Download or read book Habitat Dependence of Population Abundance and Variability in Juvenile Atlantic Salmon Salmo Salar microform written by André J. (André Joseph) Talbot and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Habitat Dependence of Population Abundance and Variability in Juvenile Atlantic Salmon Salmo Salar written by Andre J. Talbot and published by . This book was released on 1994 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ecology of Atlantic Salmon and Brown Trout written by Bror Jonsson and published by Springer Science & Business Media. This book was released on 2011-05-03 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 it is influenced by the environment in terms of growth, migration, spawning and recruitment. Salmonids appeared as freshwater fish some 50 million years ago. Atlantic salmon and brown trout evolved in the Atlantic basin, Atlantic salmon in North America and Europe, brown trout in Europe, Northern Africa and Western Asia. The species live in small streams as well as large rivers, lakes, estuaries, coastal seas and oceans, with brown trout better adapted to small streams and less well adapted to feeding in the ocean than Atlantic salmon. Smolt and adult sizes and longevity are constrained by habitat conditions of populations spawning in small streams. Feeding, wintering and spawning opportunities influence migratory versus resident lifestyles, while the growth rate influences egg size and number, age at maturity, reproductive success and longevity. Further, early experiences influence later performance. For instance, juvenile behaviour influences adult homing, competition for spawning habitat, partner finding and predator avoidance. The abundance of wild Atlantic salmon populations has declined in recent years; climate change and escaped farmed salmon are major threats. The climate influences through changes in temperature and flow, while escaped farmed salmon do so through ecological competition, interbreeding and the spreading of contagious diseases. The authors pinpoint essential problems and offer suggestions as to how they can be reduced. In this context, population enhancement, habitat restoration and management are also discussed. The text closes with a presentation of what the authors view as major scientific challenges in ecological research on these species.
Download or read book Production of Juvenile Atlantic Salmon Salmo Salar in Natural Waters written by National Research Council Canada and published by NRC Research Press. This book was released on 1993 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Up-to-date information, knowledge and research in progress in scientific fields related to natural production of juvenile Atlantic salmon and some other ecologically similar fluvial salmonids is contained in the 25 papers and 12 abstracts contained in this publication, which were prepared for an international symposium held in St. John's, Newfoundland. Studies relate to stream ecology, invertebrates and predators, habitat improvement, competitive effects, behaviour and dispersal, habitat and production of juvenile salmon, population dynamics and relationships of juvenile salmon estimates to smolt yields. A list of participants at the conference is also provided.
Download or read book Habitat Variability and the Individual Variability of Juvenile Atlantic Salmon Salmo Salar written by Mathieu Roy and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atlantic Salmon Ecology written by Øystein Aas and published by John Wiley & Sons. This book was released on 2011-07-05 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Atlantic salmon is one of the most prized and exploited species worldwide, being at the centre of a massive sports fishing industry and increasingly as the major farmed species in many countries worldwide. Atlantic Salmon Ecology is a landmark publication, both scientifically important and visually attractive. Comprehensively covering all major aspects of the relationship of the Atlantic salmon with its environment, chapters include details of migration and dispersal, reproduction, habitat requirements, feeding, growth rates, competition, predation, parasitsm, population dynamics, effects of landscape use, hydro power development, climate change, and exploitation. The book closes with a summary and look at possible future research directions. Backed by the Norwegian Research Council and with editors and contributors widely known and respected, Atlantic Salmon Ecology is an essential purchase for all those working with this species, including fisheries scientists and managers, fish biologists, ecologists, physiologists, environmental biologists and aquatic scientists, fish and wildlife department personnel and regulatory bodies. Libraries in all universities and research establishments where these subjects are studied and taught should have copies of this important publication. Comprehensive and up-to-date coverage of Atlantic Salmon Atlantic Salmon is one of the world's most commercially important species Backed by the Norwegian Research Council Experienced editor and internationally respected contributors
