Esben Moland Olsen

• Bøhn, Thomas; Strøm, John Frederik; Sanchez-Jerez, Pablo; Keeley, Nigel B.; Johansen, Torild & Gjelland, Karl Øystein [Vis alle 14 forfattere av denne artikkelen] (2024). Ecological interactions between farmed Atlantic salmon and wild Atlantic cod populations in Norway: A review of risk sources and knowledge gaps. Reviews in Aquaculture. ISSN 1753-5123. doi: 10.1111/raq.12899.
• McQueen, Kate; Sivle, Lise Doksæter; Forland, Tonje Nesse; Meager, Justin James; Skjæraasen, Jon Egil & Olsen, Esben Moland [Vis alle 8 forfattere av denne artikkelen] (2024). Continuous sound from a marine vibrator causes behavioural responses of free-ranging, spawning Atlantic cod (Gadus morhua). Environmental Pollution (1987). ISSN 0269-7491. 344. doi: 10.1016/j.envpol.2024.123322.
• Olsen, Esben Moland; Karlsen, Ørjan & Skjæraasen, Jon Egil (2023). Large females connect Atlantic cod spawning sites. Science. ISSN 0036-8075. 382(6675), s. 1181–1184. doi: 10.1126/science.adi1826.
• Synnes, Ann-Elin; Olsen, Esben Moland; Jorde, Per Erik; Knutsen, Halvor & Moland, Even (2023). Contrasting management regimes indicative of mesopredator release in temperate coastal fish assemblages. Ecology and Evolution. ISSN 2045-7758. 13(12). doi: 10.1002/ece3.10745. Fulltekst i vitenarkiv Vis sammendrag

  The absence of functional top predators has been proposed as a mechanism acting to shape fish assemblages in temperate marine ecosystems, with cascading effects on lower trophic levels. We explore this scenario by comparing the trophic and functional status of fish assemblages in Norwegian marine national parks, open to fishing, to a nearby coastal seascape that harbors a system of marine protected areas (MPAs) including a no-take zone. Demersal fish assemblages were sampled using fyke nets over three consecutive seasons. Atlantic cod (Gadus morhua) is potentially a dominant top predator in this ecosystem, and historically, this and other gadids have been targeted by the full range of former and present fisheries. In the present study, we find that average body size of the Atlantic cod was significantly larger in the zoned seascape compared to the unprotected areas (mean ± SD: 36.6 cm ± 14.38 vs. 23.4 ± 7.50; p < .001) and that the unprotected seascape was characterized by a higher abundance of mesopredator fish species. These observations are consistent with the hypothesis that the protection of top predators within MPAs aids to control the mesopredator populations and provides empirical support to the notion that the present state of many coastal fish assemblages is driven by mesopredator release linked to functional depletion of large top predators.

• Durif, Caroline; Arts, M.; Bertolini, F.; Cresci, Alessandro; Daverat, F. & Karlsbakk, Egil Erlingsson [Vis alle 16 forfattere av denne artikkelen] (2023). The evolving story of catadromy in the European eel (Anguilla anguilla). ICES Journal of Marine Science. ISSN 1054-3139. 80(9), s. 2253–2265. doi: 10.1093/icesjms/fsad149. Fulltekst i vitenarkiv Vis sammendrag

  Anguillid eels were once considered to be the classic example of catadromy. However, alternative life cycles have been reported, including skipping the freshwater phase and habitat shifting between fresh, brackish, and saltwater throughout the growth phase. There is a lack of knowledge regarding these alternate life strategies, for example, the proportion of individuals in the population that adopt them compared to classic catadromy. We provide a description of these alternate life cycle strategies in temperate anguillids, their possible drivers, and the methods available to investigate them. These methods (lethal and non-lethal), include otolith microchemistry, fatty acid and stable isotope analyses, parasite identification, blood transcriptomics, and electronic tags. We argue that since the current management framework for the European eel and other temperate eels is based mainly on the freshwater component of the population, it ignores eels growing in saline waters. Many of the factors that are thought to be responsible for the precipitous decline of the eel population are more prevalent in freshwater systems. Therefore, the contribution of saline eels may be more important than currently estimated. The habitat-shifting ability of eels may be all the more crucial for the persistence and recovery of those species that are endangered.

• Monk, Christopher; Power, Michael; Freitas, Carla; Harrison, Philip M.; Heupel, Michelle & Kuparinen, Anna [Vis alle 10 forfattere av denne artikkelen] (2023). Atlantic cod individual spatial behaviour and stable isotope associations in a no-take marine reserve. Journal of Animal Ecology. ISSN 0021-8790. 92(12), s. 2333–2347. doi: 10.1111/1365-2656.14014. Fulltekst i vitenarkiv Vis sammendrag

  Foraging is a behavioural process and, therefore, individual behaviour and diet are theorized to covary. However, few comparisons of individual behaviour type and diet exist in the wild. We tested whether behaviour type and diet covary in a protected population of Atlantic cod, Gadus morhua. Working in a no-take marine reserve, we could collect data on natural behavioural variation and diet choice with minimal anthropogenic disturbance. We inferred behaviour using acoustic telemetry and diet from stable isotope compositions (expressed as δ13C and δ15N values). We further investigated whether behaviour and diet could have survival costs. We found cod with shorter diel vertical migration distances fed at higher trophic levels. Cod δ13C and δ15N values scaled positively with body size. Neither behaviour nor diet predicted survival, indicating phenotypic diversity is maintained without survival costs for cod in a protected ecosystem. The links between diet and diel vertical migration highlight that future work is needed to understand whether the shifts in this behaviour during environmental change (e.g. fishing or climate), could lead to trophic cascades.

• McQueen, Kate; Skjæraasen, Jon Egil; Nyqvist, D; Olsen, Esben Moland; Karlsen, Ørjan & Meager, Justin James [Vis alle 10 forfattere av denne artikkelen] (2023). Behavioural responses of wild, spawning Atlantic cod (Gadus morhua L.) to seismic airgun exposure. ICES Journal of Marine Science. ISSN 1054-3139. 80(4), s. 1052–1065. doi: 10.1093/icesjms/fsad032. Fulltekst i vitenarkiv
• Strøm, John Fredrik; Bøhn, Thomas; Skjæraasen, Jon Egil; Gjelland, Karl Øystein; Karlsen, Ørjan & Johansen, Torild [Vis alle 9 forfattere av denne artikkelen] (2023). Movement diversity and partial sympatry of coastal and Northeast Arctic cod ecotypes at high latitudes. Journal of Animal Ecology. ISSN 0021-8790. 92(10), s. 1966–1978. doi: 10.1111/1365-2656.13989. Fulltekst i vitenarkiv Vis sammendrag

  Movement diversity within species represent an important but often neglected, component of biodiversity that affects ecological and genetic interactions, as well as the productivity of exploited systems. By combining individual tracking data from acoustic telemetry with novel genetic analyses, we describe the movement diversity of two Atlantic cod Gadus morhua ecotypes in two high-latitude fjord systems: the highly migratory Northeast Arctic cod (NEA cod) that supports the largest cod fishery in the world, and the more sedentary Norwegian coastal cod, which is currently in a depleted state. As predicted, coastal cod displayed a higher level of fjord residency than NEA cod. Of the cod tagged during the spawning season, NEA cod left the fjords permanently to a greater extent and earlier compared to coastal cod, which to a greater extent remained resident and left the fjords temporarily. Despite this overall pattern, horizontal movements atypical for the ecotypes were common with some NEA cod remaining within the fjords year-round and some coastal cod displaying a low fjord fidelity. Fjord residency and exit timing also differed with spawning status and body size, with spawning cod and large individuals tagged during the feeding season more prone to leave the fjords and earlier than non-spawning and smaller individuals. While our results confirm a lower fjord dependency for NEA cod, they highlight a movement diversity within each ecotype and sympatric residency between ecotypes, previously undetected by population-level monitoring. This new knowledge is relevant for the management, which should base their fisheries advice for these interacting ecotypes on their habitat use and seasonal movements.

