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13 páginas, 4 figuras, 1 foto. ; The structure and dynamics of ecological communities can be determined by both top-down (e.g., predation) and bottom-up (e.g., energy inputs) processes, which can act synergistically and across spatial and temporal scales. Here we aimed at understanding the role of multiple controls in a Mediterranean rocky sublittoral marine community that harbors a diverse algal community and strongly interacting herbivores, and which is subject to marked seasonality in energy inputs. We conducted an experiment by manipulating densities of the major consumers of benthic algae (fishes and sea urchins) in ;100-m 2 enclosures in a marine reserve, and monitored algal assemblages over two and a half years. Most algae showed a marked annual cycle, with a biomass peak in late spring/summer and low biomass in winter, following seasonal fluctuations in resource availability, indicating the existence of bottom-up processes. Sea urchins reduced the abundance of most algal species, indicating the existence of top-down processes. The effect of fish grazing on algal abundances was significantly weaker. Sea urchin grazing was inhibited when predatory fish were present. Multivariate analysis showed that the interaction between seasonal resource inputs and herbivory induced the formation of algal assemblages characterized by different species abundances. The organization of algal assemblages was determined by the synergistic interaction between top-down and bottom-up processes: top-down control regulated total algal abundance, while bottom-up control determined seasonal fluctuations. ; This study was funded by grant MAR1999-0526 from the Spanish Department of Education and Science, and by the Department of the Environment of the Catalan Government. ; Peer reviewed

12 pages, 6 figures, 4 tables. ; Increasing anthropogenic pressures urge enhanced knowledge and understanding of the current state of marine biodiversity. This baseline information is pivotal to explore present trends, detect future modifications and propose adequate management actions for marine ecosystems. Coralligenous outcrops are a highly diverse and structurally complex deep-water habitat faced with major threats in the Mediterranean Sea. Despite its ecological, aesthetic and economic value, coralligenous biodiversity patterns are still poorly understood. There is currently no single sampling method that has been demonstrated to be sufficiently representative to ensure adequate community assessment and monitoring in this habitat. Therefore, we propose a rapid non-destructive protocol for biodiversity assessment and monitoring of coralligenous outcrops providing good estimates of its structure and species composition, based on photographic sampling and the determination of presence/absence of macrobenthic species. We used an extensive photographic survey, covering several spatial scales (100s of m to 100s of km) within the NW Mediterranean and including 2 different coralligenous assemblages: Paramuricea clavata (PCA) and Corallium rubrum assemblage (CRA). This approach allowed us to determine the minimal sampling area for each assemblage (5000 cm2 for PCA and 2500 cm2 for CRA). In addition, we conclude that 3 replicates provide an optimal sampling effort in order to maximize the species number and to assess the main biodiversity patterns of studied assemblages in variability studies requiring replicates. We contend that the proposed sampling approach provides a valuable tool for management and conservation planning, monitoring and research programs focused on coralligenous outcrops, potentially also applicable in other benthic ecosystems. ; The research was funded by the Spanish International Cooperation Agency for Development (AECID) (S. Kipson, Research Fellowship 2009-11), the French Government (Service de coope´ration et d'action culturelle) (S. Kipson, Fellowship 2007), the Spanish Ministry of Science and Innovation (E. Casas, Doctoral Fellowship), Parc National de Port-Cros, French Agence Nationale pour la Recherche (ANR) (MEDCHANGE Project), the Total Foundation (MedDiversa Project) and the Spanish Ministry of Science and Innovation (Biorock project ref. CTM2009–08045). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. ; Peer reviewed

Background. The Life+ Indemares project (www.indemares.es) aimed to better understand the natural and socioeconomic values of several marine areas along the territorial waters of the Spanish State, leading to an informed decision-making process for the designation of new protected areas for the marine environment. One of the 10 areas selected corresponded to the "South-West Gulf of Lions Canyon System" (https://eunis.eea.europa.eu/sites/ESZZ16001), located in the north-eastern part of the Iberian Peninsula. It includes the submarine canyons of Cap de Creus and Lacaze-Duthiers and their adjacent continental shelf. The Marine Biodiversity, Ecology and Conservation Research Group from the Institute of Marine Sciences of Barcelona (ICM-CSIC) produced a detailed evaluation of the physical and ecological characteristics of the seabed and water column habitats, providing the necessary scientific information for its proposal as a Site of Community Importance to the European Union. Faunistic catalogue. An ecosystem-based approach to the management of Cap de Creus marine area after protection measures are put in place requires a comprehensive knowledge of its benthic ecosystem, which includes the continental shelf and submarine canyon. The methodology employed to identify and characterize its main benthic communities down to 400 m depth was based on images collected through underwater video platforms, such as Remotely Operated Vehicles (ROVs) and manned submersibles. The involvement of taxonomists allowed for the identification of most of the organisms observed in the images down to species or genus level, a task that could only be achieved due to the high-quality footage recorded and the set of biological samples collected. This detailed work led to the development of a photographic catalogue that served as basis for the set of ecological studies developed subsequently. Acknowledging that the identification of benthic species from imagery still has its caveats, we felt that this faunistic inventory should be made ...

