Blar i Brage IMR på forfatter "Hjermann, Dag Ø."
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Adaptive management of living marine resources by integrating different data sources and key ecological processes (ADMAR): A joint effort by IMR and CEES
Handegard, Nils Olav; Stenseth, Nils Christian; Dankel, Dorothy Jane; Durant, Joël M.; Eikeset, Anne Maria; Enberg, Katja; Hjermann, Dag Ø.; Huse, Geir; Pennington, Michael; Skern-Mauritzen, Mette; Stige, Leif Christian; Subbey, Samuel; Vølstad, Jon Helge (ICES CM documents;2010/R:26 Poster;, Working paper, 2010-09) -
Bridging the gap between aquatic and terrestrial ecology
Stergiou, Konstantinos I.; Browman, Howard I.; Stenseth, Nils Christian; Mysterud, Atle; Durant, Joël M.; Hjermann, Dag Ø.; Ottersen, Geir (Journal article; Peer reviewed, 2005-12-08) -
Climate and the match or mismatch between predator requirements and resource availability
Durant, Joël M.; Hjermann, Dag Ø.; Ottersen, Geir; Stenseth, Nils Christian (Journal article; Peer reviewed, 2007-04-20)Climate influences a population through a variety of processes, including reproduction, growth, migration patterns and phenology. Climate may operate either directly through metabolic and reproductive processes or indirectly ... -
Climatic effects filtered through the food web affect the dynamics of Arcto-Norwegian cod
Hjermann, Dag Ø.; Eikeset, Anne Maria; Bogstad, Bjarte; Ottersen, Geir; Stenseth, Nils Christian (ICES CM documents, Working paper, 2005)The world's largest cod stock, the Arcto-Norwegian cod (a.k.a. North-East Arctic cod), is heavily influenced by temperature in two ways: First, cod recruitment tends to be high when Barents Sea temperature in the spawning ... -
Cod in a changing climate Match-mismatch and Threshold for the North Sea cod recruitment
Durant, Joël M.; Hjermann, Dag Ø.; Stenseth, Nils Christian; Beaugrand, Grégory (ICES CM documents;2005 / AA:01, Working paper, 2005)Climatic changes are disrupting otherwise tight trophic interactions between predator and prey. Most of the earlier studies have primarily focused on the temporal dimension of the relationship in the framework of the ... -
Combining hydrographical particles-tracking models with spatial analyses to evaluate spatial dynamics of cod larvae and 0-group in the Barents Sea
Hidalgo, Manuel; Gusdal, Yvonne; Dingsør, Gjert Endre; Ciannelli, Lorenzo; Hjermann, Dag Ø.; Ottersen, Geir; Stige, Leif Christian; Fossum, Ingerid; Melsom, Arne; Stenseth, Nils Christian (ICES CM Documents;2009/C:06, Working paper, 2009)Recruitment ecology of cod has been an important focus within the framework of GLOBEC. A large part of this work focused on understanding the spatiotemporal component of cod populations. For the early pelagic life stages, ... -
Direct and indirect climate forcing in a multi-species marine system
Ottersen, Geir; Stige, Leif Christian; Dalpadado, Padmini; Chan, Kung-Sik; Hjermann, Dag Ø.; Lajus, Dmitry L.; Yaragina, Natalia A.; Stenseth, Nils Christian (Journal article; Peer reviewed, 2010-10)Interactions within and between species complicate quantification of climate effects, by causing indirect, often delayed, effects of climate fluctuations and compensation of mortality. Here we identify direct and indirect ... -
Dramatic changes in spawning stock age-structure of Barents Sea cod
Ottersen, Geir; Hjermann, Dag Ø.; Stenseth, Nils Christian (ICES CM documents, Working paper, 2004)Atlantic Cod (Gadus morhua) is one of the commercially most important fish species in the North Atlantic and plays a central role in several ecosystems. Fishing pressure has been heavy over a prolonged period and the ... -
Environmental toxicology: Population modeling of cod larvae shows high sensitivity to loss of zooplankton prey
Stige, Leif Christian; Ottersen, Geir; Hjermann, Dag Ø.; Dalpadado, Padmini; Jensen, Louise K.; Stenseth, Nils Christian (Journal article; Peer reviewed, 2010-12-30)Two factors determine whether pollution is likely to affect a population indirectly through loss of prey: firstly, the sensitivity of the prey to the pollutants, and secondly, the sensitivity of the predator population to ... -
Environmental toxicology: Population modeling of cod larvae shows high sensitivity to loss of zooplankton prey
Stige, Leif Christian; Ottersen, Geir; Hjermann, Dag Ø.; Dalpadado, Padmini; Jensen, Louise K.; Stenseth, Nils Christian (Journal article; Peer reviewed, 2010-12-30)Two factors determine whether pollution is likely to affect a population indirectly through loss of prey: firstly, the sensitivity of the prey to the pollutants, and secondly, the sensitivity of the predator population to ... -
