Bror Jonsson - Academia.edu (original) (raw)
Papers by Bror Jonsson
Biogeosciences Discussions
We assess the ability of ocean biogeochemical models to represent seasonal structures in biomass ... more We assess the ability of ocean biogeochemical models to represent seasonal structures in biomass and net community production (NCP) in the Southern Ocean. Two models are compared to observations on daily to seasonal time scales in four different sections of the region. We use daily satellite fields of Chlorophyll (Chl) as a proxy for biomass, and in-situ observations of O<sub>2</sub> and Ar supersaturation (ΔO<sub>2</sub>Ar) to estimate NCP. ΔO<sub>2</sub>Ar is converted to the flux of biologically generated O<sub>2</sub> from sea to air ("O<sub>2</sub> bioflux"). All data are aggregated to a climatological year with a daily resolution. To account for potential regional differences within the Southern Ocean, we conduct separate analyses of sections south of South Africa, around the Drake Passage, south of Australia, and south of New Zealand. <br><br> We find that the models simulate the upp...
Ecology of Freshwater Fish
Conservation Science and Practice
Wild Atlantic salmon (Salmo salar) are in decline over the entire distribution area, and populati... more Wild Atlantic salmon (Salmo salar) are in decline over the entire distribution area, and populations are enhanced by supportive breeding. Parental fish are sampled in rivers, crossed and the offspring reared in hatcheries until smolting when released, ready for ocean migration. Naturally reproducing salmon entering the River Imsa from the ocean were monitored from 1976 through 2013, and since 1982, supportive breeders spawning in the river were also monitored. The supportive breeders were first-generation salmon, reared for 1-2 years in a hatchery before being released at the mouth of the river so they could migrate to sea (i.e., sea-ranching). Wild and sea-ranched salmon live in the ocean for 1-2 years before they return to the river for spawning. In years when only wild adults were present, mean number of smolts produced per 100 m 2 river area and female breeder was 0.47. When there were 5% wild females, the mean production was only 0.088 (19%). The gradual decrease in offspring production with decreasing proportion of wild females (r 2 = .41) indicates that the reduced offspring production was caused by inferior spawning behavior of hatchery females or reduced survival of their offspring in nature. Previous experimental evidence suggests that wild males fertilize the eggs of wild but also hatchery females. It is discussed how epigenetic effects caused by hatchery environments influence the developing juveniles, lead to phenotypic changes that may reduce their fitness in nature even after free ranging for a year or more in the ocean before they return and spawn.
Aquaculture Environment Interactions
Nature Ecology & Evolution
Interbreeding between domesticated and wild animals occurs in several species. This gene flow has... more Interbreeding between domesticated and wild animals occurs in several species. This gene flow has long been anticipated to induce genetic changes in life-history traits of wild populations, thereby influencing population dynamics and viability. Here, we show that individuals with high levels of introgression (domesticated ancestry) have altered age and size at maturation in 62 wild Atlantic salmon Salmo salar populations, including seven ancestral populations to breeding lines of the domesticated salmon. This study documents widespread changes to life-history traits in wild animal populations following gene flow from selectively bred, domesticated conspecifics. The continued high abundance of escaped, domesticated Atlantic salmon thus threatens wild Atlantic salmon populations by inducing genetic changes in fitness-related traits. Our results represent key evidence and a timely warning concerning the potential ecological impacts of the globally increasing use of domesticated animals.
