Search

Abstract--The movements of maturing Pacific salmon (Oncorhynchus spp.) from marine waters into rivers pose challenges for their physiology, especially in basins affected by human structures and increasing temperatures. This study [...]

Adult Atlantic salmon (Salmo salar) return to natal rivers several months before spawning and during summer can be subjected to temperatures that exceed their upper temperature tolerance limits. Salmon use thermal refuges to minimize exposure to high temperatures, but little information exists regarding behavioral thermoregulation by adult Atlantic salmon. We examined behavioral thermoregulation by Atlantic salmon during summer in-river residence in a Quebec river with a novel combination of thermal infrared remote sensing, river temperature monitoring, and acoustic telemetry. Adults engaged in behavioural thermoregulation at cooler ambient river temperatures (17-19 [degrees]C) than previously recorded for this species and maintained body temperature within a narrow range (16-20 [degrees]C) via use of cool and warm refuges. Adults used large, stable, stratified pools as refuges, allowing multiple individuals to thermoregulate simultaneously without leaving the pool. Low river discharge and high temperatures can be physical barriers to salmon migration, preventing them from accessing suitable refuges (e.g., pools). Identifying and maintaining connectivity to thermal refuges may be critical for persistence of Atlantic salmon populations as climate changes and rivers warm. Les saumons atlantiques (Salmo salar) adultes reviennent dans leurs rivieres natales plusieurs mois avant le frai et, durant l'ete, peuvent etre exposes a des temperatures depassant leur limite de tolerance thermique superieure. Bien que les saumons utilisent frequemment les refuges thermiques pour minimiser leur exposition aux temperatures elevees, peu d'information existe sur la thermoregulation comportementale des saumons atlantiques adultes. Nous avons examine la thermoregulation comportementale de saumons atlantiques durant leur periode de residence estivale dans une riviere du Quebec en utilisant une combinaison novatrice de teledetection infrarouge thermique, de mesure de la temperature de la riviere et de telemetrie acoustique. Les adultes font preuve de thermoregulation comportementale a des temperatures ambiantes plus faibles (17-19 [degrees]C) que celles observees anterieurement pour cette espece et maintiennent leur temperature corporelle dans une fourchette restreinte (16-20 [degrees]C) en utilisant des refuges frais et chauds. Les adultes utilisent les fosses profondes thermiquement stratifiees comme refuges stables, ce qui permet a de multiples individus de reguler en meme temps leur temperature sans quitter la fosse. Les faibles debits et les temperatures elevees peuvent constituer des barrieres physiques a la migration des saumons, les empechant d'acceder a des refuges convenables (p. ex. fosses). La reconnaissance des refuges thermiques et le maintien de leur connectivite pourraient etre essentiels a la persistance des populations de saumons atlantiques dans un contexte de changements climatiques et de rechauffement des rivieres., Introduction Salmonid species have narrow temperature tolerance ranges, making them highly susceptible to environmental warming resulting from climate change (Brett 1956; Portner and Farrell 2008; Jonsson and Jonsson 2009). Outside [...]

Author(s): Ine Vandewauw [1, 2]; Katrien De Clercq [1, 2, 3]; Marie Mulier [1, 2]; Katharina Held [1, 2, 3]; Silvia Pinto [1, 2]; Nele Van Ranst [1, 2]; Andrei [...]

Author(s): Rose Z. Hill ; Diana M. Bautista There's nothing cosier than sitting by the fire on a cold night, and mammals have an amazing ability to find the perfect [...]

Just a few months after graduation, Caroline Donelan '16 celebrated another important achievement. The Fiber Science & Apparel Design (FSAD) student published her first academic paper, which appeared in the [...]