Blar i Brage IMR på forfatter "Vølstad, Jon Helge"
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Fisketuristenes fangster er kartlagt : Recording the catches of fishing tourists
Hauge, Marie; Nilsen, Merete; Vølstad, Jon Helge (Havforskningsnytt;Nr. 7 - 2010, Working paper, 2010)Figures from the Institute of Marine Research show that fishing tourists using the organised tourism industry catch an estimated 3,300 tonnes each year. The estimate is based on advanced statistical methods, practical field ... -
Hummerfisket 2017 og 2018: Innsats og fangst
Kleiven, Alf Ring; Lyle, Jeremy; Ferter, Keno; Espeland, Sigurd Heiberg; Kleiven, Portia Joy Nillos; Christensen, Lene; Vølstad, Jon Helge (Rapport fra havforskningen;2019 - 39, Research report, 2019)I 2017 ble det innført obligatorisk påmelding til hummerfisket for både fritidsfiskere og yrkesfiskere. Dette har lagt grunnlaget for muligheten til å beregne total innsats og fangst av hummer i Norge. Etter hummersesongen ... -
Instituttets infrastrukturprosjekt Sea2Data
Handegard, Nils Olav; Gjøsæter, Harald; Johansen, Geir Odd; Krakstad, Jens-Otto; Moksness, Erlend; Sagen, Helge; Vølstad, Jon Helge; Westgård, Trond (Conference object, 2010-11-03) -
Integrating complementary survey methods to estimate catches in Norway’s complex marine recreational hook-and-line fishery
Ferter, Keno; Otterå, Håkon Magne; Christman, Mary C.; Kleiven, Alf Ring; Weltersbach, Marc Simon; Gundersen, Sofie; Djønne, Christine; Bjelland, Otte; Hartill, Bruce; Lyle, Jeremy; Hyder, Kieran; Borch, Trude Kristin; Vølstad, Jon Helge (Peer reviewed; Journal article, 2022)Marine recreational fishing is popular in Norway, but current estimates of the catches by resident and tourist anglers are lacking due to several challenges, in particular Norway’s long and intricate coastline with no ... -
Kveite i norske farvann. Status og utfordringer for forvaltning og forskning
Høines, Åge S.; Bjelland, Otte; Michalsen, Kathrine; Vølstad, Jon Helge; Helle, Kristin; Vollen, Tone; Nedreaas, Kjell Harald; Albert, Ole Thomas (Rapport fra Havforskningen;Nr.1-2009, Working paper, 2009-05)Kveite, eller atlantisk kveite og hvitkveite som den også kalles for å skille den fra blåkveite, er den største beinfisken i norske farvann og har i alle år hatt en spesiell status i fiskeri og folkeminne. Som mange andre ... -
A novel probabilistic survey method for at sea sampling in pelagic fisheries – the Norwegian catch sampling lottery
Otterå, Håkon Magne; Wathne, Jens A.; Fuglebakk, Edvin; Slotte, Aril; Svendsen, Bjørn Vidar; Vølstad, Jon Helge (Peer reviewed; Journal article, 2022)Reliable information on the age- and size-structure of the annual harvest of major commercial fish stocks is crucial input to analytical stock assessments. Such information is usually obtained from landing data (census of ... -
Optimum size of sampling unit for estimating the density of marine populations
Pennington, Michael; Vølstad, Jon Helge (ICES CM Documents;1989/D:22, Working paper, 1989)Data from several trawling experiments and from some scallop dredge surveys indicate that, within limits, a srnaller sampling unit can be more effective than a larger unit for marine abundance surveys. Taking into account ... -
Probability-based surveying using self-sampling to estimate catch and effort in Norway’s coastal tourist fishery
Vølstad, Jon Helge; Korsbrekke, Knut; Nilsen, Merete; Nilsson, Gro N.; Pennington, Michael; Subbey, Samuel; Wienerroither, Rupert (Journal article; Peer reviewed, 2011-06-08)Recreational fishing as a tourist activity has become an increasingly important part of the Norwegian travel industry and may contribute significantly to the fishing mortality on Norwegian coastal cod (Gadus morhua). ... -
Recreational sea fishing in Europe in a global context—Participation rates, fishing effort, expenditure, and implications for monitoring and assessment