SUMMARY 1. Annual energy, carbon, nitrogen and phosphorus fluxes across the river mouth by Atlant... more SUMMARY 1. Annual energy, carbon, nitrogen and phosphorus fluxes across the river mouth by Atlantic salmon were estimated for 18 years (1976-94) in the Norwegian River Imsa. The total energy content of the emigrating smolts in each year varied considerably with a mean value of 237 · 103 kJ. That of returning adults also varied between years with a mean
Hydrobiologia, 1997
Habitat utilization and the life history of browntrout Salmo trutta and Arctic charr Salvelinus a... more Habitat utilization and the life history of browntrout Salmo trutta and Arctic charr Salvelinus alpinus were investigated in fivesympatric populations and five allopatric brown troutpopulations in Høylandet catchment, a atmosphaericlow deposition area in Mid Norway. There was asignificant inverse correlation in abundance ofepibenthic Arctic charr and brown trout in theselakes, indicating that the latter species is dominant.The largest numbers of
Journal of Coastal Conservation, 2014
Your article is protected by copyright and all rights are held exclusively by Springer Science +B... more Your article is protected by copyright and all rights are held exclusively by Springer Science +Business Media Dordrecht. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
Environ Biol Fish, 1988
... Page 4. 186 nology of the lake was thoroughly described by Lastein (1983) Jdnsson (1987), Kai... more ... Page 4. 186 nology of the lake was thoroughly described by Lastein (1983) Jdnsson (1987), Kairesalo et al. (1987) and J6nasson &amp;amp;amp;amp;amp; Lindegaard (1987). ... In the surf zone, Ol m, 4-5 species of orthocladine chironomids are most abundant (Lindegaard 1980,1982). ...
Behavioral Ecology and Sociobiology, Mar 31, 1990
This paper documents differences in seasonal time of river ascent and descent, and instream behav... more This paper documents differences in seasonal time of river ascent and descent, and instream behavior of adult wild and sea-ranched Atlantic salmon (Salmo salar) of the Norwegian River Imsa stock during the period 1981-1989. Wild fish use River Imsa as a nursery, and at an age of 2 years most of them migrate to the sea as smolts. The sea ranched fish are hatchery reared offspring of the River Imsa stock and are released as smolts at the mouth of the river. They are thus deprived of juvenile river life and a downstream smolt migration. Wild and sea ranched salmon feed for 1 or more years in the Norwegian Sea before homing as spawners. Both groups returned simultaneously to coastal Norway, but sea ranched fish ascended the river later and descended sooner after spawning than wild fish. All wild females and almost all wild males (96.2%) spawned in the river, whereas 13.5% and 36.7%, respectively, of the mature sea-ranched females and males left the river unspawned. The annual number, but not the proportion, of unspawned fish increased with increasing density of adult salmon in the river. Unspawned females were medium sized and small (45-70 cm); unspawned males were medium sized and large (50-90 cm). Independent of the density of spawners in the river, sea ranched fish moved up-and downstream the river more often than wild fish. More than 20% of the sea-ranched salmon and less than 1% of the wild salmon passed a trap 100 m above the river outlet more than once in each direction during the same spawning reason. Moreover, sea-ranched salmon were about twice as often seriously injured during spawning as wild fish. Lack of juvenile experience from the river may be the main reason for the behavioral differences between sea-ranched and wild fish.
... In regulated rivers, rapid fluc-tuations in water level should be avoided, and the migratory ... more ... In regulated rivers, rapid fluc-tuations in water level should be avoided, and the migratory activity of the fish can be stimu-lated ... Changes in Changed character Sources Morphology Body form and size Taylor 1986; Swain et al. ... 1999 Physiology and Heart abnormity Poppe et al. ...
Canadian Journal of Fisheries and Aquatic Sciences, Dec 1, 1994
We quantified divergence in phenotype of sea-ranched, farmed, and wild Atlantic salmon (Salmo sal... more We quantified divergence in phenotype of sea-ranched, farmed, and wild Atlantic salmon (Salmo salar) of a common genetic stock (River Imsa, Norway). These first-generation fish were also contrasted with a fifth-generation farmed population (Norwegian commercial strain) and with wild and multigeneration sea-ranched populations of coho salmon (Oncorhynchus kisutch). In comparisons using mature Atlantic salmon male parr, cultured juveniles had smaller heads and fins and narrower caudal peduncles and could be distinguished from wild juveniles with 100% accuracy. When juveniles were reared to adulthood in the natural marine environment, some environmentally induced differences due to juvenile hatchery rearing persisted but many disappeared. This was particularly true for head and trunk morphology. Greater adult divergence from the wild state was observed in multigeneration sea-ranched coho salmon, suggesting that evolutionary changes may accumulate with time. Continued farming of salmon juveniles through adulthood increased environmentally induced phenotypic divergence considerably. Both rayed-fin sizes and body streamlining decreased. Fifth-generation Norwegian farmed salmon showed the greatest morphological differences. Both the proportion of a fish&amp;amp;amp;#39;s life history and number of generations spent in culture are thus probably important determinants of phenotypic divergence of cultured fish from their wild state.