Extension of the match-mismatch hypothesis to predator-controlled systems
Durant, Joël M.; Hjermann, Dag Ø.; Falkenhaug, Tone; Gifford, Dian J.; Naustvoll, Lars-Johan; Sullivan, Barbara K.; Beaugrand, Grégory; Stenseth, Nils Christian (Journal article; Peer reviewed, 2013-01-31)Differential change in the phenology of predators and prey is a potentially important climate-mediated mechanism influencing populations. The match-mismatch hypothesis describes the effect of predator-prey population ... -
Fish and oil in the Lofoten–Barents Sea system: synoptic review of the effect of oil spills on fish populations
Hjermann, Dag Ø.; Melsom, Arne; Dingsør, Gjert Endre; Durant, Joël M.; Eikeset, Anne Maria; Røed, Lars Petter; Ottersen, Geir; Storvik, Geir; Stenseth, Nils Christian (Journal article; Peer reviewed, 2007-06-06)The Lofoten-Barents Sea area, which contains some of the most valuable fish stocks of the Atlantic Ocean, is being considered for offshore oil production. We review the effects of a hypothetical oil spill on fishes in this ... -
Indirect climatic forcing of the Barents Sea capelin: a cohort effect
Hjermann, Dag Ø.; Stenseth, Nils Christian; Ottersen, Geir (Journal article; Peer reviewed, 2004-06-08)Planktivorous capelin is a key species in the Barents Sea, being of great importance in the exploitation of plankton production in this subarctic region. However, in years with a successful reproduction of the Norwegian ... -
Landscape dynamics and predator-prey interactions in marine environments
Ciannelli, Lorenzo; Bailey, Kevin; Frank, Kenneth T.; Hjermann, Dag Ø.; Ottersen, Geir; Stenseth, Nils Christian (ICES CM documents, Working paper, 2004)In several sub-arctic marine ecosystems of the North Atlantic capelin are the primary prey item for cod, and the trophic interaction between capelin and cod is a central energetic pathway. However, in the North Pacific ... -
Pros and cons of using seabirds as ecological indicators
Durant, Joël M.; Hjermann, Dag Ø.; Frederiksen, Morten; Charrassin, Jean-Benoit; Le Maho, Yvon; Sabarros, Philippe Sunil; Crawford, Robert J.M.; Stenseth, Nils Christian (Journal article; Peer reviewed, 2009-07-14)Climate change and overfishing are increasingly causing unanticipated changes in marine ecosystems (e.g. shifts in species dominance). In order to understand and anticipate these changes, there is a crucial need for ... -
Reversing the Match-mismatch relationship: the prey point of view
Durant, Joël M.; Hjermann, Dag Ø.; Stenseth, Nils Christian (ICES CM documents;2009/ P:08, Working paper, 2009)Climate influences populations through a variety of processes. One mechanism that may be particularly important is the role of climate in disrupting un-equally the phenology of the predator and prey in a food chain. The ... -
Seasonal plankton dynamics along a cross-shelf gradient
Stenseth, Nils Christian; Llope, Marcos; Anadón, Ricardo; Ciannelli, Lorenzo; Chan, Kung-Sik; Hjermann, Dag Ø.; Bagøien, Espen; Ottersen, Geir (Journal article; Peer reviewed, 2006-08-08)Much interest has recently been devoted to reconstructing the dynamic structure of ecological systems on the basis of time-series data. Using 10 years of monthly data on phyto- and zooplankton abundance from the Bay of ... -
Trophic interactions affecting a key ecosystem component: a multi-stage analysis of the recruitment of the Barents Sea capelin
Hjermann, Dag Ø.; Bogstad, Bjarte; Dingsør, Gjert Endre; Gjøsæter, Harald; Ottersen, Geir; Eikeset, Anne Maria; Stenseth, Nils Christian (Journal article; Peer reviewed, 2010-08-10)The Barents Sea stock of capelin (Mallotus villosus) has suffered three major collapses (>90% reduction) since 1985 due to recruitment failures. As capelin is a key species in the area, these population collapses have had ... -
Trophic interactions affecting a key ecosystem component: a multi-stage analysis of the recruitment of the Barents Sea capelin
Hjermann, Dag Ø.; Bogstad, Bjarte; Dingsør, Gjert Endre; Gjøsæter, Harald; Ottersen, Geir; Eikeset, Anne Maria; Stenseth, Nils Christian (Journal article; Peer reviewed, 2010-08-10)The Barents Sea stock of capelin (Mallotus villosus) has suffered three major collapses (>90% reduction) since 1985 due to recruitment failures. As capelin is a key species in the area, these population collapses have had ... -
Trophic interactions affecting a key ecosystem component: a multi-stage analysis of the recruitment of the Barents Sea capelin
Hjermann, Dag Ø.; Bogstad, Bjarte; Dingsør, Gjert Endre; Gjøsæter, Harald; Ottersen, Geir; Eikeset, Anne Maria; Stenseth, Nils Christian (ICES CM documents;2009/ C:07, Working paper, 2009)