Aggregate Formation During the Viral Lysis of a Marine Diatom

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Yosuke Yamada

2018-05-01

Full Text Available Recent studies have suggested that the viral lysis of microbes not only facilitates the conversion of particulate organic matter into dissolved organic matter, but also promotes the formation of organic aggregates, which enhance the export of organic carbon from the surface ocean to the deep sea. However, experimental data supporting this proposition are limited. Here, we tested the hypothesis that the viral infection of marine diatoms enhances aggregate formation. We used a model system consisting of Chaetoceros tenuissimus, a bloom-forming diatom with an approximate cell size of 3–10 μm, and a DNA virus, CtenDNAV type II, which replicates in the nucleus of C. tenuissimus. The volume of large particles (50–400 μm in equivalent spherical diameters, determined from photographic images was measured over time (up to 15 days in the diatom-alone control and a virus-added diatom culture. We also determined the concentrations of Coomassie-stainable particles (CSP, proteinaceous particles and transparent exopolymeric particles (TEP, acid-polysaccharide-rich particles with colorimetric methods. The total volume of large particles was significantly higher (5–59 fold in the virus-added diatoms than in the diatom-alone control during the period in which the viral lysis of the diatoms proceeded. One class of large particles produced in the virus-added diatoms was flake-shaped. The flakes were tightly packed and dense, and sank rapidly, possibly playing an important role in the vertical delivery of materials from the surface to the deep sea. The bulk CSP concentrations tended to be higher in the virus-added diatoms than in the diatom-alone control, whereas the reverse was true for the TEP. These results suggest that proteinaceous polymers are involved in aggregate formation. Our data support the emerging notion that the viral lysis of microbes facilitates aggregate formation and the export of organic carbon in the ocean.

Effect of UV-B radiation on the marine diatom bellerochea yucatanensis

International Nuclear Information System (INIS)

Doehler, G.

1982-01-01

There exists no information about the UV-B fluence on several photosynthetic products and nitrogen metabolism. The present report describes the effect of low levels of UV-B radiation on pigments, 14 C- and 15 N-incorporation of the marine diatom Bellerochea yucatanensis. (orig./AJ)

Diatom-based characterization of iberian coastal environments at different time scales

OpenAIRE

Ferreira, Tânia Maria de Azevedo, 1978-

2014-01-01

Tese de doutoramento, Geologia (Geologia Económica e do Ambiente), Universidade de Lisboa, Faculdade de Ciências, 2014 This thesis presents the mesoscale characterization of the evolution of two lagoon systems, Traba (550 years of sedimentary sequence) and Melides (1745 years of sedimentary sequence), using sedimentological, geochemical and biological, particularly diatoms, indicators. Also, a characterization of 18 present-day transitional environments (coastal lakes and ponds...

Role of Diatoms in the Spatial-Temporal Distribution of Intracellular Nitrate in Intertidal Sediment

DEFF Research Database (Denmark)

Stief, P.; Kamp, A.; de Beer, D.

2013-01-01

Intracellular nitrate storage allows microorganisms to survive fluctuating nutrient availability and anoxic conditions in aquatic ecosystems. Here we show that diatoms, ubiquitous and highly abundant microalgae, represent major cellular reservoirs of nitrate in an intertidal flat of the German Wa...... in anaerobic nitrate respiration. Due to the widespread dominance of diatoms in microphytobenthos, the total nitrate pool in coastal marine sediments may generally be at least two times larger than derived from porewater measurements and partially be recycled to ammonium....

Coastal Geographic Structures in Coastal-Marine Environmental Management

Science.gov (United States)

Baklanov, P. Ya.; Ganzei, K. S.; Ermoshin, V. V.

2018-01-01

It has been proposed to distinguish the coastal geographic structures consisting of a spatial combination of three interconnected and mutually conditioned parts (coastal-territorial, coastal, coastal-marine), which are interlinked with each other by the cumulative effect of real-energy flows. Distinguishing specific resource features of the coastal structures, by which they play a connecting role in the complex coastalmarine management, has been considered. The main integral resource feature of the coastal structures is their connecting functions, which form transitional parts mutually connecting the coastal-territorial and coastalmarine environmental management.

Diatom species abundance and morphologically-based dissolution proxies in coastal Southern Ocean assemblages

Science.gov (United States)

Warnock, Jonathan P.; Scherer, Reed P.

2015-07-01

Taphonomic processes alter diatom assemblages in sediments, thus potentially negatively impacting paleoclimate records at various rates across space, time, and taxa. However, quantitative taphonomic data is rarely included in diatom-based paleoenvironmental reconstructions and no objective standard exists for comparing diatom dissolution in sediments recovered from marine depositional settings, including the Southern Ocean's opal belt. Furthermore, identifying changes to diatom dissolution through time can provide insight into the efficiency of both upper water column nutrient recycling and the biological pump. This is significant in that reactive metal proxies (e.g. Al, Ti) in the sediments only account for post-depositional dissolution, not the water column where the majority of dissolution occurs. In order to assess the range of variability of responses to dissolution in a typical Southern Ocean diatom community and provide a quantitative guideline for assessing taphonomic variability in diatoms recovered from core material, a sediment trap sample was subjected to controlled, serial dissolution. By evaluating dissolution-induced changes to diatom species' relative abundance, three preservational categories of diatoms have been identified: gracile, intermediate, and robust. The relative abundances of these categories can be used to establish a preservation grade for diatom assemblages. However, changes to the relative abundances of diatom species in sediment samples may reflect taphonomic or ecological factors. In order to address this complication, relative abundance changes have been tied to dissolution-induced morphological change to the areolae of Fragilariopsis curta, a significant sea-ice indicator in Southern Ocean sediments. This correlation allows differentiation between gracile species loss to dissolution versus ecological factors or sediment winnowing. These results mirror a similar morphological dissolution index from a parallel study utilizing

Diatom-Specific Oligosaccharide and Polysaccharide Structures Help to Unravel Biosynthetic Capabilities in Diatoms

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Bruno Gügi

2015-09-01

Full Text Available Diatoms are marine organisms that represent one of the most important sources of biomass in the ocean, accounting for about 40% of marine primary production, and in the biosphere, contributing up to 20% of global CO2 fixation. There has been a recent surge in developing the use of diatoms as a source of bioactive compounds in the food and cosmetic industries. In addition, the potential of diatoms such as Phaeodactylum tricornutum as cell factories for the production of biopharmaceuticals is currently under evaluation. These biotechnological applications require a comprehensive understanding of the sugar biosynthesis pathways that operate in diatoms. Here, we review diatom glycan and polysaccharide structures, thus revealing their sugar biosynthesis capabilities.

Mapping the diatom redox-sensitive proteome provides insight into response to nitrogen stress in the marine environment.

Science.gov (United States)

Rosenwasser, Shilo; Graff van Creveld, Shiri; Schatz, Daniella; Malitsky, Sergey; Tzfadia, Oren; Aharoni, Asaph; Levin, Yishai; Gabashvili, Alexandra; Feldmesser, Ester; Vardi, Assaf

2014-02-18

Diatoms are ubiquitous marine photosynthetic eukaryotes responsible for approximately 20% of global photosynthesis. Little is known about the redox-based mechanisms that mediate diatom sensing and acclimation to environmental stress. Here we used a quantitative mass spectrometry-based approach to elucidate the redox-sensitive signaling network (redoxome) mediating the response of diatoms to oxidative stress. We quantified the degree of oxidation of 3,845 cysteines in the Phaeodactylum tricornutum proteome and identified approximately 300 redox-sensitive proteins. Intriguingly, we found redox-sensitive thiols in numerous enzymes composing the nitrogen assimilation pathway and the recently discovered diatom urea cycle. In agreement with this finding, the flux from nitrate into glutamine and glutamate, measured by the incorporation of (15)N, was strongly inhibited under oxidative stress conditions. Furthermore, by targeting the redox-sensitive GFP sensor to various subcellular localizations, we mapped organelle-specific oxidation patterns in response to variations in nitrogen quota and quality. We propose that redox regulation of nitrogen metabolism allows rapid metabolic plasticity to ensure cellular homeostasis, and thus is essential for the ecological success of diatoms in the marine ecosystem.

A Pliocene marine diatom δ18O record of terrestrial-marine feedbacks and orbitally-paced cryogenic brine formation in the McMurdo Dry Valleys

Science.gov (United States)

Dodd, J. P.; Abbott, T.; Gibbons, J. A.

2017-12-01

Orbital frequencies are well documented in a number of terrestrial and marine climate records throughout the Cenozoic; however, assessing the feedbacks and timing of terrestrial-marine systems on glacial-interglacial timescales is often challenging. This is particularly the case in high-latitude, near-shore environments where traditional proxy records like benthic foraminifera are absent. Here we present oxygen isotope (δ18O and δ17O) values from marine diatom silica in the mid-Pliocene (3.5 - 4.7Ma) section of the AND-1B core from McMurdo Sound, Antarctica. Diatom silica δ18O values range between +28.1 and +36.4‰ VSMOW. Over a range of temperatures (0 to 10°C) that reflect both growth and shallow (fall on a mixing line between marine and meteoric waters, which also supports our cryogenic brine hypothesis. The AND-1B δ18O values have an inverse relationship with the stacked benthic foraminifera δ18O record where lower δ18O values in the AND-1B diatom silica correspond with colder intervals, and we interpret variations in the diatom δ18O values as increased brine flux from the MDV to McMurdo Sound. Currently, subsurface brines in the MDV are hydrologically connected with McMurdo Sound. Density-driven transport of these brines from the MDV to the marine costal environments during the warm mid-Pliocene indicate a potentially overlooked terrestrial source of hypersaline waters. Although the lateral extent of these brines is not known, mixing between the terrestrial cryogenic brines and seawater may represent a significant flux of hypersaline water to the marine environment during warmer-than-present global conditions.

A fast Na+/Ca2+-based action potential in a marine diatom.

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Alison R Taylor

Full Text Available BACKGROUND: Electrical impulses in animals play essential roles in co-ordinating an array of physiological functions including movement, secretion, environmental sensing and development. Underpinning many of these electrical signals is a fast Na+-based action potential that has been fully characterised only in cells associated with the neuromuscular systems of multicellular animals. Such rapid action potentials are thought to have evolved with the first metazoans, with cnidarians being the earliest representatives. The present study demonstrates that a unicellular protist, the marine diatom Odontella sinensis, can also generate a fast Na+/Ca2+ based action potential that has remarkably similar biophysical and pharmacological properties to invertebrates and vertebrate cardiac and skeletal muscle cells. METHODOLOGY/PRINCIPAL FINDINGS: The kinetic, ionic and pharmacological properties of the rapid diatom action potential were examined using single electrode current and voltage clamp techniques. Overall, the characteristics of the fast diatom currents most closely resemble those of vertebrate and invertebrate muscle Na+/Ca2+ currents. CONCLUSIONS/SIGNIFICANCE: This is the first demonstration of voltage-activated Na+ channels and the capacity to generate fast Na+-based action potentials in a unicellular photosynthetic organism. The biophysical and pharmacological characteristics together with the presence of a voltage activated Na+/Ca2+ channel homologue in the recently sequenced genome of the diatom Thalassiosira pseudonana, provides direct evidence supporting the hypothesis that this rapid signalling mechanism arose in ancestral unicellular eukaryotes and has been retained in at least two phylogenetically distant lineages of eukaryotes; opisthokonts and the stramenopiles. The functional role of the fast animal-like action potential in diatoms remains to be elucidated but is likely involved in rapid environmental sensing of these widespread and

An integrative analysis of post-translational histone modifications in the marine diatom Phaeodactylum tricornutum

KAUST Repository

Veluchamy, Alaguraj

2015-05-20

Background: Nucleosomes are the building blocks of chromatin where gene regulation takes place. Chromatin landscapes have been profiled for several species, providing insights into the fundamental mechanisms of chromatin-mediated transcriptional regulation of gene expression. However, knowledge is missing for several major and deep-branching eukaryotic groups, such as the Stramenopiles, which include the diatoms. Diatoms are highly diverse and ubiquitous species of phytoplankton that play a key role in global biogeochemical cycles. Dissecting chromatin-mediated regulation of genes in diatoms will help understand the ecological success of these organisms in contemporary oceans. Results: Here, we use high resolution mass spectrometry to identify a full repertoire of post-translational modifications on histones of the marine diatom Phaeodactylum tricornutum, including eight novel modifications. We map five histone marks coupled with expression data and show that P. tricornutum displays both unique and broadly conserved chromatin features, reflecting the chimeric nature of its genome. Combinatorial analysis of histone marks and DNA methylation demonstrates the presence of an epigenetic code defining activating or repressive chromatin states. We further profile three specific histone marks under conditions of nitrate depletion and show that the histone code is dynamic and targets specific sets of genes. Conclusions: This study is the first genome-wide characterization of the histone code from a stramenopile and a marine phytoplankton. The work represents an important initial step for understanding the evolutionary history of chromatin and how epigenetic modifications affect gene expression in response to environmental cues in marine environments. © 2015 Veluchamy et al.

Evolutionary origins and functions of the carotenoid biosynthetic pathway in marine diatoms

Czech Academy of Sciences Publication Activity Database

Coesel, S.; Oborník, Miroslav; Varela, J.; Falciatore, A.; Bowler, C.

2008-01-01

Roč. 3, č. 8 (2008), s. 1-16 E-ISSN 1932-6203 R&D Projects: GA AV ČR IAA500220502 Institutional research plan: CEZ:AV0Z60220518 Keywords : marine diatoms * carotenoid pathway * evolution Subject RIV: EB - Genetics ; Molecular Biology

Characterization of Light and Nitrogen Regulated Gene Expression Pathways in Marine Diatoms

Science.gov (United States)

1992-12-31

DNA and cDNA from the seagrass Zostera marina and marine unicellular chlorophyte Dunaliella tertiolecta, using oligonucleotide primers based on...availability of carbon skeletons from photosynthesis may also function in the modulation of gene expression in diatoms. FCP abundance did not exhibit any

A First Look at Oxygen and Silicon Isotope Variations in Diatom Silica from a Pliocene Antarctic Marine Sediment Core

Science.gov (United States)

Abbott, T.; Dodd, J. P.; Hackett, H.; Scherer, R. P.

2016-02-01

Coupled oxygen (δ18O) and silicon (δ30Si) isotope variations in diatom silica (opal-A) are increasingly used as a proxy to reconstruct paleoenvironmental conditions (water temperatures, water mass mixing, nutrient cycling) in marine environments. Diatom silica is a particularly significant paleoenvironmental proxy in high latitude environments, such as the Southern Ocean, where diatom blooms are abundant and diatom frustules are well preserved in the sediment. The Andrill-1B (AND-1B) sediment core from the Ross Sea (Antarctica) preserves several Pliocene ( 4.5 Ma) age diatomite units. Here we present preliminary δ18O and δ30Si values for a diatomite subunit in the AND-1B sediment core. Initial isotope values for the AND-1B diatoms silica record relatively high variability (range δ18O: 36.3‰ to 39.9‰) that could be interpreted as large-scale changes in the water temperature and/or freshwater mixing in the Ross Sea; however, a significant concern with marine sediment of this age is isotope fractionation during diagenesis and the potential formation of opal-CT lepispheres. The effects of clay contamination on the diatom silica δ18O values have been addressed through sample purification and quantified through chemical and physical analyses of the diatom silica. The isotopic effects of opal-CT are not as clearly understood and more difficult to physically separate from the primary diatom silica. In order to better understand the isotope variations in the AND-1B diatoms, we also evaluated silicon and oxygen isotope fractionation during the transition from opal-A to opal-CT in a controlled laboratory experiment. Opal-A from cultured marine diatoms (Thalassiosira weissflogii) was subjected to elevated temperatures (150°C) in acid digestion vessels for 4 weeks to initiate opal-CT precipitation. Quantifying the effects of opal-CT formation on δ18O and δ30Si variations in biogenic silica improves our understanding of the use of diatom silica isotope values a

Photo-Oxidative Stress-Driven Mutagenesis and Adaptive Evolution on the Marine Diatom Phaeodactylum tricornutum for Enhanced Carotenoid Accumulation

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Zhiqian Yi

2015-09-01

Full Text Available Marine diatoms have recently gained much attention as they are expected to be a promising resource for sustainable production of bioactive compounds such as carotenoids and biofuels as a future clean energy solution. To develop photosynthetic cell factories, it is important to improve diatoms for value-added products. In this study, we utilized UVC radiation to induce mutations in the marine diatom Phaeodactylum tricornutum and screened strains with enhanced accumulation of neutral lipids and carotenoids. Adaptive laboratory evolution (ALE was also used in parallel to develop altered phenotypic and biological functions in P. tricornutum and it was reported for the first time that ALE was successfully applied on diatoms for the enhancement of growth performance and productivity of value-added carotenoids to date. Liquid chromatography-mass spectrometry (LC-MS was utilized to study the composition of major pigments in the wild type P. tricornutum, UV mutants and ALE strains. UVC radiated strains exhibited higher accumulation of fucoxanthin as well as neutral lipids compared to their wild type counterpart. In addition to UV mutagenesis, P. tricornutum strains developed by ALE also yielded enhanced biomass production and fucoxanthin accumulation under combined red and blue light. In short, both UV mutagenesis and ALE appeared as an effective approach to developing desired phenotypes in the marine diatoms via electromagnetic radiation-induced oxidative stress.

The genome of the diatom Thalassiosira pseudonana: Ecology,evolution, and metabolism

Energy Technology Data Exchange (ETDEWEB)

Ambrust, E.V.; Berges, J.; Bowler, C.; Green, B.; Martinez, D.; Putnam, N.; Zhou, S.; Allen, A.; Apt, K.; Bechner, M.; Brzezinski, M.; Chaal, B.; Chiovitti, A.; Davis, A.; Goodstein, D.; Hadi, M.; Hellsten,U.; Hildebrand, M.; Jenkins, B.; Jurka, J.; Kapitonov, V.; Kroger, N.; Lau, W.; Lane, T.; Larimer, F.; Lippmeier, J.; Lucas, S.; Medina, M.; Montsant, A.; Obornik, M.; Parker, M. Schnitzler; Palenik, B.; Pazour,G.; Richardson, P.; Rynearson, T.; Saito, M.; Schwartz, D.; Thamatrakoln,K.; Valentin, K.; Vardi, A.; Wilkerson, F.; Rokhsar, D.; Vardi, A.; Wilkerson, F.P.; Rokhsar, D.S.

2004-09-01

Diatoms are unicellular algae with plastids acquired by secondary endosymbiosis. They are responsible for {approx}20% of global carbon fixation. We report the 34 Mbp draft nuclear genome of the marine diatom, Thalassiosira pseudonana and its 129 Kbp plastid and 44 Kbp mitochondrial genomes. Sequence and optical restriction mapping revealed 24 diploid nuclear chromosomes. We identified novel genes for silicic acid transport and formation of silica-based cell walls, high-affinity iron uptake, biosynthetic enzymes for several types of polyunsaturated fatty acids, utilization of a range of nitrogenous compounds and a complete urea cycle, all attributes that allow diatoms to prosper in the marine environment. Diatoms are unicellular, photosynthetic, eukaryotic algae found throughout the world's oceans and freshwater systems. They form the base of short, energetically-efficient food webs that support large-scale coastal fisheries. Photosynthesis by marine diatoms generates as much as 40% of the 45-50 billion tonnes of organic carbon produced each year in the sea (1), and their role in global carbon cycling is predicted to be comparable to that of all terrestrial rainforests combined (2, 3). Over geological time, diatoms may have influenced global climate by changing the flux of atmospheric carbon dioxide into the oceans (4). A defining feature of diatoms is their ornately patterned silicified cell wall or frustule, which displays species-specific nano-structures of such fine detail that diatoms have long been used to test the resolution of optical microscopes. Recent attention has focused on biosynthesis of these nano-structures as a paradigm for future silica nanotechnology (5). The long history (over 180 million years) and dominance of diatoms in the oceans is reflected by their contributions to vast deposits of diatomite, most cherts and a significant fraction of current petroleum reserves (6). As photosynthetic heterokonts, diatoms reflect a fundamentally

Limits to gene flow in a cosmopolitan marine planktonic diatom.

Science.gov (United States)

Casteleyn, Griet; Leliaert, Frederik; Backeljau, Thierry; Debeer, Ann-Eline; Kotaki, Yuichi; Rhodes, Lesley; Lundholm, Nina; Sabbe, Koen; Vyverman, Wim

2010-07-20

The role of geographic isolation in marine microbial speciation is hotly debated because of the high dispersal potential and large population sizes of planktonic microorganisms and the apparent lack of strong dispersal barriers in the open sea. Here, we show that gene flow between distant populations of the globally distributed, bloom-forming diatom species Pseudo-nitzschia pungens (clade I) is limited and follows a strong isolation by distance pattern. Furthermore, phylogenetic analysis implies that under appropriate geographic and environmental circumstances, like the pronounced climatic changes in the Pleistocene, population structuring may lead to speciation and hence may play an important role in diversification of marine planktonic microorganisms. A better understanding of the factors that control population structuring is thus essential to reveal the role of allopatric speciation in marine microorganisms.

Carbohydrade metabolism in suspended and attached cells of marine fouling diatom, Navicula sp.

Digital Repository Service at National Institute of Oceanography (India)

Bhosle, N.B.; Sawant, S.S.; Garg, A.; Wagh, A.B.

A marine fouling diatom, @iNavicula@@ sp. was cultured in the laboratory under 12-hour light : 12-hour dark conditions. Cells in suspension and attached to the flask walls were analyzed for chlorophyll a, cell organic carbon, total cell carbohydrate...

Marine diatom study and stratigraphy of cenozoic sediments in the coastal plain between Morro da Jureia and Barra do Una, State of Sao Paulo, Brazil

International Nuclear Information System (INIS)

Servant-Vildary, S.; Soguio, K.

1992-01-01

Samples of sediments obtained from cores of four wells drilled by Nuclebras, in the coastal plain of State of Sao Paulo, have been here studied from diatom flora viewpoint. The irregular surface of the crystalline pre-Cambrian basements rocks is locally covered by the Pliocene Pariquera-Acu Formation - like deposits, whose contact with the Quaternary sediments is flat, being situated about 40 m bellow the present sea-level. The contact between the Holocene Santos Formation and the probable Pleistocene Cananeia Formation is very difficult to be recognized. It has been tentatively established based on two radiocarbon ages. Dominantly clayey-silty intervals from the wells F-003 and F-004, probably related to the Cananeia Formation, have been selectively sampled and studied for definition of their diatom flora assemblage. (author)

Thalassiosira mala (Bacillariophyta), a potentially harmful, marine ...

Indian Academy of Sciences (India)

Thalassiosira malaitalic> (Bacillariophyta), a potentially harmful, marine diatom from Chilka Lake and other coastal localities of Odisha, India: Nomenclature, ... Department of Biological Science, Florida State University, Tallahassee, FL 32306–4370, USA; Department of Biology, Valdosta State University, Valdosta, GA ...

Diatom species composition and indices for determining the ecological status of coastal Mediterranean Spanish lakes

Directory of Open Access Journals (Sweden)

Antón-Garrido, Beatriz

2013-12-01

Full Text Available Diatom indices have been used and tested mainly for assessing the ecological status of rivers and deep lakes, but there are scarce studies that determine their effectiveness in shallow lakes and in coastal Mediterranean lakes. This study evaluates the validity of several common diatom indices (SPI, BDI, CEC and TDIL for the determination of the ecological quality of three coastal lakes (Valencia, Spain and presents descriptions and ecological data of the main diatom species recorded. Diatom samples were collected from phytobenthos, both from epiphyton of the dominant submerged macrophytes and the sediment. The ecological status of the systems was determined according to different physico-chemical variables and was compared with the results obtained from epiphytic diatom communities. The results showed discrepancies among diatom indices and also with the state determined by the environmental variables. The effectiveness of the indices depended on the number of species assessed for each index with respect to the total species recorded and the suitability of the weight assigned to each species. The results reveal the need to gather more information about the composition and ecology of the diatoms and microalgae characteristic of coastal Mediterranean standing waters. This work contributes to their better knowledge.Los índices de diatomeas han sido aplicados y contrastados principalmente en la evaluación del estado ecológico de los sistemas lóticos y lagos profundos, pero son escasos los estudios sobre su eficacia en lagos someros y lagunas litorales mediterráneas. Este trabajo evalúa la validez de varios índices conocidos de diatomeas (IPS, IBD, CEE y TDIL para la determinación de la calidad ecológica de tres lagunas litorales (Valencia, España y presenta las descripciones y datos ecológicos de las principales especies de diatomeas registradas. Las muestras de diatomeas se recogieron del fitobentos, tanto del epifiton desarrollado sobre

Cadmium sensitivity, uptake, subcellular distribution and thiol induction in a marine diatom: Exposure to cadmium

International Nuclear Information System (INIS)

Wang Mengjiao; Wang Wenxiong

2011-01-01

The aims of this study were to (1) evaluate the changes in the Cd tolerance of a marine diatom after exposure under different Cd concentrations for various durations and (2) to explore the potential subcellular and biochemical mechanisms underlying these changes. The 72-h toxicity, short-term Cd uptake, subcellular Cd distribution, as well as the synthesis of phytochelatins (PCs) were measured in a marine diatom Thalassiosira nordenskioeldii after exposure to a range of free Cd ion concentrations ([Cd 2+ ], 0.01-84 nM) for 1-15 days. Surprisingly, the diatoms did not acquire higher resistance to Cd after exposure; instead their sensitivity to Cd increased with a higher exposed [Cd 2+ ] and a longer exposure period. The underlying mechanisms could be traced to the responses of Cd cellular accumulation and the intrinsic detoxification ability of the preconditioned diatoms. Generally, exposure to a higher [Cd 2+ ] and for a longer period increased the Cd uptake rate, cellular accumulation, as well as the Cd concentration in metal-sensitive fraction (MSF) in these diatoms. In contrast, although PCs were induced by the environmental Cd stress (with PC 2 being the most affected), the increased intracellular Cd to PC-SH ratio implied that the PCs' detoxification ability had reduced after Cd exposure. All these responses resulted in an elevated Cd sensitivity as exposed [Cd 2+ ] and duration increased. This study shows that the physiological/biochemical and kinetic responses of phytoplankton upon metal exposure deserve further investigation.

Evolutionary origins and functions of the carotenoid biosynthetic pathway in marine diatoms.

Directory of Open Access Journals (Sweden)

Sacha Coesel

Full Text Available Carotenoids are produced by all photosynthetic organisms, where they play essential roles in light harvesting and photoprotection. The carotenoid biosynthetic pathway of diatoms is largely unstudied, but is of particular interest because these organisms have a very different evolutionary history with respect to the Plantae and are thought to be derived from an ancient secondary endosymbiosis between heterotrophic and autotrophic eukaryotes. Furthermore, diatoms have an additional xanthophyll-based cycle for dissipating excess light energy with respect to green algae and higher plants. To explore the origins and functions of the carotenoid pathway in diatoms we searched for genes encoding pathway components in the recently completed genome sequences of two marine diatoms. Consistent with the supplemental xanthophyll cycle in diatoms, we found more copies of the genes encoding violaxanthin de-epoxidase (VDE and zeaxanthin epoxidase (ZEP enzymes compared with other photosynthetic eukaryotes. However, the similarity of these enzymes with those of higher plants indicates that they had very probably diversified before the secondary endosymbiosis had occurred, implying that VDE and ZEP represent early eukaryotic innovations in the Plantae. Consequently, the diatom chromist lineage likely obtained all paralogues of ZEP and VDE genes during the process of secondary endosymbiosis by gene transfer from the nucleus of the algal endosymbiont to the host nucleus. Furthermore, the presence of a ZEP gene in Tetrahymena thermophila provides the first evidence for a secondary plastid gene encoded in a heterotrophic ciliate, providing support for the chromalveolate hypothesis. Protein domain structures and expression analyses in the pennate diatom Phaeodactylum tricornutum indicate diverse roles for the different ZEP and VDE isoforms and demonstrate that they are differentially regulated by light. These studies therefore reveal the ancient origins of several

Evolutionary origins and functions of the carotenoid biosynthetic pathway in marine diatoms.

Science.gov (United States)

Coesel, Sacha; Oborník, Miroslav; Varela, Joao; Falciatore, Angela; Bowler, Chris

2008-08-06

Carotenoids are produced by all photosynthetic organisms, where they play essential roles in light harvesting and photoprotection. The carotenoid biosynthetic pathway of diatoms is largely unstudied, but is of particular interest because these organisms have a very different evolutionary history with respect to the Plantae and are thought to be derived from an ancient secondary endosymbiosis between heterotrophic and autotrophic eukaryotes. Furthermore, diatoms have an additional xanthophyll-based cycle for dissipating excess light energy with respect to green algae and higher plants. To explore the origins and functions of the carotenoid pathway in diatoms we searched for genes encoding pathway components in the recently completed genome sequences of two marine diatoms. Consistent with the supplemental xanthophyll cycle in diatoms, we found more copies of the genes encoding violaxanthin de-epoxidase (VDE) and zeaxanthin epoxidase (ZEP) enzymes compared with other photosynthetic eukaryotes. However, the similarity of these enzymes with those of higher plants indicates that they had very probably diversified before the secondary endosymbiosis had occurred, implying that VDE and ZEP represent early eukaryotic innovations in the Plantae. Consequently, the diatom chromist lineage likely obtained all paralogues of ZEP and VDE genes during the process of secondary endosymbiosis by gene transfer from the nucleus of the algal endosymbiont to the host nucleus. Furthermore, the presence of a ZEP gene in Tetrahymena thermophila provides the first evidence for a secondary plastid gene encoded in a heterotrophic ciliate, providing support for the chromalveolate hypothesis. Protein domain structures and expression analyses in the pennate diatom Phaeodactylum tricornutum indicate diverse roles for the different ZEP and VDE isoforms and demonstrate that they are differentially regulated by light. These studies therefore reveal the ancient origins of several components of the

Coastal marine contamination in Colombia

International Nuclear Information System (INIS)

Garay T, Jesus A; Marin Z, Bienvenido; Velez G, Ana Maria

2002-01-01

The paper tries about the problem of the marine contamination and their marked influence in the health of the coastal ecosystems, of their narrow relationship with the growing increase of the populations that they inhabit the coastal areas and of equal it forms, with the increment of the domestic, agricultural and industrial activities that, for the wrong handling and inadequate control of the solid and liquid waste, they affect the marine environment with significant implications at ecological, socioeconomic level and of health. Another component of the environmental problem of the marine ecosystems in the country, resides in that don't exist in general normative on the chemical quality and sanitary for its marine waters, that which limits the categorization of this agreement ecosystems with its environmental quality, conditioning this the lack of adequate mechanisms to mitigate the causes that originate the deterioration of the quality of the Colombian coasts

Dangerous relations in the Arctic marine food web: Interactions between toxin producing Pseudo-nitzschia diatoms and Calanus copepodites

DEFF Research Database (Denmark)

Hardardottir, Sara; Pancic, Marina; Tammilehto, Anna

2015-01-01

Diatoms of the genus Pseudo-nitzschia produce domoic acid (DA), a toxin that is vectored in the marine food web, thus causing serious problems for marine organisms and humans. In spite of this, knowledge of interactions between grazing zooplankton and diatoms is restricted. In this study, we...... examined the interactions between Calanus copepodites and toxin producing Pseudo-nitzschia. The copepodites were fed with different concentrations of toxic P. seriata and a strain of P. obtusa that previously was tested to be non-toxic. The ingestion rates did not differ among the diets (P. seriata, P...

Effect of UV-B radiation on biomass production, pigmentation and protein content of marine diatoms

International Nuclear Information System (INIS)

Doehler, G.

1984-01-01

Several species of marine diatoms were grown at + 18 0 C and + 22 0 C under normal air conditions (0.035 vol.% CO 2 ) at a light/dark alteration of 14.8 h. Intensity of white light was 1 mW (approx.= 5000 lux). An artifical nutrient solution of 35per mille salinity was used. Algae - harvested during exponential growth - were exposed to different intensities of UV-B radiation (439, 717 and 1230 J m -2 m -1 ) for 2 days. UV-B radiation depressed the growth of all tested marine diatoms. Low levels of UV-B resulted in a slight increase of the biomass production (dry weight) compared to not UV-B treated cells. Enhanced UV-B doses caused a diminution of the primary productivity in all species. Algae exposed to UV-B stress showed a marked decrease in the protein and pigment content (chlorophyll a, chlorophyll c 1 + c 2 and carotenoids). In + 22 0 C grown cells of Lauderia annulata and Thalassiosira rotula were more sensitive to UV-B radiation than those cultures grown at + 18 0 C. Bellerochea yucatanensis cells grown at + 22 0 C were less affected after UV-B exposure than at + 18 0 C grown algae. The UV-B sensibility and growth of the individual species varied in a mixture of several marine diatoms. Results were discussed with reference to the UV-B effect on metabolic processes. (orig.)

Diatom records in the Quaternary marine sequences around the Japanese Islands

OpenAIRE

Koizumi, Itaru; Yamamoto, Hirofumi

2016-01-01

Understanding the Quaternary is a key to estimating what the Earth's climate will be like in the future. Such studies demand high-resolution analyses based on paleoclimatic proxy records of changing Earth's orbital forcing and solar insolation that affect the climate system. Quaternary diatom biostratigraphy and paleoceanography have been well established based on the Quaternary marine sequences obtained by piston coring and deep-sea drilling around the Japanese Islands. This paper firstly re...

Decadal variations in diatoms and dinoflagellates on the inner shelf of the East China Sea, China

Science.gov (United States)

Abate, Rediat; Gao, Yahui; Chen, Changping; Liang, Junrong; Mu, Wenhua; Kifile, Demeke; Chen, Yanghang

2017-11-01

Diatoms and dinoflagellates are two major groups of phytoplankton that flourish in the oceans, particularly in coastal zone and upwelling systems, and their contrasting production have been reported in several world seas. However, this information is not available in the coastal East China Sea (ECS). Thus, to investigate and compare the decadal trends in diatoms and dinoflagellates, a sediment core, 47 cm long, was collected from the coastal zone of the ECS. Sediment chlorophyll- a (Chl- a), phytoplankton-group specific pigment signatures of diatoms and dinoflagellates, and diatom valve concentrations were determined. The sediment core covered the period from 1961 to 2011 AD. The chlorophyll- a contents ranged from 2.32 to 73 µg/g dry sediment (dw) and averaged 9.81 µg/g dw. Diatom absolute abundance ranged from 29152 to 177501 valve/gram (v/g) dw and averaged 72137 v/g dw. Diatom valve and diatom specific pigment marker concentrations were not significantly correlated. Peridinin increased after the 1980s in line with intensified use of fertilizer and related increases in nutrient inputs into the marine environment. The increased occurrence of dinoflagellate dominance after the 1980s can be mostly explained by the increase in nutrients. However, the contribution of dinoflagellates to total phytoplankton production (Chl- a) decreased during the final decade of this study, probably because of the overwhelming increase in diatom production that corresponded with the construction of the Three Gorges Dam (TGD) and related light availability. Similarly, the mean ratio of fucoxanthin/peridinin for the period from 1982 to 2001 was 6% less than for 1961 to 1982, while the ratio for 2001 to 2011 was 45.3% greater than for 1982 to 2001. The decadal variation in the fucoxanthin/peridinin ratio implies that dinoflagellate production had been gradually increasing until 2001. We suggest that the observed changes can be explained by anthropogenic impacts, such as nutrient

Diuron causes sinking retardation and physiochemical alteration in marine diatoms Thalassiosira pseudonana and Skeletonema marinoi-dohrnii complex.