Download or read book Age Growth and Mortality of Juvenile Atlantic Salmon in Streams written by Patrick W. Bley and published by . This book was released on 1987 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Territoriality and Population Regulation in Juvenile Salmonids written by István Imre and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Territorial behaviour is thought to play a role in limiting population density. Consequently the factors that affect territory size would also influence population density. I examined the relationship between visibility and territory size in young-of-the year (YOY) rainbow trout (Oncorhynchus mykiss) to test the hypothesis that increasing habitat heterogeneity results in a reduction in territory size and consequently in higher population density. As predicted, the territory size decreased with decreasing visibility. However, the decrease in territory size did not produce an increase in density, perhaps because few individuals defended territories or because the experiment was too short for population density to reach an equilibrium. The optimal size of a contiguous territory is predicted (1) to remain unchanged at low food abundance levels and (2) to decrease only when food abundance is high enough to reduce territory size below the contiguous optimum. I manipulated food abundance to test this model, using YOY steelhead trout (Oncorhynchus mykiss). Increasing competition resulted in increasing mortality, higher propensity to emigrate, higher variance in body mass, lower growth, lower population density, lower biomass and lower percent habitat saturation. Territory size did not change with food abundance. Increasing levels of intraspecific competition in stream-dwelling salmonid populations often lead to density dependent mortality and emigration. However, density dependent growth is less frequently detected. I examined the relationship between average fork length and density of YOY Atlantic salmon (Salmo salar), to investigate (1) whether there is evidence for density dependent growth, (2) the shape of the relationship, and (3) the effect of spatial and temporal scale on the ability to detect density dependent growth. There was a negative relationship, described by a power curve, between the average body size and density of YOY Atlantic salmon. Most of the variation in body size was explained by YOY density, with year, location and older salmon density accounting for a minor proportion of the variation. Density dependent growth was equally well detected within and across years. Spatial scale did not affect the ability to detect density dependent growth. My analysis suggested that YOY Atlantic salmon populations are regulated by two different mechanisms: density dependent growth at low densities and density dependent mortality at high densities.
Download or read book Habitat Suitability Index Models written by Jon G. Stanley and published by . This book was released on 1995 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Model was developed by evaluating individual suitability indices of 17 environmental variables that have been shown to afffect productivity or survival of nonmigratory freshwater life history stages of Atlantic salmon (Salmo salar L.).
Download or read book Further Evaluation of Juvenile Atlantic Salmon Salmo Salar L Abundance in the Experimental Ponds Area Relative to Subsequent Adult Returns to the Gander River and the Empirical Evidence for Density dependent Marine Mortality written by R. Knoechel and published by . This book was released on 2000 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Observations of Temporal and Spatial Variability in Density and Relative Condition Factor of Juvenile Atlantic Salmon Salmo Salar L in the Harry s River Drainage System Insular Newfoundland from 1987 1997 written by FitzGerald, Jennifer Lesa and published by . This book was released on 1998 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Distribution and Habitat Use by Juvenile Atlantic Salmon Salmo Salar at Multiple Spatial Scales and Implications for Habitat Modelling and Fish habitat Management written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Juvenile Atlantic Salmon Salmo Salar L Abundance in the Experimental Ponds Area Relative to Subsequent Adult Returns to the Gander River as an Index of Marine Survival Apparent Evidence for Density dependent Marine Mortality written by R. Knoechel and published by . This book was released on 1999 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Individual Variability in Activity Patterns of Juvenile Atlantic Salmon Salmo Salar written by Cindy Breau and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: To describe the activity patterns of juvenile Atlantic salmon, I monitored the behaviour of 35 age-0+ (emerged from gravel in the spring) and eight age-1+ (emerged from gravel in the spring of the previous year) fish over an eight-week-summer field season. Active fish were visible on their home range whereas inactive fish were assumed to be sheltering. My data were consistent with the prediction of the Asset Protection Principle that larger individuals will take fewer chances in order to reduce risk of predation. Indeed, 1+ fish (larger and older) were more active at night than during the day, whereas 0+ fish were almost exclusively active during the day. In contrast to my expectations, however, daytime activity did not peak at the optimal water temperature of 17°C found in laboratory studies of other populations. Rather, the activity of 1+ fish peaked at 20.7°C, whereas the activity of 0+ fish continued to increase until 23°C and then leveled off between 23-27°C. Once individuals were active, season and light intensity were the variables that most influenced their foraging rate. There was considerable individual variability within an age-class in how fish responded to environmental variables. The causes of this individual variability and the consequences for growth deserve further study.
