Sipuncula inhabiting the coral Oculina patagonica in the western Mediterranean Sea

Background: We analyzed the sipunculan fauna inhabiting the scleractinian coral Oculina patagonica in the Marine Reserve of Tabarca Island (western Mediterranean). Results: Five sipunculan species were collected from 2011 to 2014: Phascolosoma stephensoni, P. granulatum, P. cf. agassizii, Aspidosiphon misakiensis, and Golfingia vulgaris. All five species were reported for the first time inhabiting O. patagonica; with P. cf. agassizii being a new record for the Iberian Peninsula. The average abundance of sipunculans inhabiting the coral was 468.75 ± 158.04 ind m−2, representing the second most abundant taxonomic group, in biomass, after Mollusca. Conclusions: Sipunculan diversity was low comparing with tropical reefs, but species abundances were higher than in soft-bottom nearby areas and community structure appears to be more homogeneous. There may be a considerable contribution to the erosion of the coral skeleton by sipunculans

Observations on the ecology and reproductive biology of the sipunculan worm Aspidosiphon muelleri in temperate waters

A population of the sipunculan worm Aspidosiphon muelleri, located in temperate waters of the western Mediterranean Sea, was monitored monthly for a year. Some aspects related to its ecology and reproductive biology are shown in the present work. The sex-ratio for this population was close to 1:1 (54% females vs 46% males), thus indicating a dioecious reproduction, although showing a lack of sexual dimorphism. Oocytes were detected in females from 4–5 mm; this size might be reached by A. muelleri in a few months. The population density increased notably during the summer (June–August). The spawning event date was indirectly estimated from the average size of the oocytes and the percentage of females with free oocytes in the coelom. Both variables were significantly correlated to shallow water temperature (Pearson correlation; P = 0.003 and P = 0.001, respectively). Oocyte size was also significantly correlated to average irradiance level (Pearson correlation; P = 0.044). Spawning took place between August and September (when the water temperature is getting close to its annual maximum) and may last only a few weeks in these temperate waters. The abundance of A. muelleri decreased drastically in September, likely as a consequence of the spawning event effort. Bivalves of the species Epilepton clarkiae were collected together with specimens of A. muelleri living inside the polychaete tubes used as shelters by the sipunculans, with a prevalence of 11.64%. To a lesser extent some Foraminifera were also reported attached to the body of the sipunculans.This research was funded by ‘Mancomunidad Canales del Taibilla’

Seasonal effects of waterfowl grazing on submerged macrophytes: The role of flowers

Seasonal effects of waterfowl (Fulica atra and Anas platyrhynchos) grazing on submerged macrophytes (Ruppia cirrhosa and Potamogeton pectinatus) and the mediating role of flowers on plant consumption were evaluated by exclusion cages and tethering experiments deployed in a Mediterranean lagoon throughout the annual cycle. Despite the low waterfowl abundance recorded in summer, exclusion-cage experiments evidenced intense herbivory on the biomass, canopy height and flowers of R. cirrhosa (flowers abundance was ∼8 times higher inside exclusion cages; 1015.7 ± 269.8 flw m−2). For P. pectinatus, exclusion cage experiments did not evidence waterfowl consumption, in spite of the presence of flowers, which suggest preference for reproductive tissues of R. cirrhosa. In addition, the higher abundance of R. cirrhosa flowers compared to P. pectinatus (∼10 times higher inside the exclusion cages) was likely influenced by more intense herbivory on the former species. Although waterfowl abundance increased in autumn and winter, experiments did not evidence herbivory effects during that period, possibly because of enhanced availability of alternative resources and decreased plant biomass and canopy height reducing encounter rates. Hence, our results suggest that waterfowl effects on submerged macrophytes in Mediterranean aquatic ecosystems are strongly influenced by seasonal changes in the availability of food resources and its flowering events. The higher herbivory on R. cirrhosa and its flowers in summer suggest that waterfowl grazing may be driven by food preference for reproductive tissues, and could have a strong effect on the community structure and abundance of submerged macrophytes

Epiphytes and nutrient contents influence Sarpa salpa herbivory on Caulerpa spp vs. seagrass species in Mediterranean meadows

