Nina Jonsson

Nina Jonsson
Norwegian Institute for Nature Research | NINA · Department of Landscape Ecology

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113
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9,814
Citations
Citations since 2017
14 Research Items
3545 Citations
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20172018201920202021202220230100200300400500600
20172018201920202021202220230100200300400500600
20172018201920202021202220230100200300400500600

Publications

Publications (113)
Article
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Environmental factors influencing parents or offspring during embryogenesis can have knock-on effects at later life stages of the offspring. These effects may prepare the progeny for conditions that they may encounter as larvae, juveniles and/or adults. Here, we give examples on how knock-on effects of temperature and predator cues can affect pheno...
Article
Full-text available
Individual growth of juvenile offspring of anadromous and freshwater resident brown trout Salmo trutta and crosses between the two from the River Imsa, Norway was estimated. The juveniles were incubated until hatching at two temperatures (±SD), either 4.4 ± 1.5 °C or 7.1 ± 0.6 °C. Growth rate was estimated during 22 days in August‐September when th...
Article
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When rehabilitating and reintroducing trout Salmo trutta in rivers, it is a goal that as many as possible survive, home and form self‐sustaining populations. Hatchery‐reared, anadromous Salmo trutta have significant lower ability to return to the area where they were raised if (a) transported in a closed tank to sea and released 5 km from the River...
Article
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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 wer...
Article
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Temperature during embryonic development affects ecological traits and influences the ability to rapidly adapt to the prevailing conditions in changing environments. Here, we review examples of how these developmental effects are manifested in life-history traits from studies of various fish species, with examples of impacts on somatic growth, age...
Article
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Here, we show that adult Atlantic salmon Salmo salar returned about 2 weeks later from the feeding areas in the North Atlantic Ocean to the Norwegian coast, through a phenotypically plastic mechanism, when they developed as embryos in c. 3°C warmer water than the regular incubation temperature. This finding has relevance to changes in migration tim...
Article
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Using a national perspective, Mo et al. (2018) described and expressed concern over the recent invasion into Norwegian rivers of adult pink salmon Oncorhynchus gorbuscha (Walbaum 1792), which were counted in thousands in 2017.
Article
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Habitats modify the population ecology of species. Here, we show how low water level influences abundance and size of adult anadromous brown trout (Salmo trutta) entering a small, South Norwegian stream for spawning. After smolting, the fish appear chiefly to feed within 10 km of the home stream. In the autumn, South Norwegian streams typically flo...
Chapter
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Habitat use and life histories are central issues in the ecology of species. There are close associations between how individuals and populations exploit, compete for, and share habitats and food resources in time and space, and their ability to grow, survive and reproduce (i.e. their fitness). Individuals exploiting rich habitats can grow larger a...
Article
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Long-distance migratory species can reduce mortality risks by synchronizing the migration event and create confusion by swamping predators with high densities. To reduce confusion, predators are known to primarily select aberrant prey. We hypothesized that at the start of their sea sojourn, particularly small and large Atlantic salmon (Salmo salar...
Article
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Occurrence of domesticated organisms in nature is a major biological issue. Many can survive and reproduce with wild conspecifics, but little is known about the ecology of hybrid offspring. Here, we investigated recapture, homing and growth of released offspring of farmed (domesticated), and wild Atlantic salmon Salmo salar and their crosses. The f...
Article
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Populations are retained at reduced levels by resource competition and environmental stochasticity. In the Norwegian River Imsa, the relationship between fecundity of Atlantic salmon (Salmo salar) spawners and number of smolts per unit river area was investigated for cohorts spawned from 1976 to 2011. Annual number of smolts produced per unit area...
Article
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This study gives the probabilistic reaction norm for length at different ages of smolting before seaward migration of Atlantic salmon Salmo salar, spawning in the Norwegian River Imsa. The reaction norm was compared with the optimal length at smolting estimated as the product of survival and female fecundity on the return, given their length at smo...