Transactions of the American Fisheries Society, Nov 1, 1986
Page 1. Transactions of the American Fisheries Society 115:864-871, 1986 ¸ Copyright by the Ameri... more Page 1. Transactions of the American Fisheries Society 115:864-871, 1986 ¸ Copyright by the American Fisheries Society 1986 Life-History Characteristics of the European Eel Anguilla anguilla in the Imsa River, Norway LEIF ...
Her publiseres resultater av NINA og NIKUs eget forskningsarbeid, problemoversikter, kartlegging ... more Her publiseres resultater av NINA og NIKUs eget forskningsarbeid, problemoversikter, kartlegging av kunnskapsnivået innen et emne, og litteraturstudier. Rapporter utgis også som et alternativ eller et supplement til internasjonal publisering, der tidsaspekt, materialets art, målgruppe m.m. gjør dette nødvendig. Opplag: Normalt 300-500 NINA Oppdragsmelding NIKU Oppdragsmelding Dette er det minimum av rapportering som NINA og NIKU gir til oppdragsgiver etter fullført forsknings-eller utredningsprosjekt. I tillegg til de emner som dekkes av fagrapportene, vil oppdragsmeldingene også omfatte befaringsrapporter, seminar-og konferanseforedrag, års-rapporter fra overvåkningsprogrammer, o.a. Opplaget er begrenset. (Normalt 50-100)
Ecol Freshw Fish, 2003
... In the present contribution, we review aspects of the biology of Atlantic salmon (Salmo salar... more ... In the present contribution, we review aspects of the biology of Atlantic salmon (Salmo salar),brown trout (Salmo trutta) and Arctic ... rivers and there have been instances where consecutive spawners switched to alternate spawning (Conne River) and vice versa (Gander River). ...
Biogeosciences Discussions
We assess the ability of ocean biogeochemical models to represent seasonal structures in biomass ... more We assess the ability of ocean biogeochemical models to represent seasonal structures in biomass and net community production (NCP) in the Southern Ocean. Two models are compared to observations on daily to seasonal time scales in four different sections of the region. We use daily satellite fields of Chlorophyll (Chl) as a proxy for biomass, and in-situ observations of O<sub>2</sub> and Ar supersaturation (ΔO<sub>2</sub>Ar) to estimate NCP. ΔO<sub>2</sub>Ar is converted to the flux of biologically generated O<sub>2</sub> from sea to air ("O<sub>2</sub> bioflux"). All data are aggregated to a climatological year with a daily resolution. To account for potential regional differences within the Southern Ocean, we conduct separate analyses of sections south of South Africa, around the Drake Passage, south of Australia, and south of New Zealand. <br><br> We find that the models simulate the upp...
Ecology of Freshwater Fish
Conservation Science and Practice
Wild Atlantic salmon (Salmo salar) are in decline over the entire distribution area, and populati... more Wild Atlantic salmon (Salmo salar) are in decline over the entire distribution area, and populations are enhanced by supportive breeding. Parental fish are sampled in rivers, crossed and the offspring reared in hatcheries until smolting when released, ready for ocean migration. Naturally reproducing salmon entering the River Imsa from the ocean were monitored from 1976 through 2013, and since 1982, supportive breeders spawning in the river were also monitored. The supportive breeders were first-generation salmon, reared for 1-2 years in a hatchery before being released at the mouth of the river so they could migrate to sea (i.e., sea-ranching). Wild and sea-ranched salmon live in the ocean for 1-2 years before they return to the river for spawning. In years when only wild adults were present, mean number of smolts produced per 100 m 2 river area and female breeder was 0.47. When there were 5% wild females, the mean production was only 0.088 (19%). The gradual decrease in offspring production with decreasing proportion of wild females (r 2 = .41) indicates that the reduced offspring production was caused by inferior spawning behavior of hatchery females or reduced survival of their offspring in nature. Previous experimental evidence suggests that wild males fertilize the eggs of wild but also hatchery females. It is discussed how epigenetic effects caused by hatchery environments influence the developing juveniles, lead to phenotypic changes that may reduce their fitness in nature even after free ranging for a year or more in the ocean before they return and spawn.
