Diel-depth distributions of fish larvae off the Balearic Islands (western Mediterranean) under two environmental scenarios

Final workshop IDEADOS: The wrapping up of the IDEADOS project, International Workshop on Environment, Ecosystems and Demersal Resources and fisheries, 14-16 November 2012, Palma de Mallorca, SpainPeer reviewe

Формирование модели системы воспитания в школе на основе интеграции общего и дополнительного образования (из опыта работы)

Trabajo presentado en la European Hydrogen Energy Conference - EHEC, celebrada en Sevilla (España) del 12 al 14 de mayo de 2014.There is a growing interest in the development of power sources that use renewable fuels and reduce emission of pollutants. This interest is justified by the heightening concern about environmental degradation, energy security as well as the possible exhaustion of the fossil fuel resources. One example is the use of biogas (mainly composed by CH4 and CO2) which is generated from anaerobic digestion of sewage or wastewater [1]. In order to produce hydrogen from this renewable gas, it is necessary a reforming step. There are two alternatives: 1) carbon dioxide reforming (DR: CH4 + CO2 2H2 + 2CO) and 2) steam reforming (SR: CH4 + H2O 3H2 + CO). The first reaction has two drawbacks: the deactivation of the catalyst due to carbon deposition [2] and the participation of reverse water-gas-shift (RWGS: H2 + CO2 H2O + CO) which decreases the amount of the produced hydrogen. On the other hand, steam reforming is the most extended way to produce hydrogen from CH4, but it is necessary to eliminate the CO2 from the feed. Since previous studies [3] had reported good results when La-promoted catalysts, obtained from hydrotalcite-like precursor calcination, were used in dry reforming of methane, this catalyst will be used for these tests. The aim of this work is to study the influence of H2O addition over dry reforming and the addition of CO2 over steam reforming using a La-promoted catalyst obtained from hydrotalcite-like precursor.Financial support from Comunidad de Madrid (DIVERCELCM, S2009/ENE-1475) is gratefully acknowledged.Peer Reviewe

Seasonal and interannual variability of dissolved oxygen around the Balearic Islands from hydrographic data

Oceanographic data obtained between 2001 and 2011 by the Spanish Institute of Oceanography (IEO, Spain) have been used to characterise the spatial distribution and the temporal variability of the dissolvedoxygen around the Balearic Islands (Mediterranean Sea). The study area includes most of the Western Mediterranean Sea, from the Alboran Sea to Cape Creus,atthe border between France and Spain. Dissolved Oxygen (DO) at thewatersurface is found to be in a state of equilibrium exchange with the atmosphere. In the spring and summer a subsurface oxygen supersaturation is observed due to the biological activity, above the subsurface fluorescence maximum. Minimum observed values of dissolved oxygen are related to theLevantine Intermediate Waters (LIW). An unusual minimum of dissolved oxygen concentrations were also recorded in the Alboran Sea Oxygen Minimum Zone. The Western Mediterranean Deep Waters (WMDW) and the Western Intermediate Waters (WIW) show higher values of dissolved oxygenthanthe Levantine Intermediate Waters due to their more recent formation. Using these dissolved oxygen concentrations it is possible to showthat the Western Intermediate Waters move southwards across the Ibiza Channel and the deep water circulates around the Balearic Islands. It has also been possible to characterise the seasonal evolution of the different watermassesandtheir dissolved oxygen content in a station in the Algerian sub-basin. Keywords: Ocean circulation, dissolved oxygen, water masses, Western Mediterranean Sea, Balearic SeaPost-print

Dynamic prokaryotic communities in the dark western Mediterranean Sea

Dark ocean microbial dynamics are fundamental to understand ecosystem metabolism and ocean biogeochemical processes. Yet, the ecological response of deep ocean communities to environmental perturbations remains largely unknown. Temporal and spatial dynamics of the meso- and bathypelagic prokaryotic communities were assessed throughout a 2-year seasonal sampling across the western Mediterranean Sea. A common pattern of prokaryotic communities’ depth stratification was observed across the different regions and throughout the seasons. However, sporadic and drastic alterations of the community composition and diversity occurred either at specific water masses or throughout the aphotic zone and at a basin scale. Environmental changes resulted in a major increase in the abundance of rare or low abundant phylotypes and a profound change of the community composition. Our study evidences the temporal dynamism of dark ocean prokaryotic communities, exhibiting long periods of stability but also drastic changes, with implications in community metabolism and carbon fluxes. Taken together, the results highlight the importance of monitoring the temporal patterns of dark ocean prokaryotic communities.Versión del editor2,92