Kieran, Hyder; Weltersbach, Marc Simon; Armstrong, Mark; Ferter, Keno; Townhill, Bryony; Ahvonen, Anssi; Arlinghaus, Robert; Baikov, Andrei; Bellanger, Manuel; Birzaks, Janis; Borch, Trude Kristin; Cambie, Giulia; de Graaf, Martin; Diogo, Hugo M C; Dziemian, Lukasz; Gordoa, Ana; Grzebielec, Ryszard; Hartill, Bruce; Kagervall, Anders; Kapiris, Kostas; Karlsson, Martin; Kleiven, Alf Ring; Lejk, Adam M; Levrel, Harold; Lovell, Sabrina; Lyle, Jeremy; Miolanen, Pentti; Monkman, Graham; Morales-Nin, Beatriz; Mugerza, Estanis; Martinez, Roi; O'Reilly, Paul F; Olesen, Hans Jakob; Papadopoulos, Anastasios; Pita, Pablo; Radford, Zachary; Radtke, Krzysztof; Roche, William; Rocklin, Delphine; Ruiz, Jon; Scougal, Callum; Silvestri, Roberto; Skov, Christian; Steinback, Scott; Sundeløf, Andreas; Svagzdys, Arvydas; Turnbull, David; van der Hammen, Tessa; van Voorhees, David; van Winsen, Frankwin; Verleye, Thomas J; Veiga, Pedro; Vølstad, Jon Helge; Zarauz, Lucia; Zolubas, Tomas; Strehlow, Harry Vincent (Journal article; Peer reviewed, 2017)Marine recreational fishing (MRF) is a high-participation activity with large economic value and social benefits globally, and it impacts on some fish stocks. Although reporting MRF catches is a European Union legislative ... -
Recruitment regime shifts and nonstationarity are widespread phenomena in harvestable stocks experiencing pronounced climate fluctuations
Ma, Shuyang; Huse, Geir; Ono, Kotaro; Nash, Richard David Marriott; Sandø, Anne Britt; Nedreaas, Kjell Harald; Hjøllo, Solfrid Sætre; Sundby, Svein; Clegg, Thomas L; Vølstad, Jon Helge; Kjesbu, Olav Sigurd (Peer reviewed; Journal article, 2023)Methods to reliably identify jump discontinuities in biological time series and to assess the specific contribution of various covariates are rapidly progressing. Here, we took advantage of these statistical improvements ... -
Self-sampling of the Norwegian Springs Spawning Herring fishery – optimizing data collections to achieve sufficientprecision in stock assessment. ICES CM 2016/O:467 s
Aanes, Sondre; Vølstad, Jon Helge (ICES CM documents;2016/O:467, Lecture, 2016) -
A simulation approach to assessing bias in a fisheries self-sampling programme
Clegg, Tom; Fuglebakk, Edvin; Ono, Kotaro; Vølstad, Jon Helge; Nedreaas, Kjell Harald (Peer reviewed; Journal article, 2021)The hierarchical structure and non-probabilistic sampling in fisher self-sampling programmes makes it difficult to evaluate biases in total catch estimates. While so, it is possible to evaluate bias in the reported component ... -
Spatial and temporal variations in seabird bycatch: Incidental bycatch in the Norwegian coastal gillnet-fishery
Bærum, Kim Magnus; Anker-Nilssen, Tycho; Christensen-Dalsgaard, Signe; Fangel, Kirstin; Williams, Tom; Vølstad, Jon Helge (Peer reviewed; Journal article, 2019)The general decline of seabird populations worldwide raises large concerns. Although multiple factors are interacting to cause the observed trends, increased mortality from incidental bycatch in fisheries has proven to be ... -
Total Catch of a Red-Listed Marine Species Is an Order of Magnitude Higher than Official Data
Kleiven, Alf Ring; Olsen, Esben Moland; Vølstad, Jon Helge (Journal article; Peer reviewed, 2012-02-17)Accurate information on total catch and effort is essential for successful fisheries management. Officially reported landings, however, may be underestimates of total catch in many fisheries. We investigated the fishery ... -
Using acoustic surveys to improve the prediction of bottom trawl indices of abundance
Ona, Egil; Pennington, Michael; Vølstad, Jon Helge (ICES CM documents, Working paper, 1991) -
The value of applying commercial fishers' experience to designed surveys for identifying characteristics of essential fish habitat for adult summer flounder
Slacum, H.W.; Vølstad, Jon Helge; Weber, E.D.; Richkus, W.A.; Diaz, R.J.; Tallent, C.O. (Journal article; Peer reviewed, 2008-06)Identifying the habitat requirements of marine fish is necessary to conserve and manage their populations, but these requirements are poorly understood for many species. One method of screening for important habitat ...