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...
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
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
... 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;amp; Lindegaard (1987). ... In the surf zone, Ol m, 4-5 species of orthocladine chironomids are most abundant (Lindegaard 1980,1982). ...
... 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;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 ...
... 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). ...
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...
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
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
... 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;amp; Lindegaard (1987). ... In the surf zone, Ol m, 4-5 species of orthocladine chironomids are most abundant (Lindegaard 1980,1982). ...
... 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;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 ...
... 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). ...
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