Blar i Published in cooperation with others på forfatter "Thorsen, Anders"
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Bio-physical properties of Norwegian coastal cod eggs
Jung, Kyung-Mi; Sundby, Svein; Thorsen, Anders; Folkvord, Arild; Kjesbu, Olav Sigurd (ICES CM documents;2009/C:11, Working paper, 2009)Vertical distribution of fish eggs and larvae is a key factor for transport and retention of the offspring, and for problems linked to mixing/separation between populations, and hence for mechanism maintaining genetic ... -
Demonstration of maternal effects of Atlantic cod: Combining the use of unique mesocosm and novel molecular techniques – A new EU-project
Svåsand, Terje; Ajiad, Adnan Mosa; Dahle, Geir; Jakobsen, Tore; Kjesbu, Olav Sigurd; Moksness, Erlend; Otterå, Håkon; Solemdal, Per; Thorsen, Anders (ICES CM documents, Working paper, 2000)One of the effects of fishing is a reduction in average age and size in exploited fish stocks, leading to an increasing proportion of recruit spawners in the stock. Current management practice assumes equal viability of ... -
Estimation of potential and realised fecundity of fish
Thorsen, Anders; Kjesbu, Olav Sigurd; Witthames, Peter R. (ICES CM documents, Working paper, 2005) -
Evaluating the effectiveness of biological reference points in conserving reproductive potential
Marshall, C. Tara; Yaragina, Natalia A.; Thorsen, Anders (ICES CM documents, Working paper, 2001) -
How variable is the fecundity within and between cod stocks?
Lambert, Yvan; Kjesbu, Olav Sigurd; Kraus, G.; Marteinsdottir, Gudrun; Thorsen, Anders (ICES CM documents, Working paper, 2005)Stock reproductive potential is determined by the number of fish at age, sex ratio, proportion of mature female at age and fecundity. Fecundity data, which are fundamental in estimating egg production are not collected ... -
Overview of the EU fair project "STEREO" (Stock effects on recruitment relationships)
MacKenzie, Brian; Heath, Michael; Ådlandsvik, Bjørn; Backhaus, Jan O.; Bogstad, Bjarte; Gallego, Alejandro; Godø, Olav Rune; Gudmundsdottir, Asta; Harms, Ingo H.; Heilmann, J.P.; Jonsson, Sigurður; Kjesbu, Olav Sigurd; MacKenzie, Eddie; Marteinsdottir, Gudrun; Nielsen, Einar E.; Scott, Beth; Strugnell, G.; Stefánsson, Gunnar; Thorsen, Anders; Visser, Andre W.; Wright, Peter (ICES CM Documents;1999/Y:10, Working paper, 1999)The overall objective of the STEREO project is to improve the methodology for determining limit reference points for the biomass of exploited fish stocks. Limit reference points set boundaries which are intended to ... -
The potential importance of the paternal contribution to the ‘Stock Reproductive Potential’ of North-East Arctic cod (Gadus morhua)
Nash, Richard D.M.; Kjesbu, Olav Sigurd; Thorsen, Anders; Fonn, Merete; Krüger-Johnsen, Maria; Trippel, Ed (ICES CM documents, Working paper, 2005)Over the years there has been a growing interest in determining the real stock reproductive potential (SRP) as a means of understanding the dynamics of a fish population. For the purposes of assessment the spawning stock ... -
Prey-specific gastric evacuation of Norwegian spring spawning herring (Clupea harengus)
Broms, Cecilie; Melle, Webjørn; Thorsen, Anders (ICES CM Documents;2004/P:39, Working paper, 2004)Gastric evacuation rates have earlier mainly been measured based on laboratory experiments. The aim of this study is to obtain information of gastric evacuation rates when the herring are feeding in their natural environment. ... -
Size of spawning Arcto-Norwegian cod (Gadus morhua L.) and the effects on their eggs and early larvae
Solemdal, Per; Bergh, Øivind; Dahle, Geir; Falk-Petersen, Inger-Britt; Fyhn, Hans Jørgen; Grahl-Nielsen, Otto; Haaland, J.M.; Kjesbu, Olav Sigurd; Løken, Sissel; Opstad, Ingegjerd; Pedersen, Torstein; Skiftesvik, Anne Berit; Thorsen, Anders (ICES CM Documents;1993/G:41, Working paper, 1993)Using a new method for determining the stage of spawning in batch spawners, a positive correlation between the length of Arcto-Norwegian cod females, having spawned 25-75% of their eggs, and the egg diameter was established. ... -
Spawner quality effects on two measures of reproductive potential: have we been counting our eggs before they've hatched?
Marshall, C. Tara; Kjesbu, Olav Sigurd; Thorsen, Anders; Solemdal, Per (ICES CM documents, Working paper, 1999)Recent studies have found positive associations between recruitment and indices of spawner quality (condition) for stocks exhibiting an indeterminate relationship between recruitment and spawner biomass. This suggests ... -
Systematic bias in estimates of reproductive potential of cod stocks: implications for stock/recruit theory and management
Marshall, C. Tara; Needle, Coby L.; Thorsen, Anders; Kjesbu, Olav Sigurd; Yaragina, Natalia A. (ICES CM documents, Working paper, 2005)Stock/recruit relationships, describing the relationship between the parental population and the number of offspring produced, are a central tool in population ecology. For fish populations the stock/recruit relationship ...