• Varnes, Bjørg Karin & Olsen, Esben Moland (2023). Fish community dynamics in a coastal no-take marine protected area compared to a harvested area before and after protection from fishing. ICES Journal of Marine Science. ISSN 1054-3139. 80(5), s. 1462–1471. doi: 10.1093/icesjms/fsad074. Fulltekst i vitenarkiv Vis sammendrag

  An ecosystem's ability to maintain key functions during environmental change is largely determined by its biodiversity. We compared fish species composition, richness, diversity, catch per unit effort (CPUE), and fish size between a 1.5 km2 no-take marine protected area (MPA) and a nearby fished area on the southern Norwegian coast annually for one decade (2011–2021), including before-protection status. In total, >26 thousand fish representing 31 species were sampled using a beach seine. No significant effect of protection was detected on either species richness, diversity, or evenness. For selected species of small-bodied intermediate predators, there was a significant decline in mean body size in the MPA area compared to the fished area, indicative of a response to protection involving trophic interactions. No significant effect of the MPA was detected on either CPUE or body size of Atlantic cod (Gadus morhua), a top predator mainly captured at the juvenile stage by our sampling. The limited responses seen in this study may be linked to the small size of the MPA compared to the dispersal and movement capabilities of species such as the cod.

• De Benito-Abelló, Carmela; Bentes, Luís; Sousa, Inês; Pedaccini, Marie; Villegas-Ríos, David & Olsen, Esben Moland [Vis alle 8 forfattere av denne artikkelen] (2022). Among-individual variation in white seabream (Diplodus sargus) spatial behaviour and protection in a coastal no-take area. ICES Journal of Marine Science. ISSN 1054-3139. 79(8), s. 2265–2276. doi: 10.1093/icesjms/fsac157.
• McQueen, Kate; Meager, Justin James; Nyqvist, Daniel; Skjæraasen, Jon Egil; Olsen, Esben Moland & Karlsen, Ørjan [Vis alle 9 forfattere av denne artikkelen] (2022). Spawning Atlantic cod (Gadus morhua L.) exposed to noise from seismic airguns do not abandon their spawning site. ICES Journal of Marine Science. ISSN 1054-3139. 79(10), s. 2697–2708. doi: 10.1093/icesjms/fsac203. Fulltekst i vitenarkiv
• Oomen, Rebekah Alice; Knutsen, Halvor; Olsen, Esben Moland; Jentoft, Sissel; Stenseth, Nils Christian & Hutchings, Jeffrey (2022). Warming Accelerates the Onset of the Molecular Stress Response and Increases Mortality of Larval Atlantic Cod. Integrative and Comparative Biology. ISSN 1540-7063. 62(6), s. 1784–1801. doi: 10.1093/icb/icac145. Fulltekst i vitenarkiv
• Skjæraasen, Jon Egil; Karlsen, Ørjan; Langangen, Øystein Ole Gahr; Meier, Sonnich; Dunlop, Katherine Mary & van der Meeren, Terje [Vis alle 14 forfattere av denne artikkelen] (2022). Attraction of cod Gadus morhua from coastal spawning grounds to salmon farms. Aquaculture Environment Interactions. ISSN 1869-215X. 14, s. 229–242. doi: 10.3354/aei00440. Fulltekst i vitenarkiv Vis sammendrag

  Wild fish aggregate at aquaculture net-pens, but the underlying mechanisms are not fully understood. This study examined how salmon farms attract coastal Atlantic cod Gadus morhua from their inshore spawning grounds. Acoustic receivers were deployed at 5 known cod spawning grounds and 6 salmon Salmo salar farms located at varying distances from these grounds in a mid-Norway study site. Cod were caught at each spawning ground annually from 2017-2019, fitted with acoustic transmitters and released (n = 535). A total of 289 tagged cod (54%) were detected at the salmon farms, with more cod detected at farms closest to the focal spawning grounds and at operational farms. The latter result is likely linked to the availability of feeding opportunities at farm locations. Those cod that were detected by the receivers spent less time at farms farther from their release locations. For the farm-associated cod, 70% were detected for <1 wk at the farms. However, 48 cod spent >1 mo close to the farms, with 1 individual staying 720 d underneath the farm. A total of 135 cod visited 2 or more farms, with farms in proximity more connected in terms of inter-farm movement. Some of the cod utilizing these local spawning grounds likely have considerable dietary input from salmon feed.

• Dunlop, Katherine Mary; Staby, Arved; van der Meeren, Terje; Keeley, Nigel B.; Olsen, Esben Moland & Bannister, Raymond [Vis alle 7 forfattere av denne artikkelen] (2022). Habitat associations of juvenile Atlantic cod (Gadus morhua L.) and sympatric demersal fish communities within shallow inshore nursery grounds. Estuarine, Coastal and Shelf Science. ISSN 0272-7714. 279. doi: 10.1016/j.ecss.2022.108111. Fulltekst i vitenarkiv Vis sammendrag

  Resolving the relationship between demersal fish and sublittoral biotic habitats and substrates is a key element in the protection of important nursery grounds for strengthening fish recruitment. In Norway, coastal Atlantic cod (Gadus morhua L.) is a commercially and culturally important demersal fish for Norwegian coastal communities, and in recent decades the stock has declined to such an extent that a plan to rebuild the stock to biologically safe limits has been implemented. Yet, little is known about the specific biotic and abiotic habitat associations of the early-life stages of coastal cod, which is important for the management and protection of the species. The same shallow, sublittoral zones are inhabited by juveniles and adults of other commercial demersal gadoids and wrasses. This study presents novel findings on associations between juvenile coastal cod and other demersal fish species with seafloor substrates and biological habitats, inferred from five years of extensive fyke net surveys. Newly settled 0-group cod were typically associated with eel grass and red algae biotic habitats on sand and shell sand substrates. However, there was an ontogenic habitat shift amongst one year old (1-group) individuals that became more ubiquitous with their biotic habitat or substrate type choices. The juvenile gadoids saithe (Pollachius virens) and pollack (Pollachius pollachius), were most associated with hard bottom dominated sites with saithe being more abundant at exposed sites, compared to pollack. Goldsinny wrasse (Ctenolabrus rupestris) and corkwing wrasse (Symphodus melops) appeared to favor sugar kelp forests and red algae. Overall, the study identifies the specific sublittoral biotic habitats and substrates important to different early life stages of juvenile coastal cod and other commercially important demersal fish, providing critical information needed for identifying candidate coastal habitats for protection.

• Sørdalen, Tonje Knutsen; Halvorsen, Kim Aleksander Tallaksen & Olsen, Esben Moland (2022). Protection from fishing improves body growth of an exploited species. Proceedings of the Royal Society of London. Biological Sciences. ISSN 0962-8452. 289(1987). doi: 10.1098/rspb.2022.1718. Fulltekst i vitenarkiv Vis sammendrag

  Hunting and fishing are often size-selective, which favours slow body growth. In addition, fast growth rate has been shown to be positively correlated with behavioural traits that increase encounter rates and catchability in passive fishing gears such as baited traps. This harvest-induced selection should be effectively eliminated in no-take marine-protected areas (MPAs) unless strong density dependence results in reduced growth rates. We compared body growth of European lobster (Homarus gammarus) between three MPAs and three fished areas. After 14 years of protection from intensive, size-selective lobster fisheries, the densities in MPAs have increased considerably, and we demonstrate that females moult more frequently and grow more during each moult in the MPAs. A similar, but weaker pattern was evident for males. This study suggests that MPAs can shield a wild population from slow-growth selection, which can explain the rapid recovery of size structure following implementation. If slow-growth selection is a widespread phenomenon in fisheries, the effectiveness of MPAs as a management tool can be higher than currently anticipated.

