Browsing Articles by Author "Kjesbu, Olav Sigurd"

Now showing items 1-20 of 43

    • Bioenergetics of egg production in Northeast Atlantic mackerel changes the perception of fecundity type and annual trends in spawning stock biomass 

      Jansen, Teunis; Slotte, Aril; dos Santos Schmidt, Thassya Christina; Sparrevohn, Claus Reedtz; Jacobsen, Jan Arge; Kjesbu, Olav Sigurd (Peer reviewed; Journal article, 2021)
      Egg surveys are used worldwide for the estimation of spawning stock biomass (SSB) of small pelagic fish species, requiring detailed knowledge about their reproductive biology. In the present study, we revisit the current ...

    • Development of a new ‘ultrametric’ method for assessing spawning progression in female teleost serial spawners 

      Anderson, Kelli C.; Alix, Maud; Charitonidou, Katerina; Thorsen, Anders; Thorsheim, Grethe Beate; Ganias, Kostas; dos Santos Schmidt, Thassya Christina; Kjesbu, Olav Sigurd (Peer reviewed; Journal article, 2020)

    • Drift indices confirm that rapid larval displacement is essential for recruitment success in high-latitude oceans 

      Tiedemann, Maik; Slotte, Aril; Nash, Richard David Marriott; Stenevik, Erling Kåre; Kjesbu, Olav Sigurd (Peer reviewed; Journal article, 2021)
      Larval drift is a key process for successful fish recruitment. We used Norwegian spring-spawning herring (Clupea harengus) as model species to investigate the relationship between larval drift and recruitment. Larval drift ...

    • Effects of ration on the maturation and fecundity in captive Atlantic herring (Clupea harengus) 

      Ma, Y.; Kjesbu, Olav Sigurd; Jørgensen, Terje (Journal article; Peer reviewed, 1998)
      We examined the effects of amount of food on vitellogenic oocyte size and number (fecundity) between two experimental groups of Atlantic herring (Clupea harengus) kept in separate but identical compartments of a large ...

    • Egg buoyancy variability in local populations of Atlantic cod (Gadus morhua) 

      Jung, Kyung-Mi; Folkvord, Arild; Kjesbu, Olav Sigurd; Agnalt, Ann-Lisbeth; Thorsen, Anders; Sundby, Svein (Journal article; Peer reviewed, 2012-06-29)
      Previous studies have found strong evidences for Atlantic cod (Gadus morhua) egg retention in fjords, which are caused by the combination of vertical salinity structure, estuarine circulation, and egg specific gravity, ...

    • Environmental influences on Norwegian spring-spawning herring (<i>Clupea harengus</i> L.) larvae reveal recent constraints in recruitment success 

      Tiedemann, Maik; Nash, Richard David Marriott; Stenevik, Erling Kåre; Stiasny, Martina, H.; Slotte, Aril; Kjesbu, Olav Sigurd (Peer reviewed; Journal article, 2020)
      The lack of any abundant recruiting year class of Norwegian spring-spawning (NSS) herring between 2005 and 2015 contributed to an approximate reduction of 40% in the spawning-stock biomass since 2009, i.e. from 7 to 4 ...

    • Environmental stressors may cause unpredicted, notably lagged life-history responses in adults of the planktivorous Atlantic herring 

      dos Santos Schmidt, Thassya Christina; Devine, Jennifer Ann; Slotte, Aril; Claireaux, Marion; Johannessen, A; Enberg, Katja; Oskarsson, Gudmundur; Kennedy, James; Kurita, Yutaka; Kjesbu, Olav Sigurd (Peer reviewed; Journal article, 2020)
      Here we challenge traditional views on the direction of change in teleost body condition and reproductive traits in response to abiotic and biotic factors by studying the data-rich, planktivorous Norwegian spring-spawning ...