Article
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Effect of increased temperature during egg maturation on the mass of single eggs produced by the offspring was investigated experimentally in Atlantic salmon Salmo salar. Mass of eggs produced by next-generation females was larger when their mothers experienced warmer water during the last two months of egg maturation, relative to those that experi...
Article
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Annual mean total length (LT) of wild one-sea-winter (1SW) Atlantic salmon Salmo salar of the Norwegian River Imsa decreased from 63 to 54 cm with a corresponding decrease in condition factor (K) for cohorts migrating to sea from 1976 to 2010. The reduction in LT is associated with a 40% decline in mean individual mass, from 2 to 1·2 kg. Hatchery f...
Chapter
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Fennoscandian rivers were colonized postglacially. Early colonization was from the sea and through the Baltic Ice Lake. Salmonids, cottids, smelts Osmerus eperlanus, three-spined sticklebacks Gasterosteus aculeatus, roach Rutilus rutilus and European minnow Phoxinus phoxinus were early immigrants. The species diversity varies among countries and wi...
Chapter
Full-text available
Fennoscandian rivers were colonized postglacially. Early colonization was from the sea and through the Baltic Ice Lake. Salmonids, cottids, smelts Osmerus eperlanus, three-spined sticklebacks Gasterosteus aculeatus, roach Rutilus rutilus and European minnow Phoxinus phoxinus were early immigrants. The species diversity varies among countries and wi...
Article
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Anadromous trout Salmo trutta exhibits sexual size dimorphism (SSD ); females were larger than males in populations where male mean total length (LT ) at maturity was below 49 cm and females were smaller than males when mean male LT was above 49 cm, the slope of the regression of female on male LT was 0·59. In streams with mean annual discharge bel...
Article
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The expression of fitness-related traits, such as egg and gonad size, often varies among habitats and exhibits clinal variation along climatic and latitudinal gradients. However, the mechanisms allowing such variations are obscure and have been ascribed to both phenotypic plasticity and genetic adaptation. We experimentally tested whether variation...
Article
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We tested whether marine survival and migration pattern differed between naturally and hatchery produced European trout Salmo trutta of different origins. The hatchery fish were released 150 m above the river estuary of the southwestern, Norwegian River Imsa, the home of the local population. Recaptures were used as proxy for survival. Wild and loc...
Article
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Conditions fish encounter during embryogenesis and early life history can leave lasting effects not only on morphology, but also on growth rate, life-history and behavioural traits. The ecology of offspring can be affected by conditions experienced by their parents and mother in particular. This review summarizes such early impacts and their ecolog...
Article
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Whether time of seaward migration of young Atlantic salmon Salmo salar influences their subsequent survival and growth was investigated in the River Imsa, south-western Norway. Salmo salar were tagged when moving downstream through a trap near the outlet between 1976 and 2010 and recaptured on their adult return. Most descended as smolts in April a...
Article
In this work, the contact stresses and temperatures during hot and cold rolling have been measured. A work roll containing three different sensors was used for the measurements. There were two contact devices for directly measuring forces and one temperature sensor. One sensor was the "ROLLSURF" sensor. Results obtained with this sensor have been p...
Article
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Migrations between different habitats are key events in the lives of many organisms. Such movements involve annually recurring travel over long distances usually triggered by seasonal changes in the environment. Often, the migration is associated with travel to or from reproduction areas to regions of growth. Young anadromous Atlantic salmon (Salmo...
Article
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1. The reaction norm between growth rate, age and size at maturity in ectotherms is widely debated in ecological literature. It has been proposed that the effect depends on whether growth is affected by food quality or temperature (called the Berrigan–Charnov puzzle). The present experiment tested this for Atlantic salmon (Salmo salar). 2. We enhan...
Article
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Abstract: Field studies have revealed that many ectotherms mature younger and smaller in warmer environments although they grow faster. This has puzzled ecologists because the direct effect of factors that accelerate growth is expected to be larger, not smaller size. We tested this experimentally for Atlantic salmon (Salmo salar) at two winter temp...