• Villegas-Ríos, David; Freitas, Carla; Moland, Even & Olsen, Esben Moland (2022). Eco-evolutionary dynamics of Atlantic cod spatial behavior maintained after the implementation of a marine reserve. Evolutionary Applications. ISSN 1752-4571. doi: 10.1111/eva.13483. Fulltekst i vitenarkiv
• Rohtla, Mehis; Moland, Even; Skiftesvik, Anne Berit; Thorstad, Eva Bonsak; Bosgraaf, Sebastian & Olsen, Esben Moland [Vis alle 8 forfattere av denne artikkelen] (2022). Overwintering behaviour of yellow-stage European eel (Anguilla anguilla) in a natural marine fjord system. Estuarine, Coastal and Shelf Science. ISSN 0272-7714. 276. doi: 10.1016/j.ecss.2022.108016. Fulltekst i vitenarkiv Vis sammendrag

  Like many animals, northern temperate eel can enter a hibernation-like state and become dormant during the winter. Knowledge of overwintering behaviour in eel is sparse and mainly based on anecdotal observations and a few experimental studies on thermal tolerance. We studied European eel (Anguilla anguilla) overwintering behaviour in a Skagerrak fjord in Southern Norway, during three consecutive years, using an array of acoustic receivers and acoustic tags with depth and temperature sensors. We obtained results from 55 yellow eel, of which 19 were studied for one winter, 35 for two winters and one for three winters. Dormancy was inferred to begin in September for the earliest individuals and lasted until May for the last, with the majority of eel dormant from at least late October–November until mid-April. The timing of dormancy was mainly related to photoperiod and less to temperature. More than 50% of eel became dormant when day length was <9 h and became active when day length was >14 h. Approximately 10% of eel remained active during the winter and 31% of eel changed their pattern between consecutive years. Some dormant individuals exhibited activity periods that interrupted their dormancy. Eel in the outer fjord nearer the open sea became dormant before eel in the inner more freshwater part of the fjord, and were dormant longer. Acoustic telemetry Overwintering North sea Winter ecology Dormancy Photoperiod

• Haraldstad, Tormod; Forseth, Torbjørn; Olsen, Esben Moland; Haugen, Thrond Oddvar & Höglund, Erik (2022). Empirical support for sequential imprinting during downstream migration in Atlantic salmon (Salmo salar) smolts. Scientific Reports. ISSN 2045-2322. 12. doi: 10.1038/s41598-022-17690-2. Fulltekst i vitenarkiv Vis sammendrag

  The precise homing of Atlantic salmon to their natal river and spawning grounds is the foundation for locally adapted genetically differentiated populations across rivers or across river sections. A sequential imprinting hypothesis states that salmon smolts may imprint on environmental clues along the outward migration route and then use this in reverse order to direct the spawning migration later in life. In this study, we provide empirical support for this hypothesis. PIT-tagged wild Atlantic salmon using a 2 km hydropower tunnel as downstream migrating smolts had a 18% (1SW) and 23% (2SW) lower probability of successfully migrating through the parallel river stretch as adult spawners compared to spawners that migrated through the same river stretch as smolts. These findings highlight how a fine-scale riverine migration route may be imprinted in wild Atlantic salmon smolts. From an applied perspective, these results stress the importance of not depriving smolts from parts of their migration route to ensure successful return of adults to their natal spawning grounds.

• Johansen, Kurt; Olsen, Esben Moland; Haraldstad, Tormod; Arlinghaus, Robert & Höglund, Erik (2022). Digital Data Help Explain Drivers of Angler Satisfaction: An Example from Southern Norway. North American Journal of Fisheries Management. ISSN 0275-5947. 42(5), s. 1165–1172. doi: 10.1002/nafm.10810. Fulltekst i vitenarkiv Vis sammendrag

  We analyzed trip-level self-reports collected by a cell phone app to understand angler satisfaction of fishing for sea trout Salmo trutta (anadromous Brown Trout) in southern Norway. We found no clear support for a positive relationship between trip outcome (catch or no catch) and angler satisfaction level. In the cases where sea trout was caught, however, there was a positive relationship between fish size and angler satisfaction level. A total of 52% of the captured sea trout were voluntarily released, and releases were unrelated to fish size. In conclusion, digital data collected via a cell phone app are useful to reveal patterns of angler behavior and satisfaction.

• Knutsen, Jan Atle; Kleiven, Alf Ring; Olsen, Esben Moland; Knutsen, Halvor; Espeland, Sigurd Heiberg & Sørdalen, Tonje Knutsen [Vis alle 15 forfattere av denne artikkelen] (2022). Lobster reserves as a management tool in coastal waters: Two decades of experience in Norway. Marine Policy. ISSN 0308-597X. 136. doi: 10.1016/j.marpol.2021.104908. Fulltekst i vitenarkiv Vis sammendrag

  The positive effects of reduced fishing pressure in marine protected areas (MPAs) are now well documented globally. Yet, evidence of MPA benefits from long-term replicated before-after control-impact (BACI) studies and their usefulness in protecting target species are still rare, especially in northern temperate areas. Scientific rigor in the monitoring of MPAs is considered important for obtaining trust and compliance and can increase interest and enthusiasm for the benefits of marine conservation. Off the coast of southern Norway, a MPA imple- mentation process started up in 2002. Based on comprehensive consultations with local fishers and managers, four experimental lobster reserves were appointed in 2004. Two years later (2006), the reserves came into effect as the Norwegian Directorate of Fisheries implemented regulations as a by-law of the Saltwater Fisheries Act that effectively banned all fixed gear. Long-term monitoring of the MPAs and adjacent control areas has enabled a rigorous scientific evaluation of the effects of these MPAs on lobster populations, including effects on density, growth, demography, behavior, and phenotypic diversity. As protection effects started to manifest, the lobster reserves attracted high public attention and were soon considered a credible supplement to traditional fisheries management. In the period from 2002 to 2021, more than 50 lobster reserves have been implemented in Norway. Here, we review the experiences since the lobster reserves were designated, implemented, and embraced by local communities in Norway, and over two decades have become an important tool for fishery management. Thoughts on the future of MPAs along the coast of Norway are discussed.

• Sodeland, Marte; Jentoft, Sissel; Jorde, Per Erik; Mattingsdal, Morten; Albretsen, Jon & Kleiven, Alf Ring [Vis alle 12 forfattere av denne artikkelen] (2022). Stabilizing selection on Atlantic cod supergenes through a millennium of extensive exploitation. Proceedings of the National Academy of Sciences of the United States of America. ISSN 0027-8424. 119(8). doi: 10.1073/pnas.2114904119. Fulltekst i vitenarkiv Vis sammendrag

  Life on Earth has been characterized by recurring cycles of ecological stasis and disruption, relating biological eras to geological and climatic transitions through the history of our planet. Due to the increasing degree of ecological abruption caused by human influences many advocate that we now have entered the geological era of the Anthropocene, or “the age of man.” Considering the ongoing mass extinction and ecosystem reshuffling observed worldwide, a better understanding of the drivers of ecological stasis will be a requisite for identifying routes of intervention and mitigation. Ecosystem stability may rely on one or a few keystone species, and the loss of such species could potentially have detrimental effects. The Atlantic cod (Gadus morhua) has historically been highly abundant and is considered a keystone species in ecosystems of the northern Atlantic Ocean. Collapses of cod stocks have been observed on both sides of the Atlantic and reported to have detrimental effects that include vast ecosystem reshuffling. By whole-genome resequencing we demonstrate that stabilizing selection maintains three extensive “supergenes” in Atlantic cod, linking these genes to species persistence and ecological stasis. Genomic inference of historic effective population sizes shows continued declines for cod in the North Sea–Skagerrak–Kattegat system through the past millennia, consistent with an early onset of the marine Anthropocene through industrialization and commercialization of fisheries throughout the medieval period.

• Kleiven, Alf Ring; Espeland, Sigurd Heiberg; Stiansen, Stian; Ono, Kotaro; Zimmermann, Fabian & Olsen, Esben Moland (2022). Technological creep masks continued decline in a lobster (Homarus gammarus) fishery over a century. Scientific Reports. ISSN 2045-2322. 12. doi: 10.1038/s41598-022-07293-2. Fulltekst i vitenarkiv Vis sammendrag

  Fishery-dependent data are frequently used to inform management decisions. However, inferences about stock development based on commercial data such as Catch-Per-Unit-Effort (CPUE) can be severely biased due to a phenomenon known as technological creep, where fishing technology improves over time. Here we show how trap improvement over nine decades has driven technological creep in a European lobster (Homarus gammarus) fishery. We combined fishing data, experimental fishing with contemporary and older trap types, and information on depletion effects during fishing seasons. The resulting standardized CPUE time series indicates a 92% decline in lobster abundance between 1928 and 2019 compared to 70% if technological creep is not corrected for. Differences are most pronounced within the last 40 years when the most substantial shift in gear technology occurred: an uncorrected CPUE index suggests an 8% increase in lobster abundance during this period, while the corrected CPUE index declined by 57%. We conclude that technological creep has masked a continuous stock decline, particularly in recent decades and largely driven by the shift from one- to two-chambered traps, as well as the ability of newer trap designs to capture larger lobsters. Our study confirms the importance of adequate standardization, including technological development, when using fishery dependent CPUE for monitoring and management of data-limited fisheries.

