Exceptionally high but still growing predatory reef fish biomass after 23 years of protection in a Marine Protected Area

Marine Protected Areas (MPAs) help replenish fish assemblages, though different trophic levels may show diverse recovery patterns. Long-term protection is required to achieve total recovery but poaching events may prevent the achievement of full carrying capacity. Here, we have analysed the effect of long-term protection on the entire reef fish community and the different trophic levels in the Cabo de Palos-Islas Hormigas MPA (SE Spain; SW Mediterranean Sea) in order to assess their recovery patterns after 23 years of protection. We compared the values for carrying capacity obtained with the maximum values achieved at regional scale, and we assessed the effect of a reduction in the surveillance over a few years, during which poaching events increased, on the recovery patterns. We found that, overall, biomass of fishes increased with time while density diminished. In particular, piscivorous and macro-invertivore fish increased while the other trophic groups remained constant or declined, suggesting top-down processes. For the entire study period, those trophic groups were approaching carrying capacity; however, when accounting only for the period in which enforcement was high and constant, they grew exponentially, indicating that full carrying capacity may have not been achieved yet. When compared to other Mediterranean MPAs, the Cabo de Palos-Islas Hormigas MPA showed values for biomass that were disproportionately higher, suggesting that local factors, such as habitat structure and associated oceanographic processes, may be responsible for the dynamics found. Our results help to understand the potential trajectories of fish assemblages over a consolidated MPA and highlight empirically how the reduction of surveillance in a period may change the recovery patterns

Spatial genetic structure in the saddled sea bream (Oblada melanura [Linnaeus, 1758]) suggests multi-scaled patterns of connectivity between protected and unprotected areas in the Western Mediterranean Sea

Marine protected areas (MPAs) and networks of MPAs are advocated worldwide for the achievement of marine conservation objectives. Although the knowledge about population connectivity is considered fundamental for the optimal design of MPAs and networks, the amount of information available for the Mediterranean Sea is currently scarce. We investigated the genetic structure of the saddled sea bream ( Oblada melanura) and the level of genetic connectivity between protected and unprotected locations, using a set of 11 microsatellite loci. Spatial patterns of population differentiation were assessed locally (50-100 km) and regionally (500-1000 km), considering three MPAs of the Western Mediterranean Sea. All values of genetic differentiation between locations (Fst and Jost's D) were non-significant after Bonferroni correction, indicating that, at a relatively small spatial scale, protected locations were in general well connected with non-protected ones. On the other hand, at the regional scale, discriminant analysis of principal components revealed the presence of a subtle pattern of genetic heterogeneity that reflects the geography and the main oceanographic features (currents and barriers) of the study area. This genetic pattern could be a consequence of different processes acting at different spatial and temporal scales among which the presence of admixed populations, large population sizes and species dispersal capacity, could play a major role. These outcomes can have important implications for the conservation biology and fishery management of the saddled sea bream and provide useful information for genetic population studies of other coastal fishes in the Western Mediterranean Sea.This research was supported by the European project ‘InitialTraining Network for Monitoring Mediterranean Marine ProtectedAreas’ (MMMPA: FP7-PEOPLE-2011-ITN) [grant number 290056].Irene Mu˜noz was supported by Fundación Séneca (Murcia, Spain)through the Post-doctoral fellowship 19149/PD/13-N and CarlosVergara-Chen was partially supported by the “Sistema Nacionalde Investigación (SNI) of the Secretaría Nacional de Ciencia, Tec-nología e Innovación (SENACYT)” of Panama. Authors wish to thankDr. Josep Lloret (Univeristy of Girona), Prof. Patrice Francour, Prof.Patricia Pierson, Pierre Vandenbussche and Guillaume Spennato(University of Nice), Serge Moreau and Gilles Garnier (Port-Crosand Porquerolles National Park) and Chiara Adamuccio for assis-tance during field works. Authors wish to thank the editor andtwo anonymous reviewers for their useful comments which havehelped us to improve the manuscript.info:eu-repo/semantics/publishedVersio

Density dependence in marine protected populations: a review

The cessation or reduction of fishing in marine protected areas (MPAs) should promote an increase in abundance and mean size and age of previously exploited populations. Thus density-dependent changes in life-history characteristics should occur when populations are allowed to recover in MPAs. In this review, we synthesize the existing information on resource limitation in marine ecosystems, density-dependent changes in life-history traits of exploited populations and evidence for biomass export from MPAs. Most evidence for compensatory changes in biological variables has been derived from observations on populations depleted by high fishing mortality or on strong year classes, but these changes are more evident in juveniles than in adults and in freshwater rather than in marine systems. It is unclear if adults of exploited marine populations are resource limited. This may suggest that exploited populations are controlled mainly by density-independent processes, which could be a consequence of the depleted state of most exploited populations. MPAs could be a useful tool for testing these hypotheses. If we assume that resources become limiting inside MPAs, it is plausible that, if suitable habitats exist, mobile species will search for resources outside of the MPAs, leading to export of biomass to areas which are fished. However, it is not possible to establish from the available data whether this export will be a response to resource limitation inside the MPAs, the result of random movements across MPA boundaries or both. We discuss the implications of this process for the use of MPAs as fisheries management tools.Financial support was provided by the EU CEC DGXII – MAST III contract number: MAS3-ct97-0155