Mediterranean seagrass ecosystems are endangered by increased colonization of Caulerpa species, which may replace them, affecting key ecosystem processes. The fish Sarpa salpa (L.) is one of the main macroherbivores in the western Mediterranean seagrass meadows which is known to feed on a wide range of macroalgae such as Caulerpa species. In order to elucidate if this consumption could minimize the spread of invasive species, during summer-autumn 2012, we investigate the importance of S. salpa herbivory pressure on C. prolifera and C. cylindracea compared to Posidonia oceanica and Cymodocea nodosa in a mixed meadow. A combination of field experiments and dietary analyses were used to investigate consumption rates, dietary contributions, and feeding preferences for the different macrophytes, including the role of epiphytes and nutrient contents in mediating fish herbivory. In summer, C. nodosa was the most consumed macrophyte (12.75 ± 3.43 mg WW·d−1), probably influenced by higher fish densities, higher nutritional quality of leaves and epiphytes, and by differences in epiphyte composition. Feeding observations suggest that fish may have a variable diet, although with a consistent selection of mixed patches with C. nodosa and C. prolifera. Indeed, food choice experiments suggest that when seagrass leaves are not epiphytized, fish prefer feeding on C. prolifera. Gut content and stable isotopic analyses supported the dietary importance of epiphytes and C. prolifera but also suggested that C. cylindracea could occasionally be an important food item for S. salpa. Our results highlight the role of epiphytes in S. salpa feeding decisions but also suggest that C. nodosa and C. prolifera may have an important contribution to fish diet. The variability in S. salpa diet confirm the need to carry out multiple approach studies for a better understanding of its potential influence over different macrophytes species.This research was funded by the Department of Marine Science and Applied Biology (University of Alicante)

Evidencia de la respuesta a un enterramiento a corto plazo de la fauna macrobentónica asociada a la fanerógama marina del Mediterráneo Cymodocea nodosa

Sedimentation and burial affect a variety of habitats worldwide, especially within coastal marine systems. In the Mediterranean, seagrasses like Cymodocea nodosa are commonly subjected to sedimentation and, although the response of C. nodosa has been documented, few studies have included macrofaunal responses. We used a manipulative field experiment to examine the effects of a single small-scale, pulse burial event on benthic invertebrate macrofauna. Burial did not affect the total abundance, richness, or diversity of higher taxa nor the live abundance or diversity after 5 days. However, live higher taxa richness decreased by day 3. After 5 days, such decrease reversed and partial recovery seemed to occur. Almost 2 months later, three of the buried plots remained with some additional sedimentation, but the other three had lost their sediment. We compared faunal metrics of buried plots between days 5 and 54 and found greater diversity on day 54, providing evidence that macrofaunal recovery apparent 5 days after burial seemed to persist. Although we likely underestimated the effects and can only be conservative with our conclusions, taken together our results suggest small-scale, pulse burial events can have some negative effects on the C. nodosa-associated benthic macrofaunal community, but the community can recover within a few weeks.La sedimentación y el enterramiento afectan a una gran variedad de hábitats en todo el mundo, especialmente en los sistemas costeros marinos. En el Mediterráneo, las fanerógamas marinas como Cymodocea nodosa suelen estar expuestas a la sedimentación y, a pesar de que la respuesta de C. nodosa ha sido documentada previamente, muy pocos estudios hacen referencia a cómo responde la macrofauna. Se ha usado un experimento manipulativo en el campo para examinar los efectos de un enterramiento súbito y puntual a pequeña escala sobre la fauna de invertebrados macrobentónicos. El enterramiento no afectó a la abundancia total, riqueza o diversidad de especies, ni tampoco a la abundancia o diversidad de individuos vivos 5 días después del enterramiento. Sin embargo, la riqueza de taxones vivos disminuyó a partir del día 3. Pasados 5 días, esa disminución revirtió y parece tener lugar una recuperación parcial. Casi 2 meses después, tres de las parcelas enterradas todavía presentaron algún tipo de sedimentación adicional, pero las otras tres habían perdido el sedimento. Se compararon las métricas de la fauna encontrada en los días 5 y 54 en las parcelas enterradas, y se encontró una alta diversidad para el día 54, evidenciando que la aparente recuperación que tuvo lugar 5 días después del enterramiento parece persistir. A pesar de que probablemente hemos subestimado los efectos y debemos ser conservadores con nuestras conclusiones, al examinar los resultados conjuntamente, sugieren que estos eventos repentinos y puntuales de enterramiento a pequeña escala pueden tener efectos negativos sobre la comunidad de fauna macrobentónica asociada a C. nodosa, la cual se recuperaría en unas pocas semanas

Benthic community recovery from brine impact after the implementation of mitigation measures

In many regions, seawater desalination is a growing industry that has its impact on benthic communities. This study analyses the effect on benthic communities of a mitigation measure applied to a brine discharge, using polychaete assemblages as indicator. An eight-year study was conducted at San Pedro del Pinatar (SE Spain) establishing a grid of 12 sites at a depth range of 29–38 m during autumn. Brine discharge started in 2006 and produced a significant decrease in abundance, richness and diversity of polychaete families at the location closest to the discharge, where salinity reached 49. In 2010, a diffuser was deployed at the end of the pipeline in order to increase the mixing, to reduce the impact on benthic communities. After implementation of this mitigation measure, the salinity measured close to discharge was less than 38.5 and a significant recovery in polychaete richness and diversity was detected, to levels similar to those before the discharge. A less evident recovery in abundance was also observed, probably due to different recovery rates of polychaete families. Some families like Paraonidae and Magelonidae were more tolerant to this impact. Others like Syllidae and Capitellidae recovered quickly, although still affected by the discharge, while some families such as Sabellidae and Cirratulidae appeared to recover more slowly.These surveys were funded by the Mancomunidad de Canales del Taibilla