    • Establishing the Foundation for the Global Observing System for Marine Life 

      Satterthwaite, Erin V.; Bax, Nicholas J.; Miloslavich, Patricia; Ratnarajah, Lavenia; Canonico, Gabrielle; Dunn, Daniel; Simmons, Samantha E.; Carini, Roxanne J.; Evans, Karen; Allain, Valerie; Appeltans, Ward; Batten, Sonia; Benedetti-Cecchi, Lisandro; Bernard, Anthony T. F.; Bristol, Sky; Benson, Abigail; Buttigieg, Pier Luigi; Gerhardinger, Leopoldo Cavaleri; Chiba, Sanae; Davies, Tammy E.; Duffy, J. Emmett; Giron-Nava, Alfredo; Hsu, Astrid J.; Kraberg, Alexandra C.; Kudela, Raphael M.; Lear, Dan; Montes, Enrique; Muller-Karger, Frank E.; O’Brien, Todd D.; Obura, David; Provoost, Pieter; Pruckner, Sara; Rebelo, Lisa-Maria; Selig, Elizabeth R.; Kjesbu, Olav Sigurd; Starger, Craig; Stuart-Smith, Rick D.; Vierros, Marjo; Waller, John; Weatherdon, Lauren V.; Wellman, Tristan P.; Zivian, Anna (Peer reviewed; Journal article, 2021)
      Maintaining healthy, productive ecosystems in the face of pervasive and accelerating human impacts including climate change requires globally coordinated and sustained observations of marine biodiversity. Global coordination ...

    • Experimental Parameterisation of Principal Physics in Buoyancy Variations of Marine Teleost Eggs 

      Jung, Kyung-Mi; Folkvord, Arild; Kjesbu, Olav Sigurd; Sundby, Svein (Journal article; Peer reviewed, 2014-08-14)
      It is generally accepted that the high buoyancy of pelagic marine eggs is due to substantial influx of water across the cell membrane just before ovulation. Here we further develop the theoretical basis by applying laboratory ...

    • Extent and ecological importance of escape through spawning in sea-cages for Atlantic cod 

      Uglem, Ingebrigt; Knutsen, Øyvind; Kjesbu, Olav Sigurd; Hansen, Øyvind J.; Mork, Jarle; Bjørn, Pål Arne; Varne, Rebekka; Nilsen, Rune; Ellingsen, Ingrid; Dempster, Tim (Journal article; Peer reviewed, 2012-11-14)
      The culture of certain fish species to sizes at which they can reproduce has led to the escape of fertilised eggs or ‘escape through spawning’. To investigate the extent and ecological importance of spawning in sea-cages ...

    • The fate of vitellogenic follicles in experimentally monitored Atlantic cod Gadus morhua (L.): Application to stock assessment 

      Witthames, Peter R.; Thorsen, Anders; Kjesbu, Olav Sigurd (Journal article; Peer reviewed, 2010-05)
      In this paper we report on the fate of vitellogenic follicles (VF) as either alpha atretic follicles (αF) or post-ovulatory follicles (POFs) using histology and captive Atlantic cod (Gadus morhua) in three experiments. In ...

    • Fecundity and growth of Atlantic cod (Gadus morhua L.) along a latitudinal gradient 

      Thorsen, Anders; Witthames, Peter R.; Marteinsdottir, Gudrun; Nash, Richard D.M.; Kjesbu, Olav Sigurd (Journal article; Peer reviewed, 2010-05)
      Some fish species have wide distribution areas that span very different habitats. In this investigation we have studied Atlantic cod (Gadus morhua), which is an example of such a species, to demonstrate how this may have ...

    • From gametogenesis to spawning: How climate-driven warming affects teleost reproductive biology 

      Alix, Maud; Kjesbu, Olav Sigurd; Anderson, Kelli C. (Peer reviewed; Journal article, 2020)
      Ambient temperature modulates reproductive processes, especially in poikilotherms such as teleosts. Consequently, global warming is expected to impact the reproductive function of fish, which has implications for wild ...

    • Genomic stability through time despite decades of exploitation in cod on both sides of the Atlantic 

      Pinsky, Malin L; Eikeset, Anne Maria; Helmerson, Cecilia; Bradbury, Ian R.; Bentzen, Paul; Morris, Corey; Gondek, Agata; Baalsrud, Helle Tessand; Brieuc, Marine Servane Ono; Kjesbu, Olav Sigurd; Godiksen, Jane Aanestad; Barth, Julia Maria Isis; Matschiner, Michael; Stenseth, Nils Christian; Jakobsen, Kjetill Sigurd; Jentoft, Sissel; Star, Bastiaan (Peer reviewed; Journal article, 2021)
      The mode and extent of rapid evolution and genomic change in response to human harvesting are key conservation issues. Although experiments and models have shown a high potential for both genetic and phenotypic change in ...

    • Half a century of high-latitude fisheries oceanography research on the "recruitment problem" in Northeast Arctic cod (Gadus morhua) 

      Kjesbu, Olav Sigurd; Tiedemann, Maik; Alix, Maud; Thorsen, Anders; Sundby, Svein (Peer reviewed; Journal article, 2023)
      Predicting recruitment in a reliable fashion is a great challenge within operational fisheries advice. Here, we consulted the unique but undercommunicated IMR Cod Larva Project (1975–1990), its spin-offs, placed in an ...