Download or read book Dispersal and Density dependent Growth of Early Juvenile Atlantic Salmon Salmo Salar written by Eric Brunsdon and published by . This book was released on 2015 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dispersal from nesting sites and habitat selection are essential for the fitness of young individuals and shapes the distribution, growth and persistence of populations. These processes are important to consider when releasing captive bred young individuals into the wild to restore extirpated or depleted populations. However, few studies have evaluated how manipulating densities during release affects the dispersal and growth of individuals with respect to crucial life history traits. I manipulated the density of young-of-the-year (YOY) Atlantic salmon to evaluate the effect of two stocking techniques on the life history characteristics of surviving fish. Salmon were either point-stocked (all fish released in a small area at the upstream end of a reach) or spread-stocked (fish were released evenly over the entire reach) in 14 reaches of the Boquet River, New York. I used snorkeling and electrofishing surveys to characterize the density, dispersal, growth and survival of salmon stocked via each technique. Density decreased and growth rate increased with distance downstream in point-stocking reaches, whereas density and growth were relatively constant within spread-stocking reaches. Overall, density, growth and survival did not differ between the two stocking techniques due to the greater-than-expected degree of dispersal observed in point-stocking reaches. YOY dispersed up to 1600m, with 41% moving over 200m downstream. Growth rate of individual fish was density-dependent, following the negative power curve observed in previous studies. My results provide insights into how the growth and survival of released individuals are altered via stocking techniques, ultimately shaping their distribution and persistence.
Download or read book Spatio temporal Variability of Atlantic Salmon Juvenile Abundance in a Canandian Stream written by Clarisse Boulenger and published by . This book was released on 2011 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, a Hierarchical Bayesian Model (HBM) was built w estimate the spatio-temporal distribution of wild Atlantic salmon (Salmo salar) juveniles in the Catamaran brook (New Brunswick, Canada) from a large data set of successive removal data via electrofishing. The most original part of our modelling approach is the mixture modelling approach introduced to model the spatio-temporal distribution of the density that enables to capture both very high and very low densities. Moreover, the mixture mode' introduced a latent variable with an ecological interpretation linked with the process of accessibility w certain sectors of the Catamaran brook. This work is an application illustrating how the HBM framework is powerful and flexible for processing multiyear and multisite successive removal data and this model provides a framework for structuring further research and data collection in the future. The FIBM provides 21-years Lime series of abundance estimates for the three age classes of A. salmon juvenile in the Catamaran brook. At the scale of the whole watershed, the time series of abundance estimates highlighted a huge between year variability of the 0+ 'juveniles. Moreover, the time series of 0+ abundance estimates allowed a first examinatio.0 of the Stock-Recruitment relationship but only an environmental control of the Recruitment success by the water discharge was pointed out. The spatialized structure of the model gave access to estimate of the relative contribution of each sector to the juvenile production. The greatest temporal variability of the contribution between reaches vas observed for the 0+ age group which seems related to the between year variability of accessibility during the spawning migration. An upstream migration of juveniles from die Gorge to the Middle reach between the 0+ and the 1+ stages was also pointed out.
Download or read book Relative Abundance of Farmed Atlantic Salmon Salmo Salar L 1758 Juveniles in Wild Samples from Three Southwestern New Brunswick Rivers written by Michael J. W. Stokesbury and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A procedure of classification using a discriminant function analysis was developed to determine the farmed or native natal origin of Atlantic salmon juveniles in the Magaguadavic River, New Brunswick. Farmed juveniles enter this river as escapees from three commercial aquaculture hatcheries. The procedure evaluated measured scale characteristics from the first year of growth, of farmed and native juveniles of known origin, for their power as predictors of derivation. Eight scale characteristics proved to be significant predictors of origin. In a jackknife cross-validation, the function developed from the characteristics proved to be 90.3% accurate in predicting the origin of juvenile Atlantic salmon in the Magaguadavic River. The procedure was then applied to unknown origin juveniles sampled from the Magaguadavic, Waweig and Digdequash rivers in New Brunswick. All of these rivers support hatcheries. Juvenile salmon sampled in the Magaguadavic River in 1996, 1997 and 1998, were determined to be 34%, 63% and 42% of farmed origin, respectively. During 1998, 9% of the juveniles from the Digdequash River were of farmed origin, and 42% of the juveniles in the Waweig River were of farmed origin. The study indicated that substantial numbers of farmed juveniles escaped from hatcheries and occupied juvenile salmon habitat in all three rivers.
