1
|
Molina-Pardines C, Haro-Moreno JM, López-Pérez M. Phosphate-related genomic islands as drivers of environmental adaptation in the streamlined marine alphaproteobacterial HIMB59. mSystems 2023; 8:e0089823. [PMID: 38054740 PMCID: PMC10734472 DOI: 10.1128/msystems.00898-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 10/17/2023] [Indexed: 12/07/2023] Open
Abstract
IMPORTANCE These results shed light on the evolutionary strategies of microbes with streamlined genomes to adapt and survive in the oligotrophic conditions that dominate the surface waters of the global ocean. At the individual level, these microbes have been subjected to evolutionary constraints that have led to a more efficient use of nutrients, removing non-essential genes named as "streamlining theory." However, at the population level, they conserve a highly diverse gene pool in flexible genomic islands resulting in polyclonal populations on the same genomic background as an evolutionary response to environmental pressures. Localization of these islands at equivalent positions in the genome facilitates horizontal transfer between clonal lineages. This high level of environmental genomic heterogeneity could explain their cosmopolitan distribution. In the case of the order HIMB59 within the class Alphaproteobacteria, two factors exert evolutionary pressure and determine this intraspecific diversity: phages and the concentration of P in the environment.
Collapse
Affiliation(s)
- Carmen Molina-Pardines
- Evolutionary Genomics Group, División de Microbiología, Universidad Miguel Hernández, San Juan, Alicante, Spain
| | - Jose M. Haro-Moreno
- Evolutionary Genomics Group, División de Microbiología, Universidad Miguel Hernández, San Juan, Alicante, Spain
| | - Mario López-Pérez
- Evolutionary Genomics Group, División de Microbiología, Universidad Miguel Hernández, San Juan, Alicante, Spain
| |
Collapse
|
2
|
Macias D, Huertas IE, Garcia-Gorriz E, Stips A. Non-Redfieldian dynamics driven by phytoplankton phosphate frugality explain nutrient and chlorophyll patterns in model simulations for the Mediterranean Sea. PROGRESS IN OCEANOGRAPHY 2019; 173:37-50. [PMID: 32255863 PMCID: PMC7099761 DOI: 10.1016/j.pocean.2019.02.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The relative abundance of nitrate (N) over phosphate (P) measured as a molar ratio (N:P) is typically considered to determine the macronutrient limiting marine primary production. In low-complexity biogeochemical models, a simple threshold value is usually applied based on the canonical Redfield ratio (N:P = 16). However, the N:P ratio is not constant in many oceanic areas, especially marginal, semi-enclosed seas, such as the Mediterranean basin. In this work, a flexible definition of the N:P ratio based on the capacity of phytoplankton to modulate phosphate uptake according to its availability in seawater, the so-called Line of Frugality, is incorporated into the biogeochemical model MedERGOM. This modification allows the acquisition of a more realistic representation of the stoichiometry of nutrients in the Mediterranean basin and allows to better reproduce the observed phytoplankton biomass in productive areas such as the Gulf of Gabes and the Adriatic Sea. This approach is, thus, especially suitable for coastal areas in which basin-scale biogeochemical models fail to reproduce patterns observed by remote sensing or in situ measurements. Our results show that implementation of the stoichiometric flexibility of phytoplankton in a low-complexity biogeochemical model enhances the reproducibility of ecosystem dynamics without increasing the computational demand, representing a simple approximation easily implemented in models aiming to describe regions with a Non-Redfieldian stoichiometry.