• Moland, Even; Fernández-Chacón, Albert; Sørdalen, Tonje Knutsen; Villegas-Rios, David; Thorbjørnsen, Susanna Huneide & Halvorsen, Kim Aleksander Tallaksen [Vis alle 14 forfattere av denne artikkelen] (2021). Restoration of Abundance and Dynamics of Coastal Fish and Lobster Within Northern Marine Protected Areas Across Two Decades. Frontiers in Marine Science. ISSN 2296-7745. doi: 10.3389/fmars.2021.674756. Fulltekst i vitenarkiv
• Haraldstad, Tormod; Haugen, Thrond Oddvar; Olsen, Esben M.; Forseth, Torbjørn & Höglund, Erik (2021). Hydropower-induced selection of behavioural traits in Atlantic salmon (Salmo salar). Scientific Reports. ISSN 2045-2322. 11. doi: 10.1038/s41598-021-95952-1. Fulltekst i vitenarkiv Vis sammendrag

  Renewable energy projects such as hydropower facilities contribute towards meeting the world`s growing energy demands and urgent need for mitigating climate change. However, such infrastructure has the potential to substantially alter the environment which, in turn, can induce new challenges related to for instance fish migration conditions. As a consequence, local adaptations related to pre-development migration conditions may be affected for influenced populations. To explore selection regimes operating at a river hydropower plant, we monitored Atlantic salmon smolt individuals during their seaward migration. When passing the hydropower plant, the smolts chose between a surface fish passage or a submerged turbine intake. Smolts were scored for behavioural type (basal locomotor activity, net restrain (a measure of escape responses) and willingness to leave a familiar environment) prior to their migration choice, and we found that smolts with high basal activity had higher probability of using the fish passage than the turbine intake. In addition, migration route choice was a partly consistent trait in that fish that had previously passed a hydroelectric facility by using a fish passage rather than the turbine intake were significantly more likely to use it again when faced with the same choice. Higher mortality among turbine migrants could potentially reduce or eliminate particular behaviour types within populations- and the corresponding population genetic diversity that is essential to cope with future environmental challenges.

• Skjæraasen, Jon Egil; Karlsen, Ørjan; Langangen, Øystein Ole Gahr; van der Meeren, Terje; Keeley, Nigel B. & Myksvoll, Mari Skuggedal [Vis alle 12 forfattere av denne artikkelen] (2021). Impact of salmon farming on Atlantic cod spatio-temporal reproductive dynamics. Aquaculture Environment Interactions. ISSN 1869-215X. 13, s. 399–412. doi: 10.3354/AEI00415. Fulltekst i vitenarkiv
• Villegas-Ríos, David; Claudet, Joachim; Freitas, Carla; Moland, Even; Thorbjørnsen, Susanna Huneide & Alonso-Fernández, Alexandre [Vis alle 7 forfattere av denne artikkelen] (2021). Time at risk: Individual spatial behaviour drives effectiveness of marine protected areas and fitness. Biological Conservation. ISSN 0006-3207. 263, s. 1–11. doi: 10.1016/j.biocon.2021.109333. Fulltekst i vitenarkiv
• Kristensen, Martin Lykke; Olsen, Esben Moland; Moland, Even; Knutsen, Halvor; Grønkjær, Peter & Koed, Anders [Vis alle 8 forfattere av denne artikkelen] (2021). Disparate movement behavior and feeding ecology in sympatric ecotypes of Atlantic cod. Ecology and Evolution. ISSN 2045-7758. 11(16), s. 11477–11490. doi: 10.1002/ece3.7939. Fulltekst i vitenarkiv
• Fernández-Chacón, Albert; Buttay, Lucie; Moland, Even; Knutsen, Halvor & Olsen, Esben Moland (2021). Demographic responses to protection from harvesting in a long-lived marine species. Biological Conservation. ISSN 0006-3207. 257, s. 1–10. doi: 10.1016/j.biocon.2021.109094. Fulltekst i vitenarkiv
• Thorbjørnsen, Susanna Huneide; Moland, Even; Villegas-Ríos, David; Bleeker, Katinka; Knutsen, Halvor & Olsen, Esben Moland (2021). Selection on fish personality differs between a no-take marine reserve and fished areas. Evolutionary Applications. ISSN 1752-4571. 14(7), s. 1807–1815. doi: 10.1111/eva.13242. Fulltekst i vitenarkiv
• Freitas, Carla; Villegas-Ríos, David; Moland, Even & Olsen, Esben Moland (2021). Sea temperature effects on depth use and habitat selection in a marine fish community. Journal of Animal Ecology. ISSN 0021-8790. 90(7), s. 1787–1800. doi: 10.1111/1365-2656.13497. Fulltekst i vitenarkiv
• Martin, Angela Helen; Pearson, Heidi; Saba, Grace & Olsen, Esben Moland (2021). Integral functions of marine vertebrates in the ocean carbon cycle and climate change mitigation. One Earth. ISSN 2590-3330. 4(5), s. 680–693. doi: 10.1016/j.oneear.2021.04.019. Fulltekst i vitenarkiv Vis sammendrag

  In the last decade, the ocean has absorbed a quarter of the Earth’s greenhouse gas emissions through the carbon (C) cycle, a naturally occurring process. Aspects of the ocean C cycle are now being incorporated into climate change mitigation and adaptation plans. Currently, too little is known about marine vertebrate C functions for their inclusion in policies. Fortunately, marine vertebrate biology, behavior, and ecology through the lens of C and nutrient cycling and flux is an emerging area of research that is rich in existing data. This review uses literature and trusted data sources to describe marine vertebrate C interactions, provides quantification where possible, and highlights knowledge gaps. Implications of better understanding the integral functions of marine vertebrates in the ocean C cycle include the need for consideration of these functions both in policies on nature-based climate change mitigation and adaptation, and in management of marine vertebrate populations.

• Claireaux, Marion; Dos Santos Schmidt, Thassya C.; Olsen, Esben Moland; Slotte, Aril; Varpe, Øystein & Heino, Mikko [Vis alle 7 forfattere av denne artikkelen] (2020). Eight decades of adaptive changes in herring reproductive investment: The joint effect of environment and exploitation. ICES Journal of Marine Science. ISSN 1054-3139. 78(2), s. 631–639. doi: 10.1093/icesjms/fsaa123. Fulltekst i vitenarkiv Vis sammendrag

  Reproductive investment is a central trait for population dynamics and productivity. Fishing and environmental variations are major drivers affecting population structure, dynamics, and adaptation of life-history and behavioural traits. However, those factors are often considered independently, and few studies take into account their joint effect. In this study, we investigate the contribution of environment, fishing pressure, and intra-specific competition to variation in the reproductive investment of the Norwegian spring-spawning herring (Clupea harengus), a stock that has been fished for centuries, and monitored for decades. Reproductive investment and post-spawning weight were affected differently by growth rate (measured as mean age-at-length), sea surface temperature, North Atlantic Oscillation, and spawning stock biomass in periods with no fishing, unselective fishing, and low but size-selective fishing. We hypothesize that those changes can be explained by direct effects of exploitation such as age truncation and changes in migration patterns. Our results highlight how fishing, by affecting population-level dynamics, can modify the impact of environmental variations on life-history traits. Clupea harengus, environmental variation, fishing, Norwegian spring-spawning herring, trade-offs

• Perälä, Tommi; Olsen, Esben Moland & Hutchings, Jeffrey (2020). Disentangling conditional effects of multiple regime shifts on Atlantic cod productivity. PLOS ONE. ISSN 1932-6203. 15(11), s. 1–16. doi: 10.1371/journal.pone.0237414. Fulltekst i vitenarkiv
• Villegas-Ríos, David; Freitas, Carla; Moland, Even; Thorbjørnsen, Susanna Huneide & Olsen, Esben M. (2020). Inferring individual fate from aquatic acoustic telemetry data. Methods in Ecology and Evolution. ISSN 2041-210X. 11(10), s. 1186–1198. doi: 10.1111/2041-210X.13446. Fulltekst i vitenarkiv
• Fernández-Chacón, Albert; Villegas-Ríos, David; Moland, Even; Baskett, Marissa L.; Olsen, Esben Moland & Carlson, Stephanie M. (2020). Protected areas buffer against harvest selection and rebuild phenotypic complexity. Ecological Applications. ISSN 1051-0761. 30(5). doi: 10.1002/eap.2108. Fulltekst i vitenarkiv
• Sørdalen, Tonje Knutsen; Halvorsen, Kim Aleksander Tallaksen; Vøllestad, Leif Asbjørn; Moland, Even & Olsen, Esben Moland (2020). Marine protected areas rescue a sexually selected trait in European lobster. Evolutionary Applications. ISSN 1752-4571. 13(9), s. 2222–2233. doi: 10.1111/eva.12992. Fulltekst i vitenarkiv
• Haraldstad, Tormod; Höglund, Erik; Kroglund, Frode; Olsen, Esben Moland; Hawley, Kate Louise & Haugen, Thrond Oddvar (2020). Anthropogenic and natural size-related selection act in concert during brown trout (Salmo trutta) smolt river descent. Hydrobiologia. ISSN 0018-8158. 2020. doi: 10.1007/s10750-020-04329-4. Fulltekst i vitenarkiv Vis sammendrag

