Freshwater habitat of Atlantic salmon (Salmo salar)

2000 ◽  
Vol 57 (2) ◽  
pp. 497-506 ◽  
Author(s):  
Agnès Bardonnet ◽  
Jean-Luc Baglinière

This perspective summarizes our knowledge of the freshwater habitat of Atlantic salmon (Salmo salar). The article is organized by life stage and identifies areas where more research is needed. For example, little is known of the kelt and presmolt life stages despite their importance in stock maintenance. We also believe that further investigation is required to assess the relevance of variables currently used to characterize habitat and that more attention should be focussed on adult and embryo-larva habitat requirements. We also discuss the fact that the majority of research is directed at habitat at the micro (i.e., immediate area around the fish) and macro scales (area of the geomorphological unit), while the influence of habitat at higher spatial scales should also be considered.

2019 ◽  
Vol 76 (12) ◽  
pp. 2225-2234
Author(s):  
Camille J. Macnaughton ◽  
David Deslauriers ◽  
Erinn L. Ipsen ◽  
Emily Corey ◽  
Eva C. Enders

Standard metabolic rates (SMRs) for Atlantic salmon (Salmo salar) have been calculated independently for different life stages and populations, but the absence of a comprehensive SMR model limits its application for modelling the energy use or life stage-specific growth. Atlantic salmon respiration data were compiled from a meta-analysis of 26 publications, and exponential or optimal relationships were fitted to the metadata to estimate respiration equation parameters and generate confidence intervals dependent on temperature and body mass. While model parameters were significant for both models, mass-corrected standard metabolic rates (g O2·day−1) increased as a function of water temperature (°C) and decreased beyond ∼16 °C following an optimal relationship (AICoptimal = –9185.50 versus AICexponential = –8948.95; ΔAIC = 236.55). Juvenile Atlantic salmon growth (cohorts 1 and 2) from bioenergetics simulations did not vary between Little Southwest Miramichi and Northwest Miramichi rivers; however, variation between simulations using the different respiration models (i.e., exponential versus optimal) led to differences in the way fish allocate energy throughout the year. Results from this analysis will inform conservation efforts for the species throughout its current range and predict the energetic requirements at juvenile life stages.


1998 ◽  
Vol 55 (S1) ◽  
pp. 9-21 ◽  
Author(s):  
Carol L Folt ◽  
Keith H Nislow ◽  
Mary E Power

The Atlantic salmon (Salmo salar) is a model species for studying scale issues (i.e., the extent, duration, and resolution of a study or natural process) in ecology. Major shifts in behavior and habitat use over ontogeny, along with a relatively long life span and large dispersal and migration distances, make scale issues critical for effective conservation, management, and restoration of this species. The scale over which a process occurs must be linked to the research design and we illustrate this with a discussion of resource tracking by Atlantic salmon. Identifying scale inconsistencies (e.g., when a process is evident at one scale but not another) is shown to be an effective means by which some scale-dependent processes are understood. We review the literature to assess the temporal and spatial scales used in Atlantic salmon research and find most current studies appear to sacrifice spatial and temporal extent for increased resolution. Finally, we discuss research strategies for expanding the temporal and spatial scales in salmon research, such as conducting multiple scales studies to elucidate scale inconsistencies, identifying mechanisms, and using techniques and approaches to generalize across studies and over time and space.


2019 ◽  
Vol 76 (12) ◽  
pp. 2364-2376 ◽  
Author(s):  
Kristin Bøe ◽  
Michael Power ◽  
Martha J. Robertson ◽  
Corey J. Morris ◽  
J. Brian Dempson ◽  
...  

Owing to the iteroparous nature of Atlantic salmon (Salmo salar), a seaward migrating cohort may consist of juveniles and adults that differ in size, maturity, experience, and in the motivation and consequences of migratory movements. Few studies have investigated the role of ontogeny in shaping intrapopulation variability in movement patterns among Atlantic salmon monitored under the same environmental conditions. This study contrasted the movements of smolts and kelts in two Canadian (Newfoundland) populations from marine entry through coastal embayments and quantified the influence of local water temperatures on movement patterns. Significant differences in migration routes, migration speed, and diel movements between smolts and kelts were present. Kelts generally displayed faster, more directed, and less nocturnal movements compared with smolts. Temperature influenced seaward movement positively, as well as the degree of diurnal movement. Prolonged nearshore residency by smolts and kelts in the two embayments was accompanied by a considerable improvement in ocean thermal conditions, hypothesized to promote open ocean entry during conditions favorable to migration performance.


2019 ◽  
Vol 102 (3) ◽  
pp. 419-424
Author(s):  
María Gabriela Lobos ◽  
Claudio Sáez ◽  
Alejandra Chavarría ◽  
Maritza Sepúlveda ◽  
Patricia Díaz ◽  
...  

