Population structure and gene flow reversals in Atlantic salmon (Salmo salar) over contemporary and long-term temporal scales: effects of population size and life history

2007 ◽  
Vol 16 (21) ◽  
pp. 4504-4522 ◽  
Author(s):  
FRISO P. PALSTRA ◽  
MICHAEL F. O’CONNELL ◽  
DANIEL E. RUZZANTE
Keyword(s):  
Population Structure ◽  
Life History ◽  
Gene Flow ◽  
Atlantic Salmon ◽  
Population Size ◽  
Salmo Salar ◽  
Temporal Scales ◽  
Atlantic Salmon Salmo Salar ◽  
Flow Reversals

A temporal perspective on population structure and gene flow in Atlantic salmon (Salmo salar) in Newfoundland, Canada

2010 ◽  
Vol 67 (2) ◽  
pp. 225-242 ◽  
Author(s):  
Friso P. Palstra ◽  
Daniel E. Ruzzante
Keyword(s):  
Population Dynamics ◽  
Population Structure ◽  
Gene Flow ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Environmental Changes ◽  
Population Connectivity ◽  
Temporal Perspective ◽  
Atlantic Salmon Salmo Salar ◽  
Contemporary Gene Flow

Studying population structure and gene flow patterns on temporal scales facilitates an evaluation of the consequences of demographic, physical, and environmental changes on the stability and persistence of populations. Here, we examine temporal genetic variation within and among Atlantic salmon ( Salmo salar ) rivers in Newfoundland and Labrador, Canada, using samples collected over a period of six decades (1951–2004). Our objective was to evaluate temporal changes in population connectivity associated with the closure of a commercial marine fishery. Despite demographic instability, we find that population structure remained temporally stable over more than 50 years. However, age structure can affect results when not taken into consideration, particularly in populations of large effective size where genetic drift is not strong. Where weak signals of genetic differentiation did not complicate analyses, contemporary migration was often asymmetric, yet low, suggesting patterns of intermittent gene flow. Nevertheless, we find some links between changes in population dynamics and contemporary gene flow. These findings may therefore imply that management decisions impacting the contemporary population dynamics of individual Atlantic salmon rivers can also affect the genetic stability of this species as a whole.

Importance of the Variation in Life History Parameters of Atlantic Salmon (Salmo salar)

1985 ◽  
Vol 42 (3) ◽  
pp. 615-618 ◽  
Author(s):  
Richard L. Saunders ◽  
Charles B. Schom
Keyword(s):  
Life History ◽  
Atlantic Salmon ◽  
Population Size ◽  
Salmo Salar ◽  
Great Variability ◽  
Mature Male ◽  
Life History Parameters ◽  
Atlantic Salmon Salmo Salar ◽  
Sexually Mature ◽  
Mature Male Parr

Atlantic salmon (Salmo salar) demonstrate great variability in their life history; individuals from a given year-class can spawn during several years and can, therefore, breed with salmon from other year-classes. Atlantic salmon can mature after 1–4 sea-winters and some males mature as parr, during the second through fifth years, before going to sea. Salmon may survive to spawn more than once; some spawn several times. This variability in life history may be a safeguard against loss of small stocks through several successive years of reproductive failure, since nonspawning individuals in the river or at sea could spawn in subsequent years. Spawning populations are frequently quite small. The effective spawning population size may be potentially much larger, however, since members of several year-classes, including sexually mature male parr and anadromous adults of various ages, contribute to spawning. The level of inbreeding may be relatively low, since a number of year-classes, each with different sets of parents, are represented during spawning.

Significance of Mature Male Parr in a Small Population of Atlantic Salmon (Salmo salar)

1989 ◽  
Vol 46 (6) ◽  
pp. 928-931 ◽  
Author(s):  
Jan Hennsng L'abée-Lund
Keyword(s):  
Atlantic Salmon ◽  
Population Size ◽  
Effective Population Size ◽  
Salmo Salar ◽  
Small Population ◽  
Mature Male ◽  
Effective Population ◽  
Atlantic Salmon Salmo Salar ◽  
Mature Male Parr

The spawning population of Atlantic salmon, Salmo salar, (mature male parr and adults (anadromous salmon)) were assessed in the River Baevra, central Norway, when the river was treated with rotenone in November 1986. The spawning population of adults consisted of 15 males and 19 females. The spawning population of males consisted of 167 mature male parr per adult male. The effective population size of adults was small; Na = 33.5 individuals. The presence of mature male parr theoretically increased the effective population size to Na = 71.7 individuals. This increase indicated that mature male parr brought the effective population size above a recommended minimum (Na = 50) to ensure long term viability.