  By hindering migration and inducing direct turbine mortality during downstream migration, hydropower is regarded as one of the most serious threats to anadromous salmonids. Yet, little attention has been paid to long-term turbine-induced selection mechanisms effecting fish populations. This work evaluates turbine and post-turbine survival of PIT-tagged wild brown trout smolts. By estimating individual river and sea survival rates, we were able to compare survival rates of smolts that had migrated through the turbine with smolts that had bypassed the turbine, as well as investigate both natural and anthropogenic size-selective mechanisms operative on the population. Total river-descent survival probability was 0.20 for turbine migrants and 0.44 for bypass migrants. The surviving turbine migrants were significantly smaller than their bypass counterparts and more exposed to predation from Northern pike. The estimated mean-adjusted selection gradient was − 0.76 for turbine migrants and + 1.85 for the bypass migrants. The resulting disruptive selection may ultimately lead to increased phenotypic smolt size variation provided sufficient additive genetic variance associated with smolt size. Mitigation measures at hydropower plants are thus essential for preserving sustainable populations of anadromous fish and maintaining population genetic variation.

• Haraldstad, Tormod; Haugen, Thrond Oddvar; Kroglund, Frode; Olsen, Esben Moland & Höglund, Erik (2019). Migratory passage structures at hydropower plants as potential physiological and behavioural selective agents. Royal Society Open Science. ISSN 2054-5703. 6(11). doi: 10.1098/rsos.190989. Fulltekst i vitenarkiv Vis sammendrag

  Anthropogenic activities affect fish populations worldwide. River dams have profound impacts on ecosystems by changing habitats and hindering migration. In an effort to counteract such effects, a range of mitigation measures have been installed at hydroelectric power plants. However, not all individuals in a population use these measures, potentially creating strong selection processes at hydroelectric power plants. This may be especially true during migration; fish can get heavily delayed or pass through a hydropower turbine, thus facing increased mortality compared with those using a safe bypass route. In this study, we quantify migration route choices of descending wild passive integrated transponder (PIT)-tagged Atlantic salmon smolts released upstream from a hydroelectric plant. We demonstrate how only a few metres’ displacement of bypass canals can have a large impact on the fish guidance efficiency (FGE). The proportion of fish using the bypasses increased from 1% to 34% when water was released in surface gates closer to the turbine intake. During a period of low FGE, we observed two different smolt migratory strategies. While some individuals spent little time in the forebay before migrating through the turbine tunnel, others remained there. We suggest that these groups represent different behavioural types, and that suboptimal mitigation measures at hydropower intakes may, therefore, induce strong selection on salmon behavioural traits. The ultimate outcome of these selection mechanisms is discussed in light of potential trade-offs between turbine migration mortality coast and optimal sea entrance timing survival benefits.

• Ono, Kotaro; Knutsen, Halvor; Olsen, Esben M; Ruus, Anders; Hjermann, Dag Ø & Stenseth, Nils Chr (2019). Possible adverse impact of contaminants on Atlantic cod population dynamics in coastal ecosystems. Proceedings of the Royal Society of London. Biological Sciences. ISSN 0962-8452. 286(1908), s. 1–9. doi: 10.1098/rspb.2019.1167. Fulltekst i vitenarkiv Vis sammendrag

  While many in-laboratory ecotoxicological studies have shown the adverse impact of pollutants to the fitness of an individual, direct evidence from the field on the population dynamics of wildlife animals has been lacking. Here, we provide empirical support for a negative effect of pollution on Atlantic cod (Gadus morhua) population dynamics in coastal waters of Norway by combining unique time series of juvenile cod abundance, body size, environmental concentration of toxic contaminants and a spatially structured population dynamics model. The study shows that mercury concentration might have decreased the reproductive potential of cod in the region despite the general decline in the environmental concentration of mercury, cadmium and hexachlorobenzene since the implementation of national environmental laws. However, some cod populations appeared to be more resistant to mercury pollution than others, and the strength and shape of mercury effect on cod reproductive potential was fjord-specific. Additionally, cod growth rate changed at scales smaller than fjords with a gradient related to the exposure to the open ocean and offshore cod. These spatial differences in life-history traits emphasize the importance of local adaptation in shaping the dynamics of local wildlife populations. Finally, this study highlights the possibility to mitigate pollution effects on natural populations by reducing the overall pollution level, but also reveals that pollution reduction alone is not enough to rebuild local cod populations. Cod population recovery probably requires complementary efforts on fishing regulation and habitat restoration.

• Moland, Even; Carlson, Stephanie; Villegas-Rios, David; Wiig, Jørgen Ree & Olsen, Esben Moland (2019). Harvest selection on multiple traits in the wild revealed by aquatic animal telemetry. Ecology and Evolution. ISSN 2045-7758. 9, s. 6480–6491. doi: 10.1002/ece3.5224. Fulltekst i vitenarkiv
• Olsen, Esben Moland; Halvorsen, Kim Aleksander Tallaksen; Larsen, Torkel & Kuparinen, Anna (2019). Potential for managing life history diversity in a commercially exploited intermediate predator, the goldsinny wrasse (Ctenolabrus rupestris). ICES Journal of Marine Science. ISSN 1054-3139. 76(2), s. 410–417. doi: 10.1093/icesjms/fsy183. Fulltekst i vitenarkiv
• Kleiven, Portia Joy Nillos; Espeland, Sigurd Heiberg; Olsen, Esben Moland; Abesamis, Rene A.; Moland, Even & Kleiven, Alf Ring (2019). Fishing pressure impacts the abundance gradient of European lobsters across the borders of a newly established marine protected area. Proceedings of the Royal Society of London. Biological Sciences. ISSN 0962-8452. 286(1894). doi: 10.1098/rspb.2018.2455. Fulltekst i vitenarkiv
• Thorbjørnsen, Susanna Huneide; Moland, Even; Simpfendorfer, Colin A.; Heupel, Michelle R.; Knutsen, Halvor & Olsen, Esben Moland (2019). Potential of a no‐take marine reserve to protect home ranges of anadromous brown trout (Salmo trutta). Ecology and Evolution. ISSN 2045-7758. 9(1), s. 417–426. doi: 10.1002/ece3.4760. Fulltekst i vitenarkiv
• Barth, Julia Maria Isis; Villegas-Ríos, David; Freitas, Carla; Moland, Even; Star, Bastiaan & André, Carl [Vis alle 15 forfattere av denne artikkelen] (2019). Disentangling structural genomic and behavioral barriers in a sea of connectivity. Molecular Ecology. ISSN 0962-1083. 28(6), s. 1394–1411. doi: 10.1111/mec.15010. Fulltekst i vitenarkiv
• Haraldstad, Tormod; Höglund, Erik; Kroglund, Frode; Lamberg, Anders; Olsen, Esben Moland & Haugen, Thrond Oddvar (2018). Condition-dependent skipped spawning in anadromous brown trout (Salmo trutta). Canadian Journal of Fisheries and Aquatic Sciences. ISSN 0706-652X. 75(12), s. 2313–2319. doi: 10.1139/cjfas-2017-0076. Vis sammendrag

  Repeat spawners of anadromous salmonids may contribute significantly to population resilience by providing multiple cohorts to both seawater and freshwater life stages. In this study, winter survival of sea trout (Salmo trutta Linnaeus, 1758) post spawners (kelts) was 89%. Sea survival increased linearly with female length with a return probability between 30% and 50%, whereas males attained a maximum return probability of 60% at 520 mm. Of the returning sea trout, 40% skipped spawning and they had significantly lower condition factor as kelts compared with those who returned after one summer. These results suggest that sex-specific differences in individual post-spawning growth–survival trade-off exist and that energetic status of descending kelts may influence the probability to skip spawning. We discuss to what extent hydropower may reduce post-spawning survival due to blocking of river descent opportunities, potentially altering the fitness landscape and favouring new life-history adaptations. From a management perspective, it is concluded that it is crucial to maintain connectivity in regulated rivers, allowing fish to complete repetitive spawning and feeding migrations, thus contributing to population productivity.