Science.gov (United States)

Khanam, Mst Ruhina Margia; Shimasaki, Yohei; Hosain, Md Zahangir; Mukai, Koki; Tsuyama, Michito; Qiu, Xuchun; Tasmin, Rumana; Goto, Hiroshi; Oshima, Yuji

2017-05-01

The present research investigated the effect of diuron on sinking rate and the physiochemical changes in two marine diatoms, Thalassiosira pseudonana (single-celled species) and Skeletonema marinoi-dohrnii complex (chain-forming species). The results revealed that the sinking rate of both diatoms exposed to diuron at a level of 50% effective concentration for growth (EC50) decreased significantly compared with the control. Photosynthetic performance (Fv/Fm and PI ABS ) of both diatoms also decreased significantly with diuron exposure. The number of cells per chain in S. marinoi-dohrnii decreased significantly with diuron treatment, but T. pseudonana cell diameter remained stable. Neutral lipid concentration per cell was significantly higher compared with control at 72 h in both diatom species exposed to EC50 level diuron. And water-soluble protein concentration per cell at 72 h was lower than control in the T. pseudonana EC50 group only. These biochemical changes may decrease specific gravity of cells and seems to cause a decreased sinking rate in diatoms. The positive significant correlation between the numbers of cells per chain and sinking rate in S. marinoi-dohrnii indicated that chain length is also an important factor in sinking rate regulation for chain-forming diatoms. Thus, our present study suggested that suppression of photosynthetic performance and the resultant physiochemical changes induced the decreased sinking rate that may inhibit the normal survival strategy (avoidance from the surface layer where strong light either causes photo-inhibition or interrupts resting cell formation). Therefore, the use of antifouling agents should be considered for the sustainable marine environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Shift in the species composition of the diatom community in the eutrophic Mauritanian coastal upwelling: Results from a multi-year sediment trap experiment (2003-2010)

Science.gov (United States)

Romero, Oscar E.; Fischer, Gerhard

2017-12-01

A multiannual, continuous sediment trap experiment was conducted at the mooring site CBeu (Cape Blanc eutrophic, ca. 20 °N, ca. 18 °W; trap depth = 1256-1296 m) in the high-productive Mauritanian coastal upwelling. Here we present fluxes and the species-specific composition of the diatom assemblage, and fluxes of biogenic silica (BSi, opal) and total organic carbon (TOC) for the time interval June 2003-Feb 2010. Flux ranges of studied parameters are (i) total diatoms = 1.2 ∗ 108-4.7 ∗ 104 valves m-2 d-1 (average = 5.9 × 106 valves ± 1.4 × 107); (ii) BSi = 296-0.5 mg m-2 d-1 (average = 41.1 ± 53.5 mg m-2 d-1), and (iii) TOC = 97-1 mg m-2 d-1 (average = 20.5 ± 17.8 mg m-2 d-1). Throughout the experiment, the overall good match of total diatom, BSi and TOC fluxes is reasonably consistent and reflects well the temporal occurrence of the main Mauritanian upwelling season. Spring and summer are the most favorable seasons for diatom production and sedimentation: out of the recorded 14 diatom maxima of different magnitude, six occurred in spring and four in summer. The diverse diatom community at site CBeu is composed of four main assemblages: benthic, coastal upwelling, coastal planktonic and open-ocean diatoms, reflecting different productivity conditions and water masses. A striking feature of the temporal variability of the diatom populations is the persistent pattern of seasonal groups' contribution: benthic and coastal upwelling taxa dominated during the main upwelling season in spring, while open-ocean diatoms were more abundant in fall and winter, when the upper water column becomes stratified, upwelling relaxes and productivity decreases. The relative abundance of benthic diatoms strongly increased after 2006, yet their spring-summer contribution remained high until the end of the trap experiment. The occurrence of large populations of benthic diatoms at the hemipelagic CBeu site is interpreted to indicate transport from shallow waters via nepheloid

The marine and coastal environmental quality in Colombia

International Nuclear Information System (INIS)

2005-01-01

An analysis of the problem is made, generated by the contamination in the sea and coasts of Colombia, an inventory and characterization of sources of contamination, state of the chemical and sanitary quality of the marine and coastal waters, effects of the contamination about the ecosystems and the life quality in the coastal and marine areas

Spectral radiation dependent photoprotective mechanism in the diatom Pseudo-nitzschia multistriata.

Directory of Open Access Journals (Sweden)

Christophe Brunet

Full Text Available Phytoplankton, such as diatoms, experience great variations of photon flux density (PFD and light spectrum along the marine water column. Diatoms have developed some rapidly-regulated photoprotective mechanisms, such as the xanthophyll cycle activation (XC and the non-photochemical chlorophyll fluorescence quenching (NPQ, to protect themselves from photooxidative damages caused by excess PFD. In this study, we investigate the role of blue fluence rate in combination with red radiation in shaping photoacclimative and protective responses in the coastal diatom Pseudo-nitzschia multistriata. This diatom was acclimated to four spectral light conditions (blue, red, blue-red, blue-red-green, each of them provided with low and high PFD. Our results reveal that the increase in the XC pool size and the amplitude of NPQ is determined by the blue fluence rate experienced by cells, while cells require sensing red radiation to allow the development of these processes. Variations in the light spectrum and in the blue versus red radiation modulate either the photoprotective capacity, such as the activation of the diadinoxanthin-diatoxanthin xanthophyll cycle, the diadinoxanthin de-epoxidation rate and the capacity of non-photochemical quenching, or the pigment composition of this diatom. We propose that spectral composition of light has a key role on the ability of diatoms to finely balance light harvesting and photoprotective capacity.

Mechanisms of carbon dioxide acquisition and CO2 sensing in marine diatoms: a gateway to carbon metabolism.

Science.gov (United States)

Matsuda, Yusuke; Hopkinson, Brian M; Nakajima, Kensuke; Dupont, Christopher L; Tsuji, Yoshinori

2017-09-05

Diatoms are one of the most successful marine eukaryotic algal groups, responsible for up to 20% of the annual global CO 2 fixation. The evolution of a CO 2 -concentrating mechanism (CCM) allowed diatoms to overcome a number of serious constraints on photosynthesis in the marine environment, particularly low [CO 2 ] aq in seawater relative to concentrations required by the CO 2 fixing enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO), which is partly due to the slow diffusion rate of CO 2 in water and a limited CO 2 formation rate from [Formula: see text] in seawater. Diatoms use two alternative strategies to take up dissolved inorganic carbon (DIC) from the environment: one primarily relies on the direct uptake of [Formula: see text] through plasma-membrane type solute carrier (SLC) 4 family [Formula: see text] transporters and the other is more reliant on passive diffusion of CO 2 formed by an external carbonic anhydrase (CA). Bicarbonate taken up into the cytoplasm is most likely then actively transported into the chloroplast stroma by SLC4-type transporters on the chloroplast membrane system. Bicarbonate in the stroma is converted into CO 2 only in close proximity to RubisCO preventing unnecessary CO 2 leakage. CAs play significant roles in mobilizing DIC as it is progressively moved towards the site of fixation. However, the evolutionary types and subcellular locations of CAs are not conserved between different diatoms, strongly suggesting that this DIC mobilization strategy likely evolved multiple times with different origins. By contrast, the recent discovery of the thylakoid luminal θ-CA indicates that the strategy to supply CO 2 to RubisCO in the pyrenoid may be very similar to that of green algae, and strongly suggests convergent coevolution in CCM function of the thylakoid lumen not only among diatoms but among eukaryotic algae in general. In this review, both experimental and corresponding theoretical models of the diatom CCMs are

Effects of titanium dioxide nanoparticles derived from consumer products on the marine diatom Thalassiosira pseudonana.

Science.gov (United States)

Galletti, Andrea; Seo, Seokju; Joo, Sung Hee; Su, Chunming; Blackwelder, Pat

2016-10-01

Increased manufacture of TiO 2 nanoproducts has caused concern about the potential toxicity of these products to the environment and in public health. Identification and confirmation of the presence of TiO 2 nanoparticles derived from consumer products as opposed to industrial TiO 2 NPs warrant examination in exploring the significance of their release and resultant impacts on the environment. To this end, we examined the significance of the release of these particles and their toxic effect on the marine diatom algae Thalassiosira pseudonana. Our results indicate that nano-TiO 2 sunscreen and toothpaste exhibit more toxicity in comparison to industrial TiO 2 and inhibited the growth of the marine diatom T. pseudonana. This inhibition was proportional to the exposure time and concentrations of nano-TiO 2 . Our findings indicate a significant effect, and therefore, further research is warranted in evaluation and assessment of the toxicity of modified nano-TiO 2 derived from consumer products and their physicochemical properties.

UV-B induces DNA damage and DNA synthesis delay in the marine diatom Cyclotella sp

NARCIS (Netherlands)

Buma, A.G.J.; Van Hannen, E.J.; Veldhuis, M.; Gieskes, W.W.C.

1996-01-01

The effect of UV-B on the occurrence of DNA damage and consequences for the cell cycle were studied in the marine diatom Cyclotella sp. DNA damage was quantified by immunofluorescent detection of thymine dimers in nuclear DNA of single cells using flow cytometry. A total UV-B dose (biologically

UV-B induces DNA damage and DNA synthesis delay in the marine diatom Cyclotella sp.

NARCIS (Netherlands)

Buma, A.G.J.; van Hannen, E.J; Veldhuis, M.J W; Gieskes, W.W C

The effect of UV-B on the occurrence of DNA damage and consequences for the cell cycle were studied in the marine diatom Cyclotella sp. DNA damage was quantified by immunofluorescent detection of thymine dimers in nuclear DNA of single cells using flow cytometry. A total UV-B dose (biologically

Improvement of Neutral Lipid and Polyunsaturated Fatty Acid Biosynthesis by Overexpressing a Type 2 Diacylglycerol Acyltransferase in Marine Diatom Phaeodactylum tricornutum

Directory of Open Access Journals (Sweden)

Ying-Fang Niu

2013-11-01

Full Text Available Microalgae have been emerging as an important source for the production of bioactive compounds. Marine diatoms can store high amounts of lipid and grow quite quickly. However, the genetic and biochemical characteristics of fatty acid biosynthesis in diatoms remain unclear. Glycerophospholipids are integral as structural and functional components of cellular membranes, as well as precursors of various lipid mediators. In addition, diacylglycerol acyltransferase (DGAT is a key enzyme that catalyzes the last step of triacylglyceride (TAG biosynthesis. However, a comprehensive sequence-structure and functional analysis of DGAT in diatoms is lacking. In this study, an isoform of diacylglycerol acyltransferase type 2 of the marine diatom Phaeodactylum tricornutum was characterized. Surprisingly, DGAT2 overexpression in P. tricornutum stimulated more oil bodies, and the neutral lipid content increased by 35%. The fatty acid composition showed a significant increase in the proportion of polyunsaturated fatty acids; in particular, EPA was increased by 76.2%. Moreover, the growth rate of transgenic microalgae remained similar, thereby maintaining a high biomass. Our results suggest that increased DGAT2 expression could alter fatty acid profile in the diatom, and the results thus represent a valuable strategy for polyunsaturated fatty acid production by genetic manipulation.

Chronic Iron Limitation Confers Transient Resistance to Oxidative Stress in Marine Diatoms.

Science.gov (United States)

Graff van Creveld, Shiri; Rosenwasser, Shilo; Levin, Yishai; Vardi, Assaf

2016-10-01

Diatoms are single-celled, photosynthetic, bloom-forming algae that are responsible for at least 20% of global primary production. Nevertheless, more than 30% of the oceans are considered "ocean deserts" due to iron limitation. We used the diatom Phaeodactylum tricornutum as a model system to explore diatom's response to iron limitation and its interplay with susceptibility to oxidative stress. By analyzing physiological parameters and proteome profiling, we defined two distinct phases: short-term (chronic (>5 d, phase II) iron limitation. While at phase I no significant changes in physiological parameters were observed, molecular markers for iron starvation, such as Iron Starvation Induced Protein and flavodoxin, were highly up-regulated. At phase II, down-regulation of numerous iron-containing proteins was detected in parallel to reduction in growth rate, chlorophyll content, photosynthetic activity, respiration rate, and antioxidant capacity. Intriguingly, while application of oxidative stress to phase I and II iron-limited cells similarly oxidized the reduced glutathione (GSH) pool, phase II iron limitation exhibited transient resistance to oxidative stress, despite the down regulation of many antioxidant proteins. By comparing proteomic profiles of P. tricornutum under iron limitation and metatranscriptomic data of an iron enrichment experiment conducted in the Pacific Ocean, we propose that iron-limited cells in the natural environment resemble the phase II metabolic state. These results provide insights into the trade-off between optimal growth rate and susceptibility to oxidative stress in the response of diatoms to iron quota in the marine environment. © 2016 American Society of Plant Biologists. All Rights Reserved.

Kinetic control on Zn isotope signatures recorded in marine diatoms

Science.gov (United States)

Köbberich, Michael; Vance, Derek

2017-08-01

Marine diatoms dominate the oceanic cycle of the essential micronutrient zinc (Zn). The stable isotopes of zinc and other metals are increasingly used to understand trace metal micronutrient cycling in the oceans. One clear feature of the early isotope data is the heavy Zn isotope signature of the average oceanic dissolved pool relative to the inputs, potentially driven by uptake of light isotopes into phytoplankton cells and export to sediments. However, despite the fact that diatoms strip Zn from surface waters across the Antarctic polar front in the Southern Ocean, the local upper ocean is not isotopically heavy. Here we use culturing experiments to quantify the extent of Zn isotope fractionation by diatoms and to elucidate the mechanisms driving it. We have cultured two different open-ocean diatom species (T. oceanica and Chaetoceros sp.) in a series of experiments at constant medium Zn concentration but at bioavailable medium Fe ranging from limiting to replete. We find that T. oceanica can maintain high growth rates and Zn uptake rates over the full range of bioavailable iron (Fe) investigated, and that the Zn taken up has a δ66Zn that is unfractionated relative to that of the bioavailable free Zn in the medium. The studied representative of the genus Chaetoceros, on the other hand, shows more significantly reduced Zn uptake rates at low Fe and records more variable biomass δ66Zn signatures, of up to 0.85‰ heavier than the medium. We interpret the preferential uptake of heavy isotopes at extremely low Zn uptake rates as potentially due to either of the following two mechanisms. First, the release of extracellular polymeric substances (EPS), at low Fe levels, may preferentially scavenge heavy Zn isotopes. Second, the Zn uptake rate may be slow enough to establish pseudo-equilibrium conditions at the transporter site, with heavy Zn isotopes forming more stable surface complexes. Thus we find that, in our experiments, Fe-limitation exerts a key control that

A Sociotechnical Systems Approach To Coastal Marine Spatial Planning

Science.gov (United States)

2016-12-01

SYSTEMS APPROACH TO COASTAL MARINE SPATIAL PLANNING by Tyler B. McDonald December 2016 Thesis Advisor: Karen Holness Co-Advisor: Tom...2016 3. REPORT TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE A SOCIOTECHNICAL SYSTEMS APPROACH TO COASTAL MARINE SPATIAL PLANNING...engineering perspective and specifically used a sociotechnical systems approach . The research investigated aquaculture permitting from the

Occurrence of Priming in the Degradation of Lignocellulose in Marine Sediments.

Science.gov (United States)

Gontikaki, Evangelia; Thornton, Barry; Cornulier, Thomas; Witte, Ursula

2015-01-01

More than 50% of terrestrially-derived organic carbon (terrOC) flux from the continents to the ocean is remineralised in the coastal zone despite its perceived high refractivity. The efficient degradation of terrOC in the marine environment could be fuelled by labile marine-derived material, a phenomenon known as "priming effect", but experimental data to confirm this mechanism are lacking. We tested this hypothesis by treating coastal sediments with 13C-lignocellulose, as a proxy for terrOC, with and without addition of unlabelled diatom detritus that served as the priming inducer. The occurrence of priming was assessed by the difference in lignocellulose mineralisation between diatom-amended treatments and controls in aerobic sediment slurries. Priming of lignocellulose degradation was observed only at the initial stages of the experiment (day 7) and coincided with overall high microbial activity as exemplified by total CO2 production. Lignocellulose mineralisation did not differ consistently between diatom treatments and control for the remaining experimental time (days 14-28). Based on this pattern, we hypothesize that the faster initiation of lignocellulose mineralisation in diatom-amended treatments is attributed to the decomposition of accessible polysaccharide components within the lignocellulose complex by activated diatom degraders. The fact that diatom-degraders contributed to lignocellulose degradation was also supported by the different patterns in 13C-enrichment of phospholipid fatty acids between treatments. Although we did not observe differences between treatments in the total quantity of respired lignocellulose at the end of the experiment, differences in timing could be important in natural ecosystems where the amount of time that a certain compound is subject to aerobic degradation before burial to deeper anoxic sediments may be limited.

75 FR 5765 - NOAA Coastal and Marine Habitat Restoration Project Supplemental Funding

Science.gov (United States)

2010-02-04

...-02] RIN 0648-ZC05 NOAA Coastal and Marine Habitat Restoration Project Supplemental Funding AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce. ACTION: Notice of supplemental funding for NOAA Coastal and Marine Habitat Restoration Projects. SUMMARY...

Insights into global diatom distribution and diversity in the world’s ocean

KAUST Repository

Malviya, Shruti; Scalco, Eleonora; Audic, Sté phane; Vincent, Flora; Veluchamy, Alaguraj; Poulain, Julie; Wincker, Patrick; Iudicone, Daniele; de Vargas, Colomban; Bittner, Lucie; Zingone, Adriana; Bowler, Chris

2016-01-01

Diatoms (Bacillariophyta) constitute one of the most diverse and ecologically important groups of phytoplankton. They are considered to be particularly important in nutrient-rich coastal ecosystems and at high latitudes, but considerably less so in the oligotrophic open ocean. The Tara Oceans circumnavigation collected samples from a wide range of oceanic regions using a standardized sampling procedure. Here, a total of ∼12 million diatom V9-18S ribosomal DNA (rDNA) ribotypes, derived from 293 sizefractionated plankton communities collected at 46 sampling sites across the global ocean euphotic zone, have been analyzed to explore diatom global diversity and community composition. We provide a new estimate of diversity of marine planktonic diatoms at 4,748 operational taxonomic units (OTUs). Based on the total assigned ribotypes, Chaetoceros was the most abundant and diverse genus, followed by Fragilariopsis, Thalassiosira, and Corethron. We found only a few cosmopolitan ribotypes displaying an even distribution across stations and high abundance, many of which could not be assigned with confidence to any known genus. Three distinct communities from South Pacific, Mediterranean, and Southern Ocean waters were identified that share a substantial percentage of ribotypes within them. Sudden drops in diversity were observed at Cape Agulhas, which separates the Indian and Atlantic Oceans, and across the Drake Passage between the Atlantic and Southern Oceans, indicating the importance of these ocean circulation choke points in constraining diatom distribution and diversity. We also observed high diatom diversity in the open ocean, suggesting that diatoms may be more relevant in these oceanic systems than generally considered.

Insights into global diatom distribution and diversity in the world’s ocean

KAUST Repository

Malviya, Shruti

2016-03-01

Diatoms (Bacillariophyta) constitute one of the most diverse and ecologically important groups of phytoplankton. They are considered to be particularly important in nutrient-rich coastal ecosystems and at high latitudes, but considerably less so in the oligotrophic open ocean. The Tara Oceans circumnavigation collected samples from a wide range of oceanic regions using a standardized sampling procedure. Here, a total of ∼12 million diatom V9-18S ribosomal DNA (rDNA) ribotypes, derived from 293 sizefractionated plankton communities collected at 46 sampling sites across the global ocean euphotic zone, have been analyzed to explore diatom global diversity and community composition. We provide a new estimate of diversity of marine planktonic diatoms at 4,748 operational taxonomic units (OTUs). Based on the total assigned ribotypes, Chaetoceros was the most abundant and diverse genus, followed by Fragilariopsis, Thalassiosira, and Corethron. We found only a few cosmopolitan ribotypes displaying an even distribution across stations and high abundance, many of which could not be assigned with confidence to any known genus. Three distinct communities from South Pacific, Mediterranean, and Southern Ocean waters were identified that share a substantial percentage of ribotypes within them. Sudden drops in diversity were observed at Cape Agulhas, which separates the Indian and Atlantic Oceans, and across the Drake Passage between the Atlantic and Southern Oceans, indicating the importance of these ocean circulation choke points in constraining diatom distribution and diversity. We also observed high diatom diversity in the open ocean, suggesting that diatoms may be more relevant in these oceanic systems than generally considered.

TRIGLYCERIDE COMPOSITION OF SIXTEEN STRAINS OF MARINE DIATOM

Directory of Open Access Journals (Sweden)

Lily M.G. Panggabean

2013-07-01

Full Text Available Trigliceride or triacylglicerol (TAG composition in crude oil of sixteen strain of marine diatom has been detected by spectra analyses on an Electrospray - Ion Trap – Mass Spectrometry (ESI-IT-MS HCT Bruker-Daltonic GmbH instrument with AgNO3 used as coordination ionization agent. Biomass samples of each microalga strain were taken from early and late stationary cultures in f/2 enriched seawater and algal oils were extracted according to Bligh and Dyer. Results from spectra analysis showed that P-Pt-P (C16:0-C16:1-C16:0 were distinguished in TAG from diatom strains Chaetoceros sp.1, Chaetoceros sp.2, Thalasiossira sp.1, Thalasiossira sp.2, Thalasiossira sp.3, Navicula sp. 1, Navicula sp. 2, Navicula sp. 3, Navicula sp. 4, Nitzschia sp. 2 and Amphora sp. In contrast, TAGs in Melosira sp. included P-P-P (C16:0-C16:0-C16:0 and P-P-O (C16:0-C16:0-C18:1 were identified. TAGs from Chaetoceros sp. were the most varies among samples, i.e. P-Pt-P (C16:0-C16:1-C16:0, A-P-M (C20:4-C16:0-C14:0, P-Pt-Lt (C16:0-C16:1-C18:3, P-Pt-A (C16:0-C16:1-C20:4, D-P-P (C22:6-C16:0-C16:0, A-Ln-P (C20:4-C18:2-C16:0. Various TAGs were also detected in Nitzschia sp.2, i.e. P-Pt-M (C16:0-C16:1-C14:0, P-Pt-P (C16:0-C16:1-C16:0, P-Pt-S (C16:0-C16:1-C18:0, P-Pt-A (C16:0-C16:1-C20:4. TAGs composition in Skeletonema strains that similar to those in Nitzschia sp.1 has longer carbon, i.e. P-P-O (C16:0-C16:0-C18:1, P-O-O (C16:0-C18:1-C18:1 and O-O-O (C18:1-C18:1-C18:1. TAGs with longer carbon chain and more double bond including highly unsaturated fatty acid C20:4 were increased with culture age in diatoms Chaetoceros sp.1, Chaetoceros sp.2, Thalasiossira sp.2, Navicula sp.1 and Nitzschia sp. 2.Keywords: diatom, TAG, ESI-IT-MS, f/2, early and late stationary

Archive of Geosample Data and Information from the U.S. Geological Survey (USGS) Coastal and Marine Geology Program (CMGP) Pacific Coastal and Marine Science Center (PCMSC) Samples Repository

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. Geological Survey Coastal and Marine Geology Program (CMGP) Pacific Coastal and Marine Science Center (PCMSC) Samples Repository is a partner in the Index...

Using ATTO dyes to probe bacterial interactions with the marine diatom Pseudo-nitzschia.

Science.gov (United States)

Mehic, S.; Sison-Mangus, M.

2016-02-01

Pseudo-nitzschia blooms are known to be highly toxic and detrimental to wildlife. The neurotoxin produced by the algae can ripple through the entire food web creating a direct impact on oceanic life and human-related industries. With coastal blooms increasing in both size and duration in recent years, it is crucial that we uncover more microbial interactions that may affect the toxicity of these blooms. Current harmful algal bloom studies have shown that different bacterial consortia can have a great impact Pseudo-nitzschia physiology. More specifically, research suggests that bacteria affect both growth rates and domoic acid concentrations of laboratory grown cultures. However, these studies do not explore the attachment patterns of these bacteria with the diatom. Bacterial attachment may dictate the different types of interactions between bacteria and the diatoms, a trait that is largely unexplored in the symbiotic interactions between the two organisms. In this study, we seek to identify direct and indirect interactions between four bacteria taxa from different phyla and three different species of Pseudo-nitzschia. Our preliminary scanning electron microscopy and DAPI staining experiments hint at distinct differences in attachment among bacterial taxa. To explore this work further, we aim to employ ATTO dyes and epifluorescent microscopy on both binary and multiple cultures to visualize patterns in attachment. By utilizing ATTO dyes with distinct wavelength emissions, we can perform a series experiment that highlights the interaction between bacteria and diatoms, without inserting a fluorescent reporter gene in the bacteria. Multiple cultures will be used to identify possible cooperative or negative interactive traits between bacteria that can affect diatom host physiology. Implications on both phytoplankton physiology and nutrient cycling will be subsequently discussed.

The cost and feasibility of marine coastal restoration.

Science.gov (United States)

Bayraktarov, Elisa; Saunders, Megan I; Abdullah, Sabah; Mills, Morena; Beher, Jutta; Possingham, Hugh P; Mumby, Peter J; Lovelock, Catherine E

2016-06-01

Land-use change in the coastal zone has led to worldwide degradation of marine coastal ecosystems and a loss of the goods and services they provide. Restoration is the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed and is critical for habitats where natural recovery is hindered. Uncertainties about restoration cost and feasibility can impede decisions on whether, what, how, where, and how much to restore. Here, we perform a synthesis of 235 studies with 954 observations from restoration or rehabilitation projects of coral reefs, seagrass, mangroves, salt-marshes, and oyster reefs worldwide, and evaluate cost, survival of restored organisms, project duration, area, and techniques applied. Findings showed that while the median and average reported costs for restoration of one hectare of marine coastal habitat were around US$80000 (2010) and US$1600000 (2010), respectively, the real total costs (median) are likely to be two to four times higher. Coral reefs and seagrass were among the most expensive ecosystems to restore. Mangrove restoration projects were typically the largest and the least expensive per hectare. Most marine coastal restoration projects were conducted in Australia, Europe, and USA, while total restoration costs were significantly (up to 30 times) cheaper in countries with developing economies. Community- or volunteer-based marine restoration projects usually have lower costs. Median survival of restored marine and coastal organisms, often assessed only within the first one to two years after restoration, was highest for saltmarshes (64.8%) and coral reefs (64.5%) and lowest for seagrass (38.0%). However, success rates reported in the scientific literature could be biased towards publishing successes rather than failures. The majority of restoration projects were short-lived and seldom reported monitoring costs. Restoration success depended primarily on the ecosystem, site selection, and techniques

Environmental investigations using diatom microfossils

Science.gov (United States)

Smith, Kathryn E.L.; Flocks, James G.

2010-01-01

Diatoms are unicellular phytoplankton (microscopic plant-like organisms) with cell walls made of silica (called a frustule). They live in both freshwater and saltwater and can be found in just about every place on Earth that is wet. The shape and morphology of the diatom frustule unique to each species are used for identification. Due to the microscopic size of diatoms, high-power microscopy is required for diatom identification. Diatoms are vital to life on Earth. They are photosynthetic primary producers, using sunlight to create oxygen and organic carbon from carbon dioxide and water. They are a significant source of the oxygen we breathe, have a major impact on the global carbon cycle (Smetacek, 1999), and are a food source for many aquatic organisms (Mann, 1993). Diatom abundance has even been demonstrated to have an influence on the diversity of larger marine mammals, including whales (Marx and Uhen, 2010). Data on diatom abundance and diversity are extremely useful in environmental studies.

Occurrence of Priming in the Degradation of Lignocellulose in Marine Sediments.

Directory of Open Access Journals (Sweden)

Evangelia Gontikaki

Full Text Available More than 50% of terrestrially-derived organic carbon (terrOC flux from the continents to the ocean is remineralised in the coastal zone despite its perceived high refractivity. The efficient degradation of terrOC in the marine environment could be fuelled by labile marine-derived material, a phenomenon known as "priming effect", but experimental data to confirm this mechanism are lacking. We tested this hypothesis by treating coastal sediments with 13C-lignocellulose, as a proxy for terrOC, with and without addition of unlabelled diatom detritus that served as the priming inducer. The occurrence of priming was assessed by the difference in lignocellulose mineralisation between diatom-amended treatments and controls in aerobic sediment slurries. Priming of lignocellulose degradation was observed only at the initial stages of the experiment (day 7 and coincided with overall high microbial activity as exemplified by total CO2 production. Lignocellulose mineralisation did not differ consistently between diatom treatments and control for the remaining experimental time (days 14-28. Based on this pattern, we hypothesize that the faster initiation of lignocellulose mineralisation in diatom-amended treatments is attributed to the decomposition of accessible polysaccharide components within the lignocellulose complex by activated diatom degraders. The fact that diatom-degraders contributed to lignocellulose degradation was also supported by the different patterns in 13C-enrichment of phospholipid fatty acids between treatments. Although we did not observe differences between treatments in the total quantity of respired lignocellulose at the end of the experiment, differences in timing could be important in natural ecosystems where the amount of time that a certain compound is subject to aerobic degradation before burial to deeper anoxic sediments may be limited.

Coastal and Marine Environment Problems in East Kalimantan Province

OpenAIRE

Supriharyono

2000-01-01

Coastal and marine problems were collected from the coastal community in area of the Municipality of Balikpapan East Kalimantan Province, from fishermen, NGO's and government officials. The technique used was that of the Field Participatory Workshop's. the result of the study revealed some coastal community awarenees, coastal resources USAge, and governmental policy. The local government's failure to solve those problems was mainly due to lack of social awarenees for environmental coastal man...

Holocene sea-level changes in King George Island, West Antarctica, by virtue of geomorphological coastal evidences and diatom assemblages of sediment sections.

Science.gov (United States)

Poleshchuk, Ksenia; Verkulich, Sergey; Pushina, Zina; Jozhikov, Ilya

2015-04-01

A new curve of relative sea-level change is presented for the Fildes peninsula, King George Island, West Antarctic. This work is based on renewed paleogeography data, including coastal geomorphological evidence, diatom assemblages of lakes bottom sediments and radiocarbon datings of organics. The new data were obtained in several sections of quaternary sediments and groups of terraces, and allows us to expand and improve relevant conception about relative sea level changes in the King George Island region. The new radiocarbon datings of organics (mosses and shells) allows reconstructing Holocene conditions that maintain and cause the sea-level changes. Sea diatom assemblages of Dlinnoye lake bottom sediment core (that complies period about 8000 years B.P.) mark altitude of marine water penetrated into the lake. The altitudes of shell remains, which have certain life habits and expect specific salinity and depth conditions, coupled with their absolute datings, indicate the probable elevation of the past sea level. The Mid-Holocene marine transgression reached its maximum level of 18-20 m by 5760 years B.P. The transgression influenced the deglaciation of the Fildes peninsula and environment conditions integrally. The ratio of glacio-isostatic adjustment velocity and Holocene transgression leaded to the decrease of relative sea level during the Late Holocene excluding the short period of rising between 2000 and 1300 years B.P. Comparing this data with the curve for Bunger oasis, East Antarctica, introduced earlier gives an interesting result. Despite the maximum altitudes of relative sea-level rise in King George region were higher and occurred later than in Bunger oasis region, the short-term period of Late Holocene sea-level rising contemporizes. Besides that, this work allow to realize a correlation between regions of Antarctica and adjacent territory. That, in turn, lets answer the question of tectonic and eustatic factors ratio and their contribution to the

Structural identification of the C-25 highly branched isoprenoid pentaene in the marine diatom Rhizosolenia setigera

NARCIS (Netherlands)

Damste, JSS; Rijpstra, WIC; Hopmans, EC; Peletier, H; Gieskes, WWC; Geenevasen, JAJ

1999-01-01

2,6,10, 14-tetramethyl-7-(3-methylpent-4-enyl)-pentadeca-2,5E,9E, 13-tetraene I possessing a C-25 highly branched isoprenoid skeleton has been isolated from the marine diatom Rhizosolenia setigera and identified by H-1 and C-13 NMR spectroscopy. (C) 1999 Elsevier Science Ltd. All rights reserved.

Phytoplankton community structure in local water types at a coastal site in north-western Bay of Bengal.

Science.gov (United States)

Baliarsingh, S K; Srichandan, Suchismita; Lotliker, Aneesh A; Sahu, K C; Srinivasa Kumar, T

2016-07-01

A comprehensive analysis on seasonal distribution of phytoplankton community structure and their interaction with environmental variables was carried out in two local water types (type 1  30 m isobath) at a coastal site in north-western Bay of Bengal. Phytoplankton community was represented by 211 taxa (146 marine, 37 fresh, 2 brackish, 20 marine-fresh, and 6 marine-brackish-fresh) belonging to seven major groups including 45 potential bloom forming and 22 potential toxin producing species. The seasonal variability depicted enrichment of phytoplankton during pre-monsoon in both water types. Total phytoplankton abundance pattern observed with inter-annual shift during monsoon and post-monsoon period at both water types. In both water types, diatom predominance was observed in terms of species richness and abundance comprising of centric (82 sp.) and pennate (58 sp.) forms. Pennate diatoms, Thalassiothrix longissima and Skeletonema costatum preponderated in both the water types. The diatom abundance was higher in type 1 in comparison to type 2. In general, SiO4 found to fuel growth of the dominant phytoplankton group, diatom in both the water types despite comparative lower concentration of other macronutrients in type 2.

Archive of Geosample Data and Information from the U.S. Geological Survey (USGS) Coastal and Marine Geology Program (CMGP) Woods Hole Coastal and Marine Science Center (WHCMSC) Samples Repository

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. Geological Survey Coastal and Marine Geology Program (CMGP) Woods Hole Coastal and Marine Science Center (WHCMSC) Samples Repository is a partner in the...

Archive of Geosample Data and Information from the U.S. Geological Survey (USGS) Coastal and Marine Geology Program (CMGP) St. Petersburg Coastal and Marine Science Center (SPCMSC) Samples Repository

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. Geological Survey Coastal and Marine Geology Program (CMGP) St. Petersburg Coastal and Marine Science Center (SPCMSC) Samples Repository is a partner in the...

Preparation and method of study of fossil diatoms

Digital Repository Service at National Institute of Oceanography (India)

Setty, M.G.A.P.

Two methods of chemical concentration of diatoms occurring in fresh-water sediments, and one chemico-mechanical method of concentration for diatoms occurring in marine sediments are outlined, with emphasis on the extreme care that needs...

75 FR 51838 - Public Review of Draft Coastal and Marine Ecological Classification Standard

Science.gov (United States)

2010-08-23

... Web site. DATES: Comments on the draft Coastal and Marine Ecological Classification Standard must be... marine and coastal environments of the United States. It was developed to provide a common language that... existing classification standards. The CMECS domain extends from the coastal tidal splash zone to the deep...

Valuation of the marine and coastal resources in Colombia

International Nuclear Information System (INIS)

Newmark Umbreit, Federico; Santos Acevedo, Marisol

2002-01-01

The paper it is about the current state of the marine and coastal resources, a diagnostic is done in fisheries and aquaculture and on the cultivation of bivalve in the Colombian Caribbean; the authors mention that the use conflicts have been given by ignorance of the structure and the natural operation of highly dynamic and complex ecological systems as the marine and coastal areas, which has propitiated the accumulative environmental deterioration, incorporating elements of ecological risk permanently in the ecosystems

An integrated approach to manage coastal ecosystems and prevent marine pollution effects

Science.gov (United States)

Marcelli, Marco; Bonamano, Simone; Carli, Filippo Maria; Giovacchini, Monica; Madonia, Alice; Mancini, Emanuele; Molino, Chiara; Piermattei, Viviana; Manfredi Frattarelli, Francesco

2016-04-01

This work focuses an integrated approach based on Sea-Use-Map (SUM), backed by a permanent monitoring system (C-CEMS-Civitavecchia Coastal Environmental Monitoring System). This tool supports the management of the marine coastal area, contributing substantially to ecosystem benefits evaluation and to minimize pollution impacts. Within the Blue Growth strategy, the protection of marine ecosystems is considered a priority for the sustainable growth of marine and maritime sectors. To face this issue, the European MSP and MSFD directives (2014/89/EU; 2008/56/EC) strongly promote the adoption of an ecosystem-based approach, paying particular attention to the support of monitoring networks that use L-TER (long-term ecological research) observations and integrate multi-disciplinary data sets. Although not largely used in Europe yet, the Environmental Sensitivity Index (ESI), developed in 1979 by NOAA (and promoted by IMO in 2010), can be considered an excellent example of ecosystem-based approach to reduce the environmental consequences of an oil spill event in a coastal area. SUM is an ecosystem oriented cartographic tool specifically designed to support the sustainable management of the coastal areas, such as the selection of the best sites for the introduction of new uses or the identification of the coastal areas subjected to potential impacts. It also enables a rapid evaluation of the benefits produced by marine areas as well as of their anthropogenic disturbance. SUM integrates C-CEMS dataset, geomorphological and ecological features and knowledge on the coastal and maritime space uses. The SUM appliance allowed to obtain relevant operational results in the Civitavecchia coastal area (Latium, Italy), characterized by high variability of marine and coastal environments, historical heritage and affected by the presence of a big harbour, relevant industrial infrastructures, and touristic features. In particular, the valuation of marine ecosystem services based on

Oligocene age of the classic Belén fruit and seed assemblage of north coastal Peru based on diatom biostratigraphy

Science.gov (United States)

Manchester, Steven R.; Herrera, Fabiany; Fourtainer, Elisabeth; Barron, John A.; Martinez, Jean-Noël

2012-01-01

The Belén flora, in north coastal Peru, is the most diverse fruit and seed assemblage known from the Paleogene of South America. Almost no original paleobotanical work has been done on this assemblage since the pioneering treatments published by E.W. Berry, in the 1920’s and the precise age has not been settled. Nevertheless, the flora has been regarded as an important focal point in understanding the vegetational, orogenic and climatic history of northern South America, and in recent literature has been assumed to be early Eocene. In order to tighten the age assignment, which has varied from early Eocene to early Oligocene in the opinions of different authors, we revisited the Belén site, measured the stratigraphic section, and processed the fruit and seed-containing sediment for age-diagnostic microfossils. Although pollen and foraminifera were not recovered, the sediment is rich in diatoms. The diatom assemblage includes Lisitzinia ornata and Rocella vigilans among others, indicating a latest early Oligocene age (~30-28.5 Ma) for these deeper marine sediments that we infer to have been subsequently reworked into the Belén environment . This association leads us to consider the Belén flora, to be late Oligocene in age as is also consistent with its placement in the Mancora Formation. We also reevaluate the botanical identifications, based on the original museum specimens supplemented by more recently collected specimens. The Belén flora provides a window to extinct forests in South America before the rising of the Andes in western Peru.