Collapse
Affiliation(s)
- Diego Macias
- European Commission, Joint Research Centre, Via E. Fermi, Ispra, Varese, Italy
- Corresponding author.
| | - I. Emma Huertas
- CSIC, Instituto de Ciencias de Andalucía, Avd. Republica Saharaui, Puerto Real, Cádiz, Spain
| | - Elisa Garcia-Gorriz
- European Commission, Joint Research Centre, Via E. Fermi, Ispra, Varese, Italy
| | - Adolf Stips
- European Commission, Joint Research Centre, Via E. Fermi, Ispra, Varese, Italy
| |
Collapse
|
3
|
Carella F, Aceto S, Mangoni O, Mollica MP, Cavaliere G, Trinchese G, Aniello F, De Vico G. Assessment of the Health Status of Mussels Mytilus galloprovincialis Along the Campania Coastal Areas: A Multidisciplinary Approach. Front Physiol 2018; 9:683. [PMID: 29946265 PMCID: PMC6005891 DOI: 10.3389/fphys.2018.00683] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 05/16/2018] [Indexed: 01/21/2023] Open
Abstract
The bivalve Mytilus galloprovincialis has a broad geographic distribution, represent an important species for the ecology of coastal waters, also constituting a major aquaculture species. In the present work, molecular and tissue biomarkers were examined in mussel populations (M. galloprovincialis) located in four different areas of the coastal water of the Campania Region. During an annual life cycle, we analyzed the expression patterns of several genes commonly used to estimate cellular stress response and damage, namely p53, p63, HSP70, MT-10, and MT-20, related tissue lesions (pathogens, inflammations, digestive tubules damage), oxidative stress indicators (H2O2, SOD specific activity) and associated environmental data. The computed Principal Component Analysis showed that the areas were discernible based on the environmental data and biomarker results. About animal health status, mussels from Gulf of Pozzuoli and Naples's harbor did show a thinnest epithelial cell of digestive tubules compared to mussels sampled from other sampling sites; moreover, high prevalence of cases of intersex in three of the examinated areas were observed. The presence of a potential zoonotic pathogen (Nocardia crassostreae) was identified, appearing as an important possible emerging disease. We also reported the OIE notifiable protozoa Marteilia refringens in three areas out of four. The likely impact of both observed pathogens on the mussel health and shellfish aquaculture needs to be urgently addressed. Results are discussed considering animal histopathological health parameters and biological effects.
Collapse
Affiliation(s)
- Francesca Carella
- Department of Biology, University of Naples Federico II, Naples, Italy
| | | | | | | | | | | | | | | |
Collapse
|
4
|
Macias D, Garcia-Gorriz E, Stips A. Deep winter convection and phytoplankton dynamics in the NW Mediterranean Sea under present climate and future (horizon 2030) scenarios. Sci Rep 2018; 8:6626. [PMID: 29700363 PMCID: PMC5919909 DOI: 10.1038/s41598-018-24965-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 04/06/2018] [Indexed: 11/09/2022] Open
Abstract
Deep water convection (DC) in winter is one of the major processes driving open-ocean primary productivity in the Northwestern Mediterranean Sea. DC is highly variable in time, depending on the specific conditions (stratification, circulation and ocean-atmosphere interactions) of each specific winter. This variability also drives the interannual oscillations of open-ocean primary productivity in this important region for many commercially-important fish species. We use a coupled model system to 1) understand to what extent DC impacts phytoplankton seasonality in the present-day and 2) to explore potential changes in future scenarios (~2030). Our model represents quite accurately the present-day characteristics of DC and its importance for open-ocean phytoplankton blooms. However, for the future scenarios the importance of deep nutrients in fertilizing the euphotic layer of the NW Mediterranean decreases. The model simulates changes in surface density and on the levels of kinetic energy that make mesoscale activity associated with horizontal currents to become a more important fertilization mechanism, inducing subsequently phenological changes in seasonal plankton cycles. Because of our focus on the open-sea, an exact quantification of the impact of those changes on the overall biological production of the NW Mediterranean cannot be made at the moment.