Dynamics of actively dividing prokaryotes in the western Mediterranean Sea

Microbial community metabolism and functionality play a key role modulating global biogeochemical processes. However, the metabolic activities and contribution of actively growing prokaryotes to ecosystem energy fluxes remain underexplored. Here we describe the temporal and spatial dynamics of active prokaryotes in the different water masses of the Mediterranean Sea using a combination of bromodeoxyuridine labelling and 16S rRNA gene Illumina sequencing. Bulk and actively dividing prokaryotic communities were drastically different and depth stratified. Alteromonadales were rare in bulk communities (contributing 0.1% on average) but dominated the actively dividing community throughout the overall water column (28% on average). Moreover, temporal variability of actively dividing Alteromonadales oligotypes was evinced. SAR86, Actinomarinales and Rhodobacterales contributed on average 3–3.4% each to the bulk and 11, 8.4 and 8.5% to the actively dividing communities in the epipelagic zone, respectively. SAR11 and Nitrosopumilales contributed less to the actively dividing than to the bulk communities during all the study period. Noticeably, the large contribution of these two taxa to the total prokaryotic communities (23% SAR11 and 26% Nitrosopumilales), especially in the meso- and bathypelagic zones, results in important contributions to actively dividing communities (11% SAR11 and 12% Nitrosopumilales). The intense temporal and spatial variability of actively dividing communities revealed in this study strengthen the view of a highly dynamic deep ocean. Our results suggest that some rare or low abundant phylotypes from surface layers down to the deep sea can disproportionally contribute to the activity of the prokaryotic communities, exhibiting a more dynamic response to environmental changes than other abundant phylotypes, emphasizing the role they might have in community metabolism and biogeochemical processes.This research has been supported by RADMED-TRES (2015–2019) and ATHAPOC (CTM2014-54374-R) projects, funded by the Spanish Institute of Oceanography and the Spanish Ministry of Economy and Competitiveness, respectively. CM was supported by pre-doctoral FPI fellowship from Conselleria d’Innovació, Recerca i Turisme of the regional Government of the Balearic Islands, co-financed by the European Social Fund as part of the FSE 2014-2020 operational program.Postprin

Seasonal Niche Partitioning of Surface Temperate Open Ocean Prokaryotic Communities

Surface microbial communities are exposed to seasonally changing environmental conditions, resulting in recurring patterns of community composition. However, knowledge on temporal dynamics of open ocean microbial communities remains scarce. Seasonal patterns and associations of taxa and oligotypes from surface and chlorophyll maximum layers in the western Mediterranean Sea were studied over a 2-year period. Summer stratification versus winter mixing governed not only the prokaryotic community composition and diversity but also the temporal dynamics and co-occurrence association networks of oligotypes. Flavobacteriales, Rhodobacterales, SAR11, SAR86, and Synechococcales oligotypes exhibited contrasting seasonal dynamics, and consequently, specific microbial assemblages and potential inter-oligotype connections characterized the different seasons. In addition, oligotypes composition and dynamics differed between surface and deep chlorophyll maximum (DCM) prokaryotic communities, indicating depth-related environmental gradients as a major factor affecting association networks between closely related taxa. Taken together, the seasonal and depth specialization of oligotypes suggest temporal dynamics of community composition and metabolism, influencing ecosystem function and global biogeochemical cycles. Moreover, our results indicate highly specific associations between microbes, pointing to keystone ecotypes and fine-tuning of the microbes realized niche.En prens

2014-2021, 8 years without bottom-reaching deep water formation in the Western Mediterranean. Probably, the longest known period