Influence of diatom diversity on the ocean biological carbon pump

Science.gov (United States)

Tréguer, Paul; Bowler, Chris; Moriceau, Brivaela; Dutkiewicz, Stephanie; Gehlen, Marion; Aumont, Olivier; Bittner, Lucie; Dugdale, Richard; Finkel, Zoe; Iudicone, Daniele; Jahn, Oliver; Guidi, Lionel; Lasbleiz, Marine; Leblanc, Karine; Levy, Marina; Pondaven, Philippe

2018-01-01

Diatoms sustain the marine food web and contribute to the export of carbon from the surface ocean to depth. They account for about 40% of marine primary productivity and particulate carbon exported to depth as part of the biological pump. Diatoms have long been known to be abundant in turbulent, nutrient-rich waters, but observations and simulations indicate that they are dominant also in meso- and submesoscale structures such as fronts and filaments, and in the deep chlorophyll maximum. Diatoms vary widely in size, morphology and elemental composition, all of which control the quality, quantity and sinking speed of biogenic matter to depth. In particular, their silica shells provide ballast to marine snow and faecal pellets, and can help transport carbon to both the mesopelagic layer and deep ocean. Herein we show that the extent to which diatoms contribute to the export of carbon varies by diatom type, with carbon transfer modulated by the Si/C ratio of diatom cells, the thickness of the shells and their life strategies; for instance, the tendency to form aggregates or resting spores. Model simulations project a decline in the contribution of diatoms to primary production everywhere outside of the Southern Ocean. We argue that we need to understand changes in diatom diversity, life cycle and plankton interactions in a warmer and more acidic ocean in much more detail to fully assess any changes in their contribution to the biological pump.

Chapter D: With or Without Salt-a Comparison of Marine and Continental-Lacustrine Diatomite Deposits

Science.gov (United States)

Moyle, Phillip R.; Dolley, Thomas P.

2003-01-01

Diatoms in sedimentary deposits of marine and continental, especially lacustrine, origin have similar nutrient (for example, phosphate, nitrate, and silica) and light requirements; however, their geologic ranges and physiographic environments vary. Marine diatoms range in age from Early Cretaceous to Holocene, and continental diatoms range in age from Eocene to Holocene; however, most commercial diatomites, both marine and lacustrine, were deposited during the Miocene. Marine deposits of commercial value generally accumulated along continental margins with submerged coastal basins and shelves where wind-driven boundary currents provided the nutrient-rich upwelling conditions capable of supporting a productive diatom habitat. Commercial freshwater diatomite deposits occur in volcanic terrains associated with events that formed sediment-starved drainage basins, such as the Basin and Range Province, particularly in Nevada. Marine habitats generally are characterized by stable conditions of temperature, salinity, pH, nutrients, and water currents, in contrast to lacustrine habitats, which are characterized by wide variations in these conditions. Marine deposits generally are of higher quality and contain larger resources, owing to their greater areal extent and thickness, whereas most of the world's known diatomites are of lacustrine origin. Both types of deposit are commonly mined by open-pit methods and subjected to processing designed to remove organic matter, CO2, pore water, and inorganic contaminants in order to produce purified products. The highest quality diatomites, predominantly from marine sources, are used in filtration, although both types of deposit produce filter grades, and additional end uses include fillers, additives, absorbents, and abrasives.

Coastal marine pollution and toxicology : overview of current research and future needs

International Nuclear Information System (INIS)

Zubir Din

1996-01-01

The contents are marine pollution and toxicology studies at Universiti Sains Malaysia, their facilities, and research projects have been done on this subject. In coastal pollution monitoring and baseline studies, the emphasis have been on determination of levels of trace-metals in the coastal marine environment, in relation to other physico-chemical parameters. The future needs and goals of marine pollution and toxicology studies in Malaysia also discussed

Coastal marine pollution and toxicology : overview of current research and future needs

Energy Technology Data Exchange (ETDEWEB)

Din, Zubir [Science Univ. of Malaysia, Minden, Pulau Pinang (Malaysia). Centre for Marine and Coastal Studies

1997-12-31

The contents are marine pollution and toxicology studies at Universiti Sains Malaysia, their facilities, and research projects have been done on this subject. In coastal pollution monitoring and baseline studies, the emphasis have been on determination of levels of trace-metals in the coastal marine environment, in relation to other physico-chemical parameters. The future needs and goals of marine pollution and toxicology studies in Malaysia also discussed.

Diatom Transcriptional and Physiological Responses to Changes in Iron Bioavailability across Ocean Provinces

Directory of Open Access Journals (Sweden)

Natalie R. Cohen

2017-11-01

Full Text Available Changes in iron (Fe bioavailability influence diatom physiology and community composition, and thus have a profound impact on primary productivity and ecosystem dynamics. Iron limitation of diatom growth rates has been demonstrated in both oceanic and coastal waters of the Northeast Pacific Ocean and is predicted to become more pervasive in future oceans. However, it is unclear how the strategies utilized by phytoplankton to cope with low Fe bioavailability and resupply differ across these ocean provinces. We investigated the response of diatom communities to variable Fe conditions through incubation experiments performed in the Fe mosaic of the California Upwelling Zone and along a natural Fe gradient in the Northeast Pacific Ocean. Through coupling gene expression of two dominant diatom taxa (Pseudo-nitzschia and Thalassiosira with biological rate process measurements, we provide an in-depth examination of the physiological and molecular responses associated with varying Fe status. Following Fe enrichment, oceanic diatoms showed distinct differential expression of gene products involved in nitrogen assimilation, photosynthetic carbon fixation, and vitamin production compared to diatoms from low-Fe coastal sites, possibly driven by the chronic nature of Fe stress at the oceanic site. Genes of interest involved in Fe and N metabolism additionally exhibited divergent expression patterns between the two diatom taxa investigated, demonstrating that diverse diatoms may invoke alternative strategies when dealing with identical changes in their environment. We report here several mechanisms used distinctly by coastal or oceanic diatom communities as well as numerous taxa-specific strategies for coping with Fe stress and rearranging nutrient metabolism following Fe enrichment.

Interaction of a dinoflagellate neurotoxin with voltage-activated ion channels in a marine diatom.

Science.gov (United States)

Kitchen, Sheila A; Bourdelais, Andrea J; Taylor, Alison R

2018-01-01

The potent neurotoxins produced by the harmful algal bloom species Karenia brevis are activators of sodium voltage-gated channels (VGC) in animals, resulting in altered channel kinetics and membrane hyperexcitability. Recent biophysical and genomic evidence supports widespread presence of homologous sodium (Na + ) and calcium (Ca 2+ ) permeable VGCs in unicellular algae, including marine phytoplankton. We therefore hypothesized that VGCs of these phytoplankton may be an allelopathic target for waterborne neurotoxins produced by K. brevis blooms that could lead to ion channel dysfunction and disruption of signaling in a similar manner to animal Na + VGCs. We examined the interaction of brevetoxin-3 (PbTx-3), a K. brevis neurotoxin, with the Na + /Ca 2+ VGC of the non-toxic diatom Odontella sinensi s using electrophysiology. Single electrode current- and voltage- clamp recordings from O. sinensis in the presence of PbTx-3 were used to examine the toxin's effect on voltage gated Na + /Ca 2+ currents. In silico analysis was used to identify the putative PbTx binding site in the diatoms. We identified Na + /Ca 2+ VCG homologs from the transcriptomes and genomes of 12 diatoms, including three transcripts from O. sinensis and aligned them with site-5 of Na + VGCs, previously identified as the PbTx binding site in animals. Up to 1 µM PbTx had no effect on diatom resting membrane potential or membrane excitability. The kinetics of fast inward Na + /Ca 2+ currents that underlie diatom action potentials were also unaffected. However, the peak inward current was inhibited by 33%, delayed outward current was inhibited by 25%, and reversal potential of the currents shifted positive, indicating a change in permeability of the underlying channels. Sequence analysis showed a lack of conservation of the PbTx binding site in diatom VGC homologs, many of which share molecular features more similar to single-domain bacterial Na + /Ca 2+ VGCs than the 4-domain eukaryote channels

CO2 induced growth response in a diatom dominated phytoplankton community from SW Bay of Bengal coastal water

Science.gov (United States)

Biswas, Haimanti; Shaik, Aziz Ur Rahman; Bandyopadhyay, Debasmita; Chowdhury, Neha

2017-11-01

The ongoing increase in surface seawater CO2 level could potentially impact phytoplankton primary production in coastal waters; however, CO2 sensitivity studies on tropical coastal phytoplankton assemblages are rare. The present study investigated the interactive impacts of variable CO2 level, light and zinc (Zn) addition on the diatom dominated phytoplankton assemblages from the western coastal Bay of Bengal. Increased CO2 supply enhanced particulate organic matter (POC) production; a concomitant depletion in δ13CPOM values at elevated CO2 suggested increased CO2 diffusive influx inside the cell. Trace amount of Zn added under low CO2 level accelerated growth probably by accelerating Zn-Carbonic Anhydrase activity which helps in converting bicarbonate ion to CO2. Almost identical values of δ13CPOM in the low CO2 treated cells grown with and without Zn indicated a low discrimination between 13C and 12C probably due to bicarbonate uptake. These evidences collectively indicated the existence of the carbon concentration mechanisms (CCMs) at low CO2. A minimum growth rate was observed at low CO2 and light limited condition indicating light dependence of CCMs activity. Upon the increase of light and CO2 level, growth response was maximum. The cells grown in the low CO2 levels showed higher light stress (higher values of both diatoxanthin index and the ratio of photo-protective to light-harvesting pigments) that was alleviated by both increasing CO2 supply and Zn addition (probably by efficient light energy utilization in presence of adequate CO2). This is likely that the diatom dominated phytoplankton communities benefited from the increasing CO2 supply and thus may enhance primary production in response to any further increase in coastal water CO2 levels and can have large biogeochemical consequences in the study area.

Chronic Iron Limitation Confers Transient Resistance to Oxidative Stress in Marine Diatoms1

Science.gov (United States)

Graff van Creveld, Shiri; Rosenwasser, Shilo; Vardi, Assaf

2016-01-01

Diatoms are single-celled, photosynthetic, bloom-forming algae that are responsible for at least 20% of global primary production. Nevertheless, more than 30% of the oceans are considered “ocean deserts” due to iron limitation. We used the diatom Phaeodactylum tricornutum as a model system to explore diatom’s response to iron limitation and its interplay with susceptibility to oxidative stress. By analyzing physiological parameters and proteome profiling, we defined two distinct phases: short-term (5 d, phase II) iron limitation. While at phase I no significant changes in physiological parameters were observed, molecular markers for iron starvation, such as Iron Starvation Induced Protein and flavodoxin, were highly up-regulated. At phase II, down-regulation of numerous iron-containing proteins was detected in parallel to reduction in growth rate, chlorophyll content, photosynthetic activity, respiration rate, and antioxidant capacity. Intriguingly, while application of oxidative stress to phase I and II iron-limited cells similarly oxidized the reduced glutathione (GSH) pool, phase II iron limitation exhibited transient resistance to oxidative stress, despite the down regulation of many antioxidant proteins. By comparing proteomic profiles of P. tricornutum under iron limitation and metatranscriptomic data of an iron enrichment experiment conducted in the Pacific Ocean, we propose that iron-limited cells in the natural environment resemble the phase II metabolic state. These results provide insights into the trade-off between optimal growth rate and susceptibility to oxidative stress in the response of diatoms to iron quota in the marine environment. PMID:27503604

Hierarchical Synthesis of Coastal Ecosystem Health Indicators at Karimunjawa National Marine Park

Science.gov (United States)

Danu Prasetya, Johan; Ambariyanto; Supriharyono; Purwanti, Frida

2018-02-01

The coastal ecosystem of Karimunjawa National Marine Park (KNMP) is facing various pressures, including from human activity. Monitoring the health condition of coastal ecosystems periodically is needed as an evaluation of the ecosystem condition. Systematic and consistent indicators are needed in monitoring of coastal ecosystem health. This paper presents hierarchical synthesis of coastal ecosystem health indicators using Analytic Hierarchy Process (AHP) method. Hierarchical synthesis is obtained from process of weighting by paired comparison based on expert judgments. The variables of coastal ecosystem health indicators in this synthesis consist of 3 level of variable, i.e. main variable, sub-variable and operational variable. As a result of assessment, coastal ecosystem health indicators consist of 3 main variables, i.e. State of Ecosystem, Pressure and Management. Main variables State of Ecosystem and Management obtain the same value i.e. 0.400, while Pressure value was 0.200. Each main variable consist of several sub-variable, i.e. coral reef, reef fish, mangrove and seagrass for State of Ecosystem; fisheries and marine tourism activity for Pressure; planning and regulation, institutional and also infrastructure and financing for Management. The highest value of sub-variable of main variable State of Ecosystem, Pressure and Management were coral reef (0.186); marine tourism pressure (0.133) and institutional (0.171), respectively. The highest value of operational variable of main variable State of Ecosystem, Pressure and Management were percent of coral cover (0.058), marine tourism pressure (0.133) and presence of zonation plan, regulation also socialization of monitoring program (0.53), respectively. Potential pressure from marine tourism activity is the variable that most affect the health of the ecosystem. The results of this research suggest that there is a need to develop stronger conservation strategies to facing with pressures from marine tourism

Trans-Disciplinary Education for Sustainable Marine and Coastal Management: A Case Study in Taiwan

Directory of Open Access Journals (Sweden)

Hsiao-Chien Lee

2016-10-01

Full Text Available The present study aims to investigate the effect of a trans-disciplinary design of curricula, deemed a powerful tool for teaching and research on complex environmental problems, with a goal to help solve the real problems that climate change has brought to the coastal environment in Taiwan. Three major real-life problems in southern Taiwan—declining mullet fisheries, flooding, and coral bleaching—were integrated into four courses. Adopting a qualitative case study method, the researchers investigated the student perceptions of the trans-disciplinary learning experiences, their attitudes toward marine and coastal environmental protection, and their capability of solving the problems related to marine and coastal environments. The researchers employed various methods to analyze the student reflection reports, student self-evaluation forms, and the tape-recorded class meetings. The findings suggest the following: the trans-disciplinary curriculum stands to be an innovative yet indispensable design for coastal management education; such a curriculum benefits students by equipping them with essential knowledge and skills to succeed in future marine conservation; action learning for marine and coastal sustainability serves as the final goal of trans-disciplinary learning project; a trans-disciplinary case study on the design of curricula provides effective knowledge integration of marine and coastal sustainability.

Grazer-induced transcriptomic and metabolomic response of the chain-forming diatom Skeletonema marinoi

DEFF Research Database (Denmark)

Amato, Alberto; Sabatino, Valeria; Nylund, Göran M.

2018-01-01

Diatoms and copepods are main actors in marine food webs. The prey-predator interactions between them affect bloom dynamics, shape marine ecosystems and impact the energy transfer to higher trophic levels. Recently it has been demonstrated that the presence of grazers may affect the diatom prey b...

[Identification of marine and coastal biodiversity conservation priorities in Costa Rica].

Science.gov (United States)

Alvarado, Juan José; Herrera, Bernal; Corrales, Lenin; Asch, Jenny; Paaby, Pía

2011-06-01

Costa Rica is recognized as one of the most diverse countries in species and ecosystems, in their terrestrial realm as well as in the marine. Besides this relevance, the country presents a delay on conservation and management of marine and coastal biodiversity, with respect to terrestrial. For 2006, the marine protected surface was 5,208.8 km2, with 331.5 km of coastline, in 20 protected areas. The country has made progress on the conservation priority sites identification for terrestrial and freshwater biodiversity, with few efforts on marine planning. This research presents the analysis and results of the gap identification process, for marine and coastal biodiversity conservation in the protected areas system of Costa Rica. The analysis was built with the spatial information available on the presence and distribution of coastal and marine biodiversity, the establishment of the conservation goals and a threat analysis over the ecological integrity of this biodiversity. The selection of high-priority sites was carried out using spatial optimization techniques and the superposition over the current shape of marine protected areas, in order to identify representation gaps. A total of 19,076 km2 of conservation gaps were indentified, with 1,323 km2 in the Caribbean and 17,753 km2 in the Pacific. Recommendations are aimed at planning and strengthening the marine protected areas system, using the gaps identified as a framework. It is expected that the results of this study would be the scientific base needed for planning and sustainable use of marine biodiversity in the country.

Response of the marine diatom Thalassiosira weissflogii to iron stress

International Nuclear Information System (INIS)

Harrison, G.I.; Morel, F.M.M.

1986-01-01

The coastal diatom Thalassiosira weissflogii responds to iron limitation with decreasing growth rate, decreasing quotas of cellular iron, and increasing rates of maximum short term uptake. Growth response to steady iron limitation can be modeled according to the equations of Droop and Monod. The cellular iron quota varies from about 2 to 25 x 10 -1 mol iron per liter-cell with increasing iron; the half-saturation constant for growth, Kμ, is 1.1 x 10 -21 M (free ferric ion). In contrast, the half-saturation constant for 59 I iron uptake, K/sub rho/ is about 3 x 10 -19 M; the maximum iron uptake rate (rho/sub max/) is increased several-fold under iron limitation, resulting in a potential short term uptake rate that is a few hundred times the steady state rate. At a fixed concentration of free manganese ion, the cellular manganese quota is increased several-fold in iron-limited cultures compared to iron-sufficient cultures

Tracing biogeochemical subsidies from glacier runoff into Alaska's coastal marine food webs

Science.gov (United States)

Arimitsu, Mayumi L.; Hobson, Keith A.; Webber, D'Arcy N.; Piatt, John F.; Hood, Eran W.; Fellman, Jason B.

2018-01-01

Nearly half of the freshwater discharge into the Gulf of Alaska originates from landscapes draining glacier runoff, but the influence of the influx of riverine organic matter on the trophodynamics of coastal marine food webs is not well understood. We quantified the ecological impact of riverine organic matter subsidies to glacier-marine habitats by developing a multi-trophic level Bayesian three-isotope mixing model. We utilized large gradients in stable (δ13C, δ15N, δ2H) and radiogenic (Δ14C) isotopes that trace riverine and marine organic matter sources as they are passed from lower to higher trophic levels in glacial-marine habitats. We also compared isotope ratios between glacial-marine and more oceanic habitats. Based on isotopic measurements of potential baseline sources, ambient water and tissues of marine consumers, estimates of the riverine organic matter source contribution to upper trophic-level species including fish and seabirds ranged from 12% to 44%. Variability in resource use among similar taxa corresponded to variation in species distribution and life histories. For example, riverine organic matter assimilation by the glacier-nesting seabirds Kittlitz's murrelet (Brachyramphus brevirostris) was greater than that of the forest-nesting marbled murrelet (B. marmoratus). The particulate and dissolved organic carbon in glacial runoff and near surface coastal waters was aged (12100–1500 years BP 14C-age) but dissolved inorganic carbon and biota in coastal waters were young (530 years BP 14C-age to modern). Thus terrestrial-derived subsidies in marine food webs were primarily composed of young organic matter sources released from glacier ecosystems and their surrounding watersheds. Stable isotope compositions also revealed a divergence in food web structure between glacial-marine and oceanic sites. This work demonstrates linkages between terrestrial and marine ecosystems, and facilitates a greater understanding of how climate-driven changes

A C-25 highly branched isoprenoid alkene and C-25 and C-27 n-polyenes in the marine diatom Rhizosolenia setigera

NARCIS (Netherlands)

Sinninghe Damste, J.S; Rijpstra, W.I C; Schouten, S; Peletier, H.; van der Maarel, M.J.E.C.; Gieskes, W.W C

1999-01-01

A North Atlantic strain of the marine diatom Rhizosolenia setigera was examined for the presence of hydrocarbons. This strain biosynthesizes a highly branched isoprenoid (HBI) C-25 pentaene, in contrast to Australian strains of R. setigera which produce HBI C-30 alkenes. The more widespread

Evidence for marine microfossils from amber.

Science.gov (United States)

Girard, Vincent; Schmidt, Alexander R; Saint Martin, Simona; Struwe, Steffi; Perrichot, Vincent; Saint Martin, Jean-Paul; Grosheny, Danièle; Breton, Gérard; Néraudeau, Didier

2008-11-11

Amber usually contains inclusions of terrestrial and rarely limnetic organisms that were embedded in the places were they lived in the amber forests. Therefore, it has been supposed that amber could not have preserved marine organisms. Here, we report the discovery amber-preserved marine microfossils. Diverse marine diatoms as well as radiolarians, sponge spicules, a foraminifer, and a spine of a larval echinoderm were found in Late Albian and Early Cenomanian amber samples of southwestern France. The highly fossiliferous resin samples solidified approximately 100 million years ago on the floor of coastal mixed forests dominated by conifers. The amber forests of southwestern France grew directly along the coast of the Atlantic Ocean and were influenced by the nearby sea: shells and remnants of marine organisms were probably introduced by wind, spray, or high tide from the beach or the sea onto the resin flows.

Comparing marine and terrestrial ecosystems: Implications for the design of coastal marine reserves

Science.gov (United States)

Carr, M.H.; Neigel, J.E.; Estes, J.A.; Andelman, S.; Warner, R.R.; Largier, J. L.

2003-01-01

Concepts and theory for the design and application of terrestrial reserves is based on our understanding of environmental, ecological, and evolutionary processes responsible for biological diversity and sustainability of terrestrial ecosystems and how humans have influenced these processes. How well this terrestrial-based theory can be applied toward the design and application of reserves in the coastal marine environment depends, in part, on the degree of similarity between these systems. Several marked differences in ecological and evolutionary processes exist between marine and terrestrial ecosystems as ramifications of fundamental differences in their physical environments (i.e., the relative prevalence of air and water) and contemporary patterns of human impacts. Most notably, the great extent and rate of dispersal of nutrients, materials, holoplanktonic organisms, and reproductive propagules of benthic organisms expand scales of connectivity among near-shore communities and ecosystems. Consequently, the "openness" of marine populations, communities, and ecosystems probably has marked influences on their spatial, genetic, and trophic structures and dynamics in ways experienced by only some terrestrial species. Such differences appear to be particularly significant for the kinds of organisms most exploited and targeted for protection in coastal marine ecosystems (fishes and macroinvertebrates). These and other differences imply some unique design criteria and application of reserves in the marine environment. In explaining the implications of these differences for marine reserve design and application, we identify many of the environmental and ecological processes and design criteria necessary for consideration in the development of the analytical approaches developed elsewhere in this Special Issue.

Rising CO2 interacts with growth light and growth rate to alter photosystem II photoinactivation of the coastal diatom Thalassiosira pseudonana.

Directory of Open Access Journals (Sweden)

Gang Li

Full Text Available We studied the interactive effects of pCO(2 and growth light on the coastal marine diatom Thalassiosira pseudonana CCMP 1335 growing under ambient and expected end-of-the-century pCO(2 (750 ppmv, and a range of growth light from 30 to 380 µmol photons·m(-2·s(-1. Elevated pCO(2 significantly stimulated the growth of T. pseudonana under sub-saturating growth light, but not under saturating to super-saturating growth light. Under ambient pCO(2 susceptibility to photoinactivation of photosystem II (σ(i increased with increasing growth rate, but cells growing under elevated pCO(2 showed no dependence between growth rate and σ(i, so under high growth light cells under elevated pCO(2 were less susceptible to photoinactivation of photosystem II, and thus incurred a lower running cost to maintain photosystem II function. Growth light altered the contents of RbcL (RUBISCO and PsaC (PSI protein subunits, and the ratios among the subunits, but there were only limited effects on these and other protein pools between cells grown under ambient and elevated pCO(2.

Continuous gene flow contributes to low global species abundance and distribution of a marine model diatom

KAUST Repository

Rastogi, Achal

2017-08-15

Unlike terrestrial ecosystems where geographical isolation often leads to a restricted gene flow between species, genetic admixing in aquatic micro-eukaryotes is likely to be frequent. Diatoms inhabit marine ecosystems since the Mesozoic period and presently constitute one of the major primary producers in the world ocean. They are a highly diversified group of eukaryotic phytoplankton with estimates of up to 200,000 species. Since decades, Phaeodactylum tricornutum is used as a model diatom species to characterize the functional pathways, physiology and evolution of diatoms in general. In the current study, using whole genome sequencing of ten P. tricornutum strains, sampled at broad geospatial and temporal scales, we show a continuous dispersal and genetic admixing between geographically isolated strains. We also describe a very high level of heterozygosity and propose it to be a consequence of frequent ancestral admixture. Our finding that P. tricornutum sequences are plausibly detectable at low but broadly distributed levels in the world ocean further suggests that high admixing between geographically isolated strains may create a significant bottleneck, thus influencing their global abundance and distribution in nature. Finally, in an attempt to understand the functional implications of genetic diversity between different P. tricornutum ecotypes, we show the effects of domestication in inducing changes in the selection pressure on many genes and metabolic pathways. We propose these findings to have significant implications for understanding the genetic structure of diatom populations in nature and provide a framework to assess the genomic underpinnings of their ecological success.

Continuous gene flow contributes to low global species abundance and distribution of a marine model diatom

KAUST Repository

Rastogi, Achal; Deton-Cabanillas, Anne-Flore; Rocha Jimenez Vieira, Fabio; Veluchamy, Alaguraj; Cantrel, Catherine; Wang, Gaohong; Vanormelingen, Pieter; Bowler, Chris; Piganeau, Gwenael; Tirichine, Leila; Hu, Hanhua

2017-01-01

Unlike terrestrial ecosystems where geographical isolation often leads to a restricted gene flow between species, genetic admixing in aquatic micro-eukaryotes is likely to be frequent. Diatoms inhabit marine ecosystems since the Mesozoic period and presently constitute one of the major primary producers in the world ocean. They are a highly diversified group of eukaryotic phytoplankton with estimates of up to 200,000 species. Since decades, Phaeodactylum tricornutum is used as a model diatom species to characterize the functional pathways, physiology and evolution of diatoms in general. In the current study, using whole genome sequencing of ten P. tricornutum strains, sampled at broad geospatial and temporal scales, we show a continuous dispersal and genetic admixing between geographically isolated strains. We also describe a very high level of heterozygosity and propose it to be a consequence of frequent ancestral admixture. Our finding that P. tricornutum sequences are plausibly detectable at low but broadly distributed levels in the world ocean further suggests that high admixing between geographically isolated strains may create a significant bottleneck, thus influencing their global abundance and distribution in nature. Finally, in an attempt to understand the functional implications of genetic diversity between different P. tricornutum ecotypes, we show the effects of domestication in inducing changes in the selection pressure on many genes and metabolic pathways. We propose these findings to have significant implications for understanding the genetic structure of diatom populations in nature and provide a framework to assess the genomic underpinnings of their ecological success.

Groundfish overfishing, diatom decline, and the marine silica cycle: Lessons from Saanich Inlet, Canada, and the Baltic Sea cod crash

Science.gov (United States)

Katz, Timor; Yahel, Gitai; Yahel, Ruthy; Tunnicliffe, Verena; Herut, Barak; Snelgrove, Paul; Crusius, John; Lazar, Boaz

2009-12-01

In this study, we link groundfish activity to the marine silica cycle and suggest that the drastic mid-1980s crash of the Baltic Sea cod (Gadus morhua) population triggered a cascade of events leading to decrease in dissolved silica (DSi) and diatom abundance in the water. We suggest that this seemingly unrelated sequence of events was caused by a marked decline in sediment resuspension associated with reduced groundfish activity resulting from the cod crash. In a study in Saanich Inlet, British Columbia, Canada, we discovered that, by resuspending bottom sediments, groundfish triple DSi fluxes from the sediments and reduce silica accumulation therein. Using these findings and the available oceanographic and environmental data from the Baltic Sea, we estimate that overfishing and recruitment failure of Baltic cod reduced by 20% the DSi supply from bottom sediments to the surface water leading to a decline in the diatom population in the Baltic Sea. The major importance of the marginal ocean in the marine silica cycle and the associated high population density of groundfish suggest that groundfish play a major role in the silica cycle. We postulate that dwindling groundfish populations caused by anthropogenic perturbations, e.g., overfishing and bottom water anoxia, may cause shifts in marine phytoplankton communities.

137Cs activity and associated dose in the coastal marine environment of India

International Nuclear Information System (INIS)

Verma, G.P.; Sharma, D.N.; Jha, S.K.

2010-01-01

Coastal marine environment is important for India since a considerable percentage of the human population resides in coastal areas. Fallout radionuclides as well as non-radioactive substances have polluted the coastal marine environment of India. The introduction of 137 Cs, a fallout radionuclide, considered as global pollutant, into marine environment has created the need for marine environmental data. The main objective is to provide data on the present level of 137 Cs which is important from the standpoint of radiological health and dose associated with it. Such database will also provide benchmark which will be helpful in assessing the impact of additional contribution to marine radioactivity in the future. The results confirm that the mean annual individual dose from 137 Cs in seafood (fish) for the Indian subcontinent is 0.03 μSv. The highest annual individual dose for 137 Cs due to the ingestion offish is in the age group of 40 to 59 years which is due to the reason that the Indian annual dietary intake of fish is highest in this age group

Summary of other human activities in the coastal and marine environment

CSIR Research Space (South Africa)

Celliers, Louis

2015-01-01

Full Text Available The Western Indian Ocean (WIO) offers a wealth of opportunity for the profitable and beneficial use of coastal and marine resources – a prospect for a true ocean economy. These benefits are derived from a range of human activities in the coastal...

Diatoms as Proxies for Abrupt Events in the Hudson River Estuary

Science.gov (United States)

Skorski, W.; Abbott, D. H.; Recasens, C.; Breger, D. L.

2014-12-01

The Hudson River estuary has been subject to many abrupt events throughout its history including hurricanes, droughts and pluvials. Hurricanes in particular are rare, discrete events that if fingerprinted can be used to develop better age models for Hudson River sediments. Proxies use observed physical characteristics or biological assemblages (e.g. diatom and foraminiferal assemblages) as tools to reconstruct past conditions prior to the modern instrumental record. Using a sediment core taken from the Hudson River (CDO2-29A), in New York City, drought and pluvial layers were selected based on Cs-137 dating while hurricane layers were determined from occurrences of tropical to subtropical foraminifera. Contrary to previous studies (Weaver, 1970, Weiss et al, 1978), more than sixty different diatom species have been identified using a scanning electron microscope (SEM). Cosmopolitan, hurricane and drought assemblages have begun to be identified after observing multiple layers (Table 1). Tropical foraminifera dominated by Globigerinoides ruber pink were also found in a hurricane layer that we infer was deposited during Hurricane Belle in 1976. More diatom abundance analyses and cataloged SEM pictures will provide further insight into these proxies. Table 1 Diatom Genera and Species Environment Clarification Cyclotella caspia Planktonic, marine-brackish Cosmopolitan Karayevia clevei Freshwater Cosmopolitan Melosira sp Planktonic, marine Cosmopolitan Thalassiosira sp Marine, brackish Cosmopolitan Staurosirella leptostauron Benthic, freshwater Cosmopolitan Actinoptychus senarius Planktonic or benthic, freshwater to brackish Hurricane and pluvial layers Amphora aff. sp Benthic, marine or freshwater Hurricane layers only Nitzschia sp Benthic, marine or freshwater Hurricane layers only Gomphonema sp Freshwater Hurricane layers only Surirella sp Marine-brackish Drought layer only Triceratium sp Marine Drought layer only Other Genera and species Environment Clarification

Recreational impacts on the fauna of Australian coastal marine ecosystems.

Science.gov (United States)

Hardiman, Nigel; Burgin, Shelley

2010-11-01

This paper reviews recent research into the ecological impacts of recreation and tourism on coastal marine fauna in Australia. Despite the high and growing importance of water-based recreation to the Australian economy, and the known fragility of many Australian ecosystems, there has been relatively limited research into the effects of marine tourism and recreation, infrastructure and activities, on aquatic resources. In this paper we have reviewed the ecological impacts on fauna that are caused by outdoor recreation (including tourism) in Australian coastal marine ecosystems. We predict that the single most potentially severe impact of recreation may be the introduction and/or dispersal of non-indigenous species of marine organisms by recreational vessels. Such introductions, together with other impacts due to human activities have the potential to increasingly degrade recreation destinations. In response, governments have introduced a wide range of legislative tools (e.g., impact assessment, protected area reservation) to manage the recreational industry. It would appear, however, that these instruments are not always appropriately applied. Copyright 2010 Elsevier Ltd. All rights reserved.

Marine and coastal ecosystem services on the science-policy-practice nexus

NARCIS (Netherlands)

Drakou, Evangelia G.; Kermagoret, Charlène; Liquete, Camino; Ruiz-Frau, Ana; Burkhard, Kremena; Lillebø, Ana I.; Oudenhoven, van Alexander P.E.; Ballé-Béganton, Johanna; Rodrigues, João Garcia; Nieminen, Emmi; Oinonen, Soile; Ziemba, Alex; Gissi, Elena; Depellegrin, Daniel; Veidemane, Kristina; Ruskule, Anda; Delangue, Justine; Böhnke-Henrichs, Anne; Boon, Arjen; Wenning, Richard; Martino, Simone; Hasler, Berit; Termansen, Mette; Rockel, Mark; Hummel, Herman; Serafy, El Ghada; Peev, Plamen

2017-01-01

We compared and contrasted 11 European case studies to identify challenges and opportunities toward the operationalization of marine and coastal ecosystem service (MCES) assessments in Europe. This work is the output of a panel convened by the Marine Working Group of the Ecosystem Services

Marine oil spill risk mapping for accidental pollution and its application in a coastal city.

Science.gov (United States)

Lan, Dongdong; Liang, Bin; Bao, Chenguang; Ma, Minghui; Xu, Yan; Yu, Chunyan

2015-07-15

Accidental marine oil spill pollution can result in severe environmental, ecological, economic and other consequences. This paper discussed the model of Marine Oil Spill Risk Mapping (MOSRM), which was constructed as follows: (1) proposing a marine oil spill risk system based on the typical marine oil spill pollution accidents and prevailing risk theories; (2) identifying suitable indexes that are supported by quantitative sub-indexes; (3) constructing the risk measuring models according to the actual interactions between the factors in the risk system; and (4) assessing marine oil spill risk on coastal city scale with GIS to map the overall risk. The case study of accidental marine oil spill pollution in the coastal area of Dalian, China was used to demonstrate the effectiveness of the model. The coastal areas of Dalian were divided into three zones with risk degrees of high, medium, and low. And detailed countermeasures were proposed for specific risk zones. Copyright © 2015 Elsevier Ltd. All rights reserved.

Flow-structure-seabed interactions in coastal and marine environments

DEFF Research Database (Denmark)

Sumer, B. Mutlu

2014-01-01

Flow–structure–seabed interaction in coastal and marine environments is a rapidly growing area of research and applications. In this vision paper, this area is discussed with a view of identifying its state of the art and current research challenges. The discussion draws attention to key issues......, among other areas, as an emerging branch of Marine Civil Engineering. Predictions of the field development for the forthcoming years are also briefly outlined....

Growth inhibition of periphytic diatoms by methanol extracts of sponges and holothurians

Digital Repository Service at National Institute of Oceanography (India)

Mokashe, S.S.; Garg, A; Anil, A; Wagh, A

Crude methanol extracts of a holothurian Holothuria leucospilota, and two sponges Craniella sp. and Ircinia ramosa were tested for their inhibitory effects on the growth of two marine diatoms, Navicula subinflata and N. crucicula, by diatom plating...

The diversity and structure of marine protists in the coastal waters of China revealed by morphological observation and 454 pyrosequencing

Science.gov (United States)

Liu, Yun; Song, Shuqun; Chen, Tiantian; Li, Caiwen

2017-04-01

Pyrosequencing of the 18S rRNA gene has been widely adopted to study the eukaryotic diversity in various types of environments, and has an advantage over traditional morphology methods in exploring unknown microbial communities. To comprehensively assess the diversity and community composition of marine protists in the coastal waters of China, we applied both morphological observations and high-throughput sequencing of the V2 and V3 regions of 18S rDNA simultaneously to analyze samples collected from the surface layer of the Yellow and East China Seas. Dinoflagellates, diatoms and ciliates were the three dominant protistan groups as revealed by the two methods. Diatoms were the first dominant protistan group in the microscopic observations, with Skeletonema mainly distributed in the nearshore eutrophic waters and Chaetoceros in higher temperature and higher pH waters. The mixotrophic dinoflagellates, Gymnodinium and Gyrodinium, were more competitive in the oligotrophic waters. The pyrosequencing method revealed an extensive diversity of dinoflagellates. Chaetoceros was the only dominant diatom group in the pyrosequencing dataset. Gyrodinium represented the most abundant reads and dominated the offshore oligotrophic protistan community as they were in the microscopic observations. The dominance of parasitic dinoflagellates in the pyrosequencing dataset, which were overlooked in the morphological observations, indicates more attention should be paid to explore the potential role of this group. Both methods provide coherent clustering of samples. Nutrient levels, salinity and pH were the main factors influencing the distribution of protists. This study demonstrates that different primer pairs used in the pyrosequencing will indicate different protistan community structures. A suitable marker may reveal more comprehensive composition of protists and provide valuable information on environmental drivers.