Collapse
Affiliation(s)
- Diego Macias
- European Commission, Joint Research Centre, Directorate D- Sustainable Resources, Via E. Fermi, 21027, Ispra, VA, Italy.
| | - Elisa Garcia-Gorriz
- European Commission, Joint Research Centre, Directorate D- Sustainable Resources, Via E. Fermi, 21027, Ispra, VA, Italy
| | - Adolf Stips
- European Commission, Joint Research Centre, Directorate D- Sustainable Resources, Via E. Fermi, 21027, Ispra, VA, Italy
| |
Collapse
|
5
|
Spatio-temporal dynamics of a planktonic system and chlorophyll distribution in a 2D spatial domain: matching model and data. Sci Rep 2017; 7:220. [PMID: 28303015 PMCID: PMC5427904 DOI: 10.1038/s41598-017-00112-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 02/07/2017] [Indexed: 12/05/2022] Open
Abstract
Field data on chlorophyll distribution are investigated in a two-dimensional spatial domain of the Mediterranean Sea by using for phytoplankton abundances an advection-diffusion-reaction model, which includes real values for physical and biological variables. The study exploits indeed hydrological and nutrients data acquired in situ, and includes intraspecific competition for limiting factors, i.e. light intensity and phosphate concentration. As a result, the model allows to analyze how both the velocity field of marine currents and the two components of turbulent diffusivity affect the spatial distributions of phytoplankton abundances in the Modified Atlantic Water, the upper layer of the water column of the Mediterranean Sea. Specifically, the spatio-temporal dynamics of four phytoplankton populations, responsible for about 80% of the total chlorophyll a, are reproduced. Results for phytoplankton abundances obtained by the model are converted in chlorophyll a concentrations and compared with field data collected in twelve marine sites along the Cape Passero (Sicily)- Misurata (Libya) transect. Statistical checks indicate a good agreement between theoretical and experimental distributions of chlorophyll concentration. The study can be extended to predict the spatio-temporal behaviour of the primary production, and to prevent the consequent decline of some fish species in the Mediterranean Sea.
Collapse
|
6
|
Mangoni O, Aiello G, Balbi S, Barra D, Bolinesi F, Donadio C, Ferrara L, Guida M, Parisi R, Pennetta M, Trifuoggi M, Arienzo M. A multidisciplinary approach for the characterization of the coastal marine ecosystems of Monte Di Procida (Campania, Italy). MARINE POLLUTION BULLETIN 2016; 112:443-451. [PMID: 27422486 DOI: 10.1016/j.marpolbul.2016.07.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 07/05/2016] [Accepted: 07/06/2016] [Indexed: 06/06/2023]
Abstract
A multidisciplinary survey was carried out on the quality of water and sediments of a coastal protected marine area, embedded between the inputs from Bagnoli steel plant to the south and a sewage plant, Volturno River and Regi Lagni channel to the north. The study integrated chemical-sedimentological data with biological and ecotoxicological analyses to assess anthropogenic pressures and natural variability. Data reveal marked differences in anthropogenic pollution between southeastern and northwestern zone, with the north affected by both inorganic and organic flows and the south influenced by levels of As, Pb and Zn in the sediments above law limits, deriving from inputs of the Bagnoli brownfield site. Meiobenthic data revealed at south higher relative abundance of sensitive species to pollution and environmental stress to the south, i.e. Lobatula lobatula and Rosalina bradyi, whereas to the north relative abundance of stress tolerant Quinqueloculina lata, Quinqueloculina pygmaea and Cribroelphidium cuvilleri were determined.
