, the health of ocean ecosystems and fish populations has been threatened by overexploitation, pollution and anthropogenic‐driven climate change. Due to a lack of long‐term ecological data, we have a poor grasp of the true impact on the diet and habitat use of fishes. This information is vital if we are to recover depleted fish...
Í byrjun árs 2022 hófst átaksverkefni í þorskrannsóknum og áætlað er að verkefnið taki fimm ár. Í verkefninu er lögð áhersla á þrjú meginviðfangsefni, öll með það að markmiði að bæta ráðgjöf um veiðar á íslenska þorskstofninum. Þessari skýrslu er ætlað að gefa yfirlit yfir framgang verkefnisins árið 2022 en jafnframt er tekin saman staða þekkingar,...
Lumpfish (Cyclopterus lumpus) is a transatlantic marine fish displaying large population sizes and a high potential for dispersal and gene-flow. These features are expected to result in weak population structure. Here, we investigated population genetic structure of lumpfish throughout its natural distribution in the North Atlantic using two approa...
The availability of public genomic resources can greatly assist biodiversity assessment, conservation, and restoration efforts by providing evidence for scientifically informed management decisions. Here we survey the main approaches and applications in biodiversity and conservation genomics, considering practical factors, such as cost, time, prere...
Recent studies have uncovered patterns of genomic divergence in marine teleosts where panmixia due to high gene flow has been the general paradigm. These signatures of divergent selection are often impacted by structural variants, acting as “supergenes” facilitating local adaptation. The highly dispersing European plaice (Pleuronectes platessa)—in...
Sympatric organisms can avoid competition by occupying different ecological niches, a mechanism known as niche partitioning. In Iceland, white-beaked dolphins (Lagenorhynchus albirostris) and harbour porpoises (Phocoena phocoena) are the most common small cetaceans observed but their trophic ecology remains understudied, including the potential for...
Stock structure is of paramount importance for sustainable management of exploited resources. In that context, genetic markers have been used for more than two decades to resolve spatial structure of marine exploited resources and to fully fathom stock dynamics and interactions. While genetic markers such as allozymes and RFLP dominated the debate...
Supergenes are sets of genes that are inherited as a single marker and encode complex phenotypes through their joint action. They are identified in an increasing number of organisms, yet their origins and evolution remain enigmatic. In Atlantic cod, four megabase-scale supergenes have been identified and linked to migratory lifestyle and environmen...
Lumpfish ( Cyclopterus lumpus ) is a transatlantic marine fish displaying large population sizes and a high potential for dispersal and gene-flow. These features are expected to result in weak population structure. Here, we investigated population genetic structure of lumpfish throughout its natural distribution in the North Atlantic using two appr...
Progress in genome sequencing now enables the large-scale generation of reference genomes. Various international initiatives aim to generate reference genomes representing global biodiversity. These genomes provide unique insights into genomic diversity and architecture, thereby enabling comprehensive analyses of population and functional genomics,...
The photo identification process is based on the identification of a unique animal from a photograph of distinctive body features. Scientists compare these photographs to match one another and assign to an individual a series of observations and other relevant data.
As a leader in the use of Photo Identification in Iceland since the 1980´s, the MF...
Batoid fishes are among the most endangered marine vertebrates, yet conservation efforts have been confounded by incomplete taxonomy. Evidence suggest that the critically endangered ‘common skate’ actually represents two species: the flapper skate (Dipturus intermedius) and the blue skate (Dipturus batis). However, knowledge of the geographic range...
Supergenes are sets of genes that are inherited as a single marker and encode complex phenotypes through their joint action. They are identified in an increasing number of organisms, yet their origins and evolution remain enigmatic. In Atlantic cod, four large supergenes have been identified and linked to migratory lifestyle and environmental adapt...
Migration routes of exploited marine resources are often investigated using tracking methods such as satellite tags or Data Storage Tags (DSTs). However, this type of research crucially depends on the tagging and recapture effort, and is often unfeasible for small migratory pelagic fish such as capelin because of size constraints. We investigated t...
The rare occurrence of redfish (genus Sebastes) in the White Sea encouraged Rolskii et al. (Polar Biol 43:385-389, 2020) to investigate the species identity of two animals captured near the Sredniy Island at 40 m depth. They reported that their morphological description proved unreliable and that genetic evidence "clearly demonstrated" these redfis...
Biodiversity in the oceans has dramatically declined since the beginning of the industrial era, with accelerated loss of marine biodiversity impairing the ocean's capacity to maintain vital ecosystem services. A few organisms epitomize the damaging and long‐lasting effects of anthropogenic exploitation: some whale species, for instance, were brough...
The impacts of climate change on marine ecosystems can be seen in the changing distribution, migration, and abundance of species in the oceans. For some species this changing environment may be beneficial and can support population expansions. In the North Eastern Atlantic (NEA), the Atlantic mackerel (Scomber scombrus) is undergoing an increase in...