Accumulation of trace metals in coastal marine organisms

International Nuclear Information System (INIS)

Weers, A.W. van; Raaphorst, J.G. van

1980-01-01

ECN at Petten carries out a survey on the occurrence of trace metals in coastal marine organisms. The survey is aimed to provide an estimate of concentration factors in local marine organisms for neutron activation products released as low-level liquid radioactive waste into the North Sea. The organisms studied are red and brown seaweed, edible mussels ans shrimp. A summary of the results of analyses of iron, cobalt, zinc, silver and antimony in these organisms is presented. Concentration factors derived from mean stable-element concentrations range from about 50 for Sb in red seaweed and shrimp to about 10 4 for Fe in red seaweed and mussels. The largest variation is shown for zinc in seaweed, which variation is seasonal and most pronounced in brown seaweed. A discussion of the data is presented in relation to data from other West-European coastal areas and to data used for the radiological assessment of deep sea disposal of radioactive waste

ZONING OF COASTAL AREA FOR MARINE AQUACULTURE Š PRESENT SITUATIONS AND PROBLEMS

Directory of Open Access Journals (Sweden)

Lav Bavčević

2001-12-01

Full Text Available We already acepted that Croatian economical and geopolitical possition can bee improved only with better utilization of coastal area. Under these conditions mariculture also makes a part od sea master plan because demands for mariculture are focused on clean environmental conditions to obtain economic benefits. Increased pressure to the coastal area is global trend and if not planed and organized can provoke conflicts and can affect further development. Under these condition, marine aquaculture is frequent subject of many discussion focused on the environmental impact. Conflict of different interest in coastal area with no argumentation is putting marine aquaculture in worst position related with tourism and industry. Hard argumentations is laying in noneadequate frame of work in some facilities and to take advantake competitors are preasenting marine aquaculture in worst picture. Marine aquaculture product has to be health product, which can be completely damaged because of non-responsible approach of other activity. Mariculture also can suffer from self-pollution as for example tourism and must be well planed and managed. Fecal pollution from towns, pollution from bad controlled tourists activity, industry, influence of intensive and non controlled agriculture in coast line, are also potential danger for quality of all sea products and also cultured products from marine aquaculture. High quality of marine products can be obtained by zoning of coastal area, and in concept of these zoning it is necessary to define the zones for marine aquaculture. Procedure of zoning has to be divided in three steps: deetrmination of present status of area, definition of shore land for making mariculture related shore infrastructure and definitions of areas suitable for mariculture with limits of production. These can make positive situations with avoiding conflicts in exploitation of common resources in future. Zone for marine aquaculture has to be controlled

Comparative toxicological effects of two antifouling biocides on the marine diatom Chaetoceros lorenzianus: Damage and post-exposure recovery.

Science.gov (United States)

Chavan, Pooja; Kumar, Rajesh; Kirubagaran, Ramalingam; Venugopalan, Vayalam P

2017-10-01

Antifouling biocides are commonly used in coastal electric power stations to prevent biofouling in their condenser cooling systems. However, the environmental impact of the chemical biocides is less understood than the thermal stress effects caused by the condenser effluents. In this study, Chaetoceros lorenzianus, a representative marine diatom, was used to analyse the toxicity of two antifouling biocides, chlorine and chlorine dioxide. The diatom cells were subjected to a range of concentrations of the biocides (from 0.05 to 2mg/L, as total residual oxidants, TRO) for contact time of 30min. They were analysed for viability, genotoxicity, chlorophyll a and cell density endpoints. The cells were affected at all concentrations of the biocides (0.05-2mg/L), showing dose-dependent decrease in viability and increase in DNA damage. The treated cells were later incubated in filtered seawater devoid of biocide to check for recovery. The cells were able to recover in terms of overall viability and DNA damage, when they had been initially treated with low concentrations of the biocides (0.5mg/L of Cl 2 or 0.2mg/L of ClO 2 ). Chlorophyll a analysis showed irreparable damage at all concentrations, while cell density showed increasing trend of reduction, if treated above 0.5mg/L of Cl 2 and 0.2mg/L of ClO 2 . The data indicated that in C. lorenzianus, cumulative toxic effects and recovery potential of ClO 2 up to 0.2mg/L were comparable with those of Cl 2 , up to 0.5mg/L concentration in terms of the studied endpoints. The results indicate that at the biocide levels currently being used at power stations, recovery of the organism is feasible upon return to ambient environment. Similar studies should be carried out on other planktonic and benthic organisms, which will be helpful in the formulation of future guidelines for discharge of upcoming antifouling biocides such as chlorine dioxide. Copyright © 2017 Elsevier Inc. All rights reserved.

A new diatom growth inhibition assay using the XTT colorimetric method.

Science.gov (United States)

Jiang, Weina; Akagi, Takuya; Suzuki, Hidekazu; Takimoto, Ayaka; Nagai, Hiroshi

2016-01-01

Marine biofouling, which leads to significant operational stress and economic damage on marine infrastructures, is a major problem in marine related industries. Currently, the most common way to avoid marine biofouling involves the use of biocidal products in surface coatings. However, the need for environmentally friendly antibiofouling compounds has increased rapidly with the recent global prohibition of harmful antifoulants, such as tributyltin (TBT). In particular, periphytic diatoms have been shown to contribute significantly to biofilms, which play an important role in biofouling. Therefore, inhibiting the proliferation of fouling diatoms is a very important step in the prevention of marine biofouling. In this study, we developed a new, rapid, accurate, and convenient growth inhibition assay using the XTT colorimetric method to prevent the growth of the fouling periphytic diatom, Nitzschia amabilis Hidek. Suzuki (replaced synonym, Nitzschia laevis Hustedt). The feasibility of this method was verified by determining the growth inhibition activities of two standard photosynthetic inhibitors, DCMU and CuSO4. However, neither inhibitor had any cytotoxic activities at the range of concentrations tested. Moreover, this method was applied by screening and purification of herbicidic but non-cytotoxic compounds from cyanobacteria extracts. Our results demonstrate the utility of this newly established growth inhibition assay for the identification of marine anti-biofouling compounds. Copyright © 2016 Elsevier Inc. All rights reserved.

Risk assessment of excessive CO_2 emission on diatom heavy metal consumption

International Nuclear Information System (INIS)

Liu, Fengjiao; Li, Shunxing; Zheng, Fengying; Huang, Xuguang

2016-01-01

Diatoms are the dominant group of phytoplankton in the modern ocean, accounting for approximately 40% of oceanic primary productivity and critical foundation of coastal food web. Rising dissolution of anthropogenic CO_2 in seawater may directly/indirectly cause ocean acidification and desalination. However, little is known about dietary diatom-associated changes, especially for diatom heavy metal consumption sensitivity to these processes, which is important for seafood safety and nutrition assessment. Here we show some links between ocean acidification/desalination and heavy metal consumption by Thalassiosira weissflogii. Excitingly, under desalination stress, the relationships between Cu, Zn, and Cd were all positively correlated, especially between Cu and Zn (r = 0.989, total intracellular concentration) and between Zn and Cd (r = 0.962, single-cell intracellular concentration). Heavy metal consumption activity in decreasing order was acidification < acidification + desalination < desalination for Zn, acidification < desalination < acidification + desalination for Cu and Cd, i.e., heavy metal uptake (or release) were controlled by environmental stress. Our findings showed that heavy metal uptake (or release) was already responded to ongoing excessive CO_2 emission-driven acidification and desalination, which was important for risk assessment of climate change on diatom heavy metal consumption, food web and then seafood safety in future oceans. - Highlights: • Excessive CO_2 in seawater may causes ocean acidification and desalination. • The relationships between Cu, Zn, and Cd were all positively correlated by desalination. • Significant effects of salinity on intracellular concentration of Cu and Cd • Cu and Cd in marine phytoplankton could be regulated by metal excretion. • Heavy metal consumption was affect by excessive CO_2.

Navigating transformations in governance of Chilean marine coastal resources

NARCIS (Netherlands)

Gelcich, S.; Hughes, T.P.; Olsson, P.; Folke, C.; Defeo, O.; Fernandez, M.; Foale, S.; Gunderson, L.H.; Rodriguez-Sickert, C.; Scheffer, M.; Steneck, R.S.; Castilla, J.C.

2010-01-01

Marine ecosystems are in decline. New transformational changes in governance are urgently required to cope with overfishing, pollution, global changes, and other drivers of degradation. Here we explore social, political, and ecological aspects of a transformation in governance of Chile's coastal

Concentration factors for Cs-137 in marine algae from Japanese coastal waters

International Nuclear Information System (INIS)

Tateda, Yutaka; Koyanagi, Taku.

1994-01-01

Concentration factors (CF: Bq·kg -1 in wet algae/Bq·kg -1 in filtered seawater) for Cs-137 in Japanese coastal algae, were investigated during 1984-1990. Cs-137/Cs (stable) atom ratios were also examined to clarify the distribution equilibrium of Cs-137 in marine algae and sea water. The CFs in marine algae were within the range of 5.4-92, and the geometric mean of CF was 28±2 (standard error) in Japanese coastal species. The CFs in edible species were within the range of 5.4-67, and the geometric means of CF was 26±4 (standard error). The values of Cs-137/Cs atom ratios in marine algae and sea water indicated that Cs-137 reached an equilibrium state in partition between algae and sea water. Therefore, the CF value obtained in the present study can be regarded as an equilibrated value. Our results showed that hte CF for Cs-137 in Japanese coastal algae were consistent with the Japanese guideline CFs, but were smaller than the recommended value by IAEA. (author)

Effect of Cadmium on the population growth of the marine diatom Chaetoceros gracilis Schutt

Directory of Open Access Journals (Sweden)

Giovana Vera

2014-06-01

Full Text Available Phytoplankton constitutes the base of the trophic webs in the marine environment, so it is important to know the possible effects of pollutants on the algal populations. In the present paper the effect of cadmium on the population growth of the diatom Chaetoceros gracilis was assessed. The microalgae were cultured in the a modified “f/2” Guillard medium, and were exposed to different concentrations of cadmium between 50 and 100000 µg.–1, which produced an inhibitory effect from 20% to 99% on the population growth of Chaetoceros gracilis. Based on the dose (cadmium-response (inhibition relationship, a mean effective concentration (EC50% equal to 591 µg.L–1 of cadmium was obtained.

Invasions and extinctions reshape coastal marine food webs.

Directory of Open Access Journals (Sweden)

Jarrett E Byrnes

Full Text Available The biodiversity of ecosystems worldwide is changing because of species loss due to human-caused extinctions and species gain through intentional and accidental introductions. Here we show that the combined effect of these two processes is altering the trophic structure of food webs in coastal marine systems. This is because most extinctions ( approximately 70% occur at high trophic levels (top predators and other carnivores, while most invasions are by species from lower trophic levels (70% macroplanktivores, deposit feeders, and detritivores. These opposing changes thus alter the shape of marine food webs from a trophic pyramid capped by a diverse array of predators and consumers to a shorter, squatter configuration dominated by filter feeders and scavengers. The consequences of the simultaneous loss of diversity at top trophic levels and gain at lower trophic levels is largely unknown. However, current research suggests that a better understanding of how such simultaneous changes in diversity can impact ecosystem function will be required to manage coastal ecosystems and forecast future changes.

Diatom-inferred hydrological changes and Holocene geomorphic transitioning of Africa's largest estuarine system, Lake St Lucia

Science.gov (United States)

Gomes, M.; Humphries, M. S.; Kirsten, K. L.; Green, A. N.; Finch, J. M.; de Lecea, A. M.

2017-06-01

The diverse lagoons and coastal lakes along the east coast of South Africa occupy incised valleys that were flooded during the rise and subsequent stabilisation of relative sea-level during the Holocene. Sedimentary deposits contained within these waterbodies provide an opportunity to investigate complex hydrological and sedimentological processes, and examine sea-level controls governing system geomorphic evolution. In this paper, we combine diatom and sulfur isotope analyses from two sediment cores extracted from the northern sub-basins of Lake St Lucia, a large shallow estuarine lake that is today largely isolated from direct ocean influence behind a Holocene-Pleistocene barrier complex. Analyses allow the reconstruction of hydrological changes associated with the geomorphic development of the system over the mid-to late Holocene. The sedimentary sequences indicate that St Lucia was a shallow, partially enclosed estuary/embayment dominated by strong tidal flows prior to ∼6200 cal. BP. Infilling was initiated when sea-level rise slowed and stabilised around present day levels, resulting in the accumulation of fine-grained sediment behind an emergent proto-barrier. Diatom assemblages, dominated by marine benthic and epiphytic species, reveal a system structured by marine water influx and characterised by marsh and tidal flat habitats until ∼4550 cal. BP. A shift in the biological community at ∼4550 cal. BP is linked to the development of a back-barrier water body that supported a brackish community. Marine planktonics and enrichments in δ34S suggest recurrent, large-scale barrier inundation events during this time, coincident with a mid-Holocene sea-level highstand. Periodic marine incursions associated with episodes of enhanced storminess and overwash remained prevalent until ∼1200 cal. BP, when further barrier construction ultimately isolated the northern basins from the ocean. This study provides the first reconstruction of the palaeohydrological

Integration of wave energy and other marine renewable energy sources with the needs of coastal societies

Directory of Open Access Journals (Sweden)

Richard Manasseh

2017-04-01

Full Text Available Marine renewable energy has the potential to solve both the energy-security and coastal-protection problems affecting coastal societies. In this article, the potential benefits arising from the combination of marine renewable energy technologies with infrastructural needs for coastal protection and other local needs are analysed. Classifications of technologies are developed to inform future coastal planning. Explanations of the resources and technologies are presented in layperson’s term. The threat of coastal inundation under climate-change scenarios is a major global issue. The investment in new infrastructure demanded by cities, ports and communities at risk of inundation could very substantially reduce the levelised cost of electricity from renewable sources, provided the infrastructure is designed with the dual purpose of power generation and coastal protection. Correspondingly, the sale of electricity from such infrastructure could defray the long-term cost of installing coastal protection. Furthermore, many marine renewable energy technologies provide a platform on which other forms of renewable energy generation could be mounted. It is noted that the complex geophysical and engineering issues arising from this opportunity must be assessed considering socio-economic factors.

Interactions of aquaculture, marine coastal ecosystems, and near-shore waters: A bibliography. Bibliographies and literature of agriculture (Final)

International Nuclear Information System (INIS)

Hanfman, D.T.; Coleman, D.E.; Tibbitt, S.J.

1991-01-01

The bibliography contains selected literature citations on the interactions of aquaculture and marine coastal ecosystems. The focus is on aquaculture effluents and their impact on marine coastal ecosystems and waterways as well as the impact of pollutants on aquaculture development. Factors affecting these issues include domestic and industrial wastes, thermal discharges, acid rain, heavy metals, oil spills, and microbial contamination of marine waters and aquatic species. Coastal zone management, environmenal impact of aquaculture, and water quality issues are also included in the bibliography

[The marine coastal water monitoring program of the Italian Ministry of the Environment].

Science.gov (United States)

Di Girolamo, Irene

2003-01-01

The Ministry of the Environment carries out marine and coastal monitoring programs with the collaboration of the coastal Regions. The program in progress (2001-2003), on the basis of results of the previous one, has identified 73 particulary significant areas (57 critical areas and 16 control areas). The program investigates several parameters on water, plancton, sediments, mollusks and benthos with analyses fortnightly, six-monthly and annual. The main aim of these three year monitoring programs is to assess the quality of national marine ecosystem.

Risk assessment of excessive CO{sub 2} emission on diatom heavy metal consumption

Energy Technology Data Exchange (ETDEWEB)

Liu, Fengjiao; Li, Shunxing, E-mail: shunxing_li@aliyun.com; Zheng, Fengying; Huang, Xuguang

2016-10-01

Diatoms are the dominant group of phytoplankton in the modern ocean, accounting for approximately 40% of oceanic primary productivity and critical foundation of coastal food web. Rising dissolution of anthropogenic CO{sub 2} in seawater may directly/indirectly cause ocean acidification and desalination. However, little is known about dietary diatom-associated changes, especially for diatom heavy metal consumption sensitivity to these processes, which is important for seafood safety and nutrition assessment. Here we show some links between ocean acidification/desalination and heavy metal consumption by Thalassiosira weissflogii. Excitingly, under desalination stress, the relationships between Cu, Zn, and Cd were all positively correlated, especially between Cu and Zn (r = 0.989, total intracellular concentration) and between Zn and Cd (r = 0.962, single-cell intracellular concentration). Heavy metal consumption activity in decreasing order was acidification < acidification + desalination < desalination for Zn, acidification < desalination < acidification + desalination for Cu and Cd, i.e., heavy metal uptake (or release) were controlled by environmental stress. Our findings showed that heavy metal uptake (or release) was already responded to ongoing excessive CO{sub 2} emission-driven acidification and desalination, which was important for risk assessment of climate change on diatom heavy metal consumption, food web and then seafood safety in future oceans. - Highlights: • Excessive CO{sub 2} in seawater may causes ocean acidification and desalination. • The relationships between Cu, Zn, and Cd were all positively correlated by desalination. • Significant effects of salinity on intracellular concentration of Cu and Cd • Cu and Cd in marine phytoplankton could be regulated by metal excretion. • Heavy metal consumption was affect by excessive CO{sub 2}.

Oceanographic and Biogeochemical Insights from Diatom Genomes

Science.gov (United States)

Bowler, Chris; Vardi, Assaf; Allen, Andrew E.

2010-01-01

Diatoms are the most successful group of eukaryotic phytoplankton in the modern ocean and have risen to dominance relatively quickly over the last 100 million years. Recently completed whole genome sequences from two species of diatom, Thalassiosira pseudonana and Phaeodactylum tricornutum, have revealed a wealth of information about the evolutionary origins and metabolic adaptations that have led to their ecological success. A major finding is that they have incorporated genes both from their endosymbiotic ancestors and by horizontal gene transfer from marine bacteria. This unique melting pot of genes encodes novel capacities for metabolic management, for example, allowing the integration of a urea cycle into a photosynthetic cell. In this review we show how genome-enabled approaches are being leveraged to explore major phenomena of oceanographic and biogeochemical relevance, such as nutrient assimilation and life histories in diatoms. We also discuss how diatoms may be affected by climate change-induced alterations in ocean processes.

Collections management plan for the U.S. Geological Survey Woods Hole Coastal and Marine Science Center Data Library

Science.gov (United States)

List, Kelleen M.; Buczkowski, Brian J.; McCarthy, Linda P.; Orton, Alice M.

2015-08-17

The U.S. Geological Survey Woods Hole Coastal and Marine Science Center has created a Data Library to organize, preserve, and make available the field, laboratory, and modeling data collected and processed by Woods Hole Coastal and Marine Science Center staff. This Data Library supports current research efforts by providing unique, historic datasets with accompanying metadata. The Woods Hole Coastal and Marine Science Center’s Data Library has custody of historic data and records that are still useful for research, and assists with preservation and distribution of marine science records and data in the course of scientific investigation and experimentation by researchers and staff at the science center.

15 CFR 921.4 - Relationship to other provisions of the Coastal Zone Management Act, and to the Marine Protection...

Science.gov (United States)

2010-01-01

... the Coastal Zone Management Act, and to the Marine Protection, Research and Sanctuaries Act. 921.4... provisions of the Coastal Zone Management Act, and to the Marine Protection, Research and Sanctuaries Act. (a... affecting the state's coastal zone, must be undertaken in a manner consistent to the maximum extent...

Differentiating littering, urban runoff and marine transport as sources of marine debris in coastal and estuarine environments

Science.gov (United States)

Willis, Kathryn; Denise Hardesty, Britta; Kriwoken, Lorne; Wilcox, Chris

2017-03-01

Marine debris is a burgeoning global issue with economic, ecological and aesthetic impacts. While there are many studies now addressing this topic, the influence of urbanisation factors such as local population density, stormwater drains and roads on the distribution of coastal litter remains poorly understood. To address this knowledge gap, we carried out standardized surveys at 224 transect surveys at 67 sites in two estuaries and along the open coast in Tasmania, Australia. We explored the relative support for three hypotheses regarding the sources of the debris; direct deposition by beachgoers, transport from surrounding areas via storm water drains and coastal runoff, and onshore transport from the marine system. We found strong support for all three mechanisms, however, onshore transport from the marine reservoir was the most important mechanism. Overall, the three models together explained 45.8 percent of the variation in our observations. Our results also suggest that most debris released into the marine environment is deposited locally, which may be the answer to where all the missing plastic is in the ocean. Furthermore, local interventions are likely to be most effective in reducing land-based inputs into the ocean.

Fouling diatom community with reference to substratum variability in tropical marine environment

Digital Repository Service at National Institute of Oceanography (India)

Mitbavkar, S.; Desai, D.V.; Khandeparker, L.; Anil, A.C.; Wagh, A.B.

form encountered. The paper deals with the qualitative and quantitative aspects of diatom colonization, their community structure, and correlation between the prevailing diatom population in the environment and that in the fouling community...

Low-Molecular-Weight Metabolites from Diatoms: Structures, Biological Roles and Biosynthesis

Directory of Open Access Journals (Sweden)

Valentin Stonik

2015-06-01

Full Text Available Diatoms are abundant and important biological components of the marine environment that biosynthesize diverse natural products. These microalgae are rich in various lipids, carotenoids, sterols and isoprenoids, some of them containing toxins and other metabolites. Several groups of diatom natural products have attracted great interest due to their potential practical application as energy sources (biofuel, valuable food constituents, and prospective materials for nanotechnology. In addition, hydrocarbons, which are used in climate reconstruction, polyamines which participate in biomineralization, new apoptotic agents against tumor cells, attractants and deterrents that regulate the biochemical communications between marine species in seawaters have also been isolated from diatoms. However, chemical studies on these microalgae are complicated by difficulties, connected with obtaining their biomass, and the influence of nutrients and contaminators in their environment as well as by seasonal and climatic factors on the biosynthesis of the corresponding natural products. Overall, the number of chemically studied diatoms is lower than that of other algae, but further studies, particularly those connected with improvements in the isolation and structure elucidation technique as well as the genomics of diatoms, promise both to increase the number of studied species with isolated biologically active natural products and to provide a clearer perception of their biosynthesis.

Millimeter-sized marine plastics: a new pelagic habitat for microorganisms and invertebrates

OpenAIRE

Reisser, Julia Wiener; Shaw, Jeremy; Hallegraeff, Gustaaf; Proietti, Maíra Carneiro; Barnes, David; Thums, Michele; Wilcox, Chris; Hardesty, Britta Denise; Pattiaratchi, Charitha

2014-01-01

Millimeter-sized plastics are abundant in most marine surface waters, and known to carry fouling organisms that potentially play key roles in the fate and ecological impacts of plastic pollution. In this study we used scanning electron microscopy to characterize biodiversity of organisms on the surface of 68 small floating plastics (length range = 1.7–24.3 mm, median = 3.2 mm) from Australia-wide coastal and oceanic, tropical to temperate sample collections. Diatoms were the most diverse grou...

Spatial distribution of fallout 137Cs in the coastal marine environment of India

International Nuclear Information System (INIS)

Jha, S.K.; Gothankar, S.S.; Sartandel, S.; Pote, M.B.; Hemalatha, P.; Rajan, M.P.; Vidyasagar, D.; Indumati, S.P.; Shrivastava, R.; Puranik, V.D.

2012-01-01

The data on the fallout 137 Cs in the coastal marine environment assume significance in view of massive expansion of nuclear power plants in the Asia-Pacific region and to fulfill the benchmark study required to evaluate the possible impact of the Fukushima radioactive releases in the Asia-Pacific region. Measurements of 137 Cs in sea water, along with salinity and temperature, were carried out at 30 locations covering the coastal area of the Arabian Sea and the Bay of Bengal. For the present study the Indian coastal area is divided in three different regions. The 137 Cs concentration in sea water of the entire Indian coastal region varies from 0.30 to 1.25 Bq m −3 . The data obtained in the present study was compared with the North Indian Ocean data and it was observed that there is a 33% decrease in the Arabian Sea (region I), 50% in the high rainfall coastal area (region II) and 24% in the Bay of Bengal (region III). - Highlights: ► Benchmark value of 137 Cs in coastal environment of Arabian Sea and Bay of Bengal. ► International reference source of 137 Cs in coastal marine environment of India. ► In-situ pre-concentration technique for measurement of 137 Cs. ► Comparison of 137 Cs Indian coastal data with ASPAMARD.

Diatom assemblages as guides to flow conditions during the 2004 Indian Ocean tsunami at Phra Thong Island, Thailand

Science.gov (United States)

Sawai, Y.; Jankaew, K.; Martin, M. E.; Choowong, M.; Charoentitirat, T.; Prendergast, A.

2008-12-01

Diatom assemblages in the 2004 tsunami deposits of Phra Thong Island, Thailand represent flow conditions during the tsunami. The tsunami deposit consists of single or multiple graded beds. Diatom assemblages in the lowermost part of the deposit predominantly comprise beach and subtidal species. In the middle part of the deposit, the assemblages are dominated by marine plankton with increasing finer fractions. A mixed assemblage of freshwater, brackish, and marine species occupies the uppermost part of the deposit. Changes in flow conditions during the tsunami can explain these diatom assemblage variations. During fast current velocities, medium sand is deposited; only beach and subtidal diatoms that live attached to the sand can be incorporated into the tsunami deposit under these flow conditions. It is difficult for diatoms in suspension to settle out under fast current velocities. With decreasing current velocities, marine plankton can settle out of the water column .Finally, during the suspension stage (calm currents) between tsunami waves, the entrained freshwater, brackish, and marine species settle out with mud and plant trash. Fewer broken valves in the lowermost part of the deposit is probably a results of rapid entrainment, whilst selective breakage of marine plankton (Thalassionema nitzschioides, and Thalassiosira and Coscinodiscus spp.) in the middle part of the deposit probably results from abrasion by turbulent current before their deposition.

Inorganic carbon availability in benthic diatom communities: photosynthesis and migration.

Science.gov (United States)

Marques da Silva, Jorge; Cruz, Sónia; Cartaxana, Paulo

2017-09-05

Diatom-dominated microphytobenthos (MPB) is the main primary producer of many intertidal and shallow subtidal environments, being therefore of critical importance to estuarine and coastal food webs. Owing to tidal cycles, intertidal MPB diatoms are subjected to environmental conditions far more variable than the ones experienced by pelagic diatoms (e.g. light, temperature, salinity, desiccation and nutrient availability). Nevertheless, benthic diatoms evolved adaptation mechanisms to these harsh conditions, including the capacity to move within steep physical and chemical gradients, allowing them to perform photosynthesis efficiently. In this contribution, we will review present knowledge on the effects of dissolved inorganic carbon (DIC) availability on photosynthesis and productivity of diatom-dominated MPB. We present evidence of carbon limitation of photosynthesis in benthic diatom mats and highly productive MPB natural communities. Furthermore, we hypothesize that active vertical migration of epipelic motile diatoms could overcome local depletion of DIC in the photic layer, providing the cells alternately with light and inorganic carbon supply. The few available longer-term experiments on the effects of inorganic carbon enrichment on the productivity of diatom-dominated MPB have yielded inconsistent results. Therefore, further studies are needed to properly assess the response of MPB communities to increased CO 2 and ocean acidification related to climate change.This article is part of the themed issue 'The peculiar carbon metabolism in diatoms'. © 2017 The Author(s).

Impact of marine influence and cultivation on the diatom flora of ...

African Journals Online (AJOL)

During a limnological and palaeolimnological study of the western part of the Great Coast of Senegal, an analysis of diatoms was carried out in Thiaroye Pond in the suburbs of Dakar. Current diatom flora in the water and on floating plants, and subfossil flora in two cores were sampled in 1996 and 2003. A total of 104 ...

CO2-induced seawater acidification affects physiological performance of the marine diatom Phaeodactylum tricornutum

Directory of Open Access Journals (Sweden)

U. Riebesell

2010-09-01

Full Text Available CO2/pH perturbation experiments were carried out under two different pCO2 levels (39.3 and 101.3 Pa to evaluate effects of CO2-induced ocean acidification on the marine diatom Phaeodactylum tricornutum. After acclimation (>20 generations to ambient and elevated CO2 conditions (with corresponding pH values of 8.15 and 7.80, respectively, growth and photosynthetic carbon fixation rates of high CO2 grown cells were enhanced by 5% and 12%, respectively, and dark respiration stimulated by 34% compared to cells grown at ambient CO2. The half saturation constant (Km for carbon fixation (dissolved inorganic carbon, DIC increased by 20% under the low pH and high CO2 condition, reflecting a decreased affinity for HCO3– or/and CO2 and down-regulated carbon concentrating mechanism (CCM. In the high CO2 grown cells, the electron transport rate from photosystem II (PSII was photoinhibited to a greater extent at high levels of photosynthetically active radiation, while non-photochemical quenching was reduced compared to low CO2 grown cells. This was probably due to the down-regulation of CCM, which serves as a sink for excessive energy. The balance between these positive and negative effects on diatom productivity will be a key factor in determining the net effect of rising atmospheric CO2 on ocean primary production.

Behaviour of Radium in coastal marine water of India - Behaviour of Radium in coastal marine environment of India

Energy Technology Data Exchange (ETDEWEB)

Jha, S.K.; Sartandel, S.; Tripathi, R.M. [Environmental Radioactivity measurement Section, Health Physics Division, Bhabha Atomic Research Centre, Mumbai-400085 (India)

2014-07-01

In the recent years, there has also been an increased recognition of the radiological significance of non-nuclear process of natural radioactivity in particular {sup 226}Ra, {sup 228}Ra, {sup 222}Rn, {sup 210}Po and {sup 210}Pb produced, for example by Phosphate processing plants, offshore oil and gas installations and ceramic industries etc. Keeping this in mind, special distribution of radium was carried out to generate region specific values of Radium. The Indian Ocean differs from the Atlantic and Pacific Oceans in its limited northward extent, to only 25 deg. N. Indian subcontinent divides the Indian ocean in the north into two tropical basin namely Arabian sea and Bay of Bengal both being located within same latitude and being under the direct influence of monsoon. For measurements of {sup 226}Ra and {sup 228}Ra concentration in the coastal marine waters of India, MnO{sub 2} impregnated cartridge based in-situ pre-concentration technique was applied by passing 1000 liters of seawater at thirty locations covering Arabian Sea in the west of India and Bay of Bengal in the east. {sup 226}Ra was estimated using gamma ray peak of its daughter radionuclides {sup 214}Bi and {sup 214}Pb while {sup 228}Ra was estimated from its daughter {sup 228}Ac. {sup 214}Pb emissions occur at 295 and 352 keV; {sup 214}Bi has an emission at 609 keV. For {sup 228}Ac gamma emissions at 911 keV, 968 keV and 338 keV were used. In the coastal waters, {sup 226}Ra and {sup 228}Ra concentration was observed to be in the range of 0.69 to 4.10 mBql{sup -1} and 0.70 to 8 Bq m{sup -3} respectively with an average of 1.52 and 4.53 Bq m{sup -3}. The concentration of {sup 228}Ra was observed to be more than {sup 226}Ra in all the locations. The activity ratio of {sup 228}Ra/{sup 226}Ra in coastal marine water from the Bay of Bengal showed a ratio varying from 0.8 to 2.4 with a mean of 2.1.In the present study, activity ratio varies from 1.9 to 2.4 at Karaikkal. But the regions of Rameswaram and

NODC Standard Format Marine Birds from Coastal Alaska and Puget Sound Data (1979): Marine Bird Surveys (F041) (NODC Accession 0014160)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Marine Bird Surveys (F041) is one of a group of seven datasets related to Marine Birds from Coastal Alaska and Puget Sound Data (1979). Each dataset uses the NODC...

A marine to freshwater sediment succession from Kowhai Beach wetland, Northland : implications for Holocene sea level

International Nuclear Information System (INIS)

Hicks, H.; Nichol, S.L.

2007-01-01

An infilled wetland located behind coastal dunes in north-east Northland is used to reconstruct a local history of environmental change spanning early Holocene (c. 7000 yr BP) to modern time. Proxy indicators (sediment texture, diatoms and pollen) provide evidence for a transition from marginal marine- to brackish- to freshwater-conditions in the wetland. Radiocarbon ages constrain the chronology of this succession to 7880-7430 cal. yr BP for the early period of marine conditions, 3570-3210 cal. yr BP for the latter brackish phase and 1060-800 cal. yr BP for the change to freshwater conditions. Within this succession, the diatom record preserves a strong brackish signal at core depths above the limit of the modern tidal range. This is presented as preliminary evidence for a mid-Holocene sea level highstand for northern New Zealand of approximately 1.2 m above present mean sea level. (author). 40 refs., 7 figs., 1 tab

Derivation of a water quality guideline for aluminium in marine waters.

Science.gov (United States)

Golding, Lisa A; Angel, Brad M; Batley, Graeme E; Apte, Simon C; Krassoi, Rick; Doyle, Chris J

2015-01-01

Metal risk assessment of industrialized harbors and coastal marine waters requires the application of robust water quality guidelines to determine the likelihood of biological impacts. Currently there is no such guideline available for aluminium in marine waters. A water quality guideline of 24 µg total Al/L has been developed for aluminium in marine waters based on chronic 10% inhibition or effect concentrations (IC10 or EC10) and no-observed-effect concentrations (NOECs) from 11 species (2 literature values and 9 species tested including temperate and tropical species) representing 6 taxonomic groups. The 3 most sensitive species tested were a diatom Ceratoneis closterium (formerly Nitzschia closterium; IC10 = 18 µg Al/L, 72-h growth rate inhibition) aluminium forms of aluminate (Al(OH4 (-) ) and aluminium hydroxide (Al(OH)3 (0) ) although both dissolved, and particulate aluminium contributed to toxicity in the diatom Minutocellus polymorphus and green alga Dunaliella tertiolecta. In contrast, aluminium toxicity to the green flagellate alga Tetraselmis sp. was the result of particulate aluminium only. Four species, a brown macroalga (Hormosira banksii), sea urchin embryo (Heliocidaris tuberculata), and 2 juvenile fish species (Lates calcarifer and Acanthochromis polyacanthus), were not adversely affected at the highest test concentration used. © 2014 SETAC.

Effect of ageing on survival of benthic diatom propagules

Digital Repository Service at National Institute of Oceanography (India)

Anil, A.C.; Mitbavkar, S.; De; Hegde, S.; De; Meher, S.S.; Banerjee, D.

unfavorable for vegetative growth, many diatoms form resting stages to survive cell degradation or death (Anderson, 1975; Malone, 1980; Hargraves and French, 1983; Fryxell, 1990). Various external factors like availability of nutrients (N, P, Fe, Si.... 128, 497-508. 15 Lewis, J., Harris, A.S.D., Jones, K.J., Edmonds, R.L., 1999. Long-term survival of marine planktonic diatoms and dinoflagellates in stored sediment samples. J. Plank. Res. 21, 343- 354. Malone, T.C., 1980. Algal size. In...

Photosynthetic Pigments in Diatoms.

Science.gov (United States)

Kuczynska, Paulina; Jemiola-Rzeminska, Malgorzata; Strzalka, Kazimierz

2015-09-16

Photosynthetic pigments are bioactive compounds of great importance for the food, cosmetic, and pharmaceutical industries. They are not only responsible for capturing solar energy to carry out photosynthesis, but also play a role in photoprotective processes and display antioxidant activity, all of which contribute to effective biomass and oxygen production. Diatoms are organisms of a distinct pigment composition, substantially different from that present in plants. Apart from light-harvesting pigments such as chlorophyll a, chlorophyll c, and fucoxanthin, there is a group of photoprotective carotenoids which includes β-carotene and the xanthophylls, diatoxanthin, diadinoxanthin, violaxanthin, antheraxanthin, and zeaxanthin, which are engaged in the xanthophyll cycle. Additionally, some intermediate products of biosynthetic pathways have been identified in diatoms as well as unusual pigments, e.g., marennine. Marine algae have become widely recognized as a source of unique bioactive compounds for potential industrial, pharmaceutical, and medical applications. In this review, we summarize current knowledge on diatom photosynthetic pigments complemented by some new insights regarding their physico-chemical properties, biological role, and biosynthetic pathways, as well as the regulation of pigment level in the cell, methods of purification, and significance in industries.