Collapse
Affiliation(s)
- Olga Mangoni
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Complesso Universitario di Monte S. Angelo, Via Cintia, 80126 Naples, Italy
| | - Giuseppe Aiello
- Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse, Università degli Studi di Napoli Federico II, Largo San Marcellino, 80134 Naples, Italy
| | - Simona Balbi
- Dipartimento di Scienze Economiche e Statistiche, Università degli Studi di Napoli Federico II, Complesso Universitario di Monte S. Angelo, Via Cintia, 80126 Naples, Italy
| | - Diana Barra
- Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse, Università degli Studi di Napoli Federico II, Largo San Marcellino, 80134 Naples, Italy
| | - Francesco Bolinesi
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Complesso Universitario di Monte S. Angelo, Via Cintia, 80126 Naples, Italy
| | - Carlo Donadio
- Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse, Università degli Studi di Napoli Federico II, Largo San Marcellino, 80134 Naples, Italy
| | - Luciano Ferrara
- Dipartimento di Scienze Chimiche, Università degli Studi di Napoli Federico II, Complesso Universitario di Monte S. Angelo, Via Cintia, 80126 Naples, Italy
| | - Marco Guida
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Complesso Universitario di Monte S. Angelo, Via Cintia, 80126 Naples, Italy
| | - Roberta Parisi
- Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse, Università degli Studi di Napoli Federico II, Largo San Marcellino, 80134 Naples, Italy
| | - Micla Pennetta
- Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse, Università degli Studi di Napoli Federico II, Largo San Marcellino, 80134 Naples, Italy
| | - Marco Trifuoggi
- Dipartimento di Scienze Chimiche, Università degli Studi di Napoli Federico II, Complesso Universitario di Monte S. Angelo, Via Cintia, 80126 Naples, Italy
| | - Michele Arienzo
- Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse, Università degli Studi di Napoli Federico II, Largo San Marcellino, 80134 Naples, Italy.
| |
Collapse
|
7
|
|
8
|
Powley HR, Dürr HH, Lima AT, Krom MD, Van Cappellen P. Direct Discharges of Domestic Wastewater are a Major Source of Phosphorus and Nitrogen to the Mediterranean Sea. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:8722-8730. [PMID: 27409146 DOI: 10.1021/acs.est.6b01742] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Direct discharges of treated and untreated wastewater are important sources of nutrients to coastal marine ecosystems and contribute to their eutrophication. Here, we estimate the spatially distributed annual inputs of phosphorus (P) and nitrogen (N) associated with direct domestic wastewater discharges from coastal cities to the Mediterranean Sea (MS). According to our best estimates, in 2003 these inputs amounted to 0.9 × 10(9) mol P yr(-1) and 15 × 10(9) mol N yr(-1), that is, values on the same order of magnitude as riverine inputs of P and N to the MS. By 2050, in the absence of any mitigation, population growth plus higher per capita protein intake and increased connectivity to the sewer system are projected to increase P inputs to the MS via direct wastewater discharges by 254, 163, and 32% for South, East, and North Mediterranean countries, respectively. Complete conversion to tertiary wastewater treatment would reduce the 2050 inputs to below their 2003 levels, but at an estimated additional cost of over €2 billion yr(-1). Management of coastal eutrophication may be best achieved by targeting tertiary treatment upgrades to the most affected near-shore areas, while simultaneously implementing legislation limiting P in detergents and increasing wastewater reuse across the entire basin.
