scholarly journals Inferring Atlantic salmon post-smolt migration patterns using genetic assignment

2019 ◽  
Vol 6 (10) ◽  
pp. 190426 ◽  
Author(s):  
A. C. Harvey ◽  
M. Quintela ◽  
K. A. Glover ◽  
Ø. Karlsen ◽  
R. Nilsen ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Sea Lice ◽  
Fish Farms ◽  
Migration Routes ◽  
Migration Patterns ◽  
Genetic Assignment ◽  
Risk Of Mortality ◽  
Migratory Patterns ◽  
Inner Region ◽  
Mixed Stock

Understanding migratory patterns is important for predicting and mitigating unwanted consequences of environmental change or anthropogenic challenges on vulnerable species. Wild Atlantic salmon undergo challenging migrations between freshwater and marine environments, and the numbers of salmon returning to their natal rivers to reproduce have declined over several decades. Mortality from sea lice linked to fish farms within their seaward migration routes is proposed as a contributing factor to these declines. Here, we used 31 microsatellite markers to establish a genetic baseline for the main rivers in the Hardangerfjord, western Norway. Mixed stock analysis was used to assign Atlantic salmon post-smolts caught in trawls in 2013–2017 back to regional reporting units. Analyses demonstrated that individuals originating from rivers located in the inner region of the fjord arrived at the outer fjord later than individuals from middle and outer fjord rivers. Therefore, as post-smolts originating from inner rivers also have to migrate longer distances to exit the fjord, these data suggest that inner fjord populations are more likely to be at risk of mortality through aquaculture-produced sea lice, and other natural factors such as predation, than middle or outer fjord populations with earlier exit times and shorter journeys. These results will be used to calibrate models estimating mortality from sea lice on wild salmon for the regulation of the Norwegian aquaculture industry.

The influence of temperature and life stage in shaping migratory patterns during the early marine phase of two Newfoundland (Canada) Atlantic salmon (Salmo salar) populations

2019 ◽  
Vol 76 (12) ◽  
pp. 2364-2376 ◽  
Author(s):  
Kristin Bøe ◽  
Michael Power ◽  
Martha J. Robertson ◽  
Corey J. Morris ◽  
J. Brian Dempson ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Life Stage ◽  
Movement Patterns ◽  
Thermal Conditions ◽  
Migration Routes ◽  
Atlantic Salmon Salmo Salar ◽  
Migratory Patterns ◽  
Local Water ◽  
Migratory Movements

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.

scholarly journals Parasite induced mortality is context dependent in Atlantic salmon: insights from an individual-based model

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Knut Wiik Vollset
Keyword(s):  
Atlantic Salmon ◽  
Environmental Gradients ◽  
Population Level ◽  
Relative Effect ◽  
Host Population ◽  
Sea Lice ◽  
Fish Farms ◽  
Individual Based Model ◽  
Parasite Infestation ◽  
The Impact

AbstractAn individual-based model was parameterized to explore the impact of a crustacean ectoparasite (sea louse, Lepeophtheirus salmonis & Caligus spp.) on migrating Atlantic salmon smolt. The model explores how environmental and intrinsic factors can modulate the effect of sea lice on survival, growth and maturation of Atlantic salmon at sea. Relative to other effects, the parasite infestation pressure from fish farms and the encounter process emerge as the most important parameters. Although small variations in parasite-induced mortality may be masked by variable environmental effects, episodes of high infestation pressure from fish farms should be observable in wild populations of Atlantic salmon if laboratory studies accurately reflect the physiological effects of sea lice. Increases in temperature in the model negatively influenced fish survival by affecting the development time of the parasite at a rate that was not compensated for by the growth of the host. Discharge from rivers was parameterized to increase migration speed and influenced parasite induced mortality by decreasing time spent in areas with increased infestation pressure. Initial size and growth of the host was inversely related to the impact of the parasite because of size-dependent parasite-induced mortality in the early phase of migration. Overall, the model illustrates how environmental factors modulate effects on the host population by impacting either the parasite load or the relative effect of the parasite. The results suggest that linking population-level effects to parasite infestation pressure across climatic and environmental gradients may be challenging without correctly accounting for these effects.

scholarly journals Coastal migration patterns of the four largest Barents Sea Atlantic salmon stocks inferred using genetic stock identification methods

2019 ◽  
Vol 76 (6) ◽  
pp. 1379-1389 ◽  
Author(s):  
Martin-A Svenning ◽  
Morten Falkegård ◽  
Eero Niemelä ◽  
Juha-Pekka Vähä ◽  
Vidar Wennevik ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Barents Sea ◽  
Catch Per Unit Effort ◽  
Genetic Stock ◽  
Migration Patterns ◽  
The North ◽  
Genetic Stock Identification ◽  
Temporal And Spatial ◽  
Catch Composition ◽  
Mixed Stock

Abstract Combining detailed temporal and spatial catch data, including catch per unit effort, with a high-resolution microsatellite genetic baseline facilitated the development of stock-specific coastal migration models for the four largest Atlantic salmon (Salmo salar) populations, Målselv, Alta, Tana and Kola rivers, contributing to the Barents Sea mixed-stock fishery. Målselv salmon displayed a restricted coastal movement with 85% of the fish captured within 20 km of their natal river. Kola salmon also demonstrated limited coastal movements in Norwegian waters, with most (> 90%) caught in eastern Finnmark. Multi-sea-winter (MSW) Alta salmon were caught west of Alta fjord across a broader stretch of coast while one-sea-winter (1SW) fish migrated more extensively along the coast prior to river entry. Tana salmon, however, were detected over a broad expanse (600 km) of the North-Norwegian coast. For all populations MSW salmon dominating catches earlier in the season (May–June) while 1SW fish were more common from July to August. This study provides an example of how traditional catch and effort information may be combined with genetic methods to obtain insights into spatial and temporal changes in Atlantic salmon catch composition and their associated migration patterns in a mixed-stock coastal fishery.