Photosynthetic Pigments in Diatoms

Directory of Open Access Journals (Sweden)

Paulina Kuczynska

2015-09-01

Full Text Available Photosynthetic pigments are bioactive compounds of great importance for the food, cosmetic, and pharmaceutical industries. They are not only responsible for capturing solar energy to carry out photosynthesis, but also play a role in photoprotective processes and display antioxidant activity, all of which contribute to effective biomass and oxygen production. Diatoms are organisms of a distinct pigment composition, substantially different from that present in plants. Apart from light-harvesting pigments such as chlorophyll a, chlorophyll c, and fucoxanthin, there is a group of photoprotective carotenoids which includes β-carotene and the xanthophylls, diatoxanthin, diadinoxanthin, violaxanthin, antheraxanthin, and zeaxanthin, which are engaged in the xanthophyll cycle. Additionally, some intermediate products of biosynthetic pathways have been identified in diatoms as well as unusual pigments, e.g., marennine. Marine algae have become widely recognized as a source of unique bioactive compounds for potential industrial, pharmaceutical, and medical applications. In this review, we summarize current knowledge on diatom photosynthetic pigments complemented by some new insights regarding their physico-chemical properties, biological role, and biosynthetic pathways, as well as the regulation of pigment level in the cell, methods of purification, and significance in industries.

What if the Diatoms of the Deep Chlorophyll Maximum Can Ascend?

Science.gov (United States)

Villareal, T. A.

2016-02-01

Buoyancy regulation is an integral part of diatom ecology via its role in sinking rates and is fundamental to understanding their distribution and abundance. Numerous studies have documented the effects of size and nutrition on sinking rates. Many pelagic diatoms have low intrinsic sinking rates when healthy and nutrient-replete (deep chlorophyll maximum. The potential for ascending behavior adds an additional layer of complexity by allowing both active depth regulation similar to that observed in flagellated taxa and upward transport by some fraction of deep euphotic zone diatom blooms supported by nutrient injection. In this talk, I review the data documenting positive buoyancy in small diatoms, offer direct visual evidence of ascending behavior in common diatoms typical of both oceanic and coastal zones, and note the characteristics of sinking rate distributions within a single species. Buoyancy control leads to bidirectional movement at similar rates across a wide size spectrum of diatoms although the frequency of ascending behavior may be only a small portion of the individual species' abundance. While much remains to be learned, the paradigm of unidirectional downward movement by diatoms is both inaccurate and an oversimplification.

bioSearch : A glimpse into marine biodiversity of Indian coastal waters

Digital Repository Service at National Institute of Oceanography (India)

Kakodkar, A.P.; Alornekar, A.; DSouza, R.; Thomas, T.R.A.; Divekar, R.; Nath, I.V.A.; Kavlekar, D.P.; Ingole, B.S.; Bharathi, P.A.L.

bioSearch is a database application developed to digitize marine biodiversity of Indian coastal waters. A user can obtain information on organism’s binomial and common names, synonyms, taxonomy, morphology, ecology, economic importance, geographical...

Steady-state growth of the marine diatom Thalassiosira pseudonana

International Nuclear Information System (INIS)

Olson, R.J.; SooHoo, J.B.; Kiefer, D.A.

1980-01-01

Seasonal studies of the vertical distribution of nitrate, nitrite, and phytoplankton in the oceans and studies using 15 N as a tracer of nitrate metabolism indicate that the reduction of nitrate by phytoplankton is a source of nitrite in the upper waters of the ocean. To better understand this process, the relationship between nitrate uptake and nitrite production has been examined with continuous cultures of the small marine diatom Thalassiosira pseudonana. In a turbidostat culture, the rates of nitrite production by T. Pseudonana increase with light intensity. This process is only loosely coupled to rates of nitrate assimilation since the ratio of net nitrite production to total nitrate assimilation increases with increased rates of growth. In continuous cultures where steady-state concentrations of nitrate and nitrite were varied, T. pseudonana produced nitrite at rates which increased with increasing concentrations of nitrate. Again, the rates of nitrite production were uncoupled from rates of nitrate assimilation. The study was used to derive a mathematical description of nitrate and nitrite metabolism by T. pseudonana. The validity of this model was supported by the results of a study in which 15 N-labeled nitrite was introduced into the continuous culture, and the model was used to examine patterns in distribution of nitrite in the Antarctic Ocean and the Sargasso Sea

NODC Standard Format Marine Birds from Coastal Alaska and Puget Sound Data (1975-1978): Marine Bird Habitats (F040) (NODC Accession 0014159)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Marine Bird Habitats (F040) is one of a group of seven datasets related to Marine Birds from Coastal Alaska and Puget Sound Data (1975 -1978). Each dataset uses the...

Accumulation of radionuclides in selected marine biota from Manjung coastal area

Energy Technology Data Exchange (ETDEWEB)

Abdullah, Anisa, E-mail: coppering@ymail.com; Hamzah, Zaini; Wood, Ab. Khalik [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450, Shah Alam, Selangor (Malaysia); Saat, Ahmad [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450, Shah Alam, Selangor (Malaysia); Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Alias, Masitah [TNB Reasearch Sdn. Bhd., Kawasan Institusi Penyelidikan, 43000 Kajang, Selangor (Malaysia)

2015-04-29

Distribution of radionuclides from anthropogenic activities has been intensively studied due to the accumulation of radionuclides in marine ecosystem. Manjung area is affected by rapid population growth and socio-economic development such as heavy industrial activities including coal fired power plant, iron foundries, port development and factories, agricultural runoff, waste and toxic discharge from factories.It has radiological risk and toxic effect when effluent from the industries in the area containing radioactive materials either being transported to the atmosphere and deposited back over the land or by run off to the river and flow into coastal area and being absorbed by marine biota. Radionuclides presence in the marine ecosystem can be adversely affect human health when it enters the food chain. This study is focusing on the radionuclides [thorium (Th), uranium (U), radium-226 ({sup 226}Ra), radium-228 ({sup 228}Ra) and potassium-40 ({sup 40}K)] content in marine biota and sea water from Manjung coastal area. Five species of marine biota including Johnius dussumieri (Ikan Gelama), Pseudorhombus malayanus (Ikan Sebelah), Arius maculatus (Ikan Duri), Portunus pelagicus (Ketam Renjong) and Charybdis natator (Ketam Salib) were collected during rainy and dry seasons. Measurements were carried out using Inductively Coupled Plasma Mass Spectrometer (ICPMS). The results show that the concentration of radionuclides varies depends on ecological environment of respective marine biota species. The concentrations and activity concentrations are used for the assessment of potential internal hazard index (H{sub in}), transfer factor (TF), ingestion dose rate (D) and health risk index (HRI) to monitor radiological risk for human consumption.

Accumulation of radionuclides in selected marine biota from Manjung coastal area

International Nuclear Information System (INIS)

Abdullah, Anisa; Hamzah, Zaini; Wood, Ab. Khalik; Saat, Ahmad; Alias, Masitah

2015-01-01

Distribution of radionuclides from anthropogenic activities has been intensively studied due to the accumulation of radionuclides in marine ecosystem. Manjung area is affected by rapid population growth and socio-economic development such as heavy industrial activities including coal fired power plant, iron foundries, port development and factories, agricultural runoff, waste and toxic discharge from factories.It has radiological risk and toxic effect when effluent from the industries in the area containing radioactive materials either being transported to the atmosphere and deposited back over the land or by run off to the river and flow into coastal area and being absorbed by marine biota. Radionuclides presence in the marine ecosystem can be adversely affect human health when it enters the food chain. This study is focusing on the radionuclides [thorium (Th), uranium (U), radium-226 ( 226 Ra), radium-228 ( 228 Ra) and potassium-40 ( 40 K)] content in marine biota and sea water from Manjung coastal area. Five species of marine biota including Johnius dussumieri (Ikan Gelama), Pseudorhombus malayanus (Ikan Sebelah), Arius maculatus (Ikan Duri), Portunus pelagicus (Ketam Renjong) and Charybdis natator (Ketam Salib) were collected during rainy and dry seasons. Measurements were carried out using Inductively Coupled Plasma Mass Spectrometer (ICPMS). The results show that the concentration of radionuclides varies depends on ecological environment of respective marine biota species. The concentrations and activity concentrations are used for the assessment of potential internal hazard index (H in ), transfer factor (TF), ingestion dose rate (D) and health risk index (HRI) to monitor radiological risk for human consumption

Accumulation of radionuclides in selected marine biota from Manjung coastal area

Science.gov (United States)

Abdullah, Anisa; Hamzah, Zaini; Saat, Ahmad; Wood, Ab. Khalik; Alias, Masitah

2015-04-01

Distribution of radionuclides from anthropogenic activities has been intensively studied due to the accumulation of radionuclides in marine ecosystem. Manjung area is affected by rapid population growth and socio-economic development such as heavy industrial activities including coal fired power plant, iron foundries, port development and factories, agricultural runoff, waste and toxic discharge from factories.It has radiological risk and toxic effect when effluent from the industries in the area containing radioactive materials either being transported to the atmosphere and deposited back over the land or by run off to the river and flow into coastal area and being absorbed by marine biota. Radionuclides presence in the marine ecosystem can be adversely affect human health when it enters the food chain. This study is focusing on the radionuclides [thorium (Th), uranium (U), radium-226 (226Ra), radium-228 (228Ra) and potassium-40 (40K)] content in marine biota and sea water from Manjung coastal area. Five species of marine biota including Johnius dussumieri (Ikan Gelama), Pseudorhombus malayanus (Ikan Sebelah), Arius maculatus (Ikan Duri), Portunus pelagicus (Ketam Renjong) and Charybdis natator (Ketam Salib) were collected during rainy and dry seasons. Measurements were carried out using Inductively Coupled Plasma Mass Spectrometer (ICPMS). The results show that the concentration of radionuclides varies depends on ecological environment of respective marine biota species. The concentrations and activity concentrations are used for the assessment of potential internal hazard index (Hin), transfer factor (TF), ingestion dose rate (D) and health risk index (HRI) to monitor radiological risk for human consumption.

Diatom production in the marine environment : implications for larval fish growth and condition

DEFF Research Database (Denmark)

St. John, Michael; Clemmesen, C.; Lund, T.

2001-01-01

To test the effects of diatom production on larval fish growth and condition. laboratory experiments were performed with larval North Sea cod reared on different algal food chains. These food chains were based on cultures of (a) the diatoms Skeletonema costatum and Thalassiosira weissflogii: (b....../omega6 fatty acids in the algal source had no significant effect. The highest and lowest growth rates were observed in food chains based on H. triquetra and T. weissflogii. respectively (means for days 14-16 of 4.0 and - 4.7). The mixed diatom/dinoflagellate diet resulted in inter- mediate growth rates...... and condition. Regressions of growth rates against EPA and DHA content indicated no inhibitory effect of diatom production on growth in larval cod...

Coastal Marine Pollution in Dar es Salaam (Tanzania) relative to ...

African Journals Online (AJOL)

Pollution surveys were undertaken during 2007 and 2008 in the coastal marine environment of Dar es Salaam and the remote Ras Dege Creek. The objective was to determine the levels of microbial contamination, heavy metals and persistent organic pollutants and compare these with the recommended environmental ...

Seasonal variations in fouling diatom communities on the Yantai coast

Science.gov (United States)

Yang, Cuiyun; Wang, Jianhua; Yu, Yang; Liu, Sujing; Xia, Chuanhai

2015-03-01

Fouling diatoms are a main component of biofilm, and play an important role in marine biofouling formation. We investigated seasonal variations in fouling diatom communities that developed on glass slides immersed in seawater, on the Yantai coast, northern Yellow Sea, China, using microscopy and molecular techniques. Studies were conducted during 2012 and 2013 over 3, 7, 14, and 21 days in each season. The abundance of attached diatoms and extracellular polymeric substances increased with exposure time of the slides to seawater. The lowest diatom density appeared in winter and the highest species richness and diversity were found in summer and autumn. Seasonal variation was observed in the structure of fouling diatom communities. Pennate diatoms Cylindrotheca, Nitzschia, Navicula, Amphora, Gomphonema, and Licmophora were the main fouling groups. Cylindrotheca sp. dominated in the spring. Under laboratory culture conditions, we found that Cylindrotheca grew very fast, which might account for the highest density of this diatom in spring. The lower densities in summer and autumn might result from the emergence of fouling animals and environmental factors. The Cylindrotheca sp. was identified as Cylindrotheca closterium using18S rDNA sequencing. The colonization process of fouling diatoms and significant seasonal variation in this study depended on environmental and biological factors. Understanding the basis of fouling diatoms is essential and important for developing new antifouling techniques.

A study on biological activity of marine fungi from different habitats in coastal regions

OpenAIRE

Zhou, Songlin; Wang, Min; Feng, Qi; Lin, Yingying; Zhao, Huange

2016-01-01

In recent years, marine fungi have become an important source of active marine natural products. Former researches are limited in habitats selection of fungi with bioactive compounds. In this paper were to measure antibacterial and antitumor cell activity for secondary metabolites of marine fungi, which were isolated from different habitats in coastal regions. 195 strains of marine fungi were isolated and purified from three different habitats. They biologically active experiment results show...

Specificity of lipoxygenase pathways supports species delineation in the marine diatom genus Pseudo-nitzschia.

Directory of Open Access Journals (Sweden)

Nadia Lamari

Full Text Available Oxylipins are low-molecular weight secondary metabolites derived from the incorporation of oxygen into the carbon chains of polyunsaturated fatty acids (PUFAs. Oxylipins are produced in many prokaryotic and eukaryotic lineages where they are involved in a broad spectrum of actions spanning from stress and defense responses, regulation of growth and development, signaling, and innate immunity. We explored the diversity in oxylipin patterns in the marine planktonic diatom Pseudo-nitzschia. This genus includes several species only distinguishable with the aid of molecular markers. Oxylipin profiles of cultured strains were obtained by reverse phase column on a liquid chromatograph equipped with UV photodiode detector and q-ToF mass spectrometer. Lipoxygenase compounds were mapped on phylogenies of the genus Pseudo-nitzschia inferred from the nuclear encoded hyper-variable region of the LSU rDNA and the plastid encoded rbcL. Results showed that the genus Pseudo-nitzschia exhibits a rich and varied lipoxygenase metabolism of eicosapentaenoic acid (EPA, with a high level of specificity for oxylipin markers that generally corroborated the genotypic delineation, even among genetically closely related cryptic species. These results suggest that oxylipin profiles constitute additional identification tools for Pseudo-nitzschia species providing a functional support to species delineation obtained with molecular markers and morphological traits. The exploration of the diversity, patterns and plasticity of oxylipin production across diatom species and genera will also provide insights on the ecological functions of these secondary metabolites and on the selective pressures driving their diversification.

Global learning for local solutions: Reducing vulnerability of marine-dependent coastal communities

Science.gov (United States)

Salim, S. S.; Paytan, A.

2016-12-01

The project `Global learning for local solutions: Reducing vulnerability of marine-dependent coastal communities' (GULLS) falls within the Belmont Forum and G8 Research Councils Initiative on Multilateral Research Funding. Participants include teams from nine countries: Australia, Brazil, India, Madagascar, Mozambique, New Zealand, South Africa, the United Kingdom and the United States of America. The project focuses on five regional `hotspots' of climate and social change, defined as fast-warming marine areas and areas experiencing social tensions as a result of change: south-east Australia, Brazil, India, South Africa, and the Mozambique Channel and adjacent countries of Mozambique and Madagascar. These areas require most urgent attention and serve as valuable case studies for wider applications. The project aims to assist coastal communities and other stakeholders dependent on marine resources to adapt to climate change and variability through an integrated and trans-disciplinary approach. Combining best available global knowledge with local knowledge and conditions, it is exploring adaptation options and approaches to strengthen resilience at local and community levels, with a focus on options for reconciling the needs for food security with long-term sustainability and conservation. The project will also contribute to capacity development and empowering fishing communities and other fisheries-dependent stakeholders.A standardized vulnerability assessment framework is being developed that will be used to integrate results from natural, social and economic studies in order to identify needs and options for strengthening management and existing policies. Structured comparisons between the hot-spots will assist global efforts for adaptation and strengthening resilience in marine and coastal social-ecological systems.

Prevalence of microplastics in Singapore's coastal marine environment

International Nuclear Information System (INIS)

Ng, K.L.; Obbard, J.P. . E-mail esejpo@nus.edu.sg

2006-01-01

Microplastics have been recently identified as marine pollutants of significant concern due to their persistence, ubiquity and potential to act as vectors for the transfer and exposure of persistent organic pollutants to marine organisms. This study documents, for the first time, the presence and abundance of microplastics (>1.6 μm) in Singapore's coastal environment. An optimized sampling protocol for the collection and analysis of microplastics was developed, and beach sediments and seawater (surface microlayer and subsurface layer) samples were collected from nine different locations around the coastline. Low density microplastics were separated from sediments by flotation and polymer types were identified using Fourier transform infrared (FTIR) spectrometry. Synthetic polymer microplastics identified in beach sediments included polyethylene, polypropylene, polystyrene, nylon, polyvinyl alcohol and acrylonitrile butadiene styrene. Microplastics were detected in samples from four out of seven beach environments, with the greatest quantity found in sediments from two popular beaches in the eastern part of Singapore. Polyethylene, polypropylene and polystyrene microplastics were also found in the surface microlayer (50-60 μm) and subsurface layer (1 m) of coastal waters. The presence of microplastics in sediments and seawater is likely due to on-going waste disposal practices from industries and recreational activities, and discharge from shipping

Zinc affects differently growth, photosynthesis, antioxidant enzyme activities and phytochelatin synthase expression of four marine diatoms.

Science.gov (United States)

Nguyen-Deroche, Thi Le Nhung; Caruso, Aurore; Le, Thi Trung; Bui, Trang Viet; Schoefs, Benoît; Tremblin, Gérard; Morant-Manceau, Annick

2012-01-01

Zinc-supplementation (20 μM) effects on growth, photosynthesis, antioxidant enzyme activities (superoxide dismutase, ascorbate peroxidase, catalase), and the expression of phytochelatin synthase gene were investigated in four marine diatoms (Amphora acutiuscula, Nitzschia palea, Amphora coffeaeformis and Entomoneis paludosa). Zn-supplementation reduced the maximum cell density. A linear relationship was found between the evolution of gross photosynthesis and total chlorophyll content. The Zn treatment decreased the electron transport rate except in A. coffeaeformis and in E. paludosa at high irradiance. A linear relationship was found between the efficiency of light to evolve oxygen and the size of the light-harvesting antenna. The external carbonic anhydrase activity was stimulated in Zn-supplemented E. paludosa but was not correlated with an increase of photosynthesis. The total activity of the antioxidant enzymes did not display any clear increase except in ascorbate peroxidase activity in N. palea. The phytochelatin synthase gene was identified in the four diatoms, but its expression was only revealed in N. palea, without a clear difference between control and Zn-supplemented cells. Among the four species, A. paludosa was the most sensitive and A. coffeaeformis, the most tolerant. A. acutiuscula seemed to be under metal starvation, whereas, to survive, only N. palea developed several stress responses.

Zinc Affects Differently Growth, Photosynthesis, Antioxidant Enzyme Activities and Phytochelatin Synthase Expression of Four Marine Diatoms

Directory of Open Access Journals (Sweden)

Thi Le Nhung Nguyen-Deroche

2012-01-01

Full Text Available Zinc-supplementation (20 μM effects on growth, photosynthesis, antioxidant enzyme activities (superoxide dismutase, ascorbate peroxidase, catalase, and the expression of phytochelatin synthase gene were investigated in four marine diatoms (Amphora acutiuscula, Nitzschia palea, Amphora coffeaeformis and Entomoneis paludosa. Zn-supplementation reduced the maximum cell density. A linear relationship was found between the evolution of gross photosynthesis and total chlorophyll content. The Zn treatment decreased the electron transport rate except in A. coffeaeformis and in E. paludosa at high irradiance. A linear relationship was found between the efficiency of light to evolve oxygen and the size of the light-harvesting antenna. The external carbonic anhydrase activity was stimulated in Zn-supplemented E. paludosa but was not correlated with an increase of photosynthesis. The total activity of the antioxidant enzymes did not display any clear increase except in ascorbate peroxidase activity in N. palea. The phytochelatin synthase gene was identified in the four diatoms, but its expression was only revealed in N. palea, without a clear difference between control and Zn-supplemented cells. Among the four species, A. paludosa was the most sensitive and A. coffeaeformis, the most tolerant. A. acutiuscula seemed to be under metal starvation, whereas, to survive, only N. palea developed several stress responses.

A study on biological activity of marine fungi from different habitats in coastal regions.

Science.gov (United States)

Zhou, Songlin; Wang, Min; Feng, Qi; Lin, Yingying; Zhao, Huange

2016-01-01

In recent years, marine fungi have become an important source of active marine natural products. Former researches are limited in habitats selection of fungi with bioactive compounds. In this paper were to measure antibacterial and antitumor cell activity for secondary metabolites of marine fungi, which were isolated from different habitats in coastal regions. 195 strains of marine fungi were isolated and purified from three different habitats. They biologically active experiment results showed that fungi isolation from the mangrove habitats had stronger antibacterial activity than others, and the stains isolated from the estuarial habitats had the least antibacterial activity. However, the strains separated from beach habitats strongly inhibited tumor cell proliferation in vitro, and fungi of mangrove forest habitats had the weakest activity of inhibiting tumor. Meanwhile, 195 fungal strains belonged to 46 families, 84 genera, 142 species and also showed 137 different types of activity combinations by analyzing the inhibitory activity of the metabolites fungi for 4 strains of pathogenic bacteria and B-16 cells. The study investigated the biological activity of marine fungi isolated from different habitats in Haikou coastal regions. The results help us to understand bioactive metabolites of marine fungi from different habitats, and how to selected biological activity fungi from various marine habitats effectively.

A stress surveillance system based on calcium and nitric oxide in marine diatoms.

Directory of Open Access Journals (Sweden)

Assaf Vardi

2006-03-01

Full Text Available Diatoms are an important group of eukaryotic phytoplankton, responsible for about 20% of global primary productivity. Study of the functional role of chemical signaling within phytoplankton assemblages is still in its infancy although recent reports in diatoms suggest the existence of chemical-based defense strategies. Here, we demonstrate how the accurate perception of diatom-derived reactive aldehydes can determine cell fate in diatoms. In particular, the aldehyde (2E,4E/Z-decadienal (DD can trigger intracellular calcium transients and the generation of nitric oxide (NO by a calcium-dependent NO synthase-like activity, which results in cell death. However, pretreatment of cells with sublethal doses of aldehyde can induce resistance to subsequent lethal doses, which is reflected in an altered calcium signature and kinetics of NO production. We also present evidence for a DD-derived NO-based intercellular signaling system for the perception of stressed bystander cells. Based on these findings, we propose the existence of a sophisticated stress surveillance system in diatoms, which has important implications for understanding the cellular mechanisms responsible for acclimation versus death during phytoplankton bloom successions.

Diatom community structure on in-service cruise ship hulls.

Science.gov (United States)

Hunsucker, Kelli Zargiel; Koka, Abhishek; Lund, Geir; Swain, Geoffrey

2014-10-01

Diatoms are an important component of marine biofilms found on ship hulls. However, there are only a few published studies that describe the presence and abundance of diatoms on ships, and none that relate to modern ship hull coatings. This study investigated the diatom community structure on two in-service cruise ships with the same cruise cycles, one coated with an antifouling (AF) system (copper self-polishing copolymer) and the other coated with a silicone fouling-release (FR) system. Biofilm samples were collected during dry docking from representative areas of the ship and these provided information on the horizontal and vertical zonation of the hull, and intact and damaged coating and niche areas. Diatoms from the genera Achnanthes, Amphora and Navicula were the most common, regardless of horizontal ship zonation and coating type. Other genera were abundant, but their presence was more dependent on the ship zonation and coating type. Samples collected from damaged areas of the hull coating had a similar community composition to undamaged areas, but with higher diatom abundance. Diatom fouling on the niche areas differed from that of the surrounding ship hull and paralleled previous studies that investigated differences in diatom community structure on static and dynamically exposed coatings; niche areas were similar to static immersion and the hull to dynamic immersion. Additionally, diatom richness was greater on the ship with the FR coating, including the identification of several new genera to the biofouling literature, viz. Lampriscus and Thalassiophysa. These results are the first to describe diatom community composition on in-service ship hulls coated with a FR system. This class of coatings appears to have a larger diatom community compared to copper-based AF systems, with new diatom genera that have the ability to stick to ship hulls and withstand hydrodynamic forces, thus creating the potential for new problematic species in the biofilm.

ECONOMIC, POLITICAL, AND CIVIL SOCIETIES AT PEMUTERAN VILLAGE, BALI IN COASTAL AND MARINE ENVIRONMENTAL PRESERVATION

Directory of Open Access Journals (Sweden)

I Wayan Mudana

2013-02-01

Full Text Available This study was focused on questions (1 what factors caused the economic, political, and civil societies to invest their social capital in the preservation of marine and coastal environments at Pemuteran Village? (2 What was the social capital invested by the economic, political, and civil societies in the preservation of coastal and marine environments at Pemuteran Village like? (3 What was done to discipline the maintenance of the social capital invested in the preservation of the coastal and marine environments at Pemuteran Village? Some critical theories were used to analyze the answers to the problems. Qualitative research method with the approach of cultural studies was employed in this study. The data were collected through observation, in-depth interview, and library research. The data were qualitatively and descriptively analyzed. The result of the study showed that the cooperation among the economic, political, and civil societies to invest their social capital in the preservation of the marine and coastal environments at Pemuteran Village was based on the awareness of the condition of the natural environment, ecological smartness, meaningfulness which was economic, political, sociological, and socio-religious in nature, and developmental policy. The social capital invested by the economic, political and civil societies was in the forms of the ideologies of tri hita karana, nyegara-gunung, menyama braya, kinship system, neighborhood relation, traditional village, and administrative village. It was maintained through cultural socialization process, and physical and spiritual disciplining process.

Current status and future prospects for the assessment of marine and coastal ecosystem services: a systematic review.

Science.gov (United States)

Liquete, Camino; Piroddi, Chiara; Drakou, Evangelia G; Gurney, Leigh; Katsanevakis, Stelios; Charef, Aymen; Egoh, Benis

2013-01-01

Research on ecosystem services has grown exponentially during the last decade. Most of the studies have focused on assessing and mapping terrestrial ecosystem services highlighting a knowledge gap on marine and coastal ecosystem services (MCES) and an urgent need to assess them. We reviewed and summarized existing scientific literature related to MCES with the aim of extracting and classifying indicators used to assess and map them. We found 145 papers that specifically assessed marine and coastal ecosystem services from which we extracted 476 indicators. Food provision, in particular fisheries, was the most extensively analyzed MCES while water purification and coastal protection were the most frequently studied regulating and maintenance services. Also recreation and tourism under the cultural services was relatively well assessed. We highlight knowledge gaps regarding the availability of indicators that measure the capacity, flow or benefit derived from each ecosystem service. The majority of the case studies was found in mangroves and coastal wetlands and was mainly concentrated in Europe and North America. Our systematic review highlighted the need of an improved ecosystem service classification for marine and coastal systems, which is herein proposed with definitions and links to previous classifications. This review summarizes the state of available information related to ecosystem services associated with marine and coastal ecosystems. The cataloging of MCES indicators and the integrated classification of MCES provided in this paper establish a background that can facilitate the planning and integration of future assessments. The final goal is to establish a consistent structure and populate it with information able to support the implementation of biodiversity conservation policies.

Marennine, Promising Blue Pigments from a Widespread Haslea Diatom Species Complex

Directory of Open Access Journals (Sweden)

Romain Gastineau

2014-05-01

Full Text Available In diatoms, the main photosynthetic pigments are chlorophylls a and c, fucoxanthin, diadinoxanthin and diatoxanthin. The marine pennate diatom Haslea ostrearia has long been known for producing, in addition to these generic pigments, a water-soluble blue pigment, marennine. This pigment, responsible for the greening of oysters in western France, presents different biological activities: allelopathic, antioxidant, antibacterial, antiviral, and growth-inhibiting. A method to extract and purify marennine has been developed, but its chemical structure could hitherto not be resolved. For decades, H. ostrearia was the only organism known to produce marennine, and can be found worldwide. Our knowledge about H. ostrearia-like diatom biodiversity has recently been extended with the discovery of several new species of blue diatoms, the recently described H. karadagensis, H. silbo sp. inedit. and H. provincialis sp. inedit. These blue diatoms produce different marennine-like pigments, which belong to the same chemical family and present similar biological activities. Aside from being a potential source of natural blue pigments, H. ostrearia-like diatoms thus present a commercial potential for aquaculture, cosmetics, food and health industries.

A stress surveillance system based on calcium and nitric oxide in marine diatoms

NARCIS (Netherlands)

Vardi, A.; Formiggini, F.; Casotti, R.; De Martino, A.; Ribalet, F.; Miralto, A.; Bowler, C.

2006-01-01

Diatoms are an important group of eukaryotic phytoplankton, responsible for about 20% of global primary productivity. Study of the functional role of chemical signaling within phytoplankton assemblages is still in its infancy although recent reports in diatoms suggest the existence of chemical-based

A stress surveillance system based on calcium and nitric oxide in marine diatoms.

NARCIS (Netherlands)

Vardi, A.; Formiggini, F.; Casotti, R.; De Martino, A.; Ribalet, F.; Miralto, A.; Bowler, C.

2006-01-01

Diatoms are an important group of eukaryotic phytoplankton, responsible for about 20% of global primary productivity. Study of the functional role of chemical signaling within phytoplankton assemblages is still in its infancy although recent reports in diatoms suggest the existence of chemical-based

The Effect of Dissolved Polyunsaturated Aldehydes on Microzooplankton Growth Rates in the Chesapeake Bay and Atlantic Coastal Waters

Directory of Open Access Journals (Sweden)

Peter J. Lavrentyev

2015-05-01

Full Text Available Allelopathy is wide spread among marine phytoplankton, including diatoms, which can produce cytotoxic secondary metabolites such as polyunsaturated aldehydes (PUA. Most studies on diatom-produced PUA have been dedicated to their inhibitory effects on reproduction and development of marine invertebrates. However, little information exists on their impact on key herbivores in the ocean, microzooplankton. This study examined the effects of dissolved 2E,4E-octadienal and 2E,4E-heptadienal on the growth rates of natural ciliate and dinoflagellate populations in the Chesapeake Bay and the coastal Atlantic waters. The overall effect of PUA on microzooplankton growth was negative, especially at the higher concentrations, but there were pronounced differences in response among common planktonic species. For example, the growth of Codonella sp., Leegaardiella sol, Prorodon sp., and Gyrodinium spirale was impaired at 2 nM, whereas Strombidium conicum, Cyclotrichium gigas, and Gymnodinium sp. were not affected even at 20 nM. These results indicate that PUA can induce changes in microzooplankton dynamics and species composition.

The Effect of Dissolved Polyunsaturated Aldehydes on Microzooplankton Growth Rates in the Chesapeake Bay and Atlantic Coastal Waters

Science.gov (United States)

Lavrentyev, Peter J.; Franzè, Gayantonia; Pierson, James J.; Stoecker, Diane K.

2015-01-01

Allelopathy is wide spread among marine phytoplankton, including diatoms, which can produce cytotoxic secondary metabolites such as polyunsaturated aldehydes (PUA). Most studies on diatom-produced PUA have been dedicated to their inhibitory effects on reproduction and development of marine invertebrates. However, little information exists on their impact on key herbivores in the ocean, microzooplankton. This study examined the effects of dissolved 2E,4E-octadienal and 2E,4E-heptadienal on the growth rates of natural ciliate and dinoflagellate populations in the Chesapeake Bay and the coastal Atlantic waters. The overall effect of PUA on microzooplankton growth was negative, especially at the higher concentrations, but there were pronounced differences in response among common planktonic species. For example, the growth of Codonella sp., Leegaardiella sol, Prorodon sp., and Gyrodinium spirale was impaired at 2 nM, whereas Strombidium conicum, Cyclotrichium gigas, and Gymnodinium sp. were not affected even at 20 nM. These results indicate that PUA can induce changes in microzooplankton dynamics and species composition. PMID:25955757

NODC Standard Format Marine Birds from Coastal Alaska and Puget Sound Data (1975-1980): Marine Bird Sighting, Land Census (F034) (NODC Accession 0014156)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Standard Marine Bird Sighting, Land Census (F034) is one of a group of seven datasets related to Marine Birds from Coastal Alaska and Puget Sound Data (1975...

Indications for chlororespiration in relation to light regime in the marine diatom Thalassiosira weissflogii.

Science.gov (United States)

Dijkman, Nicole A; Kroon, Bernd M A

2002-04-01

The marine diatom Thalassiosira weissflogii was cultured under a light regime simulating the daily rise and fall of the sun. The light regime caused a daily cycle in non-photochemical quenching. Remarkable were the changes in fluorescence directly after a light-to-dark transition that occurred in addition to the changes induced by non-photochemical quenching. A transient non-photochemical reduction of PQ and of Q(A) was indicated by a transient increase in apparent F(o) and by changes in the shape of the fluorescence induction curve. The observed changes developed approximately the first 100-120 s after a light-to-dark transition and could be reversed by the application of far-red illumination. Chlororespiration is thought to cause the reduction of PQ and, as the PQ-pool is in equilibrium with Q(A), also a reduction of Q(A). The function and ecological relevance of chlororespiration are discussed.

Current Status and Future Prospects for the Assessment of Marine and Coastal Ecosystem Services: A Systematic Review

Science.gov (United States)

Liquete, Camino; Piroddi, Chiara; Drakou, Evangelia G.; Gurney, Leigh; Katsanevakis, Stelios; Charef, Aymen; Egoh, Benis

2013-01-01

Background Research on ecosystem services has grown exponentially during the last decade. Most of the studies have focused on assessing and mapping terrestrial ecosystem services highlighting a knowledge gap on marine and coastal ecosystem services (MCES) and an urgent need to assess them. Methodology/Principal Findings We reviewed and summarized existing scientific literature related to MCES with the aim of extracting and classifying indicators used to assess and map them. We found 145 papers that specifically assessed marine and coastal ecosystem services from which we extracted 476 indicators. Food provision, in particular fisheries, was the most extensively analyzed MCES while water purification and coastal protection were the most frequently studied regulating and maintenance services. Also recreation and tourism under the cultural services was relatively well assessed. We highlight knowledge gaps regarding the availability of indicators that measure the capacity, flow or benefit derived from each ecosystem service. The majority of the case studies was found in mangroves and coastal wetlands and was mainly concentrated in Europe and North America. Our systematic review highlighted the need of an improved ecosystem service classification for marine and coastal systems, which is herein proposed with definitions and links to previous classifications. Conclusions/Significance This review summarizes the state of available information related to ecosystem services associated with marine and coastal ecosystems. The cataloging of MCES indicators and the integrated classification of MCES provided in this paper establish a background that can facilitate the planning and integration of future assessments. The final goal is to establish a consistent structure and populate it with information able to support the implementation of biodiversity conservation policies. PMID:23844080

Copper-containing plastocyanin used for electron transport by an oceanic diatom.

Science.gov (United States)

Peers, Graham; Price, Neil M

2006-05-18

The supply of some essential metals to pelagic ecosystems is less than the demand, so many phytoplankton have slow rates of photosynthetic production and restricted growth. The types and amounts of metals required by phytoplankton depends on their evolutionary history and on their adaptations to metal availability, which varies widely among ocean habitats. Diatoms, for example, need considerably less iron (Fe) to grow than chlorophyll-b-containing taxa, and the oceanic species demand roughly one-tenth the amount of coastal strains. Like Fe, copper (Cu) is scarce in the open sea, but notably higher concentrations of it are required for the growth of oceanic than of coastal isolates. Here we report that the greater Cu requirement in an oceanic diatom, Thalassiosira oceanica, is entirely due to a single Cu-containing protein, plastocyanin, which--until now--was only known to exist in organisms with chlorophyll b and cyanobacteria. Algae containing chlorophyll c, including the closely related coastal species T. weissflogii, are thought to lack plastocyanin and contain a functionally equivalent Fe-containing homologue, cytochrome c6 (ref. 9). Copper deficiency in T. oceanica inhibits electron transport regardless of Fe status, implying a constitutive role for plastocyanin in the light reactions of photosynthesis in this species. The results suggest that selection pressure imposed by Fe limitation has resulted in the use of a Cu protein for photosynthesis in an oceanic diatom. This biochemical switch reduces the need for Fe and increases the requirement for Cu, which is relatively more abundant in the open sea.

Emerging contaminants in Belgian marine waters: single toxicant and mixture risks of pharmaceuticals.