Collapse
Affiliation(s)
- Helen R Powley
- Ecohydrology Research Group, Water Institute and Department of Earth and Environmental Sciences, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
| | - Hans H Dürr
- Ecohydrology Research Group, Water Institute and Department of Earth and Environmental Sciences, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
| | - Ana T Lima
- Ecohydrology Research Group, Water Institute and Department of Earth and Environmental Sciences, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
- Department of Environmental Engineering, Universidade Federal do Espírito Santo , Av. Fernando Ferrari 514, CEP 29075-910 - Vitória, Espírito Santo Brazil
| | - Michael D Krom
- Ecohydrology Research Group, Water Institute and Department of Earth and Environmental Sciences, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
- School of Earth and Environment, University of Leeds , Leeds LS2 9JT, United Kingdom
- Department of Marine Biology, Haifa University , Mt Carmel, Haifa, Israel
| | - Philippe Van Cappellen
- Ecohydrology Research Group, Water Institute and Department of Earth and Environmental Sciences, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
| |
Collapse
|
9
|
Segura-Noguera M, Blasco D, Fortuño JM. Taxonomic and Environmental Variability in the Elemental Composition and Stoichiometry of Individual Dinoflagellate and Diatom Cells from the NW Mediterranean Sea. PLoS One 2016; 11:e0154050. [PMID: 27111067 PMCID: PMC4844132 DOI: 10.1371/journal.pone.0154050] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 04/07/2016] [Indexed: 11/19/2022] Open
Abstract
Here we present, for the first time, the elemental concentration, including C, N and O, of single phytoplankton cells collected from the sea. Plankton elemental concentration and stoichiometry are key variables in phytoplankton ecophysiology and ocean biogeochemistry, and are used to link cells and ecosystems. However, most field studies rely on bulk techniques that overestimate carbon and nitrogen because the samples include organic matter other than plankton organisms. Here we used X-ray microanalysis (XRMA), a technique that, unlike bulk analyses, gives simultaneous quotas of C, N, O, Mg, Si, P, and S, in single-cell organisms that can be collected directly from the sea. We analysed the elemental composition of dinoflagellates and diatoms (largely Chaetoceros spp.) collected from different sites of the Catalan coast (NW Mediterranean Sea). As expected, a lower C content is found in our cells compared to historical values of cultured cells. Our results indicate that, except for Si and O in diatoms, the mass of all elements is not a constant fraction of cell volume but rather decreases with increasing cell volume. Also, diatoms are significantly less dense in all the measured elements, except Si, compared to dinoflagellates. The N:P ratio of both groups is higher than the Redfield ratio, as it is the N:P nutrient ratio in deep NW Mediterranean Sea waters (N:P = 20-23). The results suggest that the P requirement is highest for bacterioplankton, followed by dinoflagellates, and lowest for diatoms, giving them a clear ecological advantage in P-limited environments like the Mediterranean Sea. Finally, the P concentration of cells of the same genera but growing under different nutrient conditions was the same, suggesting that the P quota of these cells is at a critical level. Our results indicate that XRMA is an accurate technique to determine single cell elemental quotas and derived conversion factors used to understand and model ocean biogeochemical cycles.
Collapse
Affiliation(s)
- Mariona Segura-Noguera
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Barcelona, Catalonia
| | - Dolors Blasco
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Barcelona, Catalonia
| | - José-Manuel Fortuño
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Barcelona, Catalonia
| |
Collapse
|
10
|
Lauritano C, Orefice I, Procaccini G, Romano G, Ianora A. Key genes as stress indicators in the ubiquitous diatom Skeletonema marinoi. BMC Genomics 2015; 16:411. [PMID: 26018764 PMCID: PMC4445783 DOI: 10.1186/s12864-015-1574-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 04/24/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The dense phytoplankton blooms that characterize productive regions and seasons in the oceans are dominated, from high to low latitudes and from coast line to open ocean, by comparatively few, often cosmopolitan species of diatoms. These key dominant species may undergo dramatic changes due to global climate change. RESULTS In order to identify molecular stress-indicators for the ubiquitous diatom species Skeletonema marinoi, we tested stress-related genes in different environmental conditions (i.e. nutrient starvation/depletion, CO2-enrichment and combined effects of these stressors) using RT-qPCR. The data show that these stressors impact algal growth rate, inducing early aging and profound changes in expression levels of the genes of interest. CONCLUSIONS Most analyzed genes (e.g. antioxidant-related and aldehyde dehydrogenases) were strongly down-regulated which may indicate a strategy to avoid unnecessary over-investment in their respective proteins. By contrast, key genes were activated (e.g. HSPs, GOX) which may allow the diatom species to better cope with adverse conditions. We propose the use of this panel of genes as early bio-indicators of environmental stress factors in a changing ocean.