• Jorde, Per Erik; Kleiven, Alf Ring; Sodeland, Marte; Olsen, Esben Moland; Ferter, Keno & Jentoft, Sissel [Vis alle 7 forfattere av denne artikkelen] (2018). Who is fishing on what stock: Population-of-origin of individual cod (Gadus morhua) in commercial and recreational fisheries. ICES Journal of Marine Science. ISSN 1054-3139. 75(6), s. 2153–2162. doi: 10.1093/icesjms/fsy080. Fulltekst i vitenarkiv
• Roney, Nancy; Oomen, Rebekah Alice; Knutsen, Halvor; Olsen, Esben Moland & Hutchings, Jeffrey (2018). Fine-Scale Population Differences in Atlantic Cod Reproductive Success: A Potential Mechanism for Ecological Speciation in a Marine Fish. Ecology and Evolution. ISSN 2045-7758. s. 1–11. doi: 10.1002/ece3.4615. Fulltekst i vitenarkiv
• Knutsen, Halvor; Jorde, Per Erik; Hutchings, Jeffrey; Hemmer-Hansen, Jakob; Grønkjær, Peter & Mose Jørgensen, Kris-Emil [Vis alle 10 forfattere av denne artikkelen] (2018). Stable coexistence of genetically divergent Atlantic cod ecotypes at multiple spatial scales. Evolutionary Applications. ISSN 1752-4571. 11(9), s. 1527–1539. doi: 10.1111/eva.12640. Fulltekst i vitenarkiv
• Sørdalen, Tonje Knutsen; Halvorsen, Kim Aleksander Tallaksen; Harrison, Hugo B.; Ellis, Charlie D.; Vøllestad, Leif Asbjørn & Knutsen, Halvor [Vis alle 8 forfattere av denne artikkelen] (2018). Harvesting changes mating behaviour in European lobster. Evolutionary Applications. ISSN 1752-4571. 11(6), s. 963–977. doi: 10.1111/eva.12611. Fulltekst i vitenarkiv
• Thorbjørnsen, Susanna Huneide; Moland, Even; Huserbråten, Mats Brockstedt Olsen; Knutsen, Jan Atle; Knutsen, Halvor & Olsen, Esben Moland (2018). Replicated marine protected areas (MPAs) support movement of larger, but not more, European lobsters to neighbouring fished areas. Marine Ecology Progress Series. ISSN 0171-8630. 595, s. 123–133. doi: 10.3354/meps12546. Fulltekst i vitenarkiv
• Villegas-Rios, David; Réale, Denis; Freitas, Carla; Moland, Even & Olsen, Esben Moland (2018). Personalities influence spatial responses to environmental fluctuations in wild fish. Journal of Animal Ecology. ISSN 0021-8790. 87(5), s. 1309–1319. doi: 10.1111/1365-2656.12872. Fulltekst i vitenarkiv
• Dornelas, Maria; Antão, Laura H.; Moyes, Faye; Bates, Amanda E.; Magurran, Anne E. & Adam, Dusan [Vis alle 270 forfattere av denne artikkelen] (2018). BioTIME: A database of biodiversity time series for the Anthropocene. Global Ecology and Biogeography. ISSN 1466-822X. 27(7), s. 760–786. doi: 10.1111/geb.12729. Fulltekst i vitenarkiv
• Roney, Nancy; Oomen, Rebekah Alice; Knutsen, Halvor; Olsen, Esben Moland & Hutchings, Jeffrey (2018). Temporal variability in offspring quality and individual reproductive output in a broadcast-spawning marine fish. ICES Journal of Marine Science. ISSN 1054-3139. 75(4), s. 1353–1361. doi: 10.1093/icesjms/fsx232.
• McDermott, Susanne F.; Buhl-Mortensen, Lene; Dahle, Geir; Hart, Deborah; Haynie, Alan C. & Johannessen, Tore [Vis alle 12 forfattere av denne artikkelen] (2017). Lessons on marine protected area management in northern boreal regions from the United States and Norway. Marine Fisheries Review. ISSN 0090-1830. 79(1), s. 28–51. doi: 10.7755/MFR.79.1.2. Fulltekst i vitenarkiv Vis sammendrag

  In comparison to tropical reef systems, relatively few marine protected areas (MPA’s) exist in temperate or subarctic systems (e.g., North Pacific and North Atlantic) where species diversity is lower, abundance of individual species is often higher, and many fish species exhibit large amounts of movement during one or more of their life stages, especially as adults. A review of MPA’s in three northern areas—the Northwest Atlantic, Northeast Atlantic, and the Northeast Pacific—indicates that MPA’s can be useful management tools towards fisheries management and habitat conservation. However, achieving fishery goals, such as sustainable use of the fisheries resources, will depend on population abundance (relative to unfished conditions) and fish behavior and movement. For example, depleted populations of stationary species such as Atlantic sea scallops, Placopecten magellanicus, in the Northeast Atlantic and European lobster, Homarus grammarus, in the North Sea have responded positively to small MPA’s, whereas migratory offshore Atlantic cod, Gadus morhua, and Pacific cod, Gadus macrocephalus, apparently do not appear to benefit from closed areas because of movement into fished areas. Efficient habitat conservation requires detailed habitat mapping on relevant spatial scales. In northern boreal systems with large remote areas, this information is difficult and expensive to access. An alternative strategy of closing and protecting unexploited areas has worked well for the Aleutian Island coral closure area in Alaska. MPA’s can be effective fisheries management tools when the species to be protected have been depleted and show a small to moderate level of movement, and reproductive success is ensured. MPA’s can be effective at preserving habitat when the design is based on scientific information and takes into account the impact on the user groups.