Aquaculture ◽  
2019 ◽  
Vol 511 ◽  
pp. 734246 ◽  
Author(s):  
Thomas W.K. Fraser ◽  
P. Eckhard Witten ◽  
Sissel Albrektsen ◽  
Olav Breck ◽  
Ramon Fontanillas ◽  
...  

2010 ◽  
Vol 67 (12) ◽  
pp. 1993-2001 ◽  
Author(s):  
Anders Gravbrøt Finstad ◽  
Sigurd Einum ◽  
Leif Magnus Sættem ◽  
Bjart Are Hellen

The spatial distribution of breeders within populations may have important implications for offspring habitat availability in species where mobility of early life stages is restricted. Here we address this issue using time series of spawner distributions from eight Norwegian Atlantic salmon ( Salmo salar ) populations. Whereas spawners distribute themselves uniformly along the length of the rivers in some populations, others show a heavily skewed distribution. Linear mixed models identified pronounced and temporally consistent among-population differences in spawner distributions. Using a model of limited juvenile dispersal from nests following emergence, we show that the observed spawner distributions are predicted to result in significant proportions of rivers being inaccessible for young of the year during early life stages, and the magnitude of this effect differs among populations (e.g., ranging from 27% to 59% for dispersal distance of 250 m). Thus, assuming population regulation during early but not later juvenile stages, consistent differences in spawner distributions among populations such as those observed here may translate into differences in productivity (i.e., carrying capacity) as well as egg densities required for populations to reach their spawning targets.


1998 ◽  
Vol 55 (S1) ◽  
pp. 145-152 ◽  
Author(s):  
Jennifer L Nielsen

Molecular genetics provides data with temporal and spatial scales unavailable from other disciplines. Patterns of genetic diversity are influenced by adaptive, environmental, and stochastic factors. The rate of change in genetic markers allows investigations of diversity on temporal scales resulting from recent history (hundreds of years) to deep evolutionary time (millions of years). Cryptic spatial population structure is often revealed by molecular markers. Phylogeographic analysis of genes within populations can unite demographics with glaciation, uplift, climatic shifts, or major floods. Historically, the application of genetic markers has been largely limited to analyses of gene frequencies and patterns of diversity. The consequences of genetic rarity are controversial in relationship to endangerment or patterns of extinction. However, it is widely recognized that genes reflect a species' evolutionary past and represent the raw material underlying the diversity of biological expression throughout a species' range. DNA provides the architecture necessary for a species' adaptation and future survival. Conservation of this evolutionary legacy is important considering anthropomorphic manipulation of a species and the environment upon which it depends. In this paper I investigate evolution and genetic variation in Atlantic salmon (Salmo salar) based on the current literature. I further discuss conservation and restoration questions using molecular markers.


2005 ◽  
Vol 62 (4) ◽  
pp. 808-817 ◽  
Author(s):  
J.L. Thorley ◽  
D.M.R. Eatherley ◽  
A.B. Stephen ◽  
I. Simpson ◽  
J.C. MacLean ◽  
...  

Abstract The potential utility of rod catch and automatic fish counter data as measures of Atlantic salmon (Salmo salar) abundance in Scottish rivers was assessed. The trend (long-term) and residual (short-term) variation in the net annual count for 12 counters were compared with the trend and residual variation in either the annual or spring (February–May) rod catch, as appropriate, for the fisheries district in which the counter is located. Trends were fitted using a cubic smoothing spline and compared using reference bands. In eight of the 12 short-term comparisons, the residuals were significantly correlated. The four incongruent short-term comparisons involved the shortest time-series (≤12 years) or lowest rod catches. In eight of the 12 long-term comparisons, the trends fell within the reference bands in 50% or more of the years. Rod catch and counter data both contain useful information about Atlantic salmon abundance, albeit on different temporal and spatial scales, which should be integrated into assessment schemes.


2007 ◽  
Vol 64 (8) ◽  
pp. 1069-1079 ◽  
Author(s):  
Julie Deschênes ◽  
Marco A Rodríguez ◽  
Pierre Bérubé

We used classification trees and regression trees to relate the incidence and density of juvenile Atlantic salmon (Salmo salar) to forestry activities measured at four spatial scales (subbasin and 8, 2, and 0.5 km radii upstream of study sites) and environmental features in 120 stream reaches of the Cascapedia River basin, Québec, Canada. At all scales, incidence increased with reach size and accessibility to the reach from the river mainstem. Incidence declined with areal coverage of logging at all scales, but only in larger reaches. The time horizon over which logging effects were detected increased with spatial scale. At all scales, density in salmon-bearing reaches increased with accessibility. Density in more accessible reaches was negatively related to logging over the preceding 9 years at the subbasin and 8 km scales, but no effects of logging on density were detected at the 2 and 0.5 km scales. Overall, apparent effects of logging activities on salmon incidence and density were mostly negative and strong, but were both markedly scale-dependent and conditional on environmental context.


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