Álvarez-Losada, ÓscarArrontes, JulioMartínez, BrezoFernández, ConsolaciónViejo, Rosa M.2024-11-042024-11-042020-09Óscar Álvarez-Losada, Julio Arrontes, Brezo Martínez, Consolación Fernández, Rosa M. Viejo, A regime shift in intertidal assemblages triggered by loss of algal canopies: A multidecadal survey, Marine Environmental Research, Volume 160, 2020, 104981, ISSN 0141-1136, https://doi.org/10.1016/j.marenvres.2020.1049811879-0291 (online)0141-1136 (print)https://hdl.handle.net/10115/41047Canopy-forming macroalgae recently experienced a worldwide decline. This is relevant, because canopies sustain complex food webs in temperate coasts. We assessed the die-back of the canopy-forming alga Fucus serratus in N Spain, at its warm distributional range boundary, and its effects on associated assemblages. We combined long-term descriptive surveys with canopy-removal experiments. Results showed that rapid shifts to turf-forming communities were mostly the direct consequence of the canopy loss, rather than a concurrent process directly triggered by climate change. The switch alters the whole food web, as the prominent role of F.serratus and other cold-temperate intertidal fucoids is not being replaced by functionally equivalent species. Canopy loss caused a rapid biotic homogenization at regional scale which is spreading towards the west, from the edge to the central part of the former distributional range of F.serratus in N Spain. The most obvious effect is the ecological and functional impoverishment of the coastal system.engAttribution-NonCommercial-NoDerivatives 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/Marine ecology;Coastal zone; Canopy-forming algae; Fucus serratus; Climate change; Species distributions; Turf-forming algae; Community composition; Regime shiftsinfo:eu-repo/semantics/article10.1016/j.marenvres.2020.104981info:eu-repo/semantics/embargoedAccess