Book
Destruction of habitat is the major cause for loss of biodiversity including variation in life history and habitat ecology. Each species and population adapts to its environment, adaptations visible in morphology, ecology, behaviour, physiology and genetics. Here, the authors present the population ecology of Atlantic salmon and brown trout and how...
Article
This chapter describes important elements of the parr-smolt transformation (smolting) in Atlantic salmon and brown trout. Smolting is a preparatory physiolo­gical adaptation, which occurs in spring prior to the seaward migration. It includes morphological transformation, and changes in salinity tolerance, visual pigments, buoyancy, metabolism and b...
Article
In this chapter, we first treat density regulation of populations. The abundance of all populations varies with time, but the magnitude of the fluctuations differs among populations and species. The variation is influenced by both extrinsic and intrinsic factors. If only environment affected population densities, there would be nothing that prevent...
Article
At what age do Atlantic salmon and brown trout become sexually mature, and which factors and mechanisms determine the seasonal timing of maturation and spawning? How are resources allocated to the development of sexual characters and reproduction, and how do they maximize their reproductive output? This chapter reflects on these issues.
Article
Habitat use is a central aspect in the ecology of a species. There are close associations between how individuals and population exploit, compete for, and share habitats and food resources in time and space, and their ability to survive and reproduce (Kramer et al. 1997; Cuthill and Houston 1997). For instance, individuals exploiting rich habitats...
Article
In this book we review and synthesize ecological aspects of Atlantic salmon and brown trout with special emphasis on their life histories in relation to their habitat uses. We draw general conclusions when possible and identify gaps in knowledge. In this final chapter, we draw some main conclusions about life history consequences of present habitat...
Article
Habitat is a template, which influences life histories, behaviour and physiology of organisms, and is the origin of intraspecific variation (Southwood 1977, 1988; Poff and Ward 1990). This is a useful concept for considering relationships underlying demographic patterns observed in fish populations. As habitats differ geographically and temporally,...
Article
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This chapter reviews possible effects of expected climate change in view of current knowledge on consequences of water temperature and flow for Atlantic salmon and brown trout in their endemic range. Population-level effects influencing life-history variables, recruitment, mortality and production are especially emphasized, but also behaviour chan...
Chapter
Migration is long-distance movements made by many individuals more or less in the same direction and at the same time of the year (Endler 1977). The movements are normally followed by a return migration. Migrations are under genetic control (Northcote 1981; Svärdson and Fagerström 1982; Jonsson 1982; Kallio-Nyberg et al. 2002), but are also modulat...
Chapter
In this chapter, we describe systematics and geographical distribution of Atlantic salmon and brown trout and factors important for their success in natural systems. Both are cold water species from the northern hemisphere, but due to human aquaculture and stocking, they now occur in most parts of the world offering suitable habitats.
Chapter
Farmed Atlantic salmon escape unintentionally from hatcheries and fish farm and occur both in the Atlantic and the Pacific Oceans. These fish exploit natural feeding areas in fresh water and at sea, introgress natural populations (Fleming et al. 2000; O’Reilly et al. 2006; Castillo et al. 2008), and reduce the survival of wild populations that are...
Data
Full-text available
Summary1. We estimated the biomass and production of juvenile anadromous brown trout (Salmo trutta) and Atlantic salmon (Salmo salar) (parr) in 12 streams in the Skagerrak area of Norway to identify controlling environmental factors, such as land‐use and water chemistry.2. Production estimates correlated positively with fish density in early summer...
Article
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A special kind of transducer making it possible to measure normal and tangential contact stresses during rolling has been developed. As normal stresses are approximately ten times larger than the tangential, and since cross signals must occur, a proper calibration of the sensor is essential. Calibration must consist of a number of simultaneous appl...
Article
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The present paper reviews the effects of water temperature and flow on migrations, embryonic development, hatching, emergence, growth and life-history traits in light of the ongoing climate change with emphasis on anadromous Atlantic salmon Salmo salar and brown trout Salmo trutta. The expected climate change in the Atlantic is for milder and wette...
