title: Thermal stratification drives movement of a coastal apex predator.
abstract: A characterization of the thermal ecology of fishes is needed to better understand changes in ecosystems and species distributions arising from global warming. The movement of wild animals during changing environmental conditions provides essential information to help predict the future thermal response of large marine predators. We used acoustic telemetry to monitor the vertical movement activity of the common dentex (Dentex dentex), a Mediterranean coastal predator, in relation to the oscillations of the seasonal thermocline during two summer periods in the Medes Islands marine reserve (NW Mediterranean Sea). During the summer stratification period, the common dentex presented a clear preference for the warm suprathermoclinal layer, and adjusted their vertical movements following the depth changes of the thermocline. The same preference was also observed during the night, when fish were less active. Due to this behaviour, we hypothesize that inter-annual thermal oscillations and the predicted lengthening of summer conditions will have a significant positive impact on the metabolic efficiency, activity levels, and population dynamics of this species, particularly in its northern limit of distribution. These changes in the dynamics of an ecosystem's keystone predator might cascade down to lower trophic levels, potentially re-defining the coastal fish communities of the future.
authors.affiliation: Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Universitat de Barcelona, 08028, Barcelona, Catalonia, Spain. aspillaga@ub.edu.
authors.forename: Eneko
authors.identifier: http://orcid.org/0000-0002-8888-8731
authors.initials: E
authors.lastname: Aspillaga
authors.affiliation: Centre d'Estudis Avançats de Blanes (CEAB-CSIC), 17300, Blanes, Catalonia, Spain.|Centre de Recerca Ecològica i Aplicacions Forestals (CREAF), 08193, Cerdanyola del Vallès, Catalonia, Spain.|Institució Català de Recerca i Estudis Avançats (ICREA), 08010, Barcelona, Catalonia, Spain.
authors.forename: Frederic
authors.identifier: http://orcid.org/0000-0001-6908-3797
authors.initials: F
authors.lastname: Bartumeus
authors.affiliation: Moss Landing Marine Laboratories, 95139, Moss Landing, CA, United States of America.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Starr
authors.affiliation: Institut de Ciències del Mar (ICM-CSIC), 08003, Barcelona, Catalonia, Spain.
authors.forename: Àngel
authors.initials: À
authors.lastname: López-Sanz
authors.affiliation: Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Universitat de Barcelona, 08028, Barcelona, Catalonia, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Linares
authors.affiliation: Centre Oceanogràfic de les Balears (COB-IEO), 07015, Palma de Mallorca, Balearic Islands, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Díaz
authors.affiliation: Institut de Ciències del Mar (ICM-CSIC), 08003, Barcelona, Catalonia, Spain.|Aix-Marseille University, Mediterranean Institute of Oceanography (MIO), Université de Toulon, CNRS/IRD, Campus de Luminy, 13288 Marseille Cedex 9, France.
authors.forename: Joaquim
authors.initials: J
authors.lastname: Garrabou
authors.affiliation: Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Universitat de Barcelona, 08028, Barcelona, Catalonia, Spain.
authors.forename: Mikel
authors.initials: M
authors.lastname: Zabala
authors.affiliation: Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Universitat de Barcelona, 08028, Barcelona, Catalonia, Spain.
authors.forename: Bernat
authors.initials: B
authors.lastname: Hereu
mesh_terms: D000818:Animals; D017753:Ecosystem; D005399:Fishes; D057232:Global Warming; D008522:Mediterranean Sea; D011157:Population Dynamics; D011235:Predatory Behavior; D013686:Telemetry; D013696:Temperature