scholarly journals Telemetry observations of predation and migration behaviour of brown trout (Salmo trutta ) smolts negotiating an artificial lake

2018 ◽  
Vol 34 (8) ◽  
pp. 898-906 ◽  
Author(s):  
Michael Schwinn ◽  
Henrik Baktoft ◽  
Kim Aarestrup ◽  
Martyn C. Lucas ◽  
Anders Koed
Keyword(s):  
Brown Trout ◽  
Salmo Trutta ◽  
Artificial Lake ◽  
Migration Behaviour ◽  
Brown Trout Salmo Trutta ◽  
And Migration

scholarly journals Life History Tactics in Cohorts of a Partial Migratory Brown Trout (Salmo trutta L.) Population

ISRN Ecology ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Ivan C. Olsson ◽  
Larry A. Greenberg
Keyword(s):  
Body Size ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Female Fecundity ◽  
Trout Population ◽  
Delayed Reproduction ◽  
Brown Trout Salmo Trutta ◽  
Downstream Section ◽  
And Migration ◽  
Brown Trout Population

We monitored temporal changes in body size for three cohorts of a partial migratory, lake-migrating brown trout population. We tested if body mass differed between nonmigratory males, migrants, and other members of the cohort (females and immature males). We hypothesized that large-sized individuals would mature as nonmigratory males or migrate at younger ages than small-sized individuals. As previous studies have shown that female fecundity is influenced by body size and that more trout from the downstream section (D) of the stream migrated than from the upstream section (U), we hypothesized that there would be a greater proportion of mature males in D than U. We found that body size of males that reproduced was similar to migrants that migrated the subsequent spring and larger than other cohort members. Reproducing males had a larger body size than equal-aged males that delayed reproduction. Similarly, individuals that migrated had a larger body size than equal-aged individuals that migrated subsequently. The proportion of mature males was greater in D than in U. The fact that body size differentiation occurred late in ontogeny and that age of maturation and migration varied within cohorts suggests that the decision to mature or migrate might be conditionally dependent.

Encapsulation and migration of PIT tags implanted in brown trout (Salmo trutta L.)

Aquaculture ◽  
2010 ◽  
Vol 298 (3-4) ◽  
pp. 350-353 ◽  
Author(s):  
Cristina Gheorghiu ◽  
Jillian Hanna ◽  
John W. Smith ◽  
D. Scott Smith ◽  
Michael P. Wilkie
Keyword(s):  
Brown Trout ◽  
Salmo Trutta ◽  
Pit Tags ◽  
Brown Trout Salmo Trutta ◽  
And Migration

A continuum of life history tactics in a brown trout (Salmo trutta) population

2005 ◽  
Vol 62 (7) ◽  
pp. 1600-1610 ◽  
Author(s):  
Julien Cucherousset ◽  
Dominique Ombredane ◽  
Katia Charles ◽  
Frédéric Marchand ◽  
Jean-Luc Baglinière
Keyword(s):  
Life History ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Environmental Variability ◽  
Continuous Distribution ◽  
Juvenile Growth ◽  
Migratory Behaviour ◽  
Brown Trout Salmo Trutta ◽  
And Migration ◽  
Pit Tagging

Life history tactics of the brown trout (Salmo trutta) population of the Oir River (Normandy, France) were studied using passive integrated transponder (PIT) tagging data of five consecutive cohorts (5900 individuals) monitored between 1995 and 2002. Results demonstrate that (i) life history traits vary among cohorts, chiefly caused by environmental variability, (ii) juvenile growth, particularly second-year growth, plays an important role in the determination of the growing environment and trout exhibit variable migratory behaviour (from remaining in the natal brook to migrating in the sea) related to their juvenile growth rate, and (iii) the description of life history tactics (including juvenile growth, fine-scale migratory behaviour, and reproduction) can be clarified. Tactics are expressed along a continuum in time (age to reproduce) and space (distance of migration). Flexible life history tactics varying with juvenile growth is consistent with previous studies, but the use of empiric data on growth and migration from PIT tagging allows refining the description of life history tactics, taking into account their continuous distribution in time and space.