Long-term consequences of variation in timing and manner of fry introduction on juvenile Atlantic salmon (Salmo salar) growth, survival, and life-history expression

2004 ◽  
Vol 61 (12) ◽  
pp. 2288-2301 ◽  
Author(s):  
Benjamin H Letcher ◽  
Todd Dubreuil ◽  
Matthew J O'Donnell ◽  
Mariska Obedzinski ◽  
Kitty Griswold ◽  
...  
Keyword(s):  
Life History ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Stabilizing Selection ◽  
Fish Introduction ◽  
Poor Growth ◽  
Entire Study ◽  
Atlantic Salmon Salmo Salar ◽  
Prior Residence

We tested the influence of introduction time and the manner of introduction on growth, survival, and life-history expression of Atlantic salmon (Salmo salar). Introduction treatments included three fry stocking times and stream rearing of embryos. Despite poor growth conditions during the early stocking period, early-stocked fish were larger throughout the entire study period, likely the result of prior residence advantage. This interpretation was reinforced by the laboratory study, where early-stocked fish outgrew late-stocked fish when reared together, but not when they were reared separately. In contrast to growth, abundance of stocked fish was greatest for fish stocked during the middle period, and this stocking group produced the greatest number of smolts. Despite smaller size, survival of stream-incubated fish was generally greater than survival of stocked fish. Introduction timing had a pronounced effect on smolt age but a weak effect on extent of parr maturation. Overall, these observations indicate that small differences (~2 weeks) in introduction time can have long-term effects on size, survival, and life-history expression. Results suggest stabilizing selection on introduction times, mediated by the interaction between prior residence (advantage to fish introduced earlier) and habitat suitability (advantage to fish introduced later).

Effect of time of day, time of year, and life history strategy on time budgeting in juvenile Atlantic salmon, Salmo salar

1999 ◽  
Vol 56 (12) ◽  
pp. 2397-2403 ◽  
Author(s):  
Sveinn K Valdimarsson ◽  
Neil B Metcalfe
Keyword(s):  
Life History ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Life History Strategy ◽  
Time Of Day ◽  
Life History Strategies ◽  
Foraging Efficiency ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Time Of Year

Traditionally, behavioural studies on juvenile Atlantic salmon, Salmo salar, have been conducted during the day in summer. It is known that Atlantic salmon become nocturnal in winter, but very little is known about their behaviour at that time. Therefore, observations in a seminatural stream were carried out during the day and night, from February to June, comparing diel and seasonal differences in behaviour between fish adopting alternative life history strategies. The results showed a general trend for more activity in spring than in winter, and the fish were found to be foraging at surprisingly low light levels. There were differences in relative feeding rate between the life history strategies; the early migrant fish foraged mostly during the day whereas the delayed migrant fish did more foraging at night. There is some evidence that the early migrant fish made fewer feeding attempts over the winter, which is surprising, since they grow faster over that period. This suggests differences in foraging efficiency, which could contribute to the separation into these two life history strategies.

scholarly journals Long-term welfare effects of repeated warm water treatments on Atlantic salmon (Salmo salar)

Aquaculture ◽  
2021 ◽  
pp. 737670
Author(s):  
Lene Moltumyr ◽  
Jonatan Nilsson ◽  
Angelico Madaro ◽  
Tore Seternes ◽  
Fredrik Agerup Winger ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Welfare Effects ◽  
Warm Water ◽  
Atlantic Salmon Salmo Salar ◽  
Water Treatments

Long-term changes in migration timing of adult Atlantic salmon (Salmo salar) at the southern edge of the species distribution

2004 ◽  
Vol 61 (12) ◽  
pp. 2392-2400 ◽  
Author(s):  
Francis Juanes ◽  
Stephen Gephard ◽  
Kenneth F Beland
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Global Climate ◽  
Life History Trait ◽  
Connecticut River ◽  
Migration Timing ◽  
Atlantic Salmon Salmo Salar ◽  
The North ◽  
Long Term Changes

The Connecticut River historically represented the southernmost extent of the North American range of Atlantic salmon (Salmo salar), but the native population was extirpated 200 years ago by dam construction. An extensive restoration effort has relied upon stock transfers from more northerly rivers, especially the Penobscot River (Maine). Recent work has shown differences in age structure between donor and derivative populations. Here we focus on a related life-history trait, the timing of the adult migration. We examined 23 years of migration timing data collected at two capture locations in the Connecticut River drainage. We found that both dates of first capture and median capture dates have shifted significantly earlier by about 0.5 days·year–1. To conclude whether this is a consequence of local adaptation or a coast-wide effect, we also quantified changes in migration timing of more northerly stocks (in Maine and Canada). We found that the changes in migration timing were not unique to the Connecticut River stock and instead observed coherent patterns in the shift towards earlier peak migration dates across systems. These consistent shifts are correlated with long-term changes in temperature and flow and may represent a response to global climate change.

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