Impacts on the Deep-Sea Ecosystem by a Severe Coastal Storm

Major coastal storms, associated with strong winds, high waves and intensified currents, and occasionally with heavy rains and flash floods, are mostly known because of the serious damage they can cause along the shoreline and the threats they pose to navigation. However, there is a profound lack of knowledge on the deep-sea impacts of severe coastal storms. Concurrent measurements of key parameters along the coast and in the deep-sea are extremely rare. Here we present a unique data set showing how one of the most extreme coastal storms of the last decades lashing the Western Mediterranean Sea rapidly impacted the deep-sea ecosystem. The storm peaked the 26th of December 2008 leading to the remobilization of a shallow-water reservoir of marine organic carbon associated with fine particles and resulting in its redistribution across the deep basin. The storm also initiated the movement of large amounts of coarse shelf sediment, which abraded and buried benthic communities. Our findings demonstrate, first, that severe coastal storms are highly efficient in transporting organic carbon from shallow water to deep water, thus contributing to its sequestration and, second, that natural, intermittent atmospheric drivers sensitive to global climate change have the potential to tremendously impact the largest and least known ecosystem on Earth, the deep-sea ecosystem

Multiple Processes Regulate Long-Term Population Dynamics of Sea Urchins on Mediterranean Rocky Reefs

We annually monitored the abundance and size structure of herbivorous sea urchin populations (Paracentrotus lividus and Arbacia lixula) inside and outside a marine reserve in the Northwestern Mediterranean on two distinct habitats (boulders and vertical walls) over a period of 20 years, with the aim of analyzing changes at different temporal scales in relation to biotic and abiotic drivers. P. lividus exhibited significant variability in density over time on boulder bottoms but not on vertical walls, and temporal trends were not significantly different between the protection levels. Differences in densities were caused primarily by variance in recruitment, which was less pronounced inside the MPA and was correlated with adult density, indicating density-dependent recruitment under high predation pressure, as well as some positive feedback mechanisms that may facilitate higher urchin abundances despite higher predator abundance. Populations within the reserve were less variable in abundance and did not exhibit the hyper-abundances observed outside the reserve, suggesting that predation effects maybe more subtle than simply lowering the numbers of urchins in reserves. A. lixula densities were an order of magnitude lower than P. lividus densities and varied within sites and over time on boulder bottoms but did not differ between protection levels. In December 2008, an exceptionally violent storm reduced sea urchin densities drastically (by 50% to 80%) on boulder substrates, resulting in the lowest values observed over the entire study period, which remained at that level for at least two years (up to the present). Our results also showed great variability in the biological and physical processes acting at different temporal scales. This study highlights the need for appropriate temporal scales for studies to fully understand ecosystem functioning, the concepts of which are fundamental to successful conservation and management

MAPPING COMMUNITY INTEREST HABITATS IN THE COLUMBRETES ARCHIPELAGO, AN EXTRAORDINARY HOT SPOT OF BIODIVERSITY

The Columbretes Archipelago and their submerged surroundings are part of an unusual, Pleistocene volcanic field located in the Western Mediterranean designated as a Site of Community Importance (SCI) of the Natura 2000 Network. In the present study, 4 benthic habitats of community interest (1110, 1170, 1180 and 8330) have been identified by analyzing several sources of information. Generalized additive models (GAMs) have been used to model the potential distribution of reefs (1170) and maërl beds (1110). Our results highlight the diversity and extent of these habitats and allow comparisons to other marine SCIs of Spain. This can be attributed to the variability of the environment of this site. The Columbretes Islands combine a relatively shallow environment with volcanic structures, hydrothermalism with active degassing, current-driven sedimentary lobes and the influence of inland flows. Understanding high biodiversity spots is crucial as they offer natural laboratories to describe how ecosystems respond to the effects of global change. The knowledge obtained will be of paramount importance for the conservation of species and habitats. Furthermore, it will establish a baseline for future monitoring and assist in the development of effective management plans

Pulses of phytoplanktonic productivity may enhance sea urchin abundance and induce state shifts in Mediterranean rocky reefs

Publicado

State of knowledge on key eco-evolutionary processes and factors driving the resilience of the shallow hard bottoms and mesophotic habitats

The main goal of Deliverable 3.1. is to synthetize the information available on key eco-evolutionary processes and factors to guide the development of novel and efficient restoration actions to be planned, developed and performed within WP3. We focused on macroalgae and mesophotic coralligenous habitats since i) there are increasing evidences of relevant changes and lost of these two habitats across the whole Europe and ii) they are featured by the presence of species that are considered critical for the functioning of the coastal marine systems. In addition, these habitats display contrasted characteristics in terms of dominant groups (macroalgal species vs. macroinvertebrate), driving processes (trophic interactions-physical factors vs. competition), dynamics (fast vs. low turnover) and environmental conditions (shallow-light vs. deep-dim light habitats). [...]Grant agreement n. 689518Peer Reviewe

The Mediterranean benthic herbivores show diverse responses to extreme storm disturbances