Science.gov (United States)

Claessens, Michiel; Vanhaecke, Lynn; Wille, Klaas; Janssen, Colin R

2013-06-15

Knowledge on the effects of pharmaceuticals on aquatic marine ecosystems is limited. The aim of this study was therefore to establish the effect thresholds of pharmaceutical compounds occurring in the Belgian marine environment for the marine diatom Phaeodactylum tricornutum, and subsequently perform an environmental risk assessment for these substances. Additionally, a screening-level risk assessment was performed for the pharmaceutical mixtures. No immediate risk for acute toxic effects of these compounds on P. tricornutum were apparent at the concentrations observed in the Belgian marine environment. In two Belgian coastal harbours however, a potential chronic risk was observed for the β-blocker propranolol. No additional risks arising from the exposure to mixtures of pharmaceuticals present in the sampling area could be detected. However, as risk characterization ratios for mixtures of up to 0.5 were observed, mixture effects could emerge should more compounds be taken into account. Copyright © 2013 Elsevier Ltd. All rights reserved.

Enhancement of the reactive iron pool by marine diatoms

NARCIS (Netherlands)

Rijkenberg, Micha J. A.; Gerringa, Loes J. A.; Timmermans, Klaas R.; Fischer, Astrid C.; Kroon, Koos J.; Buma, Anita G. J.; Wolterbeek, Bert Th.; de Baar, Hein J. W.

2008-01-01

Short term (2 days) laboratory experiments were performed to study the change in irradiance induced production of Fe(II) in seawater in the presence of two open oceanic Southern Ocean diatom species, Thalassiosira sp. and Chaetoceros brevis. Three irradiance conditions were applied: 1) UVB+UVA+VIS,

Changes of the elemental distributions in marine diatoms as a reporter of sample preparation artefacts. A nuclear microscopy application

International Nuclear Information System (INIS)

Godinho, R.M.; Cabrita, M.T.; Alves, L.C.; Pinheiro, T.

2015-01-01

Studies of the elemental composition of whole marine diatoms cells have high interest as they constitute a direct measurement of environmental changes, and allow anticipating consequences of anthropogenic alterations to organisms, ecosystems and global marine geochemical cycles. Nuclear microscopy is a powerful tool allowing direct measurement of whole cells giving qualitative imaging of distribution, and quantitative determination of intracellular concentration. Major obstacles to the analysis of marine microalgae are high medium salinity and the recurrent presence of extracellular exudates produced by algae to maintain colonies in natural media and in vitro. The objective of this paper was to optimize the methodology of sample preparation of marine unicellular algae for elemental analysis with nuclear microscopy, allowing further studies on cellular response to metals. Primary cultures of Coscinodiscus wailesii maintained in vitro were used to optimize protocols for elemental analysis with nuclear microscopy techniques. Adequate cell preparation procedures to isolate the cells from media components and exudates were established. The use of chemical agents proved to be inappropriate for elemental determination and for intracellular morphological analysis. The assessment of morphology and elemental partitioning in cell compartments obtained with nuclear microscopy techniques enabled to infer their function in natural environment and imbalances in exposure condition. Exposure to metal affected C. wailesii morphology and internal elemental distribution

Changes of the elemental distributions in marine diatoms as a reporter of sample preparation artefacts. A nuclear microscopy application

Energy Technology Data Exchange (ETDEWEB)

Godinho, R.M. [Instituto de Bioengenharia e Biociências, Instituto Superior Técnico, Universidade de Lisboa, Lisboa (Portugal); Instituto Português do Mar e da Atmosfera, Lisboa (Portugal); Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Porto (Portugal); Cabrita, M.T. [Instituto Português do Mar e da Atmosfera, Lisboa (Portugal); Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Porto (Portugal); Alves, L.C. [Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Sacavém (Portugal); Pinheiro, T., E-mail: murmur@ctn.ist.utl.pt [Instituto de Bioengenharia e Biociências, Instituto Superior Técnico, Universidade de Lisboa, Lisboa (Portugal)

2015-04-01

Studies of the elemental composition of whole marine diatoms cells have high interest as they constitute a direct measurement of environmental changes, and allow anticipating consequences of anthropogenic alterations to organisms, ecosystems and global marine geochemical cycles. Nuclear microscopy is a powerful tool allowing direct measurement of whole cells giving qualitative imaging of distribution, and quantitative determination of intracellular concentration. Major obstacles to the analysis of marine microalgae are high medium salinity and the recurrent presence of extracellular exudates produced by algae to maintain colonies in natural media and in vitro. The objective of this paper was to optimize the methodology of sample preparation of marine unicellular algae for elemental analysis with nuclear microscopy, allowing further studies on cellular response to metals. Primary cultures of Coscinodiscus wailesii maintained in vitro were used to optimize protocols for elemental analysis with nuclear microscopy techniques. Adequate cell preparation procedures to isolate the cells from media components and exudates were established. The use of chemical agents proved to be inappropriate for elemental determination and for intracellular morphological analysis. The assessment of morphology and elemental partitioning in cell compartments obtained with nuclear microscopy techniques enabled to infer their function in natural environment and imbalances in exposure condition. Exposure to metal affected C. wailesii morphology and internal elemental distribution.

Intracellular Nitrate of Marine Diatoms as a Driver of Anaerobic Nitrogen Cycling in Sinking Aggregates

Directory of Open Access Journals (Sweden)

Anja Kamp

2016-11-01

Full Text Available Diatom-bacteria aggregates are key for the vertical transport of organic carbon in the ocean. Sinking aggregates also represent pelagic microniches with intensified microbial activity, oxygen depletion in the center, and anaerobic nitrogen cycling. Since some of the aggregate-forming diatom species store nitrate intracellularly, we explored the fate of intracellular nitrate and its availability for microbial metabolism within anoxic diatom-bacteria aggregates. The ubiquitous nitrate-storing diatom Skeletonema marinoi was studied as both axenic cultures and laboratory-produced diatom-bacteria aggregates. Stable 15N isotope incubations under dark and anoxic conditions revealed that axenic S. marinoi is able to reduce intracellular nitrate to ammonium that is immediately excreted by the cells. When exposed to a light:dark cycle and oxic conditions, S. marinoi stored nitrate intracellularly in concentrations > 60 mmol L-1 both as free-living cells and associated to aggregates. Intracellular nitrate concentrations exceeded extracellular concentrations by three orders of magnitude. Intracellular nitrate was used up within 2-3 days after shifting diatom-bacteria aggregates to dark and anoxic conditions. Thirty-one percent of the diatom-derived nitrate was converted to nitrogen gas, indicating that a substantial fraction of the intracellular nitrate pool of S. marinoi becomes available to the aggregate-associated bacterial community. Only 5% of the intracellular nitrate was reduced to ammonium, while 59% was recovered as nitrite. Hence, aggregate-associated diatoms accumulate nitrate from the surrounding water and sustain complex nitrogen transformations, including loss of fixed nitrogen, in anoxic, pelagic microniches. Additionally, it may be expected that intracellular nitrate not converted before the aggregates have settled onto the seafloor could fuel benthic nitrogen transformations.

Survival and bioturbation effects of common marine macrofauna in coastal soils newly flooded with seawater

DEFF Research Database (Denmark)

Valdemarsen, Thomas Bruun; Quintana, Cintia Organo; Thorsen, Sandra Walløe

Low-lying coastal soils are at risk of being permanently flooded due to global sea level rise, but how will these areas develop as habitat for marine species? We conducted an experiment to evaluate the habitat quality of flooded soils for common marine polychaetes (Marenzelleria viridis, Nereis d...

The composition of nucleation and Aitken modes particles during coastal nucleation events: evidence for marine secondary organic contribution

Directory of Open Access Journals (Sweden)

P. Vaattovaara

2006-01-01

Full Text Available Newly-formed nanometer-sized particles have been observed at coastal and marine environments world wide. Organic species have so far not been detected in those newly-formed nucleation mode particles. In this study, we applied the ultrafine organic tandem differential mobility analyzer method to study the possible existence of an organic fraction in recently formed coastal nucleation mode particles (d<20 nm at the Mace Head research station. Furthermore, effects of those nucleation events on potential cloud condensation nuclei were studied. The coastal events were typical for the Mace Head region and they occurred at low tide conditions during efficient solar radiation and enhanced biological activity in spring 2002. Additionally, a pulse height analyzer ultrafine condensation particle counter technique was used to study the composition of newly-formed particles formed in low tide conditions during a lower biological activity in October 2002. The overall results of the ultrafine organic tandem differential mobility analyzer and the pulse height analyzer ultrafine condensation particle counter measurements indicate that those coastally/marinely formed nucleation mode particles include a remarkable fraction of secondary organic products, beside iodine oxides, which are likely to be responsible for the nucleation. During clean marine air mass conditions, the origin of those secondary organic oxidation compounds can be related to marine coast and open ocean biota and thus a major fraction of the organics may originate from biosynthetic production of alkenes such as isoprene and their oxidation driven by iodine radicals, hydroxyl radicals, acid catalysis, and ozone during efficient solar radiation. During modified marine conditions, also anthropogenic secondary organic compounds may contribute to the nucleation mode organic mass, in addition to biogenic secondary organic compounds. Thus, the ultrafine organic tandem differential mobility analyzer

Suspended marine particulate proteins in coastal and oligotrophic waters

Science.gov (United States)

Bridoux, Maxime C.; Neibauer, Jaqui; Ingalls, Anitra E.; Nunn, Brook L.; Keil, Richard G.

2015-03-01

Metaproteomic analyses were performed on suspended sediments collected in one coastal environment (Washington margin, Pacific Ocean, n = 5) and two oligotrophic environments (Atlantic Ocean near BATS, n = 5, and Pacific Ocean near HOTS, n = 5). Using a database of 2.3 million marine proteins developed using the NCBI database, 443 unique peptides were detected from which 363 unique proteins were identified. Samples from the euphotic zone contained on average 2-3x more identifiable proteins than deeper waters (150-1500 m) and these proteins were predominately from photosynthetic organisms. Diatom peptides dominate the spectra of the Washington margin while peptides from cyanobacteria, such as Synechococcus sp. dominated the spectra of both oligotrophic sites. Despite differences in the exact proteins identified at each location, there is good agreement for protein function and cellular location. Proteins in surface waters code for a variety of cellular functions including photosynthesis (24% of detected proteins), energy production (10%), membrane production (9%) and genetic coding and reading (9%), and are split 60-40 between membrane proteins and intracellular cytoplasmic proteins. Sargasso Sea surface waters contain a suite of peptides consistent with proteins involved in circadian rhythms that promote both C and N fixation at night. At depth in the Sargasso Sea, both muscle-derived myosin protein and the muscle-hydrolyzing proteases deseasin MCP-01 and metalloprotease Mcp02 from γ-proteobacteria were observed. Deeper waters contain peptides predominately sourced from γ-proteobacteria (37% of detected proteins) and α-proteobacteria (26%), although peptides from membrane and photosynthetic proteins attributable to phytoplankton were still observed (13%). Relative to surface values, detection frequencies for bacterial membrane proteins and extracellular enzymes rose from 9 to 16 and 2 to 4% respectively below the thermocline and the overall balance between

Decoding size distribution patterns in marine and transitional water phytoplankton: from community to species level.

Directory of Open Access Journals (Sweden)

Leonilde Roselli

Full Text Available Understanding the mechanisms of phytoplankton community assembly is a fundamental issue of aquatic ecology. Here, we use field data from transitional (e.g. coastal lagoons and coastal water environments to decode patterns of phytoplankton size distribution into organization and adaptive mechanisms. Transitional waters are characterized by higher resource availability and shallower well-mixed water column than coastal marine environments. Differences in physico-chemical regime between the two environments have been hypothesized to exert contrasting selective pressures on phytoplankton cell morphology (size and shape. We tested the hypothesis focusing on resource availability (nutrients and light and mixed layer depth as ecological axes that define ecological niches of phytoplankton. We report fundamental differences in size distributions of marine and freshwater diatoms, with transitional water phytoplankton significantly smaller and with higher surface to volume ratio than marine species. Here, we hypothesize that mixing condition affecting size-dependent sinking may drive phytoplankton size and shape distributions. The interplay between shallow mixed layer depth and frequent and complete mixing of transitional waters may likely increase the competitive advantage of small phytoplankton limiting large cell fitness. The nutrient regime appears to explain the size distribution within both marine and transitional water environments, while it seem does not explain the pattern observed across the two environments. In addition, difference in light availability across the two environments appear do not explain the occurrence of asymmetric size distribution at each hierarchical level. We hypothesize that such competitive equilibria and adaptive strategies in resource exploitation may drive by organism's behavior which exploring patch resources in transitional and marine phytoplankton communities.

NODC Standard Format Marine Birds from Coastal Alaska and Puget Sound Data (1974-1983): Marine Bird Sighting, Ship/Aircraft Census (F033) (NODC Accession 0014155)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Marine Bird Sighting, Ship/Aircraft Census (F033) is one of a group of seven datasets related to Marine Birds from Coastal Alaska and Puget Sound Data (1974 -1983)....

Carbon content and C:N ratio of transparent exopolymeric particles (TEP) produced by bubbling exudates of diatoms

DEFF Research Database (Denmark)

Mari, Xavier

1999-01-01

The carbon content of transparent exopolymeric particles (TEP) was measured in the laboratory in particles produced by bubbling exudates of the diatom Thalassiosira weissflogii, grown under nitrogen non-limited conditions (N:P = 7). The carbon content of these particles (TEP-C) appears to vary...... a coastal area (Kattegat, Denmark), TEP carbon concentration in the surface mixed layer was on the order of 230 ± 150 µg C l-1. This is high relative to other sources of particulate organic carbon (e.g. phytoplankton) and depending on TEP turnover rates, suggests that TEP is an important pathway...... for dissolved organic carbon in coastal seas. The carbon to nitrogen ratio of TEP was measured from particles formed by bubbling exudates of the diatoms T. weissflogii, Skeletonema costatum, Chaetoceros neogracile and C. affinis. Each of these diatom species was grown under various N:P ratios, from N...

System responses to equal doses of photosynthetically usable radiation of blue, green, and red light in the marine diatom Phaeodactylum tricornutum.

Directory of Open Access Journals (Sweden)

Kristin Collier Valle

Full Text Available Due to the selective attenuation of solar light and the absorption properties of seawater and seawater constituents, free-floating photosynthetic organisms have to cope with rapid and unpredictable changes in both intensity and spectral quality. We have studied the transcriptional, metabolic and photo-physiological responses to light of different spectral quality in the marine diatom Phaeodactylum tricornutum through time-series studies of cultures exposed to equal doses of photosynthetically usable radiation of blue, green and red light. The experiments showed that short-term differences in gene expression and profiles are mainly light quality-dependent. Transcription of photosynthesis-associated nuclear genes was activated mainly through a light quality-independent mechanism likely to rely on chloroplast-to-nucleus signaling. In contrast, genes encoding proteins important for photoprotection and PSII repair were highly dependent on a blue light receptor-mediated signal. Changes in energy transfer efficiency by light-harvesting pigments were spectrally dependent; furthermore, a declining trend in photosynthetic efficiency was observed in red light. The combined results suggest that diatoms possess a light quality-dependent ability to activate photoprotection and efficient repair of photodamaged PSII. In spite of approximately equal numbers of PSII-absorbed quanta in blue, green and red light, the spectral quality of light is important for diatom responses to ambient light conditions.

Low mercury levels in marine fish from estuarine and coastal environments in southern China

International Nuclear Information System (INIS)

Pan, Ke; Chan, Heidi; Tam, Yin Ki; Wang, Wen-Xiong

2014-01-01

This study is the first comprehensive evaluation of total Hg and methylmercury (MeHg) concentrations in wild marine fish from an estuarine and a coastal ecosystem in southern China. A total of 571 fish from 54 different species were examined. Our results showed that the Hg levels were generally low in the fish, and the Hg levels were below 30 ng g −1 (wet weight) for 82% of the samples, which may be related to the reduced size of the fish and altered food web structure due to overfishing. Decreased coastal wetland coverage and different carbon sources may be responsible for the habitat-specific Hg concentrations. The degree of biomagnification was relatively low in the two systems. -- Highlights: • Total and methylmercury in marine fish from estuarine and coastal ecosystems were compared. • Hg levels were generally low in the coastal wild fish in southern China. • Overfishing and decreased wetland coverage may be responsible for the low Hg concentration. • Stable isotopes signatures reveal that the two fish communities had contrasting trophic structures. -- Overfishing and habitat-specific geochemical properties are related to the low Hg concentrations in the wild fish

The role of ultraviolet-adaptation of a marine diatom in photoenhanced toxicity of acridine.

Science.gov (United States)

Wiegman, Saskia; Barranguet, Christiane; Spijkerman, Elly; Kraak, Michiel Harm Steven; Admiraal, Wim

2003-03-01

Cultures of the marine diatom Phaeodactylum tricornutum were grown under laboratory light with a different fraction of ultraviolet radiation (UV) to study the potential role of photoadaptation in determining the sensitivity to photoenhanced toxicity of acridine. In short-term experiments, a higher acridine concentration was needed to inhibit the photosynthetic electron flux, monitored with chlorophyll a fluorescence, in algae exposed to fluorescent light (low UV) than to mercury light (high UV), consistent with the expected role of UV. The two types of light in long-term exposures led to changes in the pigment composition and photosystem I (PS I) to photosystem II (PS II) stoichiometry to optimize the utilization of fluorescent and mercury light. Despite the adaptation of the photosynthetic apparatus to a small fraction of UV, long-term exposure to mercury light did show a constant sensitivity of the photosynthetic efficiency of P. tricornutum to the phototoxic acridine. It is concluded that the prime receptor of photoenhanced toxicity may be unrelated to the photosynthetic machinery.

Effect of different CO2 concentrations on biomass, pigment content, and lipid production of the marine diatom Thalassiosira pseudonana.

Science.gov (United States)

Sabia, Alessandra; Clavero, Esther; Pancaldi, Simonetta; Salvadó Rovira, Joan

2018-02-01

The marine diatom Thalassiosira pseudonana grown under air (0.04% CO 2 ) and 1 and 5% CO 2 concentrations was evaluated to determine its potential for CO 2 mitigation coupled with biodiesel production. Results indicated that the diatom cultures grown at 1 and 5% CO 2 showed higher growth rates (1.14 and 1.29 div day -1 , respectively) and biomass productivities (44 and 48 mg AFDW L -1  day -1 ) than air grown cultures (with 1.13 div day -1 and 26 mg AFDW L -1  day -1 ). The increase of CO 2 resulted in higher cell volume and pigment content per cell of T. pseudonana. Interestingly, lipid content doubled when air was enriched with 1-5% CO 2 . Moreover, the analysis of the fatty acid composition of T. pseudonana revealed the predominance of monounsaturated acids (palmitoleic-16:1 and oleic-18:1) and a decrease of the saturated myristic acid-14:0 and polyunsaturated fatty acids under high CO 2 levels. These results suggested that T. pseudonana seems to be an ideal candidate for biodiesel production using flue gases.

Production and decomposition of new DOC by marine plankton communities: carbohydrates, refractory components and nutrient limitation

DEFF Research Database (Denmark)

Kragh, T.; Søndergaard, Morten

2009-01-01

The accumulation and biodegradation of dissolved organic carbon (DOC) and dissolved and particulate combined neutral sugars (DCNS, PCNS) were followed during a period of 22 days in experimental marine phytoplankton incubations. Five different growth regimes were established in 11 m(3) coastal...... in the mesocosms with diatoms dominating could be explained by DCNS, while only 6% was explained in the mesocosms with few diatoms. PCNS composition was similar in all mesocosms and with dominance of glucose and mannose, while DCNS were more evenly distributed with the following mole percentages fucose 15......, rhamnose 14, arabinose 6, galactose 27, glucose 20 and mannose 18%. The DCNS composition did not reflect the PCNS composition at any time during the experiment. Accumulated DCNS were quickly degraded and only 1% of the new RDOC was explained by DCNS. RDOC accumulated after day #17 in the two mesocosms...

Improving the Coastal Marine Gravity from CryoSat-2 Altimetry

Science.gov (United States)

Abulaitijiang, A.; Andersen, O. B.; Knudsen, P.

2017-12-01

The 7 years of CryoSat-2 satellite altimetry data can be potentially used to extract the high frequency components of the Earth gravity field beyond the Global Geopotential Models (GGMs) which corresponds to a resolution of 9.2 Km at the degree 2160. The Synthetic Aperture Radar (SAR) mode of the CryoSat-2 produced high precision along track observations and pushed the limits (qualified observations) to even closer to the coast by several kilometers. The conventional FFT method in deriving the marine gravity anomalies requires the input height anomalies to be gridded, and gridding in the irregular coastal zones (land-ocean transition zone) could introduce high frequency noise to the inversion. Therefore, Least Square Collocation (LSC) is preferred for the inversion. As part of a phd project, in this work, we will make use of the covariance function of the height anomalies in the coastal zones to derive the marine gravity anomalies. Using the conventional remove-compute-restore (only considering the GGMs) technique, the theoretical assumption of homogeneity and isotropy in the LSC algorithm is not always satisfied in the coastal regions and mountainous regions. Hence, the Topographic Correction (TC) using high resolution topographic grids is a critical step in the reduction of the gravity functionals (e.g., height anomaly and gravity anomaly), to comply with the theoretical assumption of LSC. In this work, the TC computation (both w.r.t. the height anomalies and gravity) will be conducted to test the performance of the signal reduction in several regions (patches) around Mediterranean, Chile, islands of Indonesia and Australian coast where the true gravity data is available. The derived marine gravity will be cross-validated against the ship-borne gravity observations. Earlier studies show that due to the presence of additional altimetry observations, 4 mGal accuracy can be achieved in the Greenland fjords, and equally good accuracy is expected from this work.

Intracellular nitrate of marine diatoms as a driver of anaerobic nitrogen cycling in sinking aggregates

DEFF Research Database (Denmark)

Kamp, Anja; Stief, Peter; Bristow, Laura A.

2016-01-01

% was recovered as nitrite. Hence, aggregate-associated diatoms accumulate nitrate from the surrounding water and sustain complex nitrogen transformations, including loss of fixed nitrogen, in anoxic, pelagic microniches. Additionally, it may be expected that intracellular nitrate not converted before...... store nitrate intracellularly, we explored the fate of intracellular nitrate and its availability for microbial metabolism within anoxic diatom-bacteria aggregates. The ubiquitous nitrate-storing diatom Skeletonema marinoi was studied as both axenic cultures and laboratory-produced diatom......-bacteria aggregates. Stable 15N isotope incubations under dark and anoxic conditions revealed that axenic S. marinoi is able to reduce intracellular nitrate to ammonium that is immediately excreted by the cells. When exposed to a light:dark cycle and oxic conditions, S. marinoi stored nitrate intracellularly...

Particulate Trace Element Cycling in a Diatom Bloom at Station ALOHA

Science.gov (United States)

Weisend, R.; Morton, P. L.; Landing, W. M.; Fitzsimmons, J. N.; Hayes, C. T.; Boyle, E. A.

2014-12-01

Phytoplankton in oligotrophic marine deserts depend on remote sources to supply trace nutrients. To examine these sources, marine particulate matter samples from the central North Pacific (Station ALOHA) were collected during the July-August 2012 HOE-DYLAN cruises and analyzed for a suite of trace (e.g., Fe, Mn) and major (e.g. Al, P) elements. Daily surface SPM samples were examined for evidence of atmospheric deposition and biological uptake, while five vertical profiles were examined for evidence of surface vertical export and subsurface horizontal transport from nearby sources (e.g., margin sediments, hydrothermal plumes). Maxima in surface particulate P (a biological tracer) corresponded with a diatom bloom, and surprisingly also coincided with maxima in particulate Al (typically a tracer for lithogenic inputs). The surface particulate Al distributions likely result from the adsorption of dissolved Al onto diatom silica frustules, not from atmospheric dust deposition. In addition, a subsurface maximum in particulate Al and P was observed four days later at 75m, possibly resulting from vertical export of the surface diatom bloom. The distributions of other bioactive trace elements (e.g. Cd, Co, Cu) will be presented in the context of the diatom bloom and other biological, chemical and physical features. A second, complementary poster is also being presented which examines the cycling of trace elements in lithogenic particles (Morton et al., "Trace Element Cycling in Lithogenic Particles at Station ALOHA").

Porous silicon and diatoms micro-shells: an example of inverse biomimetic

Science.gov (United States)

De Tommasi, Edoardo; Rea, Ilaria; Rendina, Ivo; De Stefano, Luca

2011-05-01

Porous silicon (PSi) is by far a very useful technological platform for optical monitoring of chemical and biological substances and due to its peculiar physical and morphological properties it is worldwide used in sensing experiments. On the other hand, we have discovered a natural material, the micro-shells of marine diatoms, ubiquitous unicellular algae, which are made of hydrated amorphous silica, but, most of all, show geometrical structures made of complex patterns of pores which are surprisingly similar to those of porous silicon. Moreover, under laser irradiation, this material is photoluminescent and the photoluminescence is very sensitive to the surrounding atmosphere, which means that the material can act as a transducer. Starting from our experience on PSi devices, we explore the optical and photonic properties of marine diatoms micro-shells in a sort of inverse biomimicry.

In vivo exposure to northern diatoms arrests sea urchin embryonic development.

Science.gov (United States)

Gudimova, Elena; Eilertsen, Hans C; Jørgensen, Trond Ø; Hansen, Espen

2016-01-01

There are numerous reports indicating that marine diatoms may act harmful to early developmental stages of invertebrates. It is believed that the compounds responsible for these detrimental effects are oxylipins resulting from oxidized polyunsaturated fatty acids, and that they may function as grazing deterrents. Most studies reporting these effects have exposed test organisms to diatom extracts or purified toxins, but data from in vivo exposure to intact diatoms are scarce. We have conducted sea urchin egg incubation and plutei feeding experiments to test if intact diatom cells affected sea urchin embryo development and survival. This was done by exposing the common northern sea urchins Strongylocentrotus droebachiensis and Echinus acutus to northern strains of the diatoms Chaetoceros socialis, Skeletonema marinoi, Chaetoceros furcellatus, Attheya longicornis, Thalassiosira gravida and Porosira glacialis. The intact diatom cell suspensions were found to inhibit sea urchin egg hatching and embryogenesis. S. marinoi was the most potent one as it caused acute mortality in S. droebachiensis eggs after only four hours exposure to high (50 μg/L Chla) diatom concentrations, as well as 24 h exposure to normal (20 μg/L Chla) and high diatom concentrations. The second most potent species was T. gravida that caused acute mortality after 24 h exposure to both diatom concentrations. A. longicornis was the least harmful of the diatom species in terms of embryo development arrestment, and it was the species that was most actively ingested by S. droebachiensis plutei. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Molecular fossils of diatoms. Applications in petroleum geochemistry and palaeoenvironmental studies

Energy Technology Data Exchange (ETDEWEB)

Rampen, S.W.

2009-06-11

different Proboscia species and culture experiments showed increasing chain-lengths and a decreasing degree of unsaturation for 1,14-diols with increasing growth temperature. Lipid analyses from surface sediments from the eastern South Atlantic suggested a significant relationship between long-chain 1,14-diol chain-length and sea surface temperature, but the degree of unsaturation for 1,14-diols seems also determined by other factors. Sediment trap data from the Arabian Sea confirmed that Proboscia lipids can be used as proxies for upwelling conditions and also showed that long-chain 1,15-diols are not limited to upwelling conditions. A sediment core taken from the Somali continental slope showed strong fluctuations of long-chain 1,14- and 1,15-diols with time; 1,14-diols were relatively high during the Holocene when upwelling occurred and much lower during the Late Glacial Maximum and the last Glacial when upwelling was suppressed. Elevated 1,14-diol concentrations during the first half of Marine Isotope Stage 3 and at the end of Marine Isotope Stage 5.1 suggest intensified glacial upwelling during those periods. Analyses of long-chain diols in a sediment core from the North Western Antarctic Peninsula suggest that Proboscia diatom productivity in this area is associated with upwelling of Upper Circumpolar Deep Water at the shelf break. Comparison of the diol record with melt events in Siple Dome ice core indicates that this upwelling is driven by the same climatic processes that are responsible for changes in regional climate.

Effect of holothurian and zoanthid extracts on growth of some bacterial and diatom species

Digital Repository Service at National Institute of Oceanography (India)

Gonsalves, C.

The antifouling properties of the extracts from two zoanthids, viz. Zoanthus sp, Protopalythoa sp and one holothurian species, viz. Holothuria leucospilota occurring in the coastal waters off Goa were tested against 5 bacteria and 2 diatom species...

Diatom diversity and response in metal-polluted river environment: preliminary reports from Gromolo Torrent (Liguria, Italy)

Science.gov (United States)

Capello, Marco; Tolotti, Raffaella; Bernabè, Dimitri; Carbone, Cristina; Consani, Sirio; Vagge, Greta; Cutroneo, Laura

2016-04-01

Mineral content and physico-chemical properties of the freshwaters are the main factors affecting both algal assemblages and distributions, while presence of dissolved silicon, low water conductivity, and rocky-mountain habitats host benthic diatom assemblages of high species richness. It is shown that diatoms are sensible to the freshwater acidification (used as pH indicators in acid waters), environmental and climate changes, river organic load, and heavy metal water pollution. For this characteristic, diatoms are among the major biological markers for a variety of environmental and stratigraphic applications. In particular, qualitative and quantitative analyses (assemblage analyses) together with biotic indices as well as morphological and ultrastructure parameterisation provide tools for detailed environmental control and paleo-environmental reconstructions. Severe environmental problems are typically caused by "abandoned mine" and are consequences of the cessation of the mining activity with a lack in infrastructure maintenance. The mine waters which flow into the Gromolo Torrent are almost acidic (pH varying from 2.4 to 5) and enriched in heavy metals and SO42-. This pollution is caused by Acid Mine Drainage (AMD) processes that interest the Libiola mining area, known as a typical example of active AMD processes. The aim of this work is: 1) to characterise the local benthic diatom assemblages along the acidic mine effluents that discharge from Libiola mine, the entire Gromolo torrent course, and in the marine area off the torrent mouth; 2) to identify the main diatom biomarker taxa; 3) to highlight striking situations of equilibrium-disequilibrium in the algal communities, and 4) to point out types and frequency of some teratologies affecting specific diatom taxa as a response to environmental stressors (such as metal-metalloid enrichment). A total of 17 diatom samples was collected and examined, including some marine samples. Diatoms were collected in the

The possible role of bacterial signal molecules N-acyl homoserine lactones in the formation of diatom-biofilm (Cylindrotheca sp.)

International Nuclear Information System (INIS)

Yang, Cuiyun; Fang, Shengtao; Chen, Dehui; Wang, Jianhua; Liu, Fanghua; Xia, Chuanhai

2016-01-01

Bacterial quorum sensing signal molecules N-acyl homoserine lactones (AHLs) (C10-HSL, 3-OXO-C10-HSL and 3-OH-C10-HSL) as possible chemical cues were employed to investigate the role in the formation of fouling diatom-biofilm (Cylindrotheca sp.). Results showed that AHLs promoted Chlorophyll a (Chl.a) and extracellular polymeric substance (EPS) contents in the diatom-biofilm. In the presence of AHLs-inhibitor 3, 4-Dibromo-2(5)H-furanone, which was used to avoid the possible interference of AHLs from bacteria, AHLs also increased the Chl.a and EPS contents. Scanning electron microscope and confocal laser scanning microscope analysis further demonstrated that AHLs promoted the formation of the diatom-biofilm. Non-invasive micro-test technique showed that AHLs promoted Ca 2+ efflux in Cylindrotheca sp., which implied that Ca 2+ might be correlated with AHLs-induced positive effect on the formation of diatom-biofilm. This study provides direct evidences that AHLs play an important role in developing the diatom-biofilm and AHLs-inhibitors might be promising active agents in marine antifouling. - Highlights: •AHLs effectively increase Chl.a and EPS contents in diatom-biofilm. •SEM and CLSM further demonstrate that AHLs promote the formation of diatom-biofilm. •AHLs trigger algal cellular Ca 2+ efflux. •AHLs-inhibitors might be promising active agents in marine antifouling.

Ozone pollution around a coastal region of South China Sea: interaction between marine and continental air

Science.gov (United States)

Wang, Hao; Lyu, Xiaopu; Guo, Hai; Wang, Yu; Zou, Shichun; Ling, Zhenhao; Wang, Xinming; Jiang, Fei; Zeren, Yangzong; Pan, Wenzhuo; Huang, Xiaobo; Shen, Jin

2018-03-01

Marine atmosphere is usually considered to be a clean environment, but this study indicates that the near-coast waters of the South China Sea (SCS) suffer from even worse air quality than coastal cities. The analyses were based on concurrent field measurements of target air pollutants and meteorological parameters conducted at a suburban site (Tung Chung, TC) and a nearby marine site (Wan Shan, WS) from August to November 2013. The observations showed that the levels of primary air pollutants were significantly lower at WS than those at TC, while the ozone (O3) value was greater at WS. Higher O3 levels at WS were attributed to the weaker NO titration and higher O3 production rate because of stronger oxidative capacity of the atmosphere. However, O3 episodes were concurrently observed at both sites under certain meteorological conditions, such as tropical cyclones, continental anticyclones and sea-land breezes (SLBs). Driven by these synoptic systems and mesoscale recirculations, the interaction between continental and marine air masses profoundly changed the atmospheric composition and subsequently influenced the formation and redistribution of O3 in the coastal areas. When continental air intruded into marine atmosphere, the O3 pollution was magnified over the SCS, and the elevated O3 ( > 100 ppbv) could overspread the sea boundary layer ˜ 8 times the area of Hong Kong. In some cases, the exaggerated O3 pollution over the SCS was recirculated to the coastal inshore by sea breeze, leading to aggravated O3 pollution in coastal cities. The findings are applicable to similar mesoscale environments around the world where the maritime atmosphere is potentially influenced by severe continental air pollution.

Effect of Low ph on Carbohydrate Production by a Marine Planktonic Diatom (Chaetoceros muelleri)

International Nuclear Information System (INIS)

Thornton, D.C.O.

2009-01-01

Rising carbon dioxide (CO 2 ) concentrations in the atmosphere due to human activity are causing the surface ocean to become more acidic. Diatoms play a pivotal role in biogeochemical cycling and ecosystem function in the ocean. ph affected the quantum efficiency of photosystem II and carbohydrate metabolism in a planktonic diatom (Chaetoceros muelleri), representative of a widely distributed genus. In batch cultures grown at low ph, the proportion of total carbohydrate stored within the cells decreased and more dissolved carbohydrates were exuded from the cells into the surrounding medium. Changes in productivity and the way in which diatoms allocate carbon into carbohydrates may affect ecosystem function and the efficiency of the biological carbon pump in a low ph ocean.

Prevalence of microplastics in Singapore's coastal marine environment

Energy Technology Data Exchange (ETDEWEB)

Ng, K.L. [Division of Environmental Science and Engineering, Faculty of Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore); Obbard, J.P. [Division of Environmental Science and Engineering, Faculty of Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore)]. E-mail esejpo@nus.edu.sg

2006-07-15

Microplastics have been recently identified as marine pollutants of significant concern due to their persistence, ubiquity and potential to act as vectors for the transfer and exposure of persistent organic pollutants to marine organisms. This study documents, for the first time, the presence and abundance of microplastics (>1.6 {mu}m) in Singapore's coastal environment. An optimized sampling protocol for the collection and analysis of microplastics was developed, and beach sediments and seawater (surface microlayer and subsurface layer) samples were collected from nine different locations around the coastline. Low density microplastics were separated from sediments by flotation and polymer types were identified using Fourier transform infrared (FTIR) spectrometry. Synthetic polymer microplastics identified in beach sediments included polyethylene, polypropylene, polystyrene, nylon, polyvinyl alcohol and acrylonitrile butadiene styrene. Microplastics were detected in samples from four out of seven beach environments, with the greatest quantity found in sediments from two popular beaches in the eastern part of Singapore. Polyethylene, polypropylene and polystyrene microplastics were also found in the surface microlayer (50-60 {mu}m) and subsurface layer (1 m) of coastal waters. The presence of microplastics in sediments and seawater is likely due to on-going waste disposal practices from industries and recreational activities, and discharge from shipping.

Decadal-scale changes of dinoflagellates and diatoms in the anomalous baltic sea spring bloom.

Directory of Open Access Journals (Sweden)

Riina Klais

Full Text Available The algal spring bloom in the Baltic Sea represents an anomaly from the winter-spring bloom patterns worldwide in terms of frequent and recurring dominance of dinoflagellates over diatoms. Analysis of approximately 3500 spring bloom samples from the Baltic Sea monitoring programs revealed (i that within the major basins the proportion of dinoflagellates varied from 0.1 (Kattegat to >0.8 (central Baltic Proper, and (ii substantial shifts (e.g. from 0.2 to 0.6 in the Gulf of Finland in the dinoflagellate proportion over four decades. During a recent decade (1995-2004 the proportion of dinoflagellates increased relative to diatoms mostly in the northernmost basins (Gulf of Bothnia, from 0.1 to 0.4 and in the Gulf of Finland, (0.4 to 0.6 which are typically ice-covered areas. We hypothesize that in coastal areas a specific sequence of seasonal events, involving wintertime mixing and resuspension of benthic cysts, followed by proliferation in stratified thin layers under melting ice, favors successful seeding and accumulation of dense dinoflagellate populations over diatoms. This head-start of dinoflagellates by the onset of the spring bloom is decisive for successful competition with the faster growing diatoms. Massive cyst formation and spreading of cyst beds fuel the expanding and ever larger dinoflagellate blooms in the relatively shallow coastal waters. Shifts in the dominant spring bloom algal groups can have significant effects on major elemental fluxes and functioning of the Baltic Sea ecosystem, but also in the vast shelves and estuaries at high latitudes, where ice-associated cold-water dinoflagellates successfully compete with diatoms.