Collapse
Affiliation(s)
- Chiara Lauritano
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy.
| | - Ida Orefice
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy.
| | | | - Giovanna Romano
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy.
| | - Adrianna Ianora
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy.
| |
Collapse
|
11
|
Valenti D, Denaro G, Spagnolo B, Conversano F, Brunet C. How diffusivity, thermocline and incident light intensity modulate the dynamics of deep chlorophyll maximum in Tyrrhenian Sea. PLoS One 2015; 10:e0115468. [PMID: 25629963 PMCID: PMC4309620 DOI: 10.1371/journal.pone.0115468] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 11/23/2014] [Indexed: 11/22/2022] Open
Abstract
During the last few years theoretical works have shed new light and proposed new hypotheses on the mechanisms which regulate the spatio-temporal behaviour of phytoplankton communities in marine pelagic ecosystems. Despite this, relevant physical and biological issues, such as effects of the time-dependent mixing in the upper layer, competition between groups, and dynamics of non-stationary deep chlorophyll maxima, are still open questions. In this work, we analyze the spatio-temporal behaviour of five phytoplankton populations in a real marine ecosystem by using a one-dimensional reaction-diffusion-taxis model. The study is performed, taking into account the seasonal variations of environmental variables, such as light intensity, thickness of upper mixed layer and profiles of vertical turbulent diffusivity, obtained starting from experimental findings. Theoretical distributions of phytoplankton cell concentration was converted in chlorophyll concentration, and compared with the experimental profiles measured in a site of the Tyrrhenian Sea at four different times (seasons) of the year, during four different oceanographic cruises. As a result we find a good agreement between theoretical and experimental distributions of chlorophyll concentration. In particular, theoretical results reveal that the seasonal changes of environmental variables play a key role in the phytoplankton distribution and determine the properties of the deep chlorophyll maximum. This study could be extended to other marine ecosystems to predict future changes in the phytoplankton biomass due to global warming, in view of devising strategies to prevent the decline of the primary production and the consequent decrease of fish species.
Collapse
Affiliation(s)
- Davide Valenti
- Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Theoretical Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy
- * E-mail:
| | - Giovanni Denaro
- Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Theoretical Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy
| | - Bernardo Spagnolo
- Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Theoretical Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy
- Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Catania, Italy
- Radiophysics Department, Lobachevsky State University, Nizhniy Novgorod, Russia
| | | | | |
Collapse
|
12
|
Macias D, Garcia-Gorriz E, Piroddi C, Stips A. Biogeochemical control of marine productivity in the Mediterranean Sea during the last 50 years. GLOBAL BIOGEOCHEMICAL CYCLES 2014; 28:897-907. [PMID: 26180286 PMCID: PMC4493898 DOI: 10.1002/2014gb004846] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 08/03/2014] [Indexed: 05/25/2023]
Abstract
UNLABELLED The temporal dynamics of biogeochemical variables derived from a coupled 3-D model of the Mediterranean Sea are evaluated for the last 50 years (1960-2010) against independent data on fisheries catch per unit effort (CPUE) for the same time period. Concordant patterns are found in the time series of all of the biological variables (from the model and from fisheries statistics), with low values at the beginning of the series, a later increase, with maximum levels reached at the end of the 1990s, and a posterior stabilization. Spectral analysis of the annual biological time series reveals coincident low-frequency signals in all of them. The first, more energetic signal peaks around the year 2000, while the second, less energetic signal peaks near 1982. Almost identical low-frequency signals are found in the nutrient loads of the rivers and in the integrated nutrient levels in the surface marine ecosystem. Nitrate concentration shows a maximum level in 1998, with a later stabilization to present-day values, coincident with the first low-frequency signal found in the biological series. Phosphate shows maximum concentrations around 1982 and a posterior sharp decline, in concordance with the second low-frequency signal observed in the biological series. That result seems to indicate that the control of marine productivity (plankton to fish) in the Mediterranean is principally mediated through bottom-up processes that could be traced back to the characteristics of riverine discharges. The high sensitivity of CPUE time series to environmental conditions might be another indicator of the overexploitation of this marine ecosystem. KEY POINTS Biogeochemical evolution of the Mediterranean over the past 50 yearsRiver nutrient loads drive primary and secondary productionsStrong link between low trophic levels and fisheries.
