title: Experimental evidence of the synergistic effects of warming and invasive algae on a temperate reef-builder coral.
abstract: In the current global climate change scenario, stressors overlap in space and time, and knowledge on the effects of their interaction is highly needed to understand and predict the response and resilience of organisms. Corals, among many other benthic organisms, are affected by an increasing number of global change-related stressors including warming and invasive species. In this study, the cumulative effects between warming and invasive algae were experimentally assessed on the temperate reef-builder coral Cladocora caespitosa. We first investigated the potential local adaptation to thermal stress in two distant populations subjected to contrasting thermal and necrosis histories. No significant differences were found between populations. Colonies from both populations suffered no necrosis after long-term exposure to temperatures up to 29 °C. Second, we tested the effects of the interaction of both warming and the presence of invasive algae. The combined exposure triggered critical synergistic effects on photosynthetic efficiency and tissue necrosis. At the end of the experiment, over 90% of the colonies subjected to warming and invasive algae showed signs of necrosis. The results are of particular concern when considering the predicted increase of extreme climatic events and the spread of invasive species in the Mediterranean and other seas in the future.
authors.affiliation: Departament d'Ecologia. Facultat de Biologia. Universitat de Barcelona (UB), 08028 Barcelona, Spain.
authors.forename: Diego K
authors.initials: DK
authors.lastname: Kersting
authors.affiliation: Centre d'Estudis Avançats de Blanes (CSIC), 17300 Girona, Spain.|Departament de Ciències Ambientals. Facultat de Ciències. Universitat de Girona, 17004 Girona, Spain.
authors.forename: Emma
authors.initials: E
authors.lastname: Cebrian
authors.affiliation: Departament d'Ecologia. Facultat de Biologia. Universitat de Barcelona (UB), 08028 Barcelona, Spain.
authors.forename: Clara
authors.initials: C
authors.lastname: Casado
authors.affiliation: Institut Ciències del Mar (ICM-CSIC), 08003 Barcelona, Spain.|Stazione Zoologica Anton Dohrn, 80121 Naples, Italy.
authors.forename: Núria
authors.initials: N
authors.lastname: Teixidó
authors.affiliation: Institut Ciències del Mar (ICM-CSIC), 08003 Barcelona, Spain.|Aix-Marseille University, Mediterranean Institute of Oceanography (MIO), 13288, Marseille, Cedex 9; Université de Toulon, 83957, CNRS/IRD, France.
authors.forename: Joaquim
authors.initials: J
authors.lastname: Garrabou
authors.affiliation: Departament d'Ecologia. Facultat de Biologia. Universitat de Barcelona (UB), 08028 Barcelona, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Linares
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D037421:Anthozoa / Q000502:physiology*; D000460:Chlorophyta / Q000502:physiology*; D057894:Coral Reefs; D057232:Global Warming; D058865:Introduced Species; D062312:Islands; D010788:Photosynthesis; D013312:Stress, Physiological; D013696:Temperature