Publications

Abstract The ocean is key to human survival, providing natural resources, most of the global oxygen supply, and economic development through mineral, gas, and oil deposits. Although the sea is primarily considered a silent world, it is abundant with the natural sounds of marine life communication and geological processes. Human activities, especially active sonars, shipping traffic, and underwater vehicles, have significantly affected underwater soundscapes and reduced natural sounds. We report on a joint optical fiber-based communication and sensing technology to minimize noise pollution in the ocean while achieving data transmission and ocean environment monitoring and exploration. The proposed multifunctional communication and sensing fiber system enables two-way data transfer while a) monitoring marine life and ship movement near the deployed fiber at the sea bottom and b) sensing temperature. The same fiber is simultaneously used to transfer energy that can be harvested by devices in the internet of underwater things. The proposed approach dramatically reduces the costs and effects of monitoring marine ecosystems while transferring data, monitoring oceans, and charging submerged devices in the internet of underwater things.

The spread of the novel coronavirus (SARS-CoV-2) has triggered a global emergency, that demands urgent solutions for detection and therapy to prevent escalating health, social and economic impacts. The spike protein (S) of this virus enables binding to the human receptor ACE2, and hence presents a prime target for vaccines preventing viral entry into host cells. The S proteins from SARS and SARS-CoV-2 are similar, but structural differences in the receptor binding domain (RBD) preclude the use of SARS-specific neutralizing antibodies to inhibit SARS-CoV-2. Here we used comparative pangenomic analysis of all sequenced reference Betacoronaviruses, complemented with functional and structural analyses. This analysis reveals that, among all core gene clusters present in these viruses, the envelope protein E shows a variant cluster shared by SARS and SARS-Cov2 with two completely-conserved key functional features, namely an ion-channel and a PDZ-binding motif (PBM). These features play a key role in the activation of the inflammasome causing the acute respiratory distress syndrome, the leading cause of death in SARS and SARS-CoV-2 infections. Together with functional pangenomic analysis, mutation tracking and previous evidence, on E protein as a determinant of pathogenicity in SARS, we suggest E protein as a therapeutic target for further studies to reduce complications of SARS-CoV-2 infections in COVID-19.

Understanding the immediate impacts of oil spills is essential to recognizing their long-term consequences on the marine environment. In this study, we traced the early (within one week) signals of crude oil in seawater and plankton after a major oil spill in October 2019 in the Red Sea. At the time of sampling, the plume had moved eastward, but we detected significant signs of incorporation of oil carbon into the dissolved organic carbon pool, resulting in a 10-20% increase in the ultraviolet (UV) absorption coefficient (a254) of chromophoric dissolved organic matter (CDOM), elevated oil fluorescence emissions, and depletion of the carbon isotope composition (δ13C) of the seawater. The abundance of the picophytoplankton Synechococcus was not affected, but the proportion of low nucleic acid (LNA) bacteria was significantly higher. Moreover, specific bacterial genera (Alcanivorax, Salinisphaera, and Oleibacter) were enriched in the seawater microbiome. Metagenome-assembled genomes (MAGs) suggested that such bacteria presented pathways for growing on oil hydrocarbons. Traces of polycyclic aromatic hydrocarbons (PAHs) were also detected in zooplankton tissues, revealing the rapid entry of oil pollutants into the pelagic food web. Our study emphasizes the early signs of short-lived spills as an important aspect of the prediction of long-term impacts of marine oil spills.

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 128:91-97 (1995) - doi:10.3354/meps128091 Active versus inactive bacteria: size-dependence in a coastal marine plankton community Gasol JM, del Giorgio PA, Massana R, Duarte CM By directly measuring the size distribution of active (cells that took up and reduced the redox dye CTC, 5-cyano-2,3-ditolyl tetrazolium chloride) and inactive cells in a natural coastal bacterial community, we tested the hypothesis that the likelihood of a bacterium being active in marine plankton is a function of its size. The average size of an inactive bacterium was 0.055 um3 while the average size of an active bacterium was 0.12 um3. This average size was constant even after 3 d of incubation in dialysis bags placed in situ, which increased the percentage of active bacteria in the community from 6 to ca 43%. The probability of a bacterium being active was a linear function of its size, from ca 5% for cells of 0.01 um3 to 100% for cells of the largest sizes. These results (1) support the hypothesis of Stevenson (1978, Microb Ecol 4:127-133) that very small bacteria are mainly dormant (inactive) while bigger bacteria are more likely to be active; (2) reconcile 2 apparently opposing observations, (a) commonly found higher specific activities in the larger size classes of bacterioplankton and (b) allometry regularities by which smaller unicellular organisms tend to have higher specific growth rates than larger organisms of similar metabolic mode; and (3) suggest that phagotrophic protists will preferentially crop the active portion of the bacterial community if they select their prey according to size. Bacterial size . Active bacteria . CTC . Bacterioplankton . Size and growth rates Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 128. Publication date: November 23, 1995 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1995 Inter-Research.

AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 56:1-12 (2009) - DOI: https://doi.org/10.3354/ame01310 Bacterial activity and diffusive nutrient supply in the oligotrophic Central Atlantic Ocean Josep M. Gasol1,*, Evaristo Vázquez-Domínguez1, Dolors Vaqué1, Susana Agustí2, Carlos M. Duarte2 1Departament de Biologia Marina i d'Oceanografia, Institut de Ciències del Mar-CSIC. Pg. Marítim de la Barceloneta 39-47, 08003 Barcelona, Catalunya, Spain 2IMEDEA (CSIC-UIB), Institut Mediterrani d'Estudis Avançats, c. Miquel Marquès 21, 07190 Esporles, Mallorca, Spain *Email: pepgasol@icm.csic.es ABSTRACT: Growing evidence of inorganic nutrient limitation on oceanic bacteria suggests a global dependence of bacterial activity and production on rates of nutrient supply. The present study examined whether surface bacterial abundance is significantly related to water column stability, and whether bacterial activity and growth rate are related to the rate of diffusive supply of inorganic nutrients to the mixed layer in the Central Atlantic during 2 meridional cruises. The 2 cruises were run under very different oceanic conditions, with relatively low values of bacterial activity in spring 1995 and relatively higher values in fall 1995. We obtained depth-resolved data in the second cruise and found that the integrated value of bacterial production was also related to the rate of nutrient supply, while integrated particulate primary production and chlorophyll concentration were not. There was also no relationship between particulate primary production and bacterial production. The relationship between nutrient supply and integrated bacterial production was tested with data from a mesocosm experiment showing a good fit to the pattern obtained in the Atlantic. Average bacterial production was ~21% of primary production in the Central Atlantic, with values ranging between 5 and 100%, and higher values in the tropical areas. The demonstration of a direct relationship between nutrient supply and bacterial activity helps to explain a relatively large bacterial biomass as compared to phytoplankton biomass, a low bacterial growth efficiency, and a high bacterial carbon demand relative to contemporaneous primary production often measured in the open ocean, as well as the accumulation of dissolved organic carbon (DOC) observed in nutrient-limited oligotrophic seas. KEY WORDS: Bacterial activity · Bacterial production · Central Atlantic · Nutrient supply · Primary production · Water column stability · Mediterranean mesocosms Full text in pdf format NextCite this article as: Gasol JM, Vázquez-Domínguez E, Vaqué D, Agustí S, Duarte CM (2009) Bacterial activity and diffusive nutrient supply in the oligotrophic Central Atlantic Ocean. Aquat Microb Ecol 56:1-12. https://doi.org/10.3354/ame01310Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AME Vol. 56, No. 1. Online publication date: July 09, 2009 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 2009 Inter-Research.

Climate change is a defining challenge of the 21st century, and this decade is a critical time for action to mitigate the worst effects on human populations and ecosystems. Plant science can play an important role in developing crops with enhanced resilience to harsh conditions (e.g. heat, drought, salt stress, flooding, disease outbreaks) and engineering efficient carbon-capturing and carbon-sequestering plants. Here, we present examples of research being conducted in these areas and discuss challenges and open questions as a call to action for the plant science community.

Animal telemetry is a powerful tool for observing marine animals and the physical environments that they inhabit, from coastal and continental shelf ecosystems to polar seas and open oceans. Satellite-linked biologgers and networks of acoustic receivers allow animals to be reliably monitored over scales of tens of meters to thousands of kilometres, giving insight into their habitat use, home range size, the phenology of migratory patterns and the biotic and abiotic factors that drive their distributions. Furthermore, physical environmental variables can be collected using animals as autonomous sampling platforms, increasing spatial and temporal coverage of global oceanographic observation systems. The use of animal telemetry therefore has the capacity to provide measures from a suite of essential ocean variables (EOVs) for improved monitoring of Earth's oceans. Here we outline the design features of animal telemetry systems, describe current applications and their benefits and challenges, and discuss future directions. We describe new analytical techniques that improve our ability to not only quantify animal movements but to also provide a powerful framework for comparative studies across taxa. We discuss the application of animal telemetry and its capacity to collect biotic and abiotic data, how the data collected can be incorporated into ocean observing systems, and the role these data can play in improved ocean management.