Collapse
Affiliation(s)
- Diego Macias
- European Commission, Joint Research Centre, Institute for Environment and Sustainability, Water Research Unit Ispra, Italy
| | - Elisa Garcia-Gorriz
- European Commission, Joint Research Centre, Institute for Environment and Sustainability, Water Research Unit Ispra, Italy
| | - Chiara Piroddi
- European Commission, Joint Research Centre, Institute for Environment and Sustainability, Water Research Unit Ispra, Italy
| | - Adolf Stips
- European Commission, Joint Research Centre, Institute for Environment and Sustainability, Water Research Unit Ispra, Italy
| |
Collapse
|
13
|
Denaro G, Valenti D, Spagnolo B, Basilone G, Mazzola S, Zgozi SW, Aronica S, Bonanno A. Dynamics of two picophytoplankton groups in mediterranean sea: analysis of the deep chlorophyll maximum by a stochastic advection-reaction-diffusion model. PLoS One 2013; 8:e66765. [PMID: 23826130 PMCID: PMC3691268 DOI: 10.1371/journal.pone.0066765] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 05/13/2013] [Indexed: 11/25/2022] Open
Abstract
A stochastic advection-reaction-diffusion model with terms of multiplicative white Gaussian noise, valid for weakly mixed waters, is studied to obtain the vertical stationary spatial distributions of two groups of picophytoplankton, i.e., picoeukaryotes and Prochlorococcus, which account about for 60% of total chlorophyll on average in Mediterranean Sea. By numerically solving the equations of the model, we analyze the one-dimensional spatio-temporal dynamics of the total picophytoplankton biomass and nutrient concentration along the water column at different depths. In particular, we integrate the equations over a time interval long enough, obtaining the steady spatial distributions for the cell concentrations of the two picophytoplankton groups. The results are converted into chlorophyll a and divinil chlorophyll a concentrations and compared with experimental data collected in two different sites of the Sicily Channel (southern Mediterranean Sea). The comparison shows that real distributions are well reproduced by theoretical profiles. Specifically, position, shape and magnitude of the theoretical deep chlorophyll maximum exhibit a good agreement with the experimental values.
Collapse
Affiliation(s)
- Giovanni Denaro
- Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy
| | - Davide Valenti
- Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy
| | - Bernardo Spagnolo
- Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy
| | - Gualtiero Basilone
- Istituto per l’Ambiente Marino Costiero, Centro Nazionale delle Ricerche, Unità Operativa di Supporto di Capo Granitola, Campobello di Mazara, Trapani, Italy
| | - Salvatore Mazzola
- Istituto per l’Ambiente Marino Costiero, Centro Nazionale delle Ricerche, Unità Operativa di Supporto di Capo Granitola, Campobello di Mazara, Trapani, Italy
| | | | - Salvatore Aronica
- Istituto per l’Ambiente Marino Costiero, Centro Nazionale delle Ricerche, Unità Operativa di Supporto di Capo Granitola, Campobello di Mazara, Trapani, Italy
| | - Angelo Bonanno
- Istituto per l’Ambiente Marino Costiero, Centro Nazionale delle Ricerche, Unità Operativa di Supporto di Capo Granitola, Campobello di Mazara, Trapani, Italy
| |
Collapse
|
14
|
Zaccone R, Boldrin A, Caruso G, La Ferla R, Maimone G, Santinelli C, Turchetto M. Enzymatic activities and prokaryotic abundance in relation to organic matter along a West-East Mediterranean transect (TRANSMED cruise). MICROBIAL ECOLOGY 2012; 64:54-66. [PMID: 22349935 DOI: 10.1007/s00248-012-0011-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 01/16/2012] [Indexed: 05/31/2023]
Abstract