• Villegas-Rios, David; Moland, Even & Olsen, Esben Moland (2017). Potential of contemporary evolution to erode fishery benefits from marine reserves. Fish and Fisheries. ISSN 1467-2960. 18(3), s. 571–577. doi: 10.1111/faf.12188.
• Villegas-Rios, David; Réale, Denis; Freitas, Carla; Moland, Even & Olsen, Esben Moland (2017). Individual level consistency and correlations of fish spatial behaviour assessed from aquatic animal telemetry. Animal Behaviour. ISSN 0003-3472. 124, s. 83–94. doi: 10.1016/j.anbehav.2016.12.002.
• Rogers, Lauren; Storvik, Geir Olve; Knutsen, Halvor; Olsen, Esben Moland & Stenseth, Nils Christian (2017). Fine-scale population dynamics in a marine fish species inferred from dynamic state-space models. Journal of Animal Ecology. ISSN 0021-8790. 86(4), s. 888–898. doi: 10.1111/1365-2656.12678. Fulltekst i vitenarkiv
• Halvorsen, Kim Aleksander Tallaksen; Larsen, Torkel; Sørdalen, Tonje Knutsen; Vøllestad, Leif Asbjørn; Knutsen, Halvor & Olsen, Esben Moland (2017). Impact of harvesting cleaner fish for salmonid aquaculture assessed from replicated coastal marine protected areas. Marine Biology Research. ISSN 1745-1000. 13(4), s. 359–369. doi: 10.1080/17451000.2016.1262042. Fulltekst i vitenarkiv
• Halvorsen, Kim Aleksander Tallaksen; Sørdalen, Tonje Knutsen; Vøllestad, Leif Asbjørn; Skiftesvik, Anne Berit; Espeland, Sigurd Heiberg & Olsen, Esben Moland (2017). Sex-and size-selective harvesting of corkwing wrasse (Symphodus melops)-a cleaner fish used in salmonid aquaculture. ICES Journal of Marine Science. ISSN 1054-3139. 74(3), s. 660–669. doi: 10.1093/icesjms/fsw221.
• Laurel, Benjamin J.; Cote, David; Gregory, Robert S.; Rogers, Lauren; Knutsen, Halvor & Olsen, Esben Moland (2017). Recruitment signals in juvenile cod surveys depend on thermal growth conditions. Canadian Journal of Fisheries and Aquatic Sciences. ISSN 0706-652X. 74(4), s. 511–523. doi: 10.1139/cjfas-2016-0035.
• Chacon, Albert Fernandez; Moland, Even; Espeland, Sigurd Heiberg; Kleiven, Alf Ring & Olsen, Esben Moland (2016). Causes of mortality in depleted populations of Atlantic cod estimated from multi-event modelling of mark-recapture and recovery data. Canadian Journal of Fisheries and Aquatic Sciences. ISSN 0706-652X. 74(1), s. 116–126. doi: 10.1139/cjfas-2015-0313.
• Halvorsen, Kim Aleksander Tallaksen; Sørdalen, Tonje Knutsen; Durif, Caroline; Knutsen, Halvor; Olsen, Esben Moland & Skiftesvik, Anne Berit [Vis alle 9 forfattere av denne artikkelen] (2016). Male biased sexual size dimorphism in the nest building corkwing wrasse (Symphodus melops): implications for a size regulated fishery. ICES Journal of Marine Science. ISSN 1054-3139. 73(10), s. 2586–2594. doi: 10.1093/icesjms/fsw135.
• Kleiven, Alf Ring; Chacon, Albert Fernandez; Nordahl, Jan-Harald; Moland, Even; Espeland, Sigurd Heiberg & Knutsen, Halvor [Vis alle 7 forfattere av denne artikkelen] (2016). Harvest pressure on coastal atlantic cod (Gadus morhua) from recreational fishing relative to commercial fishing assessed from tag-recovery data. PLOS ONE. ISSN 1932-6203. 11(3). doi: 10.1371/journal.pone.0149595. Fulltekst i vitenarkiv
• Sodeland, Marte; Jorde, Per Erik; Lien, Sigbjørn; Jentoft, Sissel; Berg, Paul Ragnar & Grove, Harald [Vis alle 10 forfattere av denne artikkelen] (2016). "Islands of divergence" in the Atlantic cod genome represent polymorphic chromosomal rearrangements. Genome Biology and Evolution (GBE). ISSN 1759-6653. 8(4), s. 1012–1022. doi: 10.1093/gbe/evw057. Fulltekst i vitenarkiv
• Kuparinen, Anna; Roney, Nancy E.; Oomen, Rebekah Alice; Hutchings, Jeffrey & Olsen, Esben Moland (2016). Small-scale life history variability suggests potential for spatial mismatches in Atlantic cod management units. ICES Journal of Marine Science. ISSN 1054-3139. 73(2), s. 286–292. doi: 10.1093/icesjms/fsv181.
• Roney, Nancy E.; Hutchings, Jeffrey; Olsen, Esben Moland; Knutsen, Halvor; Albretsen, Jon & Kuparinen, Anna (2016). Fine-scale life-history structure in a highly mobile marine fish. Evolutionary Ecology Research. ISSN 1522-0613. 17, s. 95–109.
• Freitas, Carla; Olsen, Esben Moland; Knutsen, Halvor; Albretsen, Jon & Moland, Even (2016). Temperature-associated habitat selection in a cold-water marine fish. Journal of Animal Ecology. ISSN 0021-8790. 85(3), s. 628–637. doi: 10.1111/1365-2656.12458. Fulltekst i vitenarkiv
• Barceló, Caren; Ciannelli, Lorenzo; Olsen, Esben Moland; Johannessen, Tore & Knutsen, Halvor (2016). Eight decades of sampling reveal a contemporary novel fish assemblage in coastal nursery habitats. Global Change Biology. ISSN 1354-1013. 22(3), s. 1155–1167. doi: 10.1111/gcb.13047.
• Catarino, Diana; Knutsen, Halvor; Verissimo, Ana; Olsen, Esben Moland; Jorde, Per Erik & Menezes, Gui [Vis alle 14 forfattere av denne artikkelen] (2015). The Pillars of Hercules as a bathymetric barrier to gene flow promoting isolation in a global deep-sea shark (Centroscymnus coelolepis). Molecular Ecology. ISSN 0962-1083. 24(24), s. 6061–6079. doi: 10.1111/mec.13453.
• Chacon, Albert Fernandez; Moland, Even; Espeland, Sigurd Heiberg & Olsen, Esben Moland (2015). Demographic effects of full vs. partial protection from harvesting: Inference from an empirical before-after control-impact study on Atlantic cod. Journal of Applied Ecology. ISSN 0021-8901. 52(5), s. 1206–1215. doi: 10.1111/1365-2664.12477.
• Espeland, Sigurd Heiberg; Albretsen, Jon; Olsen, Esben Moland & Bodvin, Torjan (2015). Modelling drift of pelagic offspring: the importance of egg surveys in providing a realistic model initialization. ICES Journal of Marine Science. ISSN 1054-3139. 72(9), s. 2578–2589. doi: 10.1093/icesjms/fsv134. Fulltekst i vitenarkiv
• Aalvik, Ida Margrethe; Moland, Even; Olsen, Esben Moland & Stenseth, Nils Christian (2015). Spatial ecology of coastal Atlantic cod Gadus morhua associated with parasite load. Journal of Fish Biology. ISSN 0022-1112. 87(2), s. 449–464. doi: 10.1111/jfb.12731. Vis sammendrag

  Acoustic tags and receivers were used to investigate the spatial ecology of coastal Atlantic cod Gadus morhua (n = 32, mean fork length: 50 cm, range: 33–80 cm) on the Norwegian Skagerrak coast in 2012. Monthly home ranges (HR), swimming activity and depth use varied considerably among individuals and through the months of June, July and August. HR sizes for the period ranged from 0·25 to 5·20 km2 (mean = 2·30 km2). Two thirds of the tagged G. morhua were infected with black spot disease Cryptocotyle lingua parasites; these fish had larger HRs and occupied deeper water compared with non-infected fish. The infected fish also tended to be more active in terms of horizontal swimming. From an ecological and evolutionary perspective, any environmental change that modifies G. morhua behaviour may therefore also alter the parasite load of the population, and its conservation and fishery status.

• Freitas, Carla; Olsen, Esben Moland; Moland, Even; Ciannelli, Lorenzo & Knutsen, Halvor (2015). Behavioral responses of Atlantic cod to sea temperature changes. Ecology and Evolution. ISSN 2045-7758. 5(10), s. 2070–2083. doi: 10.1002/ece3.1496. Fulltekst i vitenarkiv