10 pages, 4 figures, supplemental material https://royalsocietypublishing.org/doi/suppl/10.1098/rspb.2021.2384.-- Data accessibility: All data and code supporting the results are available from the Dryad Digital Repository: https://doi.org/10.5061/dryad.18931zczk ; Understanding the resilience of temperate reefs to climate change requires exploring the recovery capacity of their habitat-forming species from recurrent marine heatwaves (MHWs). Here, we show that, in a Mediterranean highly enforced marine protected area established more than 40 years ago, habitat-forming octocoral populations that were first affected by a severe MHW in 2003 have not recovered after 15 years. Contrarily, they have followed collapse trajectories that have brought them to the brink of local ecological extinction. Since 2003, impacted populations of the red gorgonian Paramuricea clavata (Risso, 1826) and the red coral Corallium rubrum (Linnaeus, 1758) have followed different trends in terms of size structure, but a similar progressive reduction in density and biomass. Concurrently, recurrent MHWs were observed in the area during the 2003–2018 study period, which may have hindered populations recovery. The studied octocorals play a unique habitat-forming role in the coralligenous assemblages (i.e. reefs endemic to the Mediterranean Sea home to approximately 10% of its species). Therefore, our results underpin the great risk that recurrent MHWs pose for the long-term integrity and functioning of these emblematic temperate reefs ; We acknowledge the 'Severo Ochoa Centre of Excellence' (CEX2019–000928-S) funding, the MCIU/AEI/FEDER [HEATMED; RTI2018-095346-B-I00], Interreg-Med Programme (5216 | 5MED18_3.2_M23_007 and 1MED15_3.2_M2_337), Foundation Prince Albert II Monaco [MIMOSA], the TOTAL-Foundation [Perfect] and the European Union's Horizon 2020 research and innovation programme (grant nos. 689518 and SEP-210597628). D.G.-G. is supported by a FPU15/05457 grant. C.L. acknowledges the support of ICREA. J.B.L is supported by the strategic Funding [UIDB/04423/2020 and UIDP/04423/2020]. N.T. received funding by the French National Research Agency-Make Our Planet Great Again [4Oceans-MOPGA and ANR-17-MPGA-0001]. D.K.K. is supported by a IJCI-2017-31457. D.G.-G., C.L., J.B.L., E.C., P.L.-S., D.K.K. and J.G. are part of the Medrecover group [2017 SGR 1521] ; Peer reviewed

Este artículo contiene 10 páginas, 4 figuras. ; Understanding the resilience of temperate reefs to climate change requires exploring the recovery capacity of their habitat-forming species from recurrent marine heatwaves (MHWs). Here, we show that, in a Mediterranean highly enforced marine protected area established more than 40 years ago, habitat-forming octocoral populations that were first affected by a severe MHW in 2003 have not recovered after 15 years. Contrarily, they have followed collapse trajectories that have brought them to the brink of local ecological extinction. Since 2003, impacted populations of the red gorgonian Paramuricea clavata (Risso, 1826) and the red coral Corallium rubrum (Linnaeus, 1758) have followed different trends in terms of size structure, but a similar progressive reduction in density and biomass. Concurrently, recurrent MHWs were observed in the area during the 2003–2018 study period, which may have hindered populations recovery. The studied octocorals play a unique habitat-forming role in the coralligenous assemblages (i.e. reefs endemic to the Mediterranean Sea home to approximately 10% of its species). Therefore, our results underpin the great risk that recurrent MHWs pose for the long-term integrity and functioning of these emblematic temperate reefs. ; We acknowledge the 'Severo Ochoa Centre of Excellence' (CEX2019–000928-S) funding, the MCIU/AEI/FEDER [HEATMED; RTI2018-095346-B-I00], Interreg-Med Programme (5216 | 5MED18_ 3.2_M23_007 and 1MED15_3.2_M2_337), Foundation Prince Albert II Monaco [MIMOSA], the TOTAL-Foundation [Perfect] and the European Union's Horizon 2020 research and innovation programme (grant nos. 689518 and SEP-210597628). D.G.-G. is supported by a FPU15/05457 grant. C.L. acknowledges the support of ICREA. J.B.L is supported by the strategic Funding [UIDB/04423/2020 and UIDP/04423/2020]. N.T. received funding by the French National Research Agency-Make Our Planet Great Again [4Oceans-MOPGA and ANR-17-MPGA-0001]. D.K.K. is supported by a IJCI-2017- 31457. D.G.-G., C.L., J.B.L., E.C., P.L.-S., D.K.K. and J.G. are part of the Medrecover group [2017 SGR 1521]. ; Peer reviewed