The distribution of extracellular enzymatic activities (EEA) [leucine aminopeptidase (LAP), ß-glucosidase (GLU), alkaline phosphatase (AP)], as well as that of prokaryotic abundance (PA) and biomass (PB), dissolved organic carbon (DOC), particulate organic carbon and particulate total nitrogen (POC, PTN), was determined in the epi-, meso-, and bathypelagic waters of the Mediterranean Sea along a West-East transect and at one Atlantic station located outside the Strait of Gibraltar. This study represents a synoptical evaluation of the microbial metabolism during early summer. Decreasing trends with depth were observed for most of the parameters (PA, PB, AP, DOC, POC, PTN). Significant differences between the western and eastern basins of the Mediterranean Sea were found, displaying higher rates of LAP and GLU and lower C/N ratios more in the eastern than in the western areas. Conversely, in the epipelagic layer, PA and PB were found to be higher in the western than in the eastern basins. PB was significantly related to DOC concentration (all data, n = 145, r = 0.53, P < 0.01), while significant correlations of EEA with POC and PTN were found in the epipelagic layer, indicating an active response of microbial metabolism to organic substrates. Specific enzyme activities normalized to cell abundance pointed out high values of LAP and GLU in the bathypelagic layer, especially in the eastern basin, while cell-specific AP was high in the epi- and bathypelagic zone of the eastern basin indicating a rapid regeneration of inorganic P for both prokaryotes and phytoplankton needs. Low activity and abundance characterized the Atlantic station, while opposite trends of these parameters were observed along the Mediterranean transect, showing the uncoupling between abundance and activity data. In the east Mediterranean Sea, decomposition processes increased probably in response to mesoscale structures which lead to organic matter downwelling.
Collapse
Affiliation(s)
- R Zaccone
- CNR-IAMC, Institute for Coastal Marine Environment, Section of Messina, Messina, Italy.
| | | | | | | | | | | | | |
Collapse
|
15
|
Emeis KC, Mara P, Schlarbaum T, Möbius J, Dähnke K, Struck U, Mihalopoulos N, Krom M. External N inputs and internal N cycling traced by isotope ratios of nitrate, dissolved reduced nitrogen, and particulate nitrogen in the eastern Mediterranean Sea. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jg001214] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
16
|
Man-Aharonovich D, Kress N, Zeev EB, Berman-Frank I, Béjà O. Molecular ecology of nifH genes and transcripts in the eastern Mediterranean Sea. Environ Microbiol 2007; 9:2354-63. [PMID: 17686031 DOI: 10.1111/j.1462-2920.2007.01353.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The eastern Mediterranean Sea is one of the most extreme oligotrophic oceanic regions on earth in terms of nutrient concentrations and primary productivity. Nitrogen fixation has been suggested to contribute to the high N : P molar ratios of approximately 28:1 found in this region. Surprisingly, no molecular biological work has been performed in situ to assess whether N(2) fixation genes actually occur in the eastern Mediterranean Sea, or to determine which organisms are responsible for this process. In this study, we examined the presence and expression of nitrogenase genes (nifH) in the upper water layer of the eastern Mediterranean. Clone libraries constructed from both DNA and reverse-transcribed PCR-amplified mRNA were examined and compared. We observed different nifH genes from diverse microbial groups, such as Cyanobacteria, Proteobacteria and methanogenic Archaea. Interestingly, numerous phylotypes were observed in coastal stations at the DNA level but none were active. However, in far offshore stations, the phylotypes observed at the DNA level were the ones that were actually active. Our preliminary study revealed diverse diazotrophs that possess and express nifH genes, which may support N(2) fixation in the eastern Mediterranean Sea.
Collapse
|