Aquaculture Environment Interactions
Nature Ecology & Evolution
Interbreeding between domesticated and wild animals occurs in several species. This gene flow has... more Interbreeding between domesticated and wild animals occurs in several species. This gene flow has long been anticipated to induce genetic changes in life-history traits of wild populations, thereby influencing population dynamics and viability. Here, we show that individuals with high levels of introgression (domesticated ancestry) have altered age and size at maturation in 62 wild Atlantic salmon Salmo salar populations, including seven ancestral populations to breeding lines of the domesticated salmon. This study documents widespread changes to life-history traits in wild animal populations following gene flow from selectively bred, domesticated conspecifics. The continued high abundance of escaped, domesticated Atlantic salmon thus threatens wild Atlantic salmon populations by inducing genetic changes in fitness-related traits. Our results represent key evidence and a timely warning concerning the potential ecological impacts of the globally increasing use of domesticated animals.
SUMMARY 1. Annual energy, carbon, nitrogen and phosphorus fluxes across the river mouth by Atlant... more SUMMARY 1. Annual energy, carbon, nitrogen and phosphorus fluxes across the river mouth by Atlantic salmon were estimated for 18 years (1976-94) in the Norwegian River Imsa. The total energy content of the emigrating smolts in each year varied considerably with a mean value of 237 · 103 kJ. That of returning adults also varied between years with a mean
Hydrobiologia, 1997
Habitat utilization and the life history of browntrout Salmo trutta and Arctic charr Salvelinus a... more Habitat utilization and the life history of browntrout Salmo trutta and Arctic charr Salvelinus alpinus were investigated in fivesympatric populations and five allopatric brown troutpopulations in Høylandet catchment, a atmosphaericlow deposition area in Mid Norway. There was asignificant inverse correlation in abundance ofepibenthic Arctic charr and brown trout in theselakes, indicating that the latter species is dominant.The largest numbers of
Journal of Coastal Conservation, 2014
Your article is protected by copyright and all rights are held exclusively by Springer Science +B... more Your article is protected by copyright and all rights are held exclusively by Springer Science +Business Media Dordrecht. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
Environ Biol Fish, 1988
... Page 4. 186 nology of the lake was thoroughly described by Lastein (1983) Jdnsson (1987), Kai... more ... Page 4. 186 nology of the lake was thoroughly described by Lastein (1983) Jdnsson (1987), Kairesalo et al. (1987) and J6nasson &amp;amp;amp;amp;amp; Lindegaard (1987). ... In the surf zone, Ol m, 4-5 species of orthocladine chironomids are most abundant (Lindegaard 1980,1982). ...
Behavioral Ecology and Sociobiology, Mar 31, 1990
This paper documents differences in seasonal time of river ascent and descent, and instream behav... more This paper documents differences in seasonal time of river ascent and descent, and instream behavior of adult wild and sea-ranched Atlantic salmon (Salmo salar) of the Norwegian River Imsa stock during the period 1981-1989. Wild fish use River Imsa as a nursery, and at an age of 2 years most of them migrate to the sea as smolts. The sea ranched fish are hatchery reared offspring of the River Imsa stock and are released as smolts at the mouth of the river. They are thus deprived of juvenile river life and a downstream smolt migration. Wild and sea ranched salmon feed for 1 or more years in the Norwegian Sea before homing as spawners. Both groups returned simultaneously to coastal Norway, but sea ranched fish ascended the river later and descended sooner after spawning than wild fish. All wild females and almost all wild males (96.2%) spawned in the river, whereas 13.5% and 36.7%, respectively, of the mature sea-ranched females and males left the river unspawned. The annual number, but not the proportion, of unspawned fish increased with increasing density of adult salmon in the river. Unspawned females were medium sized and small (45-70 cm); unspawned males were medium sized and large (50-90 cm). Independent of the density of spawners in the river, sea ranched fish moved up-and downstream the river more often than wild fish. More than 20% of the sea-ranched salmon and less than 1% of the wild salmon passed a trap 100 m above the river outlet more than once in each direction during the same spawning reason. Moreover, sea-ranched salmon were about twice as often seriously injured during spawning as wild fish. Lack of juvenile experience from the river may be the main reason for the behavioral differences between sea-ranched and wild fish.