Catastrophic storms have been observed to be one of the major elements in shaping the standing structure of marine benthic ecosystems. Yet, little is known about the effect of catastrophic storms on ecosystem processes. Specifically, herbivory is the main control mechanism of macrophyte communities in the Mediterranean, with two main key herbivores: the sea urchin Paracentrotus lividus and the fish Sarpa salpa. Consequently, the effects of extreme storm events on these two herbivores (at the population level and on their behaviour) may be critical for the functioning of the ecosystem. With the aim of filling this gap, we took advantage of two parallel studies that were conducted before, during and after an unexpected catastrophic storm event. Specifically, fish and sea urchin abundance were assessed before and after the storm in monitored fixed areas (one site for sea urchin assessment and 3 sites for fish visual transects). Additionally, we investigated the behavioural response to the disturbance of S. salpa fishes that had been tagged with acoustic transmitters. Given their low mobility, sea urchins were severely affected by the storm (ca. 50% losses) with higher losses in those patches with a higher density of sea urchins. This may be due to a limited availability of refuges within each patch. In contrast, fish abundance was not affected, as fish were able to move to protected areas (i.e. deeper) as a result of the high mobility of this species. Our results highlight that catastrophic storms differentially affect the two dominant macroherbivores of rocky macroalgal and seagrass systems due to differences in mobility and escaping strategies. This study emphasises that under catastrophic disturbances, the presence of different responses among the key herbivores of the system may be critical for the maintenance of the herbivory function

The role of Marine Reserves in protecting long-lived and structural species under a warming world: lessons from the Mediterranean Sea

The Third International Marine Protected Areas Congress (IMPAC3), 21-27 October 2013, Marseille & Corsica, FrancePeer Reviewe

Informe sobre l'estat de les poblacions de coral vermell (Corallium rubrum) a les aigües de Catalunya

38 pages, 19 figures, 2 tables, 1 annex[ES] El presente informe ha sido elaborado de forma consensuada entre los investigadores que han trabajado en diferentes instituciones de investigación de Cataluña. Los autores hemos estado trabajando en diversos aspectos de la biología y la ecología del coral rojo Corallium rubrum de las poblaciones de Cataluña y también en otros lugares del Mediterráneo durante las últimas décadas. Las informaciones que se presentan en este informe están basadas en los trabajos que los autores de este informe, así como de otros investigadores de otros países de la cuenca Mediterránea, han aportado a la comunidad científica. La fuente principal de información son publicaciones en revistas científicas de ámbito internacional de gran prestigio. Los resultados publicados han están sometidos a los más altos estándares de validación de la comunidad científica internacional. También hemos incluido datos de informes técnicos que han encargado diferentes instancias de la administración de la Generalitat de Cataluña y del Estado Español. El objetivo principal de este informe es establecer el estado de las poblaciones de coral rojo en la Costa Catalana para evaluar las medidas de gestión adecuadas para continuar las actividades pesqueras de esta especie. El informe está estructurado en dos grandes bloques. En el primer bloque aportamos un resumen sobre la información más actualizada de aspectos clave de la biología y la ecología de poblaciones del coral rojo. En el segundo bloque se presentan los datos sobre el estado de las poblaciones de la Costa Catalana y se analizan sus trayectorias en las próximas décadas basándose en las predicciones de modelos de dinámica de poblaciones disponibles. Finalmente, se proponen medidas de gestión para garantizar la continuidad de las actividades pesqueras en base a las evidencias científicas aportadas. En este informe hemos intentado restringir los tecnicismos y términos científicos a los estrictamente imprescindibles[CAT] El present informe ha estat elaborat de forma consensuada entre els investigadors que han treballat en diferents institucions de recerca de Catalunya. Els autors hem estat treballant en diversos aspectes de la biologia i l’ecologia del corall vermell Corallium rubrum de les poblacions de Catalunya i també en d’altres indrets de la Mediterrània durant els darreres dècades. Les informacions que es presenten en aquest informe estan basades en els treballs que els autors d’aquest informe, així com d’altres investigadors d’altres països de la conca Mediterrània, han aportat a la comunitat científica. La font principal d’informació són publicacions en revistes científiques d’àmbit internacional de gran prestigi. Els resultats publicats han estan sotmesos als més alts estàndards de validació de la comunitat científica internacional. També hem inclòs dades d’informes tècnics que han encarregat diferents instàncies de l’administració de la Generalitat de Catalunya i de l’Estat Espanyol. L’objectiu principal d’aquest informe és establir l’estat de les poblacions de corall vermell a la Costa Catalana per tal d’avaluar les mesures de gestió adients per continuar les activitats pesqueres amb aquesta espècie. L’informe està estructurat en dos grans blocs. En el primer bloc aportem un resum sobre la informació més actual d’aspectes clau de la biologia i l’ecologia de poblacions del corall vermell. En el segon bloc es presenten les dades sobre l’estat de les poblacions de la Costa Catalana i s’analitzen les seves trajectòries en les properes dècades basant‐se en les prediccions de models de dinàmica de poblacions disponibles. Finalment, es proposen mesures de gestió per tal de garantir la continuïtat de les activitats pesqueres en base a les evidències científiques aportades. En aquest informe hem intentat restringir els tecnicismes i termes científics als estrictament imprescindiblesPeer reviewe