The REDCAM, institutional Cooperation for the Surveillance of the Quality of the Marine and Coastal waters in Colombia

International Nuclear Information System (INIS)

Ana Maria Velez G; Marin Z, Bienvenido; Garay T, Jesus A

2003-01-01

The Colombian Marine Environment Monitoring Network (REDCAM) initiated in 2001, with the purpose of grouping the institutions and the efforts necessary to evaluate the chemical and sanitary quality of the marine and estuarine waters of Colombia; it is composed of 16 nodes and main server located at INVEMAR (Santa Marta); each node counts with hardware and software for a Input and retrieval tables and cartographic information a about the quality o marine and coastal waters of Colombia. It was established a network of field stations that covers most of the Colombian coasts. In each one, since 2001, twice a year, it has been registering the values of the main physicochemical and bacteriological variables that characterize the quality of the marine and estuarine waters. Based on this information, the following zones have been identified as critical for its marine and coastal pollution: Santa Marta, Cartagena, Barranquilla, Morrosquillo, Uraba and San Andres, in the Caribbean coast and Buenaventura, Guapi and La Tola in Pacific coast

Fate and effects of petroleum hydrocarbons in marine coastal ecosystems

International Nuclear Information System (INIS)

Vanderhorst, J.R.

1977-01-01

Preliminary results are reported from field and laboratory studies on the effects of petroleum hydrocarbons on marine organisms of Northwest Pacific coastal ecosystems. Chemical methods for the characterization of test solutions for specific hydrocarbons (benzene, toluene, xylene, and heptodecane) were developed concurrently with population and community studies of the effects of short-term and chronic exposures. Results are reported from studies on algae (Ulva), clams (protothaca staminea), crustaceans (Anomyx and Neomysis) and burrowing worms

Preparation and characteristics of biosilica derived from marine diatom biomass of Nitzschia closterium and Thalassiosira

Science.gov (United States)

Qi, Yarong; Wang, Xin; Cheng, Jay Jiayang

2017-05-01

In this study, biosilica of high purity was successfully prepared from marine diatom ( Nitzschia closterium and Thalassiosira) biomass using an optimized novel method with acid washing treatment followed by thermal treatment of the biomass. The optimal condition of the method was 2% diluted HCl washing and baking at 600°C. The SiO2 contents of N. closterium biosilica and Thalassiosira biosilica were 92.23% and 91.52%, respectively, which were both higher than that of diatomite biosilica. The SiO2 morphologies of both biosilica are typical amorphous silica. Besides, N. closterium biosilica possessed micropores and fibers with a surface area of 59.81m2/g. And Thalassiosira biosilica possessed a mesoporous hierarchical skeleton with a surface area of 9.91m2/g. The results suggest that the biosilica samples obtained in this study present highly porous structures. The prepared porous biosilica material possesses great potential to be used as drug delivery carrier, biosensor, biocatalyst as well as adsorbent in the future.

An integrated analysis of molecular acclimation to high light in the marine diatom Phaeodactylum tricornutum

DEFF Research Database (Denmark)

Nymark, Marianne; Valle, Kristin C; Brembu, Tore

2009-01-01

Photosynthetic diatoms are exposed to rapid and unpredictable changes in irradiance and spectral quality, and must be able to acclimate their light harvesting systems to varying light conditions. Molecular mechanisms behind light acclimation in diatoms are largely unknown. We set out to investiga...

Colwellia agarivorans sp. nov., an agar-digesting marine bacterium isolated from coastal seawater

Science.gov (United States)

A novel Gram-stain-negative, facultatively anaerobic, yellowish and agar-digesting marine bacterium, designated strain QM50**T, was isolated from coastal seawater in an aquaculture site near Qingdao, China. Phylogenetic analysis based on 16S rDNA sequences revealed that the novel isolate represented...

Diatoms in water quality assessment: to count or not to count them?

Czech Academy of Sciences Publication Activity Database

Brabcová, B.; Marvan, P.; Opatřilová, L.; Brabec, K.; Fránková, Markéta; Heteša, J.

2017-01-01

Roč. 795, č. 1 (2017), s. 113-127 ISSN 0018-8158 Institutional support: RVO:67985939 Keywords : diatoms * quantification * streams Subject RIV: EH - Ecology, Behaviour OBOR OECD: Marine biology, freshwater biology, limnology Impact factor: 2.056, year: 2016

Biofuel and Biochemical Analysis of Amphora coffeaeformis RR03, a Novel Marine Diatom, Cultivated in an Open Raceway Pond

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Muthu Ganesan Rajaram

2018-05-01

Full Text Available (1 Background: To increase the biochemical productivity and to reduce the production cost of microalgal biodiesel, this study aimed to investigate the effects of CO2 on biomass, fatty acids, carbon-hydrogen, and biochemical accumulation of the marine diatom, Amphora coffeaeformis RR03 (A. coffeaeformis RR03. (2 Methods: Fatty acid composition of the dry biomass of A. coffeaeformis RR03 was analysed using Gas chromatography-mass spectrometry (GC-MS. (3 Results: The results showed that A. coffeaeformis RR03 contained high biomass productivity and biochemical composition in different cultivation conditions. A. coffeaeformis RR03 showed maximum growth of 5.2 × 106/mL on 21st day cultivation under CO2 supply. The bio-crude oil production from A. coffeaeformis RR03 was 36.19 megajoule (MJ. GC-MS analysis found that the dry biomass of A. coffeaeformis RR03 contained maximum of 47.72% fatty acids of 16-octadecanoic acid methyl ester (10:12 and 19.58% pentadecanoic acid, 13-methyl-, and methyl ester (9.24. (4 Conclusion: The results of this study may suggest that a novel diatom of A. coffeaeformis RR03 could be a suitable candidate for biocrude production in order to meet the future demand of energy.

The whale pump: marine mammals enhance primary productivity in a coastal basin.

Directory of Open Access Journals (Sweden)

Joe Roman

Full Text Available It is well known that microbes, zooplankton, and fish are important sources of recycled nitrogen in coastal waters, yet marine mammals have largely been ignored or dismissed in this cycle. Using field measurements and population data, we find that marine mammals can enhance primary productivity in their feeding areas by concentrating nitrogen near the surface through the release of flocculent fecal plumes. Whales and seals may be responsible for replenishing 2.3×10(4 metric tons of N per year in the Gulf of Maine's euphotic zone, more than the input of all rivers combined. This upward "whale pump" played a much larger role before commercial harvest, when marine mammal recycling of nitrogen was likely more than three times atmospheric N input. Even with reduced populations, marine mammals provide an important ecosystem service by sustaining productivity in regions where they occur in high densities.

Screening for Viral Hemorrhagic Septicemia Virus in Marine Fish along the Norwegian Coastal Line

DEFF Research Database (Denmark)

Sandlund, Nina; Gjerset, Britt; Bergh, Øivind

2014-01-01

Viral hemorrhagic septicemia virus (VHSV) infects a wide range of marine fish species. To study the occurrence of VHSV in wild marine fish populations in Norwegian coastal waters and fjord systems a total of 1927 fish from 39 different species were sampled through 5 research cruises conducted......, and to our knowledge the first detection of VHSV in silvery pout. However, low prevalence of VHSV genotype Ib in Atlantic herring and other wild marine fish are well known in other parts of Europe. Earlier there have been a few reports of disease outbreaks in farmed rainbow trout with VHSV of genotype Ib...

Mixing of Marine and Terrestrial Sources of Strontium in Coastal Environments

Science.gov (United States)

Ryan, Saskia; Crowley, Quentin; Deegan, Eileen; Snoeck, Christophe

2017-04-01

87Sr/86Sr from bulk soils, soil extracts and plant material have been used to investigate and quantify the extent of marine-derived Sr in the terrestrial biosphere. Samples were collected along coastal transects and 87Sr/86Sr biosphere values (plant and soil) converge to marine values with increasing proximity to the coast. R2values indicate highly significant trends in certain regions. The National Soils Database (NSDB), TELLUS and TELLUS Border datasets, all of which are geochemical surveys have been employed to further test the extent of marine elemental contribution. Collectively these data cover all of Ireland and Northern Ireland, with varying degrees of sampling density. A strong spatial correlation exists between the Chemical Index of Alteration (CIA; (Al2O3-(CaO*+Na2O)-K2O)) in topsoil (CIA <60; 27% n = 11651) and areas of blanket peat. The enrichment of Ca and Na in these regions would suggest a significant marine geochemical contribution. Topsoil CIA can therefore be used to identify areas likely to feature significant marine inputs and identify regions where the 87Sr/86Sr budget may deviate from bedrock values.

Role of chemolithoautotrophic microorganisms involved in nitrogen and sulfur cycling in coastal marine sediments

NARCIS (Netherlands)

Lipsewers, Y.A.

2017-01-01

SummaryThe role of chemolithoautotrophic microorganisms has been considered to be of minor importancein coastal marine sediments although it has not been investigated in depth. Additionally,the impact of seasonal hypoxic/anoxic conditions on microbial chemolithoautotrophy in coastalmarine sediments

Impact of UV-B (290-320 nm) radiation on photosynthesis-mediated uptake of 15N-ammonia and 15N-nitrate of several marine diatoms

International Nuclear Information System (INIS)

Doehler, G.; Stolter, H.

1986-01-01

The marine diatoms Ditylum brigthwellii, Lithodesmium variabile, Odontella sinensis, Synedra planctonica and Thalassiosira rotula grown at 18 0 C under normal air conditions (0.035 vol.% CO 2 ) were exposed to different levels (439 and 717 J m -2 d -1 , weighted) of UV-B radiation for 2 d (5 h/d). Pigmentation, protein and total nitrogen content were reduced linearly to the dose of UV-B radiation. Photosynthesis-mediated uptake of 15 N-ammonia was more affected by UV-B irradiance in all tested diatoms than that of 15 N-nitrate. A species-dependent behavior in the assimilation of inorganic nitrogenous compounds has been observed: Synedra was a very sensitive species to UV-B radiation whereas the same UV-B doses had no effect on the assimilation rate of ammonia and nitrate of the Lithodesmium cells. The results were discussed with reference to the inhibition of the enzymes of the nitrogen metabolism. (author)

Marine fish diversity at Kalpakkam coastal sites of Tamilnadu

International Nuclear Information System (INIS)

Verma, Amrata; Ponnusamy, K.; Das, Subhashree; Munil Kumar, S.; Rajaram, S.; Lakra, W.S.; Pal, Asim K.; Sreedevi, K.R.

2015-01-01

In present study the marine fish diversity of Kalpakkam coastal sites of Tamil Nadu around Madras Atomic Power Station (MAPS) have been studied. The sampling was done seasonally viz post monsoon (January - March), Summer (April-June), and Premonsoon (July-September), for one year within 30 kilometer of MAPS. Total 69 species belonging to 10 order, 31 families and 42 genera were recorded. Different families such as Narcinidae -(1), Rhinobatidae-(1), Dasyatidae- (4), Clupeidae -(4), Pristigasteridae-(1), Engraulidae-(4), Ariidae-(1), Platycephalidae- (2), Polotosidae- (1), Ambassidae- (1), Sillaginidae- (1), Carangidae- (7), Sphyraenidae- (1), Scombridae- (1), Haemulidae- (1), Leiognathidae-(6), Lutjanidae-(3), Gerridae-(2), Sciaenidae- (8), Scatophagidae- (1), Mugilidae- (2), Ephippidae- (2), Mullidae- (3), Drepanidae- (1), Siganidae- (1), Paralichthyidae- (2), Trichiuridae- (1), Polynemidae- (1), Soleidae- (1), Cynoglossidae- (3), and Tetraodontidae- (1) were observed around Kalpakkam coastal sites. Among the collected species, order Perciformes was most dominant followed by Clupeiformes and Pleuronectiformes. The maximum fish collection was done during June to September and minimum during February to March. (author)

Aldehyde suppression of copepod recruitment in blooms of a ubiquitous planktonic diatom

Science.gov (United States)

Ianora, Adrianna; Miralto, Antonio; Poulet, Serge A.; Carotenuto, Ylenia; Buttino, Isabella; Romano, Giovanna; Casotti, Raffaella; Pohnert, Georg; Wichard, Thomas; Colucci-D'Amato, Luca; Terrazzano, Giuseppe; Smetacek, Victor

2004-05-01

The growth cycle in nutrient-rich, aquatic environments starts with a diatom bloom that ends in mass sinking of ungrazed cells and phytodetritus. The low grazing pressure on these blooms has been attributed to the inability of overwintering copepod populations to track them temporally. We tested an alternative explanation: that dominant diatom species impair the reproductive success of their grazers. We compared larval development of a common overwintering copepod fed on a ubiquitous, early-blooming diatom species with its development when fed on a typical post-bloom dinoflagellate. Development was arrested in all larvae in which both mothers and their larvae were fed the diatom diet. Mortality remained high even if larvae were switched to the dinoflagellate diet. Aldehydes, cleaved from a fatty acid precursor by enzymes activated within seconds after crushing of the cell, elicit the teratogenic effect. This insidious mechanism, which does not deter the herbivore from feeding but impairs its recruitment, will restrain the cohort size of the next generation of early-rising overwinterers. Such a transgenerational plant-herbivore interaction could explain the recurringly inefficient use of a predictable, potentially valuable food resource-the spring diatom bloom-by marine zooplankton.

Bacterial diversity in oil-polluted marine coastal sediments.

Science.gov (United States)

Acosta-González, Alejandro; Marqués, Silvia

2016-04-01

Marine environments harbour a persistent microbial seed which can be shaped by changes of the environmental conditions such as contamination by petroleum components. Oil spills, together with small but continuous discharges of oil from transportation and recreational activities, are important sources of hydrocarbon pollution within the marine realm. Consequently, prokaryotic communities have become well pre-adapted toward oil pollution, and many microorganisms that are exposed to its presence develop an active degradative response. The natural attenuation of oil pollutants, as has been demonstrated in many sites, is modulated according to the intrinsic environmental properties such as the availability of terminal electron acceptors and elemental nutrients, together with the degree of pollution and the type of hydrocarbon fractions present. Whilst dynamics in the bacterial communities in the aerobic zones of coastal sediments are well characterized and the key players in hydrocarbon biodegradation have been identified, the subtidal ecology of the anaerobic community is still not well understood. However, current data suggest common patterns of response in these ecosystems. Copyright © 2015 Elsevier Ltd. All rights reserved.

Payments for coastal and marine ecosystem services: prospects and principles

Energy Technology Data Exchange (ETDEWEB)

Mohammed, Essam Yassin

2012-05-15

Coastal and marine resources provide millions of impoverished people across the global South with livelihoods, and provide the world with a range of critical 'ecosystem services', from biodiversity and culture to carbon storage and flood protection. Yet across the world, these resources are fast-diminishing under the weight of pollution, land clearance, coastal development, overfishing, natural disasters and climate change. Traditional approaches to halt the decline focus on regulating against destructive practices, but to little effect. A more successful strategy could be to establish payments for ecosystem services (PES) schemes, or incorporate an element of PES in existing regulatory mechanisms. Examples from across the world suggest that PES can work to protect both livelihoods and environments. But to succeed, these schemes must be underpinned by robust research, clear property rights, equitable benefit sharing and sustainable finance.

Coastal evidence for Holocene subduction-zone earthquakes and tsunamis in central Chile

Science.gov (United States)

Dure, Tina; Cisternas, Marco; Horton, Benjamin; Ely, Lisa; Nelson, Alan R.; Wesson, Robert L.; Pilarczyk, Jessica

2015-01-01

The ∼500-year historical record of seismicity along the central Chile coast (30–34°S) is characterized by a series of ∼M 8.0–8.5 earthquakes followed by low tsunamis (tsunami (>10 m), but the frequency of such large events is unknown. We extend the seismic history of central Chile through a study of a lowland stratigraphic sequence along the metropolitan coast north of Valparaíso (33°S). At this site, higher relative sea level during the mid Holocene created a tidal marsh and the accommodation space necessary for sediment that preserves earthquake and tsunami evidence. Within this 2600-yr-long sequence, we traced six laterally continuous sand beds probably deposited by high tsunamis. Plant remains that underlie the sand beds were radiocarbon dated to 6200, 5600, 5000, 4400, 3800, and 3700 cal yr BP. Sediment properties and diatom assemblages of the sand beds—for example, anomalous marine planktonic diatoms and upward fining of silt-sized diatom valves—point to a marine sediment source and high-energy deposition. Grain-size analysis shows a strong similarity between inferred tsunami deposits and modern coastal sediment. Upward fining sequences characteristic of suspension deposition are present in five of the six sand beds. Despite the lack of significant lithologic changes between the sedimentary units under- and overlying tsunami deposits, we infer that the increase in freshwater siliceous microfossils in overlying units records coseismic uplift concurrent with the deposition of five of the sand beds. During our mid-Holocene window of evidence preservation, the mean recurrence interval of earthquakes and tsunamis is ∼500 years. Our findings imply that the frequency of historical earthquakes in central Chile is not representative of the greatest earthquakes and tsunamis that the central Chilean subduction zone has produced.

Coastal evidence for Holocene subduction-zone earthquakes and tsunamis in central Chile

Science.gov (United States)

Dure, Tina; Cisternas, Marco; Horton, Benjamin; Ely, Lisa; Nelson, Alan R.; Wesson, Robert L.; Pilarczyk, Jessica

2015-01-01

The ∼500-year historical record of seismicity along the central Chile coast (30–34°S) is characterized by a series of ∼M 8.0–8.5 earthquakes followed by low tsunamis (10 m), but the frequency of such large events is unknown. We extend the seismic history of central Chile through a study of a lowland stratigraphic sequence along the metropolitan coast north of Valparaíso (33°S). At this site, higher relative sea level during the mid Holocene created a tidal marsh and the accommodation space necessary for sediment that preserves earthquake and tsunami evidence. Within this 2600-yr-long sequence, we traced six laterally continuous sand beds probably deposited by high tsunamis. Plant remains that underlie the sand beds were radiocarbon dated to 6200, 5600, 5000, 4400, 3800, and 3700 cal yr BP. Sediment properties and diatom assemblages of the sand beds—for example, anomalous marine planktonic diatoms and upward fining of silt-sized diatom valves—point to a marine sediment source and high-energy deposition. Grain-size analysis shows a strong similarity between inferred tsunami deposits and modern coastal sediment. Upward fining sequences characteristic of suspension deposition are present in five of the six sand beds. Despite the lack of significant lithologic changes between the sedimentary units under- and overlying tsunami deposits, we infer that the increase in freshwater siliceous microfossils in overlying units records coseismic uplift concurrent with the deposition of five of the sand beds. During our mid-Holocene window of evidence preservation, the mean recurrence interval of earthquakes and tsunamis is ∼500 years. Our findings imply that the frequency of historical earthquakes in central Chile is not representative of the greatest earthquakes and tsunamis that the central Chilean subduction zone has produced.

Management of Ecological-Economic Processes of Pollution Accumulation and Assimilation in the Coastal Zone Marine Environment

Directory of Open Access Journals (Sweden)

I.E. Timchenko

2017-02-01

Full Text Available A model for managing the balance of pollution (getting into the sea with the coastal runoff assimilation and accumulation, based on the negative feedback between the coastal economic system efficiency and penalties for the sea coastal zone pollution is proposed. The model is constructed by the Adaptive Balance of Causes method and is intended for finding a rational balance of profit from the use of assimilative resources of the marine environment and the costs of maintaining its quality. The increase of pollutions in the coastal zone is taken as proportional to the volume of product realization. The decrease of pollution concentration is related to the environment protection activities paid for by the production. The model contains the agents for managing the volume of the economic system generalized production release. The agents control pollution accumulation rate at different ones of the bio-chemical processes resulting in the marine environment natural purification. Scenario analysis of ecological-economic processes in the “Land–Sea” system is carried out, and the dependencies of economic subsystem production profitability on penalty sanctions limiting the pollutant flux getting into the sea are constructed. Sea temperature and water mass dynamics effect on these processes is considered. The scenarios of their intra-annual variability are constructed. It is shown that the sea temperature and near-water wind consideration in the model have a significant effect on marine environment pollution level and production profitability. The conclusion is that the proposed adaptive simulation model “Sea–Land” can be used for forecasting the scenarios of coastal subsystem production processes (the volume of generalized product manufacturing, production cost, profitability in parallel with the forecast of pollution concentration in the sea scenarios.

Transformation techniques for metabolic engineering of diatoms and haptophytes: current state and prospects.

Science.gov (United States)

Velmurugan, Natarajan; Deka, Deepi

2018-05-01

Diatoms and haptophytes represent a key segment of the dominant phytoplankton communities that frequently form massive blooms in the photic zone of the ocean and are considered indicators of global climate changes. Diatoms and haptophytes also play a vital role in the biological carbon fixation in the carbon cycles. Carbon partitioning within diatoms and haptophytes possesses a wide range of chemical compounds and storage materials, such as lipids, carbohydrates, and chlorophyll. Among the marine microorganisms, diatoms and haptophytes have been recognized as promising sources of long- and very long-chain polyunsaturated fatty acids (PUFA). So far, a variety of approaches have been employed for genetic modification in the nuclei of diatoms and haptophytes. Studies on transformation and metabolic engineering in various intracellular genomes, such as chloroplast and mitochondria, are scarce. Particle bombardment, Agrobacterium and PEG-mediated gene transfer, and electroporation have been reported for foreign gene transformation into the diatoms and haptophytes. Antibiotics (G418 and chloramphenicol) and herbicides (zeocin, hygromycin, and norflurazon) have been successfully demonstrated as the best selection markers. Despite the availability of a wide range of molecular tools for foreign gene expression in microalgae, very few promoters (lhcf1, nr, h4, ef2, fcp, and pds) have been reported for diatoms and haptophytes. Therefore, in this review, we first summarize the significant progress that has been achieved in transgene expression in diatoms and haptophytes and highlight the importance and availability of recently developed novel tools that are suitable for transgenic expression in diatoms and haptophytes.

Taxonomic studies of centric diatoms (Diatomeae: unusual nanoplanktonic forms and new records for Brazil

Directory of Open Access Journals (Sweden)

Kaoli Pereira Cavalcante

2013-06-01

Full Text Available There have been few taxonomic studies of centric diatoms in lotic freshwater environments in Brazil, especially in terms of those including nanoplanktonic forms, which are often neglected in studies of local floras, because of their small size or confusing taxonomy. This is the first study focusing on centric diatoms in the flora of the state of Bahia, in northeastern Brazil. Plankton and periphyton attached to Eichornia crassipes were collected in the winter of 2009 in the Cachoeira River. The diatoms were analyzed and described under light and electron microscopies. Seventeen infrageneric taxa were identified. Cyclotella was represented by five taxa, and concerning of similarities between diacritical features of species in this genus, their descriptions were thoroughly detailed. This was the first time that Cyclotella atomus var. marina, previously recorded only in coastal areas of Japan and Korea, has been documented in a river in South America. We also identified two diatom taxa previously unrecorded in the flora of Brazil: C. cryptica and C. meduanae. Finally, we present a detailed light, transmission and scanning electron microscopy analysis of Skeletonema potamos, a diatom rarely found in the Brazilian literature.

Ammonium production off central Chile (36°S by photodegradation of phytoplankton-derived and marine dissolved organic matter.

Directory of Open Access Journals (Sweden)

Angel Rain-Franco

Full Text Available We investigated the production of ammonium by the photodegradation of dissolved organic matter (DOM in the coastal upwelling system off central Chile (36°S. The mean penetration of solar radiation (Z1% between April 2011 and February 2012 was 9.4 m, 4.4 m and 3.2 m for Photosynthetically Active Radiation (PAR; 400-700 nm, UV-A (320-400 nm and UV-B (280-320 nm, respectively. Ammonium photoproduction experiments were carried out using exudates of DOM obtained from cultured diatom species (Chaetoceros muelleri and Thalassiosira minuscule as well as natural marine DOM. Diatom exudates showed net photoproduction of ammonium under exposure to UVR with a mean rate of 0.56±0.4 µmol L(-1 h(-1 and a maximum rate of 1.49 µmol L(-1 h(-1. Results from natural marine DOM showed net photoproduction of ammonium under exposure to PAR+UVR ranging between 0.06 and 0.2 µmol L(-1 h(-1. We estimated the potential contribution of photochemical ammonium production for phytoplankton ammonium demand. Photoammonification of diatom exudates could support between 117 and 453% of spring-summer NH4(+ assimilation, while rates obtained from natural samples could contribute to 50-178% of spring-summer phytoplankton NH4(+ requirements. These results have implications for local N budgets, as photochemical ammonium production can occur year-round in the first meters of the euphotic zone that are impacted by full sunlight.

Hundred years of genetic structure in a sediment revived diatom population

DEFF Research Database (Denmark)

Haernstroem, Karolina; Ellegaard, Marianne; Andersen, Thorbjørn Joest

2011-01-01

This paper presents research on the genetic structure and diversity of populations of a common marine protist and their changes over time. The bloom-forming diatom Skeletonema marinoi was used as a model organism. Strains were revived from anoxic discrete layers of a 210Pb-dated sediment core...

Phytoplankton blooms in estuarine and coastal waters: Seasonal patterns and key species

Science.gov (United States)

Carstensen, Jacob; Klais, Riina; Cloern, James E.

2015-01-01

Phytoplankton blooms are dynamic phenomena of great importance to the functioning of estuarine and coastal ecosystems. We analysed a unique (large) collection of phytoplankton monitoring data covering 86 coastal sites distributed over eight regions in North America and Europe, with the aim of investigating common patterns in the seasonal timing and species composition of the blooms. The spring bloom was the most common seasonal pattern across all regions, typically occurring early (February–March) at lower latitudes and later (April–May) at higher latitudes. Bloom frequency, defined as the probability of unusually high biomass, ranged from 5 to 35% between sites and followed no consistent patterns across gradients of latitude, temperature, salinity, water depth, stratification, tidal amplitude or nutrient concentrations. Blooms were mostly dominated by a single species, typically diatoms (58% of the blooms) and dinoflagellates (19%). Diatom-dominated spring blooms were a common feature in most systems, although dinoflagellate spring blooms were also observed in the Baltic Sea. Blooms dominated by chlorophytes and cyanobacteria were only common in low salinity waters and occurred mostly at higher temperatures. Key bloom species across the eight regions included the diatoms Cerataulina pelagica and Dactyliosolen fragilissimus and dinoflagellates Heterocapsa triquetra and Prorocentrum cordatum. Other frequent bloom-forming taxa were diatom genera Chaetoceros, Coscinodiscus, Skeletonema, and Thalassiosira. Our meta-analysis shows that these 86 estuarine-coastal sites function as diatom-producing systems, the timing of that production varies widely, and that bloom frequency is not associated with environmental factors measured in monitoring programs. We end with a perspective on the limitations of conclusions derived from meta-analyses of phytoplankton time series, and the grand challenges remaining to understand the wide range of bloom patterns and

Feeding ecology of juvenile marine fish in a shallow coastal lagoon of southeastern Mexico

OpenAIRE

Daniel Arceo-Carranza; Xavier Chiappa-Carrara

2015-01-01

Many species of marine fish use coastal lagoons during early stages of their life cycles due to the protection provided by their turbid waters and complex structure of the environment, such as mangroves and mudflats, and the availability of food derived from the high productivity of these sites. In this study, we analyzed the diet of six species of juvenile marine fishes that use a karstic lagoon system in the northwest portion of the Yucatan Peninsula, Mexico. Through stomach contents analys...

Bacteriological quality and solid wastes at five coastal marine environments of Costa Rica

International Nuclear Information System (INIS)

Garcia, Vera; Acuna Gonzalez, Jenaro; Vargas Zamora, Jose A.; Garcia Cespedes, Jairo

2006-01-01

Anthropogenic waste and water bacteriological quality were surveyed twice a year in 2000 and in 2002 at five coastal marine environments in Costa Rica, one in the Caribbean (Bahia de Moin) and four in the Pacific (Bahia de Culebra, Golfo de Nicoya, Estero de Puntarenas, Bahia de Golfito). The most probable number (MPN)/100 mL of coliform bacteria was calculated after incubation series of five test tubes. A total of 14 coastal and two river water samples were collected in the Caribbean, and 32 coastal, nine estuarine and one tap water samples in the Pacific, plus 25 samples investigated for Escherichia coli in 2002. The means of 2 MPN/100 mL in June 2000 and 17 MPN/100 mL in May 2002, and faecal coliforms [es

Evolution of the Lian River coastal basin in response to Quaternary marine transgressions in Southeast China

Science.gov (United States)

Tang, Yongjie; Zheng, Zhuo; Chen, Cong; Wang, Mengyuan; Chen, Bishan

2018-04-01

The coastal basin deposit in the Lian River plain is among the thickest Quaternary sequences along the southeastern coast of China. The clastic sediment accumulated in a variety of environmental settings including fluvial, channel, estuary/coastal and marine conditions. Detailed investigation of lithofacies, grain-size distributions, magnetic susceptibility, microfossils and chronology of marine core CN01, compared with regional cores, and combined with offshore seismic reflection profiles, has allowed us to correlate the spatial stratigraphy in the inner and outer plain and the seismic units. Grain size distribution analysis of core CN-01 through compositional data analysis and multivariate statistics were applied to clastic sedimentary facies and sedimentary cycles. Results show that these methods are able to derive a robust proxy information for the depositional environment of the Lian River plain. We have also been able to reconstruct deltaic evolution in response to marine transgressions. On the basis of dating results and chronostratigraphy, the estimated age of the onset of deposition in the Lian River coastal plain was more than 260 kyr BP. Three transgressive sedimentary cycles revealed in many regional cores support this age model. Detailed lithological and microfossil studies confirm that three marine (M3, M2 and M1) and three terrestrial (T3, T2 and T1) units can be distinguished. Spatial correlation between the inner plain, outer plain (typical cores characterized by marine transgression cycles) and offshore seismic reflectors reveals coherent sedimentary sequences. Two major boundaries (unconformity and erosion surfaces) can be recognized in the seismic profiles, and these correspond to weathered reddish and/or variegated clay in the study core, suggesting that Quaternary sediment changes on the Lian River plain were largely controlled by sea-level variations and coastline shift during glacial/interglacial cycles.

Spring molybdenum enrichment in scallop shells: a potential tracer of diatom productivity in coastal temperate environments (Brittany, NW France)?

Science.gov (United States)

Barats, A.; Amouroux, D.; Pécheyran, C.; Chauvaud, L.; Thébault, J.; Donard, O. F. X.

2009-08-01

Skeletal molybdenum/calcium ([Mo]/[Ca])shell ratios were recently examined in bivalves. These ratios were determined by quantitative LA-ICP-MS analyses every third daily striae (i.e. a temporal resolution of 3 days) in 36 flat valves of the Great Scallop shells Pecten maximus (2-year old; 3 shells/year) collected in temperate coastal environments of Western Europe (42 to 49° N). Variations of ([Mo]/[Ca])shell ratio were significant and reproducible for scallops from a same population, from different years (1998-2004) and from different coastal temperate locations. ([Mo]/[Ca])shell exhibits typical profiles characterized by a background content, below the method detection limit (<0.003 μmol/mol) for most of the shell growth period, which is punctuated by a significant transient enrichment (0.031-2.1 μmol/mol) mainly occurring from May to June. The Bay of Brest (France) was especially investigated because of long term observations on scallop communities, environmental variables, and high resolution analyses of dissolved Mo in bottom seawater in 2000. In 2000, dissolved Mo exhibited significant increasing concentration just preceding a maximum of ([Mo]/[Ca])shell ratio. The environmental conditions preceding ([Mo]/[Ca])shell maximum events, both in 2000 and over the 7-year survey indicates a direct influence of the scallop environmental conditions at the sediment water interface subsequent to the intense and periodic spring bloom event. Spring maxima of ([Mo]/[Ca])shell ratio were found to be specifically related to the dynamic of spring diatom blooms and to the extent of the subsequent silicate depletion. ([Mo]/[Ca])shell records reveal thus unexpected biogeochemical routes of Mo, potentially related to coastal spring productivity.

Cadmium sensitivity, uptake, subcellular distribution and thiol induction in a marine diatom: Recovery from cadmium exposure

Energy Technology Data Exchange (ETDEWEB)

Wang Mengjiao [State Key Laboratory in Marine Pollution, Section of Marine Ecology and Biotechnology, Division of Life Science, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong); Wang Wenxiong, E-mail: wwang@ust.hk [State Key Laboratory in Marine Pollution, Section of Marine Ecology and Biotechnology, Division of Life Science, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong)

2011-01-25

Studies in the recovery from metal stress and the tolerance development to metal exposure of aquatic organisms are important for the understanding of epidemic pollution. In this study, the responses of a marine diatom, Thalassiosira nordenskioeldii, following recovery from environmental cadmium (Cd) stress were investigated. The diatoms were exposed to different concentrations of Cd for 7 days, and were then allowed different periods of time to recover. The Cd sensitivity increased after recovery from Cd stress, followed by a gradual restoration. The extent of restoration depended on both the recovery time and the environmental Cd stress during the exposure period. A complete restoration of Cd tolerance proved to be impossible for cells pre-exposed to High-Cd. The Cd cellular burden and subcellular Cd concentration decreased to the control level within the first day of recovery, indicating that the elevated sensitivity may have been due to the accumulation of functional damage caused by Cd exposure instead of a result of physical Cd accumulation. The rapid change in phytochelatins (PC) to both the increase in and the withdrawal of environmental Cd stress made it a good quantitative bioindicator of environmental Cd contamination. However, the relationships between Cd distribution in the metal sensitive fraction (MSF-Cd) or intracellular Cd to thiol ratio (intra-Cd/PC-SH) and the relative change in the median inhibition [Cd{sup 2+}] ([Cd{sup 2+}]-based-IC{sub 50}, i.e., Cd sensitivity) differed for the various exposure and recovery periods tested. Our study suggests that more attention should be given to the recovery of aquatic organisms from episodic metal exposure.

Carbonate-sensitive phytotransferrin controls high-affinity iron uptake in diatoms

Science.gov (United States)

McQuaid, Jeffrey B.; Kustka, Adam B.; Oborník, Miroslav; Horák, Aleš; McCrow, John P.; Karas, Bogumil J.; Zheng, Hong; Kindeberg, Theodor; Andersson, Andreas J.; Barbeau, Katherine A.; Allen, Andrew E.

2018-03-01

In vast areas of the ocean, the scarcity of iron controls the growth and productivity of phytoplankton. Although most dissolved iron in the marine environment is complexed with organic molecules, picomolar amounts of labile inorganic iron species (labile iron) are maintained within the euphotic zone and serve as an important source of iron for eukaryotic phytoplankton and particularly for diatoms. Genome-enabled studies of labile iron utilization by diatoms have previously revealed novel iron-responsive transcripts, including the ferric iron-concentrating protein ISIP2A, but the mechanism behind the acquisition of picomolar labile iron remains unknown. Here we show that ISIP2A is a phytotransferrin that independently and convergently evolved carbonate ion-coordinated ferric iron binding. Deletion of ISIP2A disrupts high-affinity iron uptake in the diatom Phaeodactylum tricornutum, and uptake is restored by complementation with human transferrin. ISIP2A is internalized by endocytosis, and manipulation of the seawater carbonic acid system reveals a second-order dependence on the concentrations of labile iron and carbonate ions. In P. tricornutum, the synergistic interaction of labile iron and carbonate ions occurs at environmentally relevant concentrations, revealing that carbonate availability co-limits iron uptake. Phytotransferrin sequences have a broad taxonomic distribution and are abundant in marine environmental genomic datasets, suggesting that acidification-driven declines in the concentration of seawater carbonate ions will have a negative effect on this globally important eukaryotic iron acquisition mechanism.

Coastal remote sensing – towards integrated coastal research and management

CSIR Research Space (South Africa)

Lück-Vogel, Melanie

2012-10-01

Full Text Available coastal resources and anthropogenic infrastructure for a safer future. What is the role of remote sensing? The coastal zone connects terrestrial biophysical systems with marine systems. Some marine ecosystems cannot function without intact inland... for the development of sound integrated management solutions. To date, however, remote sensing applications usually focus on areas landward from the highwater line (?terrestrial? remote sensing), while ?marine? remote sensing does not pay attention to the shallow...

Millimeter-sized marine plastics: a new pelagic habitat for microorganisms and invertebrates.