scholarly journals Probabilistic-based genetic assignment model: assignments to subcontinent of origin of the West Greenland Atlantic salmon harvest

2009 ◽  
Vol 67 (3) ◽  
pp. 537-550 ◽  
Author(s):  
Timothy F. Sheehan ◽  
Christopher M. Legault ◽  
Timothy L. King ◽  
Adrian P. Spidle
Keyword(s):  
Atlantic Salmon ◽  
North American ◽  
Dna Analysis ◽  
Biological Data ◽  
The West ◽  
Genetic Assignment ◽  
West Greenland ◽  
Assignment Model ◽  
Misclassification Rates ◽  
Mixed Stock

Abstract Sheehan, T. F., Legault, C. M., King, T. L., and Spidle, A. P. 2010. Probabilistic-based genetic assignment model: assignments to subcontinent of origin of the West Greenland Atlantic salmon harvest. – ICES Journal of Marine Science, 67: 537–550. A multistock Atlantic salmon (Salmo salar) fishery operates off the coast of West Greenland and harvests fish of North American and European origin. Annual landings peaked in 1971 at 2700 t, but declined to 22 t in 2003. Biological data are collected to characterize the catch and its stock composition. Multilocus genotypes, generated via microsatellite DNA analysis, are used to derive statistics on continent of origin and less accurate finer-scale assignments. We developed a probabilistic-based genetic assignment (PGA) model to estimate the contribution of salmon from individual North American rivers in the 2000–2003 West Greenland catch. Uncertainty associated with finer-scale assignments is addressed by incorporating estimated misclassification rates and by reporting results as distributions generated via Monte Carlo resampling. US-origin fish represented ∼1% (by number) of the salmon harvested at West Greenland during the years 2000–2003. The resulting loss of spawners to this stock complex was approximately half the estimated adult returns in 2001, but was below 4% in the other 3 years. This is the first attempt to partition the US component of the West Greenland mixed-stock fishery to its finer parts. The approach can be used to identify the effects of fishing on individual stocks within any multistock complex where genetic samples of known origin are available.

scholarly journals Genome-scale comparative analysis for host resistance against sea lice between Atlantic salmon and rainbow trout

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pablo Cáceres ◽  
Agustín Barría ◽  
Kris A. Christensen ◽  
Liane N. Bassini ◽  
Katharina Correa ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Atlantic Salmon ◽  
Candidate Genes ◽  
Protein Phosphatase ◽  
Sea Lice ◽  
Genome Wide Association Studies ◽  
Dual Specificity ◽  
Dual Specificity Protein Phosphatase ◽  
Genomic Regions ◽  
Specificity Protein

AbstractSea lice (Caligus rogercresseyi) is an ectoparasite which causes major production losses in the salmon aquaculture industry worldwide. Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) are two of the most susceptible salmonid species to sea lice infestation. The objectives of this study were to: (1) identify genomic regions associated with resistance to Caligus rogercresseyi in Atlantic salmon and rainbow trout by performing single-step Genome-Wide Association studies (ssGWAS), and (2) identify candidate genes related to trait variation based on exploring orthologous genes within the associated regions across species. A total of 2626 Atlantic salmon and 2643 rainbow trout were challenged and genotyped with 50 K and 57 K SNP panels, respectively. We ran two independent ssGWAS for sea lice resistance on each species and identified 7 and 13 regions explaining more than 1% of the genetic variance for the trait, with the most important regions explaining 3% and 2.7% for Atlantic salmon and rainbow trout, respectively. We identified genes associated with immune response, cytoskeleton function, and cell migration when focusing on important genomic regions for each species. Moreover, we found 15 common orthogroups which were present in more than one associated genomic region, within- or between-species; however, only one orthogroup showed a clear potential biological relevance in the response against sea lice. For instance, dual-specificity protein phosphatase 10-like (dusp10) and dual-specificity protein phosphatase 8 (dusp8) were found in genomic regions associated with lice density in Atlantic salmon and rainbow trout, respectively. Dusp10 and dusp8 are modulators of the MAPK pathway and might be involved in the differences of the inflammation response between lice resistant and susceptible fish from both species. Our results provide further knowledge on candidate genes related to sea lice resistance and may help establish better control for sea lice in fish populations.

Transcriptome immunomodulation of in-feed additives in Atlantic salmon Salmo salar infested with sea lice Caligus rogercresseyi

2015 ◽  
Vol 47 (1) ◽  
pp. 450-460 ◽  
Author(s):  
Gustavo Núñez-Acuña ◽  
Ana Teresa Gonçalves ◽  
Valentina Valenzuela-Muñoz ◽  
Jorge Pino-Marambio ◽  
Simon Wadsworth ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Feed Additives ◽  
Sea Lice ◽  
Atlantic Salmon Salmo Salar

scholarly journals Coinfection takes its toll: Sea lice override the protective effects of vaccination against a bacterial pathogen in Atlantic salmon

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Carolina Figueroa ◽  
Paulina Bustos ◽  
Débora Torrealba ◽  
Brian Dixon ◽  
Carlos Soto ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Bacterial Pathogen ◽  
Sea Lice ◽  
Protective Effects
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