Se alle arbeider i Cristin

• Sivle, Lise Doksæter; McQueen, Kate; de Jong, Karen; Forland, Tonje Nesse; Skjæraasen, Jon Egil & Olsen, Esben Moland [Vis alle 7 forfattere av denne artikkelen] (2023). SpawnSeis. Påvirkning av luftkanon og marin vibrator på gytende torsk.
• McQueen, Kate; Skjæraasen, Jon Egil; Nyqvist, Daniel; Olsen, Esben Moland; Karlsen, Ørjan & Meager, Justin James [Vis alle 9 forfattere av denne artikkelen] (2022). Behavioural responses of spawning Atlantic cod (Gadus morhua) to seismic airgun exposure. .
• Oomen, Rebekah Alice; Knutsen, Halvor; Moland, Even; Olsen, Esben Moland; Knutsen, Jan Atle & Bernatchez, Louis [Vis alle 8 forfattere av denne artikkelen] (2022). Nothing so boundless, nothing so patient: Obituary for Professor Jeffrey Alexander Hutchings (1958–2022). Fish and Fisheries. ISSN 1467-2960. 23(3), s. 519–521. doi: 10.1111/faf.12661.
• Stige, Leif Christian; Langangen, Øystein; Durant, Joel Marcel; Knutsen, Halvor; Olsen, Esben Moland & Ottersen, Geir (2019). Forskning på torsk. Biolog. ISSN 0801-0722. 37(2), s. 46–49.
• Sivle, Lise Doksæter; Nyqvist, Daniel; Olsen, Esben Moland & Karlsen, Ørjan (2019). Cyborg i forskinga si teneste. [Avis]. Marsteinen.
• Nyqvist, Daniel; Sivle, Lise Doksæter; Karlsen, Ørjan; Olsen, Esben Moland; de Jong, Karen & Forland, Tonje Nesse [Vis alle 7 forfattere av denne artikkelen] (2019). Behaviour of spawning cod in relation to marine seismic surveys.
• Nyqvist, Daniel; Sivle, Lise Doksæter; Karlsen, Ørjan; Olsen, Esben Moland; de Jong, Karen & Forland, Tonje Nesse [Vis alle 7 forfattere av denne artikkelen] (2019). Do seismic surveys affect the behavior of spawning cod? .
• Olsen, Esben Moland; Halvorsen, Kim Aleksander Tallaksen; Larsen, Torkel & Kuparinen, Anna (2019). Erratum: Potential for managing life history diversity in a commercially exploited intermediate predator, the goldsinny wrasse (Ctenolabrus rupestris). ICES Journal of Marine Science. ISSN 1054-3139. 76(1). doi: 10.1093/icesjms/fsy195.
• Oomen, Rebekah Alice; Knutsen, Halvor; Olsen, Esben Moland; Jentoft, Sissel; Stenseth, Nils Chr. & Hutchings, Jeffrey (2018). Transcriptomic variability in population responses of Atlantic cod to temperature.
• Thorbjørnsen, Susanna Huneide; Moland, Even; Villegas-Rios, David; Knutsen, Halvor & Olsen, Esben Moland (2018). Personality of sea trout and consequences for survival quantified using detailed movement data from a telemetry study in a southern Norwegian fjord.
• van der Meeren, Terje; Skjæraasen, Jon Egil; Myksvoll, Mari Skuggedal; Dahle, Geir; Olsen, Esben Moland & Karlsen, Ørjan [Vis alle 7 forfattere av denne artikkelen] (2018). Interaksjoner mellom lakseoppdrett og gyteområder for torsk (ICOD-prosjektet).
• van der Meeren, Terje; Skjæraasen, Jon Egil; Myksvoll, Mari Skuggedal; Dahle, Geir; Olsen, Esben Moland & Karlsen, Ørjan [Vis alle 7 forfattere av denne artikkelen] (2018). Interaksjoner mellom lakseoppdrett og gyteområder for torsk (ICOD-prosjektet).
• van der Meeren, Terje; Skjæraasen, Jon Egil; Myksvoll, Mari Skuggedal; Dahle, Geir; Olsen, Esben Moland & Karlsen, Ørjan [Vis alle 7 forfattere av denne artikkelen] (2018). Interactions of salmon farming on Atlantic cod spawning grounds (ICOD prosjektet).
• van der Meeren, Terje; Skjæraasen, Jon Egil; Myksvoll, Mari Skuggedal; Dahle, Geir; Olsen, Esben Moland & Karlsen, Ørjan [Vis alle 7 forfattere av denne artikkelen] (2018). Interactions of salmon farming on Atlantic cod spawning grounds. Vis sammendrag

  There is increasing focus on finding optimal areas for fish farming of Atlantic salmon and rainbow trout in open cages in Norwegian fjords, along the coast and in Northern Norway. The potential for overlapping fish farming installations with areas that are important spawning/nursery areas for commercial fish species (i.e. Atlantic cod) may have implications for the success of these spawning and juvenile nursery grounds and subsequently may influence the long-term health and fitness of commercial fish species. Atlantic cod is one of the species that can be influenced by the presence of the aquaculture industry. With the growth of aquaculture it is anticipated that the competition for use of coastal area between aquaculture, fisheries, and other interests will escalate in the coming years and it is important to understand the potential interactions. This presentation details a large 5-year (2015-2020) research project focusing on understanding if the establishment of fish farming activities in the vicinity of a known spawning ground of Atlantic cod will affect the migration of adult cod and their spawning and recruitment success. This project is multidisciplinary in nature, using a combination of research methodologies to disentangle the effects of fin-fish aquaculture on cod spawning grounds. Here we discuss the use of 1) acoustic telemetry to study adult spawning cod behaviour, 2) spatial and temporal sampling of cod eggs and juvenile fish, 3) DNA identification of spawning cod, cod eggs and juvenile cod and 4) sampling of benthic environmental health. This data is combined using state-of-the-art-modelling tools to increase our understanding of the interactions of coastal aquaculture with cod spawning grounds, and to predict changes in spawning and juvenile populations. This presentation will present recent data on observed changes in cod spawning/juvenile nursery grounds and shifts in benthic environmental health due to the establishment of the fish farm. The project results presented here are important new knowledge that are essential for addressing the needs for managing natural resources and environments along the Norwegian coastline with the development of the aquaculture industry, as outlined by the Norwegian authorities.

• Thorbjørnsen, Susanna Huneide; Moland, Even; Simpfendorfer, Colin A.; Heupel, Michelle R.; Knutsen, Halvor & Olsen, Esben Moland (2017). A no-take marine reserve provide benefits to anadromous sea trout (Salmo trutta).
• Thorbjørnsen, Susanna Huneide; Moland, Even; Villegas-Rios, David; Knutsen, Halvor & Olsen, Esben Moland (2017). Repeatability of sea trout behavioural traits and potential for detecting behavioural syndromes.
• Skjæraasen, Jon Egil; Karlsen, Ørjan; Olsen, Esben Moland; Moland, Even; Elvik, Kristine Marit Schrøder & van der Meeren, Terje [Vis alle 7 forfattere av denne artikkelen] (2017). The influence of salmon Salmo salar aquaculture on spawning ground use of Atlantic cod Gadus morhua.
• Barth, Julia Maria Isis; Star, Bastiaan; Matschiner, Michael; André, Carl; Knutsen, Halvor & Bradbury, Ian [Vis alle 13 forfattere av denne artikkelen] (2017). Chromosomal rearrangements as barriers to homogenization in highly mobile fish.
• Barth, Julia Maria Isis; Star, Bastiaan; Matschiner, Michael; André, Carl; Knutsen, Halvor & Bradbury, Ian [Vis alle 13 forfattere av denne artikkelen] (2017). Chromosomal rearrangements as barriers to homogenization in highly mobile fish.
• Oomen, Rebekah Alice; Knutsen, Halvor; Olsen, Esben Moland; Jentoft, Sissel; Stenseth, Nils Christian & Hutchings, Jeffrey (2016). Genetic variability in population responses of Atlantic cod to temperature.
• Oomen, Rebekah Alice; Knutsen, Halvor; Olsen, Esben Moland; Jentoft, Sissel; Stenseth, Nils Christian & Hutchings, Jeffrey (2015). The transcriptomic response of cod to temperature.
• Oomen, Rebekah Alice; Knutsen, Halvor; Olsen, Esben Moland; Jentoft, Sissel; Stenseth, Nils Christian & Hutchings, Jeffrey (2015). Genetic variability in population responses of Atlantic cod to temperature.
• Oomen, Rebekah Alice; Knutsen, Halvor; Olsen, Esben Moland; Jentoft, Sissel; Stenseth, Nils Christian & Hutchings, Jeffrey (2015). Genetic variability in population responses of Atlantic cod to environmental change and the transcriptomic response to temperature.
• Moland, Even; Chacon, Albert Fernandez; Olsen, Esben Moland & Espeland, Sigurd Heiberg (2015). Marine protected areas increase survival of Atlantic cod. Science for Environment Policy. Fulltekst i vitenarkiv
• Moland, Even & Olsen, Esben Moland (2015). Selvfisket torsk - en selvfølge? Agderposten. ISSN 0805-3723.
• Moland, Even; Synnes, Ann-Elin; Naustvoll, Lars Johan; Freitas, Carla; Norderhaug, Kjell Magnus & Thormar, Jonas [Vis alle 15 forfattere av denne artikkelen] (2021). Krafttak for kysttorsken - Kunnskap for stedstilpasset gjenoppbygging av bestander, naturtyper og økosystem i Færder- og Ytre Hvaler nasjonalparker. Havforskningsinstituttet. ISSN 1893-4536. Fulltekst i vitenarkiv Vis sammendrag

  Ytre Oslofjord har en unik kystnatur av svært stor verdi for både fastboende og tilreisende. Færder- og Ytre Hvaler nasjonalparker ligger side om side ytterst i fjorden, og skal sikre naturverdiene for kommende generasjoner. Nasjonalparkene har utformet egne forvaltningsplaner og -mål, som gjenspeiler et ønske om å legge best mulig til rette for at fiskearter, fugler, planter og insekter skal fortsette å trives innenfor parkenes grenser. Generelle mål for naturverdiene er at de skal opprettholdes med god økologisk funksjon, og et høyt biologisk mangfold.

• Aglen, Asgeir; Nedreaas, Kjell Harald; Moland, Even; Knutsen, Halvor; Kleiven, Alf Ring & Johannessen, Tore [Vis alle 11 forfattere av denne artikkelen] (2016). Oppdatert kunnskapsstatus om kystnær torsk i Sør Norge. Havforskningsinstituttet. ISSN 0071-5638.

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