scholarly journals Long-term monitoring of a brown trout (Salmo trutta) population reveals kin-associated migration patterns and contributions by resident trout to the anadromous run

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Eloïse Duval ◽  
Øystein Skaala ◽  
María Quintela ◽  
Geir Dahle ◽  
Aurélien Delaval ◽  
...  
Keyword(s):  
Population Size ◽  
Effective Population Size ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Anthropogenic Pressure ◽  
Parentage Assignment ◽  
Effective Population ◽  
Migration Timing ◽  
Brown Trout Salmo Trutta ◽  
And Migration

Abstract Background In species showing partial migration, as is the case for many salmonid fishes, it is important to assess how anthropogenic pressure experienced by migrating individuals affects the total population. We focused on brown trout (Salmo trutta) from the Guddal River in the Norwegian Hardanger Fjord system, which encompasses both resident and anadromous individuals. Aquaculture has led to increased anthropogenic pressure on brown trout during the marine phase in this region. Fish traps in the Guddal River allow for sampling all ascending anadromous spawners and descending smolts. We analyzed microsatellite DNA markers from all individuals ascending in 2006–2016, along with all emigrating smolts in 2017. We investigated (1) if there was evidence for declines in census numbers and effective population size during that period, (2) if there was association between kinship and migration timing in smolts and anadromous adults, and (3) to what extent resident trout were parents of outmigrating smolts. Results Census counts of anadromous spawners showed no evidence for a decline from 2006 to 2016, but were lower than in 2000–2005. Estimates of effective population size also showed no trends of declines during the study period. Sibship reconstruction of the 2017 smolt run showed significant association between kinship and migration timing, and a similar association was indicated in anadromous spawners. Parentage assignment of 2017 smolts with ascending anadromous trout as candidate parents, and assuming that unknown parents represented resident trout, showed that 70% of smolts had at least one resident parent and 24% had two resident parents. Conclusions The results bear evidence of a population that after an initial decline has stabilized at a lower number of anadromous spawners. The significant association between kinship and migration timing in smolts suggests that specific episodes of elevated mortality in the sea could disproportionally affect some families and reduce overall effective population size. Finally, the results based on parentage assignment demonstrate a strong buffering effect of resident trout in case of elevated marine mortality affecting anadromous trout, but also highlight that increased mortality of anadromous trout, most of which are females, may lower overall production in the system.

scholarly journals Oxidative stress and partial migration in brown trout (Salmo trutta)

2017 ◽  
Vol 95 (11) ◽  
pp. 829-835 ◽  
Author(s):  
Kim Birnie-Gauvin ◽  
Kathryn S. Peiman ◽  
Martin H. Larsen ◽  
Henrik Baktoft ◽  
Kim Aarestrup ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Capacity ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Oxidative Status ◽  
Partial Migration ◽  
Migration Strategy ◽  
Brown Trout Salmo Trutta ◽  
And Migration

During migration, animals are typically limited by their endogenous energetic resources that must be allocated to the physiological costs associated with locomotion, as well as avoiding and (or) compensating for oxidative stress. To date, there have been few attempts to understand the role of oxidative status in migration biology, particularly in fish. Semi-anadromous brown trout (Salmo trutta L., 1758) exhibit partial migration, where some individuals smoltify and migrate to sea, and others become stream residents, providing us with an excellent model to investigate the link between oxidative stress and migration. Using the brown trout, we obtained blood samples from juveniles from a coastal stream in Denmark in the fall prior to peak seaward migration that occurs in the spring, and assayed for antioxidant capacity (oxygen radical absorbance capacity) and oxidative stress levels (ratio of oxidized to reduced glutathione). We found that individuals that migrated had higher antioxidant capacity than residents and that future migration date was negatively correlated with both antioxidant capacity and body length in the fall. This study provides the first evidence that oxidative status is associated with migration strategy and timing, months in advance of the actual migration, and provides insight into the role of oxidative status in animal migration.

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