Article
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Restoration ecology, the study of renewing degraded, damaged or destroyed ecosystems and populations, is a rapidly growing field, stimulated by new know­ledge about population and community ecology, behavioural ecology, genetics and evolution. With the advancement of modern technology, the human ability to destroy habitats and use and overexploit p...
Article
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The aim of the paper was to study sea migration, growth and survival of brown trout Salmo trutta of the River Imsa, 1976-2005. The migratory S. trutta were individually tagged and fish leaving or entering the river were monitored daily in traps located near the river mouth. The mean annual duration of the sea sojourn was 6-9 months for first-time m...
Article
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Jonsson B and Jonsson N. 2008. Thinlip grey mullet Liza ramada (Mugilidae) caught in a smallNorwegian stream. Fauna norvegica 26/27: 31-33. Two individuals of thinlip grey mullet Liza ramada were collected in a southern Norwegian brook(58° 22’ N, 8° 37’ E) on 12th September 2007. The fish were 8.7 and 9.0 cm in total length, 6 and 7 g in total mass...
Article
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To what degree are population differences in resource use caused by competition and the occupation of adjacent positions along environmental gradients evidence of competition? Habitat use may be the result of a competitive lottery, or restricted by competition. We tested to what extent population differences in habitat use of two salmonids, cutthro...
Article
Full-text available
Two individuals of thinlip grey mullet Liza ramada were collected in a southern Norwegian brook (58° 22′ N, 8° 37′ E) on 12th September 2007. The fish were 8.7 and 9.0 cm in total length, 6 and 7 g in total mass, and most probably in their first year of life. The nearest known spawning area of the species is south of the English Channel, meaning th...
Article
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In this study, effects of stock origin, fish size, water flow and temperature on time of river ascent of adult Atlantic salmon Salmo salar were tested. Brood stocks were collected in eight Norwegian rivers situated between 59 and 69° N. The fish were reared to smolts, individually tagged and released in the River Imsa, south-west Norway (59° N). Ad...
Article
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Relationships between growth at sea, smolt size and age at sexual maturation of Atlantic salmon Salmo salar were tested. The fish were offspring of brood stocks sampled in eight Norwegian rivers at latitudes between 59° and 70° N, hatchery reared and released at smolting at the mouth of the River Imsa (59° N). Smolt size influenced the subsequent g...
Chapter
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Coastal populations of brown trout Salmo trutta L. vary from freshwater resident trout via partially migratory stocks consisting of anadromous (sea trout) and freshwater resident fish to chiefly anadromous populations. Within rivers, anadromous and freshwater resident fish may spawn separately or together on the same spawning grounds. When they are...
Article
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Mean size of sexually mature anadromous brown trout (sea trout) Salmo trutta in south-east Norway increased significantly with migratory distance (D) between the feeding area at sea and the spawning area in fresh water, from 32 cm for those spawning close to the river mouth to 43 cm at the spawning grounds 40 km inland. This was largely due to an i...
Article
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N. 2006. Cultured Atlantic salmon in nature: a review of their ecology and interaction with wild fish. e ICES Journal of Marine Science, 63: 1162e1181. When cultured Atlantic salmon are released into nature, they compete with wild fish for food, space, and breeding partners. As a result of morphological, physiological, ecological, and behavioural c...
Article
The only way to establish the true rolling pressure and the true friction condition in cold rolling is to conduct measurements in the roll bite. A new transducer design is therefore proposed, in order to overcome problems in previous measurements In the past 70 years. The new idea Is to increase the contact surface of the transducer, to be larger t...
Article
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Climatic conditions experienced by Atlantic salmon (Salmo salar) in their early development appear to affect parr size at the end of the first growth season and age at emigration from the nursery river. North Atlantic Oscillation indices (NAOIs) correlated positively with water temperature (degree-days) and discharge in the River Imsa during winter...
Article
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Abstract – Lipid density appears to influence life-history decisions in salmonid fishes. This study shows that parr and smolts of anadromous Atlantic salmon from a south Norwegian river have on average between 30 and 40% higher energy level than corresponding brown trout in spring and summer, which may explain differences in life-history traits bet...