Mortalidad por nodavirus en mero (Epinephelus marginatus L., 1758) de la Reserva Marina de Cabo de Palos e Islas Hormigas, Murcia

Nodaviruses affect a large number of fish species, wild and farmed. In the wild it has been isolated in various species, but it had never been associated with clinical processes on the coast of Murcia. In autumn 2017, several specimens of groupers (Epinephelus marginatus and E. costae) were detected in the Cabo de Palos Reserve with clinical symptoms compatible with nodavirus. The infection by nodavirus was confirmed by real time RT-PCR and its subsequent genotyping (RGNNV type). This finding constitutes the first regional evidence of clinical infection by nodavirus in wild fish, with the added relevance that the affected specie, the grouper, is the emblematic specie of the Cabo de Palos Marine Reserve.Los nodavirus afectan a gran número de especies de peces, silvestres y cultivadas. En silvestres se ha aislado en diversas especies, pero nunca se había asociado con procesos clínicos en el litoral de Murcia. En otoño de 2017, se detectaron diversos ejemplares de meros (Epinephelus marginatus y E. costae) en la Reserva de Cabo de Palos con sintomatología clínica compatible con nodavirus. La infección por nodavirus fue confirmada mediante RT-PCR en tiempo real y su posterior genotipado (tipo RGNNV). Este hallazgo constituye la primera evidencia regional de infección clínica por nodavirus en peces silvestres, con la relevancia añadida de que la especie afectada es la especie emblemática de la Reserva Marina de Cabo de Palos, el mero

Marine reserves: Fish life history and ecological traits matter

Copyright by the Ecological Society of AmericaMarine reserves are assumed to protect a wide range of species from deleterious effects stemming from exploitation. However, some species, due to their ecological characteristics, may not respond positively to protection. Very little is known about the effects of life history and ecological traits (e.g., mobility, growth, and habitat) on responses of fish species to marine reserves. Using 40 data sets from 12 European marine reserves, we show that there is significant variation in the response of different species of fish to protection and that this heterogeneity can be explained, in part, by differences in their traits. Densities of targeted size-classes of commercial species were greater in protected than unprotected areas. This effect of protection increased as the maximum body size of the targeted species increased, and it was greater for species that were not obligate schoolers. However, contrary to previous theoretical findings, even mobile species with wide home ranges benefited from protection: the effect of protection was at least as strong for mobile species as it was for sedentary ones. Noncommercial bycatch and unexploited species rarely responded to protection, and when they did (in the case of unexploited bentho-pelagic species), they exhibited the opposite response: their densities were lower inside reserves. The use of marine reserves for marine conservation and fisheries management implies that they should ensure protection for a wide range of species with different life-history and ecological traits. Our results suggest this is not the case, and instead that effects vary with economic value, body size, habitat, depth range, and schooling behavior.S

Estructura espacial, dinámica temporal y hábitat del poblamiento de peces litorales mediterráneos

En esta tesis se aborda la cuantificación, mediante censos visuales, de las pautas de variación espacial y temporal de los poblamientos de peces que viven en los fondos rocosos infralitorales del Mediterráneo occidental, a varias escalas espaciales, y se estima la importancia relativa de la estructura del hábitat rocoso para explicar dichas variaciones. En sucesivos estudios, utilizándose técnicas de análisis espacial, se muestra que riqueza, abundancia y diversidad de peces responden a las variaciones del hábitat estructural (distinguiéndose entre complejidad y heterogeneidad), tanto a escala local como a múltiples escalas espaciales jerarquizadas. Por otra parte, el poblamiento de peces muestra una notable estabilidad temporal, aunque ésta depende de las escalas taxonómica, espacial o analítica considerada, pudiendo esta estabilidad ser debida al efecto del hábitat sobre las poblaciones. La influencia de la estructura del hábitat rocoso puede enmascarar, e incluso contrarrestar, los beneficios esperados de la protección pesquera

Ecological effects of atlanto-mediterranean marine protected areas in the European Union

Marine Protected Areas (MPAs) are critically important to the conservation of marine biodiversity and ecological processes and to achieving a sound basis for sustainable use and development of marine environments and resources. This is clearly reflected in the statement from World Summit on Sustainable Development (Johannesburg): "MPAs are the key to achieving at least 10% of each of the world's ecological regions effectively conserved - the target established at the 6th Conference of Parties to the Convention on Biodiversity". At the same time, it is widely considered that MPAs can make a significant contribution to regional economic development and to improving the wellbeing of local communities. Fisheries are one of the main threats to marine biodiversity and ecological processes and MPAs are therefore important for conserving ecosystem services provided by the sea and sustaining tourism that depends on these. By restricting damaging activities, MPAs offer protection for marine natural resources and provide them with critical habitats they need at key times, e.g. for breeding or feeding. MPAs benefit species and habitats of regional interest and may also help to avoid or at least limit the deleterious effects of non-sustainable uses and activities, including pollution and other sources of degradation, in favour of the local economy.This publication has been developed in the framework of the project EMPAFISH (SSP8-006539) supported by the Commission of the European Communities within the Sixth Framework Programme