    • Highly mixed impacts of near-future climate change on stock productivity proxies in the North East Atlantic 

      Kjesbu, Olav Sigurd; Sundby, Svein; Sandø, Anne Britt; Alix, Maud; Hjøllo, Solfrid Sætre; Tiedemann, Maik; Skern-Mauritzen, Mette; Junge, Claudia; Fossheim, Maria; Broms, Cecilie; Søvik, Guldborg; Zimmermann, Fabian; Nedreaas, Kjell Harald; Eriksen, Elena; Höffle, Hannes; Hjelset, Ann Merete; Kvamme, Cecilie; Reecht, Yves; Knutsen, Halvor; Aglen, Asgeir; Albert, Ole Thomas; Berg, Erik; Bogstad, Bjarte; Durif, Caroline; Halvorsen, Kim Aleksander Tallaksen; Høines, Åge Sigurd; Hvingel, Carsten; Johannesen, Edda; Johnsen, Espen; Moland, Even; Myksvoll, Mari Skuggedal; Nøttestad, Leif; Olsen, Erik Joel Steinar; Skaret, Georg; Skjæraasen, Jon Egil; Slotte, Aril; Staby, Arved; Stenevik, Erling Kåre; Stiansen, Jan Erik; Stiasny, Martina H.; Sundet, Jan Henry; Vikebø, Frode Bendiksen; Huse, Geir (Peer reviewed; Journal article, 2021)
      Impacts of climate change on ocean productivity sustaining world fisheries are predominantly negative but vary greatly among regions. We assessed how 39 fisheries resources—ranging from data-poor to data-rich stocks—in the ...

    • Increasing temperature and prey availability affect the growth and swimming kinematics of Atlantic herring (Clupea harengus) larvae 

      Allan, Bridie Jean Marie; Browman, Howard; Shema, Steven; Skiftesvik, Anne Berit; Folkvord, Arild; Durif, Caroline; Kjesbu, Olav Sigurd (Peer reviewed; Journal article, 2022)
      Climate change will increase the magnitude and duration of warming events and the variability in the phenology and abundance of available prey to the early life stages of fish. These factors influence physiological, ...

    • Is it possible to photoperiod manipulate spawning time in planktivorous fish ? A long-term experiment on Atlantic herring 

      dos Santos Schmidt, Thassya Christina; Berg, Florian; Folkvord, Arild; Pires, Alessandra M.A.; Komyakova, Valeriya; Tiedemann, Maik; Kjesbu, Olav Sigurd (Peer reviewed; Journal article, 2022)
      The oocyte development (vitellogenesis) of individual fish is highly dependent upon their physiology which is influenced by both intrinsic and extrinsic factors. Thus, if individuals encounter poor biophysical conditions, ...

    • Latitudinally distinct stocks of Atlantic cod face fundamentally different biophysical challenges under on-going climate change 

      Kjesbu, Olav Sigurd; Alix, Maud; Sandø, Anne Britt; Strand, Espen; Wright, Peter J.; Johns, David G.; Thorsen, Anders; Marshall, C. Tara; Bakkeplass, Kjell Gunnar; Vikebø, Frode Bendiksen; Myksvoll, Mari Skuggedal; Ottersen, Geir; Allan, Bridie Jean Marie; Fossheim, Maria; Stiansen, Jan Erik; Huse, Geir; Sundby, Svein (Peer reviewed; Journal article, 2023)
      The reproductive success of marine ectotherms is especially vulnerable in warming oceans due to alterations in adult physiology, as well as embryonic and larval survival prospects. These vital responses may, however, differ ...

    • Latitudinally distinct stocks of Atlantic cod face fundamentally different biophysical challenges under on-going climate change 

      Kjesbu, Olav Sigurd; Alix, Maud; Sandø, Anne Britt; Strand, Espen; Wright, Peter J.; Johns, David G.; Thorsen, Anders; Marshall, C. Tara; Bakkeplass, Kjell Gunnar; Vikebø, Frode Bendiksen; Myksvoll, Mari Skuggedal; Ottersen, Geir; Allan, Bridie Jean Marie; Fossheim, Maria; Stiansen, Jan Erik; Huse, Geir; Sundby, Svein (Peer reviewed; Journal article, 2023)
      The reproductive success of marine ectotherms is especially vulnerable in warming oceans due to alterations in adult physiology, as well as embryonic and larval survival prospects. These vital responses may, however, differ ...