title: Exposure to solar radiation drives organismal vulnerability to climate: Evidence from an intertidal limpet.
abstract: Understanding the physiological abilities of organisms to cope with heat stress is critical for predictions of species' distributions in response to climate change. We investigated physiological responses (respiration and heart beat rate) of the ectotherm limpet Patella vulgata to heat stress events during emersion and the role of seasonal and microclimatic acclimatization for individual thermal tolerance limits. Individuals were collected from 5 microhabitats characterized by different exposure to solar radiation in the high intertidal zone of a semi-exposed rocky shore in winter and summer of 2014. Upper thermal tolerance limits (heat coma temperatures - HCTs, and heart rate Arrhenius break temperatures - ABTs) were determined for individuals from each microhabitat in both seasons under laboratory conditions. While we found a clear seasonal acclimatization, i.e., higher HCTs and ABTs in summer than in winter, we did not find evidence for microhabitat-specific responses that would suggest microclimatic acclimatization. However, operative limpet temperatures derived from in-situ temperature measurements suggest that individuals from sun exposed microhabitats have a much narrower thermal safety margins than those from less exposed surfaces or within crevices. Microhabitat specific thermal safety margins caused by high thermal heterogeneity at small spatial scales and the lack of short term acclimatization will likely shape small scale distribution patterns of intertidal species in response to the predicted increase in the frequency and intensity of heat waves.
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin (LEMAR, UMR CNRS 6539), Institut Universitaire Européen de la Mer (IUEM), rue Dumont d'Urville, Plouzané 29280, France; School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide SA 5001, Australia. Electronic address: coralinechapperon@gmail.com.
authors.forename: Coraline
authors.initials: C
authors.lastname: Chapperon
authors.affiliation: Ifremer, DYNECO Laboratoire d'Ecologie Benthique, Plouzané 29280, France.
authors.forename: Nils
authors.initials: N
authors.lastname: Volkenborn
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin (LEMAR, UMR CNRS 6539), Institut Universitaire Européen de la Mer (IUEM), rue Dumont d'Urville, Plouzané 29280, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Clavier
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin (LEMAR, UMR CNRS 6539), Institut Universitaire Européen de la Mer (IUEM), rue Dumont d'Urville, Plouzané 29280, France.
authors.forename: Sarah
authors.initials: S
authors.lastname: Séité
authors.affiliation: CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Campus Agrário de Vairão, 4485-661 Vairão, Portugal; Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, R. Campo Alegre, s/n, 4169-007 Porto, Portugal.
authors.forename: Rui
authors.initials: R
authors.lastname: Seabra
authors.affiliation: CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Campus Agrário de Vairão, 4485-661 Vairão, Portugal.
authors.forename: Fernando P
authors.initials: FP
authors.lastname: Lima
mesh_terms: D000064:Acclimatization; D000818:Animals; D049851:Gastropoda / Q000502:physiology* / Q000528:radiation effects; D013472:Sunlight
keywords: Acclimatization; Heat stress; Intertidal; Microhabitat; Patella vulgata; Thermal tolerance