Lack of Impact of Posidonia oceanica Leaf Nutrient Enrichment on Sarpa salpa Herbivory: Additional Evidence for the Generalist Consumer Behavior of This Cornerstone Mediterranean Herbivore

The fish Sarpa salpa (L.) is one of the main macroherbivores in the western Mediterranean. Through direct and indirect mechanisms, this herbivore can exert significant control on the structure and functional dynamics of seagrass beds and macroalgae. Past research has suggested nutritional quality of their diet influences S. salpa herbivory, with the fish feeding more intensively and exerting greater top down control on macrophytes with higher internal nutrient contents. However recent findings have questioned this notion and shown that herbivores do not preferentially feed on macrophytes with higher nutrient contents, but rather feed on a wide variety of them with no apparent selectivity. To contribute to this debate, we conducted a field fertilization experiment where we enriched leaves of the seagrass Posidonia oceanica, a staple diet for S. salpa, and examined the response by the herbivore. These responses included quantification of leaf consumption in fertilized and non-fertilized/control plots within the bed, and food choice assays where fertilized and non-fertilized/control leaves were simultaneously offered to the herbivore. Despite the duration of leaf exposure to herbivores (30 days) and abundant schools of S. salpa observed around the plots, leaf consumption was generally low in the plots examined. Consumption was not higher on fertilized than on non-fertilized leaves. Food choice experiments did not show strong evidence for selectivity of enriched leaves. These results add to a recent body of work reporting a broad generalist feeding behavior by S. salpa with no clear selectivity for seagrass with higher nutrient content. In concert, this and other studies suggest S. salpa is often generalist consumers not only dictated by diet nutrient content but by complex interactions between other traits of nutritional quality, habitat heterogeneity within their ample foraging area, and responses to predation risk.This research was co-funded by the Department of Marine Science and Applied Biology (University of Alicante) and the University of South Alabama (Alabama, USA) in a collaborative agreement

Response of amphipod assemblages to desalination brine discharge: Impact and recovery

Desalination has become an important industry whose dense, high-salinity effluent has an impact on marine communities. Without adequate dilution, brine remains on the bottom increasing bottom salinity and affecting benthic communities. Amphipods showed high sensitivity to increased salinity produced by desalination brine discharge. A decrease in abundance and diversity of amphipods was detected at the station closest to the outfall, where salinity values reached 53. This salinity was later reduced by including a diffuser at the end of the pipeline. Six months after diffuser installation, amphipod abundance increased. During the first stage of this recovery, species such as Photis longipes recovered their abundance, others such as Microdeutopus versiculatus displayed opportunistic patterns, while others needed more time for recovery, e.g. Harpinia pectinata. These differences may be dependent on the organism living habits.These surveys were funded by the Mancomunidad de Canales del Taibilla

Epidemiological trends of HIV/HCV coinfection in Spain, 2015-2019

Altres ajuts: Spanish AIDS Research Network; European Funding for Regional Development (FEDER).Objectives: We assessed the prevalence of anti-hepatitis C virus (HCV) antibodies and active HCV infection (HCV-RNA-positive) in people living with HIV (PLWH) in Spain in 2019 and compared the results with those of four similar studies performed during 2015-2018. Methods: The study was performed in 41 centres. Sample size was estimated for an accuracy of 1%. Patients were selected by random sampling with proportional allocation. Results: The reference population comprised 41 973 PLWH, and the sample size was 1325. HCV serostatus was known in 1316 PLWH (99.3%), of whom 376 (28.6%) were HCV antibody (Ab)-positive (78.7% were prior injection drug users); 29 were HCV-RNA-positive (2.2%). Of the 29 HCV-RNA-positive PLWH, infection was chronic in 24, it was acute/recent in one, and it was of unknown duration in four. Cirrhosis was present in 71 (5.4%) PLWH overall, three (10.3%) HCV-RNA-positive patients and 68 (23.4%) of those who cleared HCV after anti-HCV therapy (p = 0.04). The prevalence of anti-HCV antibodies decreased steadily from 37.7% in 2015 to 28.6% in 2019 (p < 0.001); the prevalence of active HCV infection decreased from 22.1% in 2015 to 2.2% in 2019 (p < 0.001). Uptake of anti-HCV treatment increased from 53.9% in 2015 to 95.0% in 2019 (p < 0.001). Conclusions: In Spain, the prevalence of active HCV infection among PLWH at the end of 2019 was 2.2%, i.e. 90.0% lower than in 2015. Increased exposure to DAAs was probably the main reason for this sharp reduction. Despite the high coverage of treatment with direct-acting antiviral agents, HCV-related cirrhosis remains significant in this population

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality