Local benthic assemblages in shallow rocky reefs find refuge in a marine protected area at Madeira Island Filipe Alves 1,2,3 & João Canning-Clode 1,4,5 & Cláudia Ribeiro 2,3,6 & Ignacio Gestoso 1,5 & Manfred Kaufmann 2,7,8 Received: 3 August 2018 /Revised: 16 October 2018 /Accepted: 29 October 2018 /Published online: 5 November 2018 # Springer Nature B.V. 2018 Abstract The patterns of variability in the composition and structure of benthic communities along two depth strata (5 and 10 m) and the presence of sea urchins in structuring the subtidal rocky reefs were quantified in a long-established coastal marine protected area (Garajau MPA) and in two size equivalent and contiguous impacted areas (one highly urbanized and other with high fishing pressure) at Madeira Island (northeast Atlantic). Results suggest i) the MPA could be acting as a refuge for local biodiversity, ii) communities from the highly fished area could be suffering an impoverishment of local biodiversity, and iii) communities from the highly urbanized area would be enriched by the establishment of opportunistic species. These findings support that the level of human-pressure likely plays an important role in the composition of benthic communities in this insular ecosystem, although this was more relevant at the shallower stratum where the key grazer Diadema africanum explained 65% of the variance of benthic assemblages. It is suggested that this MPA small dimension and proximity to human impacted areas are limiting the survival of predators of the D. africanum. Keywords Community structure . Diadema africanum . Macroalgae . Human pressure . Madeira Island . Sessile macrofauna Introduction Marine coastal ecosystems are highly exposed to human- induced pressures, and as a consequence are particularly vul- nerable to changes in the biotic structure and composition of ecological communities (Kappel 2005; Jiao et al. 2015; Aucelli et al. 2018). These human-induced pressures cover a wide range of activities including overfishing, urbanization, coastal development or habitat transformations, which have been increasing globally in most coastal areas (Halpern et al. 2008; Elliot 2011, 2014). For example, the removal of natural predators may indirectly influence the entire community through trophic cascades (Paine 1980; Tegner and Dayton 2000), human population density in coastal perimeter can be positively correlated with benthic grazers ’ abundance (Micheli et al. 2005; Hernández et al. 2008a), or the construc- tion of urban infrastructures (e.g., harbours, marinas) can cause dramatic decreases in the cover of dominant space oc- cupiers and promote bare space for the settlement of non- indigenous species (Stachowicz et al. 2002; Airoldi and Bulleri 2011; Canning-Clode et al. 2013). A useful strategy to address and minimize the disturbance of human activities in coastal areas has been throughout the establishment of no-take or marine protected areas (MPAs, Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11852-018-0669-y) contains supplementary material, which is available to authorized users. * Filipe Alves filipe.alves@mare-centre.pt 1 MARE, Marine and Environmental Sciences Centre, Quinta do Lorde Marina, Caniçal, Madeira, Portugal 2 CIIMAR-Madeira, Interdisciplinary Centre of Marine and Environmental Research of Madeira, Funchal, Madeira, Portugal 3 OOM, Oceanic Observatory of Madeira, Madeira Tecnopolo, Funchal, Portugal 4 Department of Oceanography and Fisheries, IMAR, Centre of the University of the Azores, Horta, Azores, Portugal 5 Smithsonian Environmental Research Center, Edgewater, NJ, USA 6 CCMAR, Centro de Ciências do Mar, Campus de Gambelas, Faro, Portugal 7 Faculty of Life Sciences, Marine Biology Station of Funchal, University of Madeira, Funchal, Portugal 8 CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Porto, Portugal Journal of Coastal Conservation (2019) 23:373–383 https://doi.org/10.1007/s11852-018-0669-y