Humpback whales were near depletion during the mid-20th century, but for the last two decades they have been recovering rapidly, particularly in polar regions the last few years. The humpback is a migrating baleen whale whose behaviour is believed to be largely discrete between their winter breeding and summer feeding grounds. Recent research on th...
As a result of ocean warming, the species composition of the Arctic seas has begun to shift in a boreal direction. One ecosystem prone to fauna shifts is the Northeast Greenland shelf. The dispersal route taken by boreal fauna to this area is, however, not known. This knowledge is essential to predict to what extent boreal biota will colonise Arcti...
Homing and site fidelity of Atlantic wolffish Anarhichas lupus was studied at the main spawning ground and four different feeding grounds in Icelandic waters. A total of 883 fish were tagged with T-bar anchor tags, whereof 349 fish also received an internally implanted data storage tag (DST). The DSTs data revealed consistent year-to-year migration...
The advent of massive parallel sequencing technologies has resulted in an increase of studies based upon complete mitochondrial genome DNA sequences that revisit the taxonomic status within and among species. Spatially distinct monophyly in such mitogenomic genealogies, i.e., the sharing of a recent common ancestor among con-specific samples collec...
Highlights
Mitochondrial monophyly is commonly employed to define evolutionary significant units.
Monophyly may be caused by insufficient sampling or a recent common ancestor.
Mitogenomic studies are generally based on few samples and prone to sampling issues.
Expanded mitogenome sampling negates previous monophyly in fin whales.
Abstract
The adve...
As a result of ocean warming, the species composition of the Arctic seas has begun to shift in a boreal direction. One ecosystem prone to fauna shifts is the Northeast Greenland shelf. The dispersal route taken by boreal fauna to this area is, however, not known. This knowledge is essential to predict to what extent boreal biota will colonise Arcti...
Chromosomal rearrangements such as inversions can play a crucial role in maintaining polymorphism underlying complex traits and contribute to the process of speciation. In Atlantic cod (Gadus morhua), inversions of several megabases have been identified that dominate genomic differentiation between migratory and nonmigratory ecotypes in the Northea...
Morphology-based identification of North Atlantic Sebastes has long been controversial and misidentification may produce misleading data, with cascading consequences that negatively affect fisheries management and seafood labelling. North Atlantic Sebastes comprises of four species, commonly known as 'redfish', but little is known about the number,...
Significance
A rich archaeological record of fish-bone remains testifies to the millennia-long human exploitation of the natural resources of the oceans. In Europe, historical evidence demonstrates that an extensive international industry developed during the Middle Ages that exported preserved cod from the Lofoten Archipelago, northern Norway, to...
A variety of sex determination mechanisms can be observed in evolutionary divergent teleosts. Sex determination is genetic in Atlantic cod (Gadus morhua), however the genomic location or size of its sex-locus is unknown. Here, we characterize the sex-locus of Atlantic cod using whole genome sequence (WGS) data of 227 wild-caught specimens. Analyzin...
Biological data were retrieved from 3694 female Atlantic wolffish Anarhichas lupus collected in Icelandic waters at four locations during the breeding season using a long–term study spanning from 2002 to 2013.The main objective was to investigate reproduction investment and timing. In the main spawning ground, little temporal differences were obser...
The occurrence of natal homing in marine fish remains a fundamental question in fish ecology as its unequivocal demonstration requires tracking of individuals from fertilization to reproduction. Here, we provide evidence of long distance natal homing (> 1000 km) over more than sixty years in Atlantic cod (Gadus morhua), through genetic analysis of...
The origin and life history of 186 Atlantic salmon caught at sea within Icelandic waters were investigated using microsatellites
to assess the origin and scales and otoliths to assess freshwater and sea age. A total of 184 samples were aged using scales
or otolithes or both. Most of the samples were from individuals in their first year at sea (72.8...
Identification of genome-wide patterns of divergence provides insight on how genomes are influenced by selection and can reveal the potential for local adaptation in spatially structured populations. In Atlantic cod – historically a major marine resource – Northeast-Arctic- and Norwegian coastal cod are recognized by fundamental differences in migr...
Chosson-P, V.; Shears, G.; Rasmussen, M.; Bertulli, C.G,; Stevick, P.; Rickert, S.; Pampoulie, C.;. Sigurjónsson, J.; Víkingson, G. A., 2015, Long-distance migration pattern of Humpback whale (Megaptera novaeangliae) from Icelandic waters. , poster presented at Society for Marine Mammalogy’s 21st Biennial Conference, San Fransisco, USA, 12-14-2015
Fishing and climate change impact the demography of marine fishes, but it is generally ignored
that many species are made up of genetically distinct locally adapted populations that may show
idiosyncratic responses to environmental and anthropogenic pressures. Here, we track 80 years
of Atlantic cod (Gadus morhua) population dynamics in West Greenl...