Article
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Letter Lipid energy reserves influence life-history decision of Atlantic salmon (Salmo salar) and brown trout (S. trutta) in fresh water Un resumen en españ ol se incluye detrás del texto principal de este artículo.
Article
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This paper reviews recent advances in our understanding of factors influencing the marine production of wild Atlantic salmon (Salmo salar). Population abundance has declined during the last 30 years because of decreased marine growth rate, survival-rate, and production of multi-sea-winter fish. Mortality appears density-independent, indicating that...
Article
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Sea-age at maturity of Atlantic salmon Salmo salar decreased with increasing values of the seasonal NAOI from February to April. Body mass increment from smolts to adults of one-sea-winter Atlantic salmon increased with increasing NAOI in May at the time when the juveniles moved to sea.
Article
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Heath et al. ([ 1 ][1]) estimated the intensity of selection and apparent rapid evolution of small eggs in a captively bred population of chinook salmon, and implicated the same process in the apparent decline in egg size of some heavily hatchery-supplemented natural populations. However, we believe
Article
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Summary • Catches of Atlantic salmon Salmo salar L. decreased in the 1980s and 1990s over its entire area in the North Atlantic and smolts were often released for stock enhancement. However, there are questions about their survival and performance relative to fully wild fish. This paper reports on the survival and sea growth of River Imsa salmon re...
Article
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Relationships between energy density (kJ·100 g–1) and body length (mm), which varied between life-history stages of Atlantic salmon (Salmo salar), were described by power functions. The variation was chiefly caused by differences in lipid concentrations. Energy densities of maturing and rematuring parr were higher than those of similarly aged smolt...
Article
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Mean estimated straying rate for Atlantic salmon Salmo salar L. leaving the River Imsa as smolts during 1976–1999 was 15% for hatchery fish and 6% for wild conspecifics. Hatchery Atlantic salmon selected for production traits during four or more generations strayed >50%. The straying rate was higher for Atlantic salmon staying 2 rather than 1 year...
Article
Full-text available
Among the species in the family Salmonidae, those represented by the genera Salmo, Salvelinus, and Oncorhynchus (subfamily Salmoninae) are the most studied. Here, various aspects of phenotypic and life-history variation of Atlantic salmon Salmo salar L., brown trout Salmo trutta L., and Arctic charr Salvelinus alpinus (L.) are reviewed. While many...
Article
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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...
Article
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1. Upstream and downstream migrating anadromous brown trout Salmo trutta were monitored daily in fish traps in the River Imsa in south-western Norway for 24 years, from 1976 to 1999. One-third of the fish descended to sea during spring (February–June) and two-thirds during autumn (September–January). 2. In spring, high water temperature appeared to...
Article
Full-text available
Summary Brown Trout Salmo trutta L. life-history traits were studied in 17 coastal streams with mean annual water discharges ≤1 m3 s−1, and with anadromous and freshwater resident trout present in all streams. Mean smolt length and age were positively correlated with mean annual water discharge and latitude. The variation (CV) in smolt length and a...
Article
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The Arctic charr Salvelinus alpinus exhibits 1–4 sympatric morphs in postglacial lakes, of which one or two are epibenthic zoobenthos feeders, one is a limnetic planktivore and one is a piscivorous form. In addition, northern rivers support partly migratory populations with anadromous and freshwater resident fish. The morphs vary in their coloratio...
Article
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Brown trout in Lake Femund migrated from the nursery streams mainly at 2 years old, but ranging between 1 and 8 years. Brown trout switched to piscivory from 3 years onwards, and a body length of 17·5 cm, according to back calculation from scales. Fast growers switched to piscivory at a younger age and smaller size than slow growers. The most slow-...
Article
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Individual egg mass and fecundity increased with somatic mass in first time and repeat spawning wild anadromous and freshwater resident brown trout Salmo trutta. The egg mass was larger for similar-sized trout in south (58° N) than mid Norway (63° N), whereas fecundity was higher in mid- than in south Norway, making total gonadal investment similar...