Deep Water Formation (DWF) appeared almost regularly every year, during central winter months, in an area located offshore the Gulf of Lions in the NW Mediterranean Sea. Since the early 1960s, the processes involved in the DWF have been monitored, more or less intensively by regular hydrographic surveys or by moored instruments. It is worth noting the international efforts carried out in late 60s-early 70s by the so-called MEDOC Group to obtain a quite precise description of the whole process. Although the intensity of the DWF, as well as the amount of the newly formed Western Mediterranean Deep Water (WMDW), have shown high interanual variability, those years when the DWF was absent were exceptional, e.g. 1990, and those not reaching the bottom were scarce, e.g. 1997. Typically, they were years with almost no cold northerly winds during winter. By contrast, in some years the amount of newly formed WMDW was exceptional, e.g. 1987, and in some cases, an extra amount of this water came from dense shelf cascading, e.g. 1999. Moreover, in some years, the so-called variable Bottom Water, a slightly warm and salty layer, appeared near the bottom. It was a layer not thicker than 300 m, attributed to a large area affected by DWF which caused an extra amount of Levantine Intermediate Water (LIW) involved in the process, e.g. 1973. Other concomitant conditions that contributed to the DWF variability across the years was the presence of a blocking anticyclone in the Balearic Sea, that would play a role in intensifying the exposure of surface water to the northerlies, e.g. 1999. In winter 2005, all the factors contributing to an intense DWF process acted simultaneously, resulting in a new structure within the WMDW. The amount of newly formed WMDW, with higher density, T and S, was so extraordinary that affected the entire western Mediterranean basin, and it was identified as the Western Mediterranean Transition (WMT). The remnants of the WMDW previous to the WMT have been uplifted as to being available for a relevant contribution to the Mediterranean Outlfow Water (MOW) through the Gibraltar sill. After the WMT, the MOW showed both lower T and S than previously recorded up to around 2015, indicating that the old WMDW has been almost completely lost by leakage and diffusion. After the 2005 episode, the WMDW has evolved, changing its TS shape and increasing both T and S at the bottom, but still maintaining a deep layer with higher stratification than before 2005. In a previous work, we attributed the long period (2014-2018) without DWF to a combination of mild winters, the absence of the old WMDW, and the deep stratification. Such a process would be similar to the recovery of the Eastern Mediterranean Transient. In the present communication we incorporate 3 new years of data to the series, discuss the current situation and try to identify the requirements for a successful bottom-reaching DWF

Phytoplankton Community Structure Is Driven by Stratification in the Oligotrophic Mediterranean Sea

The phytoplankton community composition, structure, and biomass were investigated under stratified and oligotrophic conditions during summer for three consecutive years in the Mediterranean Sea. Our results reveal that the phytoplankton community structure was strongly influenced by vertical stratification. The thermocline separated two different phytoplankton communities in the two layers of the euphotic zone, characterized by different nutrient and light availability. Picoplankton dominated in terms of abundance and biomass at all the stations sampled and throughout the photic zone. However, the structure of the picoplanktonic community changed with depth, with Synechococcus and heterotrophic prokaryotes dominating in surface waters down to the base of the thermocline, and Prochlorococcus and picoeukaryotes contributing relatively more to the community in the deep chlorophyll maximum (DCM). Light and nutrient availability also influenced the communities at the DCM layer. Prochlorococcus prevailed in deeper DCM waters characterized by lower light intensities and higher picophytoplankton abundance was related to lower nutrient concentrations at the DCM. Picoeukaryotes were the major phytoplankton contributors to carbon biomass at surface (up to 80%) and at DCM (more than 40%). Besides, contrarily to the other phytoplankton groups, picoeukaryotes cell size progressively decreased with depth. Our research shows that stratification is a major factor determining the phytoplankton community structure; and underlines the role that picoeukaryotes might play in the carbon flux through the marine food web, with implications for the community metabolism and carbon fate in the ecosystem.En prens

RETROCALCULATED LARVAL ABUNDANCE INDEX OF ATLANTIC BLUEFIN TUNA IN THE WESTERN MEDITERRANEAN SEA, 2001-2020

This document presents the update of the bluefin tuna retrocalculated larval abundance indices from the Balearic archipelago (western Mediterranean). The index has been calculated following methods presented in 2020 (SCRS/2020/067) and 2021 (SCRS/2021/033). The abundance index shows an increasing trend with a maximum value in 2020. A previous version of the index (SCRS/P/2019/055) is also provided for comparison.En prensa