Vertical divergence in marine organisms is being increasingly documented, yet much remains to be carried out to understand the role of depth in the context of phylogeographic reconstruction and the identification of management units. An ideal study system to address this issue is the beaked redfish, Sebastes mentella - one of four species of 'redfi...
Table S1 Microsatellite estimates of pairwise genetic differentiation among nine S. mentella collections.
Table S2 Genetic marker discordance among S. mentella samples for mitochondrial control region (mtDNA clades), rhodopsin SNPs and microsatellite genotype.
Table S3 Pairwise F
ST genetic differentiation among nine S. mentella collections. mtDN...
The genetic structure of Atlantic herring Clupea harengus L. was investigated in its north-easterly distribution in the Norwegian Sea and adjacent waters, using 23 neutral and one non-neutral (Cpa111) microsatellite loci. Fish from the suspected 2 main populations—the Norwegian spring-spawning herring (NSSH) and the Icelandic summer-spawning herrin...
The spectral sensitivity of visual pigments in vertebrate eyes is optimized for specific light conditions. One of such pigments, rhodopsin (RH1), mediates dim-light vision. Amino acid replacements at tuning sites may alter spectral sensitivity, providing a mechanism to adapt to ambient light conditions and depth of habitat in fish. Here we present...
Lumpfish, or lumpsucker, Cyclopterus lumpus (Linnaeus, 1758) is widely distributed in the North Atlantic Ocean. It has a considerable economic
value and substantial fisheries occur in several North Atlantic regions owing to the use of its fully ripe internal egg masses in the ovaries as an alternative
to sturgeon caviar. Despite being intensively f...
Inferring the number of genetically distinct populations and their levels of connectivity is of key importance for the sustainable management and conservation of wildlife. This represents an extra challenge in the marine environment where there are few physical barriers to gene-flow, and populations may overlap in time and space. Several studies ha...
Despite the striking physical and environmental gradients associated with depth variation in the oceans, relatively little is known about their impact on population diversification, adaptation and speciation. Changes in light associated with increasing depth are likely to alter the visual environment of organisms, and adaptive changes in visual sys...
The appeal of genetic inference methods to assess population genetic structure and guide management efforts is grounded in the correlation between the genetic similarity and gene flow among populations. Effects of such gene flow are typically genomewide; however, some loci may appear as outliers, displaying above or below average genetic divergence...
Degradation-specific processes and variation in laboratory protocols can bias the DNA sequence composition from samples of ancient or historic origin. Here, we identify a novel artifact in sequences from historic samples of Atlantic cod (Gadus morhua), which forms interrupted palindromes consisting of reverse complementary sequence at the 5' and 3'...
Due to an improved understanding of past climatological conditions, it has now become possible to study the potential concordance between former climatological models and present-day genetic structure. Genetic variability was assessed in 26 samples from different rivers of Atlantic salmon in Iceland (total of 2,352 individuals), using 15 microsatel...
Although the tendency of Atlantic salmon Salmo salar to form differentiated populations among rivers and among tributaries within large river systems (>100 km-long) is well documented, much less is known about population structure within small river systems (<30 km-long). In the present study, we investigated the genetic effects of straying of hatc...
Accurate prediction of species distribution shifts in the face of climate change requires a sound understanding of population diversity and local adaptations. Previous modeling has suggested that global warming will lead to increased abundance of Atlantic cod (Gadus morhua) in the ocean around Greenland, but the dynamics of earlier abundance fluctu...
Atlantic mackerel (Scomber scombrus L.) is a widely distributed commercially important pelagic species. Little is known about the stock structure of this species, but it is thought to be undergoing a range extension due to environmental changes. Knowledge of the stock structure under these changing conditions is fundamental for effective management...
Genetic structure of North Atlantic fin whale Balaenoptera physalus has now been studied for many years, from the early ages of allozymes to the most recently developed genetic techniques such as mtDNA and microsatellite loci, and even gene sequencing. Here in an attempt to clarify our general knowledge on the stock structure of this species, we su...
The genomic architecture underlying ecological divergence and ecological speciation
with gene flow is still largely unknown for most organisms. One central question is
whether divergence is genome-wide or localized in ‘genomic mosaics’ during early
stages when gene flow is still pronounced. Empirical work has so far been limited,
and the relative i...
The application of data storage tags bears the potential for a quantum leap in the research on fish migrations, because not only first-capture and recapture positions are known, but at least theoretically, the migration path during the period at large can be reconstructed. Position, however, cannot be measured directly but has to be estimated using...
Lumpfish (Cyclopterus lumpus L. 1758) are
widely distributed on both sides of the North Atlantic. They
are a commercially important species, but stock size estimates
have declined since the mid-1980s in Canada, Norway
and Iceland. Little is known about the biology of this species,
in particular the breeding migrations and population structure
which...
One of the main problems to the genetic structure of highly vagile pelagic species such as the cetacean lies in their almost continuous habitat, the lack of information on the location of their breeding ground and their potential connectivity. Most of the available data have often been collected at feeding grounds which might be composed of a mixtu...