... In regulated rivers, rapid fluc-tuations in water level should be avoided, and the migratory ... more ... In regulated rivers, rapid fluc-tuations in water level should be avoided, and the migratory activity of the fish can be stimu-lated ... Changes in Changed character Sources Morphology Body form and size Taylor 1986; Swain et al. ... 1999 Physiology and Heart abnormity Poppe et al. ...
Canadian Journal of Fisheries and Aquatic Sciences, Dec 1, 1994
We quantified divergence in phenotype of sea-ranched, farmed, and wild Atlantic salmon (Salmo sal... more We quantified divergence in phenotype of sea-ranched, farmed, and wild Atlantic salmon (Salmo salar) of a common genetic stock (River Imsa, Norway). These first-generation fish were also contrasted with a fifth-generation farmed population (Norwegian commercial strain) and with wild and multigeneration sea-ranched populations of coho salmon (Oncorhynchus kisutch). In comparisons using mature Atlantic salmon male parr, cultured juveniles had smaller heads and fins and narrower caudal peduncles and could be distinguished from wild juveniles with 100% accuracy. When juveniles were reared to adulthood in the natural marine environment, some environmentally induced differences due to juvenile hatchery rearing persisted but many disappeared. This was particularly true for head and trunk morphology. Greater adult divergence from the wild state was observed in multigeneration sea-ranched coho salmon, suggesting that evolutionary changes may accumulate with time. Continued farming of salmon juveniles through adulthood increased environmentally induced phenotypic divergence considerably. Both rayed-fin sizes and body streamlining decreased. Fifth-generation Norwegian farmed salmon showed the greatest morphological differences. Both the proportion of a fish&amp;amp;amp;#39;s life history and number of generations spent in culture are thus probably important determinants of phenotypic divergence of cultured fish from their wild state.
Transactions of the American Fisheries Society, Nov 1, 1986
Page 1. Transactions of the American Fisheries Society 115:864-871, 1986 ¸ Copyright by the Ameri... more Page 1. Transactions of the American Fisheries Society 115:864-871, 1986 ¸ Copyright by the American Fisheries Society 1986 Life-History Characteristics of the European Eel Anguilla anguilla in the Imsa River, Norway LEIF ...
Her publiseres resultater av NINA og NIKUs eget forskningsarbeid, problemoversikter, kartlegging ... more Her publiseres resultater av NINA og NIKUs eget forskningsarbeid, problemoversikter, kartlegging av kunnskapsnivået innen et emne, og litteraturstudier. Rapporter utgis også som et alternativ eller et supplement til internasjonal publisering, der tidsaspekt, materialets art, målgruppe m.m. gjør dette nødvendig. Opplag: Normalt 300-500 NINA Oppdragsmelding NIKU Oppdragsmelding Dette er det minimum av rapportering som NINA og NIKU gir til oppdragsgiver etter fullført forsknings-eller utredningsprosjekt. I tillegg til de emner som dekkes av fagrapportene, vil oppdragsmeldingene også omfatte befaringsrapporter, seminar-og konferanseforedrag, års-rapporter fra overvåkningsprogrammer, o.a. Opplaget er begrenset. (Normalt 50-100)
Ecol Freshw Fish, 2003
... In the present contribution, we review aspects of the biology of Atlantic salmon (Salmo salar... more ... In the present contribution, we review aspects of the biology of Atlantic salmon (Salmo salar),brown trout (Salmo trutta) and Arctic ... rivers and there have been instances where consecutive spawners switched to alternate spawning (Conne River) and vice versa (Gander River). ...