Seagrass ecosystems support human well-being by delivering a wide range of ecosystem services. Particularly important is the significant role they play in food provisioning by supporting fisheries worldwide. Despite their socio-economic importance, it is only recently when they have been considered as important social-ecological systems worldwide. Research focused on the interactions between seagrasses and human activities have been understudied and never addressed from a global approach, even though this knowledge is essential to create relevant policy and management plans, and to promote governance systems, which consider fishers’ needs and rights. Thus, we carried out a global systematic review on trade-offs and/or synergies between seagrasses and fishing activities, aiming to analyse the current state of the art on these interactions, to identify potential gaps in knowledge, and to pinpoint key research priorities. We found a total of 94 publications assessing the relationship between seagrass ecosystems and fisheries, which have tripled between 2001-2021, being most of them empirical studies (90%) with ecological scope (a total of 68). Socioeconomic studies (3%) on the subject were identified as a knowledge gap. Most studies (72%) were carried out in northern hemisphere countries, with an underrepresentation of studies in tropical regions. The studies reporting trade-off (a total of 69) interactions almost tripled those reporting synergies (a total of 31) between seagrass ecosystems and fisheries. Mechanical damage to seagrasses by fishing gear is the main source (51%) of trade-offs, followed by overfishing (28%), while aquaculture cages’ emissions (20%) are also a relevant source of trade-offs. Seafood market demand and conflicts of use were the main drivers for trade-offs. When assessing synergistic interactions, most studies (27 out of 31) reported a larger abundance or recruitment of species with commercial interest mediated by seagrass habitat provision. Globally, seagrass ecosystems are mainly affected by industrial and small-scale fisheries, including aquaculture and shellfisheries, and to a lesser extent, by recreational fisheries. Fisheries management system is not specified in more than half (53) of the reviewed publications, which represents a key knowledge gap with implications for sustainable management. Nevertheless, we document a fast increase in studies covering fishery-seagrass interactions, which, if accompanied by better reporting of the nature of the interactions and the socio-economic context of the fishery, would help improve the sustainable management of both systems.

Tropical seagrass meadows are highly productive ecosystems that thrive in oligotrophic environments. The Red Sea is characterized by strong N-S latitudinal nutrient and temperature gradients, which constrain pelagic productivity. To date, the influence of these natural gradients have not been assessed in metabolic rates for local seagrass communities. Here we report metabolic rates (gross primary production, respiration, and net community production) in four common species of seagrass (Halodule uninervis, Halophila ovalis, Halophila stipulacea, and Thalassia hemprichii) along latitudinal and thermal gradients in the Red Sea. In addition, we quantified leaf nutrient concentration (nitrogen, phosphorous, and iron), and correlate this with latitude. Our results show that average metabolic rates and aboveground biomass of seagrass meadows in the Red Sea were generally in the lower range when compared to global values reported for the same species forming meadows. The optimum temperature of Red Sea seagrass meadows varied among species with declines along the sequence: H. stipulacea > T. hemprichii > H. uninervis ~ H. ovalis. Gross primary production for H. uninervis – a seagrass thermophile – was lowest in higher latitudes and increased toward lower latitudes during the summer months. While temperature was identified as a strong driver of metabolic rates across seagrass meadows, leaf concentration of phosphorous and iron (but not nitrogen), were below nutrient sufficiency thresholds, indicating these two elements might be limiting for seagrass meadows in the Red Sea.

ABSTRACT The smallest members of the sunlit-ocean microbiome (prokaryotes and picoeukaryotes) participate in a plethora of ecosystem functions with planetary-scale effects. Understanding the processes determining the spatial turnover of this assemblage can help us better comprehend the links between microbiome species composition and ecosystem function. Ecological theory predicts that selection , dispersal and drift are main drivers of species distributions, yet, the relative quantitative importance of these ecological processes in structuring the surface-ocean microbiome is barely known. Here we quantified the role of selection, dispersal and drift in structuring surface-ocean prokaryotic and picoeukaryotic assemblages by using community DNA-sequence data collected during the global Malaspina expedition. We found that dispersal limitation was the dominant process structuring picoeukaryotic communities, while a balanced combination of dispersal limitation, selection and drift shaped prokaryotic counterparts. Subsequently, we determined the agents exerting abiotic selection as well as the spatial patterns emerging from the action of different ecological processes. We found that selection exerted via temperature had a strong influence on the structure of prokaryotic communities, particularly on species co-occurrences, a pattern not observed among communities of picoeukaryotes. Other measured abiotic variables had limited selective effects on microbiome structure. Picoeukaryotes presented a higher differentiation between neighbouring communities and a higher distance-decay when compared to prokaryotes, agreeing with their higher dispersal limitation. Finally, drift seemed to have a limited role in structuring the sunlit-ocean microbiome. The different predominance of ecological processes acting on particular subsets of the ocean microbiome suggests uneven responses to environmental change. SIGNIFICANCE STATEMENT The global ocean contains one of the largest microbiomes on Earth and changes on its structure can impact the functioning of the biosphere. Yet, we are far from understanding the mechanisms that structure the global ocean microbiome, that is, the relative importance of environmental selection , dispersal and random events ( drift ). We evaluated the role of these processes at the global scale, based on data derived from a circumglobal expedition and found that these ecological processes act differently on prokaryotes and picoeukaryotes, two of the main components of the ocean microbiome. Our work represents a significant contribution to understand the assembly of marine microbial communities, providing also insights on the links between ecological mechanisms, microbiome structure and ecosystem function.