Directory of Open Access Journals (Sweden)

Julia Reisser

Full Text Available Millimeter-sized plastics are abundant in most marine surface waters, and known to carry fouling organisms that potentially play key roles in the fate and ecological impacts of plastic pollution. In this study we used scanning electron microscopy to characterize biodiversity of organisms on the surface of 68 small floating plastics (length range = 1.7-24.3 mm, median = 3.2 mm from Australia-wide coastal and oceanic, tropical to temperate sample collections. Diatoms were the most diverse group of plastic colonizers, represented by 14 genera. We also recorded 'epiplastic' coccolithophores (7 genera, bryozoans, barnacles (Lepas spp., a dinoflagellate (Ceratium, an isopod (Asellota, a marine worm, marine insect eggs (Halobates sp., as well as rounded, elongated, and spiral cells putatively identified as bacteria, cyanobacteria, and fungi. Furthermore, we observed a variety of plastic surface microtextures, including pits and grooves conforming to the shape of microorganisms, suggesting that biota may play an important role in plastic degradation. This study highlights how anthropogenic millimeter-sized polymers have created a new pelagic habitat for microorganisms and invertebrates. The ecological ramifications of this phenomenon for marine organism dispersal, ocean productivity, and biotransfer of plastic-associated pollutants, remains to be elucidated.

From nitrogen enrichment to oxygen depletion: a mechanistic model of coastal marine ecosystems response

DEFF Research Database (Denmark)

Cosme, Nuno Miguel Dias; Koski, Marja; Hauschild, Michael Zwicky

Nitrogen (N) emissions from anthropogenic sources may enrich coastal waters and lead to marine eutrophication impacts. Processes describing N-limited primary production (PP), zooplankton grazing, and bacterial respiration of sinking organic carbon, were modelled to quantify the potential dissolved...... oxygen (DO) consumption as a function of N input. Such indicator is the basis for an eXposure Factor (XF) applied in Life Cycle Impact Assessment (LCIA) to estimate impacts from N enrichment. The Large Marine Ecosystems (LME) biogeographical classification system was adopted to address the spatial...

Summer Epiphytic Diatoms from Terra Nova Bay and Cape Evans (Ross Sea, Antarctica) - A Synthesis and Final Conclusions

Science.gov (United States)

Majewska, Roksana; Convey, Peter; De Stefano, Mario

2016-01-01

Despite recent advances in polar marine biology and related fields, many aspects of the ecological interactions that are crucial for the functioning of Antarctic shallow water habitats remain poorly understood. Although epiphytic diatoms play an essential role in the Antarctic marine food web, basic information regarding their ecology, biodiversity and biogeography is largely unavailable. Here, we synthesise studies on Ross Sea epiphytic diatoms collected during 11 summer Antarctic expeditions between the years 1989/90 and 2011/12, presenting a full list of diatom taxa associated with three macroalgal species (Iridaea cordata, Phyllophora antarctica, and Plocamium cartilagineum) and their epiphytic sessile fauna. Diatom communities found during the three summer months at various depths and sampling stations differed significantly in terms of species composition, growth form structure and abundances. Densities ranged from 21 to >8000 cells mm-2, and were significantly higher on the surface of epiphytic micro-fauna than on any of the macroalgal species examined. Generally, host organisms characterized by higher morphological heterogeneity (sessile microfauna, ramified Plocamium) supported richer diatom communities than those with more uniform surfaces (Iridaea). Differences between epiphytic communities associated with different macroalgae were reflected better in species composition than in growth form structure. The latter changed significantly with season, which was related strongly to the changing ice conditions. A general trend towards an increasing number of erect forms in deeper waters and tube-dwelling diatoms in the shallowest sites (2–5 m) was also observed. This study explores further important and largely previously unknown aspects of relationships and interactions between Antarctic epiphytic diatoms and their micro- and macro-environments. PMID:27078637

Shared Epizoic Taxa and Differences in Diatom Community Structure Between Green Turtles (Chelonia mydas) from Distant Habitats.

Science.gov (United States)

Majewska, Roksana; de Vijver, Bart Van; Nasrolahi, Ali; Ehsanpour, Maryam; Afkhami, Majid; Bolaños, Federico; Iamunno, Franco; Santoro, Mario; De Stefano, Mario

2017-11-01

The first reports of diatoms growing on marine mammals date back to the early 1900s. However, only recently has direct evidence been provided for similar associations between diatoms and sea turtles. We present a comparison of diatom communities inhabiting carapaces of green turtles Chelonia mydas sampled at two remote sites located within the Indian (Iran) and Atlantic (Costa Rica) Ocean basins. Diatom observations and counts were carried out using scanning electron microscopy. Techniques involving critical point drying enabled observations of diatoms and other microepibionts still attached to sea turtle carapace and revealed specific aspects of the epizoic community structure. Species-poor, well-developed diatom communities were found on all examined sea turtles. Significant differences between the two host sea turtle populations were observed in terms of diatom abundance and their community structure (including growth form structure). A total of 12 and 22 diatom taxa were found from sea turtles in Iran and Costa Rica, respectively, and eight of these species belonging to Amphora, Chelonicola, Cocconeis, Navicula, Nitzschia and Poulinea genera were observed in samples from both locations. Potential mechanisms of diatom dispersal and the influence of the external environment, sea turtle behaviour, its life stage, and foraging and breeding habitats, as well as epibiotic bacterial flora on epizoic communities, are discussed.

Spatial distribution of fallout 137Cs in coastal marine water of Tamil Nadu coast

International Nuclear Information System (INIS)

Hemalatha, P.; Rajaram, S.; Lenka, P.; Jha, S.K.; Puranik, V.D.

2010-01-01

Very little information on the fallout 137 Cs activity exists for the Bay of Bengal. Normally the volume of sea water required for detecting fall out level of 137 Cs in coastal marine environment ranges from 100 litres to 1000 litres. The studies on distribution of 137 Cs in surface seawater of Tamil Nadu in Bay of Bengal were carried out in April 2009. On the eastern coastal lines of Bay of Bengal in Tamil Nadu, seven offshore locations were selected namely Chennai, Pondicherry, Karaikal, Rameshwaram, Tuticorin, Nagercoil and Kanyakumari. In situ preconcentration method was adopted and the experiments were carried out using motor boats well equipped to carry the instruments and provide power supply to operate the pump. 1000 litres of seawater was passed each time through CFCN filters at all the locations at a flow rate of 8 litres per minute. The activity concentrations of 137 Cs was in the range of 0.90 to 2.2 Bq/m 3 . These data represents reference values for coastal environment of Tamil Nadu and will be used to estimate radionuclide inventory in Indian marine environment, particularly of East Coast. The 137 Cs activity indicates that there are no new inputs of these radionuclides into the area. (author)

Marine and coastal ecosystem services on the science–policy–practice nexus: challenges and opportunities from 11 European case studies

NARCIS (Netherlands)

Drakou, E.G.; Kermagoret, C.; Liquete, C.; Ruiz-Frau, A.; Burkhard, K.; Lillebø, A.I.; van Oudenhoven, A.P.E.; Ballé-Béganton, J.; Rodrigues, J.G.; Nieminen, E.; Oinonen, S.; Ziemba, A.; Gissi, E.; Depellegrin, D.; Veidemane, K.; Ruskule, A.; Delangue, J.; Böhnke-Henrichs, A.; Boon, A.; Wenning, R.; Martino, S.; Hasler, B.; Termansen, M.; Rockel, M.; Hummel, H.; El Serafy, G.; Peev, P.

2017-01-01

We compared and contrasted 11 European case studies to identify challenges and opportunitiestoward the operationalization of marine and coastal ecosystem service (MCES) assessments inEurope. This work is the output of a panel convened by the Marine Working Group of theEcosystemServices Partnership

Biophotonics of diatoms

DEFF Research Database (Denmark)

Gössling, Johannes Wilhelm

Diatoms are unicellular microalgae present in all aquatic environments on earth. Due to their high photosynthetic productivity and abundance, diatoms are main components of aquatic food webs and among the main contributors of global photosynthetic carbon fixation. A unique feature of diatoms...

Probing the evolutionary history of epigenetic mechanisms: what can we learn from marine diatoms

Directory of Open Access Journals (Sweden)

Achal Rastogi

2015-07-01

Full Text Available Recent progress made on epigenetic studies revealed the conservation of epigenetic features in deep diverse branching species including Stramenopiles, plants and animals. This suggests their fundamental role in shaping species genomes across different evolutionary time scales. Diatoms are a highly successful and diverse group of phytoplankton with a fossil record of about 190 million years ago. They are distantly related from other super-groups of Eukaryotes and have retained some of the epigenetic features found in mammals and plants suggesting their ancient origin. Phaeodactylum tricornutum and Thalassiosira pseudonana, pennate and centric diatoms, respectively, emerged as model species to address questions on the evolution of epigenetic phenomena such as what has been lost, retained or has evolved in contemporary species. In the present work, we will discuss how the study of non-model or emerging model organisms, such as diatoms, helps understand the evolutionary history of epigenetic mechanisms with a particular focus on DNA methylation and histone modifications.

Effects of the oxylipin-producing diatom Skeletonema marinoi on gene expression levels of the calanoid copepod Calanus sinicus.

Science.gov (United States)

Lauritano, Chiara; Carotenuto, Ylenia; Vitiello, Valentina; Buttino, Isabella; Romano, Giovanna; Hwang, Jiang-Shiou; Ianora, Adrianna

2015-12-01

Diatoms are eukaryotic unicellular plants that constitute one of the major components of marine phytoplankton, comprising up to 40% of annual productivity at sea and representing 25% of global carbon-fixation. Diatoms have traditionally been considered a preferential food for zooplankton grazers such as copepods, but, in the last two decades, this beneficial role has been challenged after the discovery that many species of diatoms produce toxic metabolites, collectively termed oxylipins, that induce reproductive failure in zooplankton grazers. Diatoms are the dominant natural diet of Calanus sinicus, a cold-temperate calanoid copepod that supports secondary production of important fisheries in the shelf ecosystems of the Northwest Pacific Ocean, Yellow Sea, Sea of Japan and South China Sea. In this study, the effect of the oxylipin-producing diatom Skeletonema marinoi on C. sinicus has been evaluated by analyzing expression level changes of genes involved in defense and detoxification systems. Results show that C. sinicus is more resistant to a diet of this diatom species in terms of gene expression patterns, compared to the congeneric species Calanus helgolandicus which is an important constituent of the temperate waters of the Atlantic Ocean and northern Mediterranean Sea. These findings contribute to the better understanding of genetic and/or phenotypic flexibility of copepod species and their capabilities to cope with stress by identifying molecular markers (such as stress and detoxification genes) as biosensors for environmental perturbations (e.g. toxins and contaminants) affecting marine copepods. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Phenotypic plasticity of southern ocean diatoms: key to success in the sea ice habitat?

Directory of Open Access Journals (Sweden)

Olivia Sackett

Full Text Available Diatoms are the primary source of nutrition and energy for the Southern Ocean ecosystem. Microalgae, including diatoms, synthesise biological macromolecules such as lipids, proteins and carbohydrates for growth, reproduction and acclimation to prevailing environmental conditions. Here we show that three key species of Southern Ocean diatom (Fragilariopsis cylindrus, Chaetoceros simplex and Pseudo-nitzschia subcurvata exhibited phenotypic plasticity in response to salinity and temperature regimes experienced during the seasonal formation and decay of sea ice. The degree of phenotypic plasticity, in terms of changes in macromolecular composition, was highly species-specific and consistent with each species' known distribution and abundance throughout sea ice, meltwater and pelagic habitats, suggesting that phenotypic plasticity may have been selected for by the extreme variability of the polar marine environment. We argue that changes in diatom macromolecular composition and shifts in species dominance in response to a changing climate have the potential to alter nutrient and energy fluxes throughout the Southern Ocean ecosystem.

Geochemical peculiarities of marine sediment in coastal areas of India

International Nuclear Information System (INIS)

Gothankar, S.S.; Jha, S.K.; Tripathi, R.M.

2014-01-01

To understand the impact of anthropogenic activity on coastal marine environment, sediment samples were collected covering the west and east coast of India. The elemental concentration was determined using EDXRF technique. The east coast showed lower Rb/Sr ratio reflecting higher fraction of biogenic deposits, the higher ratio at the west coast reflects higher fraction of terrigenous detritus. The concentration of Pb and Ni was found higher at Rameshwaram and Okha respectively. The result indicates the impact of land based source of pollutant in few locations due to the anthropogenic activities. (author)

Monitoring ship noise to assess the impact of coastal developments on marine mammals.

Science.gov (United States)

Merchant, Nathan D; Pirotta, Enrico; Barton, Tim R; Thompson, Paul M

2014-01-15

The potential impacts of underwater noise on marine mammals are widely recognised, but uncertainty over variability in baseline noise levels often constrains efforts to manage these impacts. This paper characterises natural and anthropogenic contributors to underwater noise at two sites in the Moray Firth Special Area of Conservation, an important marine mammal habitat that may be exposed to increased shipping activity from proposed offshore energy developments. We aimed to establish a pre-development baseline, and to develop ship noise monitoring methods using Automatic Identification System (AIS) and time-lapse video to record trends in noise levels and shipping activity. Our results detail the noise levels currently experienced by a locally protected bottlenose dolphin population, explore the relationship between broadband sound exposure levels and the indicators proposed in response to the EU Marine Strategy Framework Directive, and provide a ship noise assessment toolkit which can be applied in other coastal marine environments. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Marine debris in beaches of the Southwestern Atlantic: An assessment of their abundance and mass at different spatial scales in northern coastal Argentina.

Science.gov (United States)

Becherucci, Maria Eugenia; Rosenthal, Alan Federico; Seco Pon, Juan Pablo

2017-06-15

Argentina is currently undergoing an intensive development of coastal-oriented tourism due to the temperate climate and coastal sceneries of the Southwestern Atlantic and particularly its wide ocean-open sandy beaches, which may turn into an important contributor of marine debris to the beaches. This study was designed to assess at four spatial scales (i) the variation of the abundance and mass of marine debris and (ii) the composition and sources of these items in sandy-tourist beaches of coastal zones of the province of Buenos Aires, in northern Argentina. The abundance and mass of marine debris shifted between sampling localities (separated by ~1.5×10 5 m) and beaches (~3×10 4 m). Debris was primarily from recreational and fishing activities and over 20mm in size. Tackling the complications associated with marine debris in northern Argentina may include intensive educational and advertising campaigns oriented chiefly to beach users and fisherman. Copyright © 2017. Published by Elsevier Ltd.

Effect of chlorination on the development of marine biofilms dominated by diatoms

Digital Repository Service at National Institute of Oceanography (India)

Patil, J.S.; Jagadeesan, V.

, and Thalassionema did not increase in density after chlorine treatment. It was also demonstrated that diatoms can colonize, grow and photosynthesize on chlorine-treated surfaces. Under pulse chlorination (treatment every 6 h), irrespective of chlorine concentration...

Navigating transformations in governance of Chilean marine coastal resources

Science.gov (United States)

Gelcich, Stefan; Hughes, Terry P.; Olsson, Per; Folke, Carl; Defeo, Omar; Fernández, Miriam; Foale, Simon; Gunderson, Lance H.; Rodríguez-Sickert, Carlos; Scheffer, Marten; Steneck, Robert S.; Castilla, Juan C.

2010-01-01

Marine ecosystems are in decline. New transformational changes in governance are urgently required to cope with overfishing, pollution, global changes, and other drivers of degradation. Here we explore social, political, and ecological aspects of a transformation in governance of Chile's coastal marine resources, from 1980 to today. Critical elements in the initial preparatory phase of the transformation were (i) recognition of the depletion of resource stocks, (ii) scientific knowledge on the ecology and resilience of targeted species and their role in ecosystem dynamics, and (iii) demonstration-scale experimental trials, building on smaller-scale scientific experiments, which identified new management pathways. The trials improved cooperation among scientists and fishers, integrating knowledge and establishing trust. Political turbulence and resource stock collapse provided a window of opportunity that triggered the transformation, supported by new enabling legislation. Essential elements to navigate this transformation were the ability to network knowledge from the local level to influence the decision-making processes at the national level, and a preexisting social network of fishers that provided political leverage through a national confederation of artisanal fishing collectives. The resultant governance scheme includes a revolutionary national system of marine tenure that allocates user rights and responsibilities to fisher collectives. Although fine tuning is necessary to build resilience of this new regime, this transformation has improved the sustainability of the interconnected social–ecological system. Our analysis of how this transformation unfolded provides insights into how the Chilean system could be further developed and identifies generalized pathways for improved governance of marine resources around the world. PMID:20837530

The potential for a fish ladder to mitigate against the loss of marine-estuarine-freshwater connectivity in a subtropical coastal lake

CSIR Research Space (South Africa)

Weerts, Steven P

2014-01-01

Full Text Available Increasing water demand in coastal regions has resulted in the construction of weirs and barrages in coastal freshwaters. These form barriers to migrations of estuarine and euryhaline marine fishes and crustaceans. This study assessed the impact...

Red and green algal origin of diatom membrane transporters: insights into environmental adaptation and cell evolution.

Directory of Open Access Journals (Sweden)

Cheong Xin Chan

Full Text Available Membrane transporters (MTs facilitate the movement of molecules between cellular compartments. The evolutionary history of these key components of eukaryote genomes remains unclear. Many photosynthetic microbial eukaryotes (e.g., diatoms, haptophytes, and dinoflagellates appear to have undergone serial endosymbiosis and thereby recruited foreign genes through endosymbiotic/horizontal gene transfer (E/HGT. Here we used the diatoms Thalassiosira pseudonana and Phaeodactylum tricornutum as models to examine the evolutionary origin of MTs in this important group of marine primary producers. Using phylogenomics, we used 1,014 diatom MTs as query against a broadly sampled protein sequence database that includes novel genome data from the mesophilic red algae Porphyridium cruentum and Calliarthron tuberculosum, and the stramenopile Ectocarpus siliculosus. Our conservative approach resulted in 879 maximum likelihood trees of which 399 genes show a non-lineal history between diatoms and other eukaryotes and prokaryotes (at the bootstrap value ≥70%. Of the eukaryote-derived MTs, 172 (ca. 25% of 697 examined phylogenies have members of both red/green algae as sister groups, with 103 putatively arising from green algae, 19 from red algae, and 50 have an unresolved affiliation to red and/or green algae. We used topology tests to analyze the most convincing cases of non-lineal gene history in which red and/or green algae were nested within stramenopiles. This analysis showed that ca. 6% of all trees (our most conservative estimate support an algal origin of MTs in stramenopiles with the majority derived from green algae. Our findings demonstrate the complex evolutionary history of photosynthetic eukaryotes and indicate a reticulate origin of MT genes in diatoms. We postulate that the algal-derived MTs acquired via E/HGT provided diatoms and other related microbial eukaryotes the ability to persist under conditions of fluctuating ocean chemistry, likely

Geophysical detection of marine intrusions in Black Sea coastal areas (Romania) using VES and ERT data

OpenAIRE

CHITEA, Florina; GEORGESCU, Paul; IOANE, Dumitru

2011-01-01

Abstract. Communities living in coastal areas depend in a great extent on the fresh water resources exploited from aquifers which are usually in a natural hydrodynamic equilibrium with the sea water. The contamination of fresh water with marine saltwater determines a significant increase in the aquifers electric conductivity, allowing an efficient application of resistivity methods in detecting and monitoring the marine intrusions. We present case studies from Romania (Costinesti and Vama Vec...

Diatom paleoecology Pass Key core 37, Everglades National Park, Florida Bay

Science.gov (United States)

Pyle, Laura; Cooper, S.R.; Huvane, J.K.

1998-01-01

During the 20th century, there have been large-scale anthropogenic modifications to the South Florida ecosystem. The effects of these changes on Florida Bay and its biological communities are currently of political and scientific interest. This study is part of a larger effort to reconstruct the history of environmental changes in the bay, using paleoecological techniques. We are using diatom indicators preserved in Florida Bay sediments to infer long-term water quality, productivity, nutrient, and salinity changes. We are also obtaining information concerning the natural variability of the ecosystem. Diatoms are microscopic algae, the remains of which are generally well preserved in sediments, and their distributions are closely linked to water quality. Diatoms were extracted from a 70-cm sediment core collected from the Pass Key mudbank of Florida Bay by the U.S. Geological Survey. Between 300-500 diatom valves from each of 15 core samples were identified and counted. Estimates of absolute abundance, species richness, Shannon-Wiener diversity, and centric:pennate ratios were calculated for each sample that was counted. Information on the ecology of the diatom species is presented, and changes in diatom community composition are evaluated. Samples contained an average of four million diatom valves per gram of sediment. Major changes in the diatom community are evident down core. These include increases in the percent abundance of marine diatoms in the time period represented by the core, probably the result of increasing salinity at Pass Key. Benthic diatoms become less abundant in the top half of the core. This may be related to a number of factors including the die-off of sea grass beds or increased turbidity of the water column. Once the chronology of the Pass Key core 37 is established, these down-core changes can be related to historical events and compared with other indicators in the sedimentary record that are currently being investigated by U.S Geological

Molecular evidence of the toxic effects of diatom diets on gene expression patterns in copepods.

Directory of Open Access Journals (Sweden)

Chiara Lauritano

Full Text Available Diatoms are dominant photosynthetic organisms in the world's oceans and are considered essential in the transfer of energy through marine food chains. However, these unicellular plants at times produce secondary metabolites such as polyunsaturated aldehydes and other products deriving from the oxidation of fatty acids that are collectively termed oxylipins. These cytotoxic compounds are responsible for growth inhibition and teratogenic activity, potentially sabotaging future generations of grazers by inducing poor recruitment in marine organisms such as crustacean copepods.Here we show that two days of feeding on a strong oxylipin-producing diatom (Skeletonema marinoi is sufficient to inhibit a series of genes involved in aldehyde detoxification, apoptosis, cytoskeleton structure and stress response in the copepod Calanus helgolandicus. Of the 18 transcripts analyzed by RT-qPCR at least 50% were strongly down-regulated (aldehyde dehydrogenase 9, 8 and 6, cellular apoptosis susceptibility and inhibitor of apoptosis IAP proteins, heat shock protein 40, alpha- and beta-tubulins compared to animals fed on a weak oxylipin-producing diet (Chaetoceros socialis which showed no changes in gene expression profiles.Our results provide molecular evidence of the toxic effects of strong oxylipin-producing diatoms on grazers, showing that primary defense systems that should be activated to protect copepods against toxic algae can be inhibited. On the other hand other classical detoxification genes (glutathione S-transferase, superoxide dismutase, catalase, cytochrome P450 were not affected possibly due to short exposure times. Given the importance of diatom blooms in nutrient-rich aquatic environments these results offer a plausible explanation for the inefficient use of a potentially valuable food resource, the spring diatom bloom, by some copepod species.

Multiple stressors, nonlinear effects and the implications of climate change impacts on marine coastal ecosystems.

Science.gov (United States)

Hewitt, Judi E; Ellis, Joanne I; Thrush, Simon F

2016-08-01

Global climate change will undoubtedly be a pressure on coastal marine ecosystems, affecting not only species distributions and physiology but also ecosystem functioning. In the coastal zone, the environmental variables that may drive ecological responses to climate change include temperature, wave energy, upwelling events and freshwater inputs, and all act and interact at a variety of spatial and temporal scales. To date, we have a poor understanding of how climate-related environmental changes may affect coastal marine ecosystems or which environmental variables are likely to produce priority effects. Here we use time series data (17 years) of coastal benthic macrofauna to investigate responses to a range of climate-influenced variables including sea-surface temperature, southern oscillation indices (SOI, Z4), wind-wave exposure, freshwater inputs and rainfall. We investigate responses from the abundances of individual species to abundances of functional traits and test whether species that are near the edge of their tolerance to another stressor (in this case sedimentation) may exhibit stronger responses. The responses we observed were all nonlinear and some exhibited thresholds. While temperature was most frequently an important predictor, wave exposure and ENSO-related variables were also frequently important and most ecological variables responded to interactions between environmental variables. There were also indications that species sensitive to another stressor responded more strongly to weaker climate-related environmental change at the stressed site than the unstressed site. The observed interactions between climate variables, effects on key species or functional traits, and synergistic effects of additional anthropogenic stressors have important implications for understanding and predicting the ecological consequences of climate change to coastal ecosystems. © 2015 John Wiley & Sons Ltd.

Climate warming and estuarine and marine coastal ecosystems

International Nuclear Information System (INIS)

Kennedy, V.S.

1994-01-01

Estuaries are physically controlled, resilient coastal ecosystems harboring environmentally tolerant species in diluted seawater. Marine coastal systems are less stressed physically and contain some environmentally less tolerant species. Both systems are biologically productive and economically significant. Because of their complex structure and function, it is difficult to predict accurately the effects of climate change, but some broad generalizations can be made. If climate warming occurs, it will raise sea-level, heat shallow waters, and modify precipitation, wind, and water circulation patterns. Rapid sea-level rise could cause the loss of salt marshes, mangrove swamps, and coral reefs, thus diminishing the ecological roles of these highly productive systems. Warmer waters could eliminate heat-sensitive species from part of their geographical range while allowing heat-tolerant species to expand their range, depending on their ability to disperse. Most thermally influenced losses of species will probably only be local, but changed distributions may lead to changed community function. It is more difficult to predict the effects of modified precipitation, wind, and water circulation patterns, but changes could affect organisms dependent on such patterns for food production (e.g., in upwelling regions) or for retention in estuaries. Aquacultural and fishery-related enterprises would be affected negatively in some regions and positively in others. 73 refs

Environmental impact of condenser effluents into coastal marine environments: need for continuous monitoring

International Nuclear Information System (INIS)

Venugopal, V.P.

2015-01-01

Electric plants working on the principle of steam-water cycle require large amounts of water for condenser cooling purpose. Nuclear power plants require, on an average, about 3m 3 cooling water per minute per megawatt of electricity generated. Owning to the scarcity of large sources of freshwater for cooling, newer power plants, particularly in water-stressed parts of the world, tend to get located in coastal regions, where they can make use of the abundant seawater. However, this also poses a problem, in terms of the biofouling potential of coastal marine environments. Sessile benthic organism, which are generally present as part of the coastal marine ecosystem, extend their habitat into the cooling water system of the power plant. It is often observed that massive growth of such fouling organisms may endanger normal operation of the cooling water system, unless appropriate control measures are adopted. Presence of calcareous organisms such as mussels and barnacles in the pre-condenser sections of the power plant is a common sight; but these organisms, when lodged inside condenser tubes, can not only reduce the heat transfer efficiency but also can cause localized corrosion and tube leakage, leading of ingress of seawater into the steam-water system. It is, therefore, important that appropriate control measures are adopted to discourage the growth of the organisms. However, this needs to be done in an environmentally sustainable manner, as the cooling water is ultimately discharged back into the sea. The presentation aims to give and overview of the biofouling problems generally encountered in a typical tropical coastal power station operating in India and the chemical control measures adopted and their effectiveness. The talk also throws light on the more recent advances in biofouling control such as surface modification and use of nanotechnology which, in the foreseeable future, may provide more lasting and environmentally sustainable solutions. (author)

The ISMAR high frequency coastal radar network: Monitoring surface currents for management of marine resources

DEFF Research Database (Denmark)

Carlson, Daniel Frazier

2015-01-01

The Institute of Marine Sciences (ISMAR) of the National Research Council of Italy (CNR) established a High Frequency (HF) Coastal Radar Network for the measurement of the velocity of surface currents in coastal seas. The network consists of four HF radar systems located on the coast of the Gargano...... Promontory (Southern Adriatic, Italy). The network has been operational since May 2013 and covers an area of approximately 1700 square kilometers in the Gulf of Manfredonia. Quality Assessment (QA) procedures are applied for the systems deployment and maintenance and Quality Control (QC) procedures...

Climate change impacts on U.S. coastal and marine ecosystems

Science.gov (United States)

Scavia, Donald; Field, John C.; Boesch, Donald F.; Buddemeier, Robert W.; Burkett, Virginia; Cayan, Daniel R.; Fogarty, Michael; Harwell, Mark A.; Howarth, Robert W.; Mason, Curt; Reed, Denise J.; Royer, Thomas C.; Sallenger, Asbury H.; Titus, James G.

2002-01-01

Increases in concentrations of greenhouse gases projected for the 21st century are expected to lead to increased mean global air and ocean temperatures. The National Assessment of Potential Consequences of Climate Variability and Change (NAST 2001) was based on a series of regional and sector assessments. This paper is a summary of the coastal and marine resources sector review of potential impacts on shorelines, estuaries, coastal wetlands, coral reefs, and ocean margin ecosystems. The assessment considered the impacts of several key drivers of climate change: sea level change; alterations in precipitation patterns and subsequent delivery of freshwater, nutrients, and sediment; increased ocean temperature; alterations in circulation patterns; changes in frequency and intensity of coastal storms; and increased levels of atmospheric CO2. Increasing rates of sea-level rise and intensity and frequency of coastal storms and hurricanes over the next decades will increase threats to shorelines, wetlands, and coastal development. Estuarine productivity will change in response to alteration in the timing and amount of freshwater, nutrients, and sediment delivery. Higher water temperatures and changes in freshwater delivery will alter estuarine stratification, residence time, and eutrophication. Increased ocean temperatures are expected to increase coral bleaching and higher CO2 levels may reduce coral calcification, making it more difficult for corals to recover from other disturbances, and inhibiting poleward shifts. Ocean warming is expected to cause poleward shifts in the ranges of many other organisms, including commercial species, and these shifts may have secondary effects on their predators and prey. Although these potential impacts of climate change and variability will vary from system to system, it is important to recognize that they will be superimposed upon, and in many cases intensify, other ecosystem stresses (pollution, harvesting, habitat destruction

Spatial distribution of radium in coastal marine waters of Tamil Nadu

International Nuclear Information System (INIS)

Hemalatha, P.; Jha, S.K.; Rajaram, S.; Puranik, V.D.

2010-01-01

This paper presents the radium activity levels in the coastal area covering the entire south eastern coast of Tamil Nadu from Chennai to Kanyakumari. Radium-226 (T 1/2 =1620 y), a α-emitter in the decay chain of elements, of the primordial uranium, is a ubiquitous component of the natural radiation in marine environment. It has a high degree of radiotoxicity, and is found in most abiotic and biotic materials, leading to direct exposure to biota and indirect human radiation exposure. Uptake of 226 Ra in biological systems depends upon the availability of the nuclide. In the light of the possible radio ecological significance in the environment, the present study has been undertaken to investigate the distribution of 226 Ra in the marine components of the Tamil Nadu coast for which no such data are available

Structural strength deterioration of coastal bridge piers considering non-uniform corrosion in marine environments

Science.gov (United States)

Guo, Anxin; Yuan, Wenting; Li, Haitao; Li, Hui

2018-04-01

In the aggressive marine environment over a long-term service period, coastal bridges inevitably sustain corrosion-induced damage due to high sea salt and humidity. This paper investigates the strength reduction of coastal bridges, especially focusing on the effects of non-uniform corrosion along the height of bridge piers. First, the corrosion initiation time and the degradation of reinforcement and concrete are analyzed for bridge piers in marine environments. To investigate the various damage modes of the concrete cover, a discretization method with fiber cells is used for calculating time-dependent interaction diagrams of cross-sections of the bridge piers at the atmospheric zone and the splash and tidal zone under a combination of axial force and bending moment. Second, the shear strength of these aging structures is analyzed. Numerical simulation indicates that the strength of a concrete pier experiences dramatic reduction from corrosion initiation to the spalling of the concrete cover. Strength loss in the splash and tidal zone is more significant than in the atmospheric zone when structures' service time is assumed to be the same.

Genetic diversity and temporal variation of the marine Synechococcus community in the subtropical coastal waters of Hong Kong.

Science.gov (United States)

Jing, Hongmei; Zhang, Rui; Pointing, Stephen B; Liu, Hongbin; Qian, Peiyuan

2009-03-01

The phylogenetic diversity of the marine Synechococcus community in the subtropical coastal waters of Hong Kong, China, was examined through intergenic transcribed spacer clone libraries. All the sequences obtained fell within both marine cluster A (MC-A) and B (MC-B), with MC-A phylotypes dominating throughout the year. Distinct phylogenetic lineages specific to Hong Kong waters were detected from both MC-A and MC-B. The highest Synechococcus community diversity occurred in December, but the highest Synechococcus abundance occurred in August. On the other hand, both the abundance and diversity of Synechococcus showed a minimum in February. The remarkable seasonal variations of Synechococcus diversity observed were likely the result of the changes of hydrographic condition modulated by monsoons. Principal component analysis revealed that the in situ abiotic water characteristics, especially salinity and water turbidity, explained much of the variability of the marine Synechococcus population diversity in Hong Kong coastal waters. In addition, the temporal changes of Synechococcus abundance were largely driven by water temperature.

The Marine Realms Information Bank family of digital libraries: access to free online information for coastal and marine science

Science.gov (United States)

Lightsom, Frances L.; Allwardt, Alan O.

2007-01-01

Searching the World Wide Web for reliable information about specific topics or locations can be frustrating: too many hits, too little relevance. A well-designed digital library, offering a carefully selected collection of online resources, is an attractive alternative to web search engines. The U.S. Geological Survey (USGS) provides three digital libraries for coastal and marine science to serve the needs of a diverse audience--scientists, public servants, educators, and the public.

Interactions of bacteria with diatoms: Influence on natural marine biofilms.

Digital Repository Service at National Institute of Oceanography (India)

Khandeparker, L.; DeCosta, P.M.; Anil, A.C.; Sawant, S.S.

therein). In fact, biofilms are considered a reservoir and source of dissemination for V. cholerae (Shikuma & Hadfield 2010). Nutrient concentrations in the surrounding waters also affect the progression of the biofilm community (Qian et al. 2007... to render diatom monocultures near axenic (Patil & Anil 2005c). The following diluents were used – Aged Sea Water (ASW; unenriched control), ASW+streptomycin (ASW+S), ASW+chloramphenicol (ASW+C), f/2 medium (Guillard and Ryther, 1962) prepared in ASW [f...

Type A natural resource damage assessment models for Great Lakes environments (NRDAM/GLE) and coastal and marine environments (NRDAM/CME)

International Nuclear Information System (INIS)

French, D.P.; Reed, M.

1993-01-01

A computer model of the physical fates, biological effects, and economic damages resulting from releases of oil and other hazardous materials has been developed by ASA to be used in Type A natural resource damage assessments under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). Natural Resource Damage Assessment Models for Great Lakes Environments (NRDAM/GLE) and for Coastal and Marine Environments (NRDAM/GLE) and for Coastal and Marine Environments (NRDAM/CME) will become available. These models will also support NOAA's damage assessment regulations under the Oil Pollution Act of 1990. The physical and biological models are three-dimensional. Direct mortality from toxic concentrations and oiling, impacts of habitat loss, and food web losses are included in the model. Estimation of natural resource damages is based both on the lost value of injured resources and on the costs for restoration or replacement of those resources. A coupled geographical information system (GIS) allows gridded representation of complex coastal boundaries, variable bathymetry, shoreline types, and multiple biological habitats. The models contain environmental, geographical, chemical, toxicological, biological, restoration and economic databases with the necessary information to estimate damages. Chemical and toxicological data are included for about 470 chemicals and oils. Biological data are unique to 77 coastal and marine plus 11 Great Lakes provinces, and to habitat type. Restoration and economic valuations are also regionally specific

Evolution and metabolic significance of the urea cycle in photosynthetic diatoms

Czech Academy of Sciences Publication Activity Database

Allen, A. E.; Dupont, Ch. L.; Oborník, Miroslav; Horák, Aleš; Nunes-Nesi, A.; McCrow, J. P.; Zheng, H.; Johnson, D. A.; Hu, H.; Fernie, A. R.; Bowler, Ch.

2011-01-01

Roč. 473, č. 7346 (2011), s. 203-209 ISSN 0028-0836 R&D Projects: GA ČR GA206/08/1423 Institutional research plan: CEZ:AV0Z60220518 Keywords : CARBAMOYL-PHOSPHATE SYNTHETASE * PHAEODACTYLUM-TRICORNUTUM * MAXIMUM-LIKELIHOOD * PHYLOGENETIC RECONSTRUCTION * MOLECULAR EVOLUTION * SEQUENCE ALIGNMENT * DIVERGENCE TIMES * MARINE DIATOMS * MIXED MODELS * TREE Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 36.280, year: 2011

Millimeter-Sized Marine Plastics: A New Pelagic Habitat for Microorganisms and Invertebrates

Science.gov (United States)

Reisser, Julia; Shaw, Jeremy; Hallegraeff, Gustaaf; Proietti, Maira; Barnes, David K. A.; Thums, Michele; Wilcox, Chris; Hardesty, Britta Denise; Pattiaratchi, Charitha

2014-01-01

Millimeter-sized plastics are abundant in most marine surface waters, and known to carry fouling organisms that potentially play key roles in the fate and ecological impacts of plastic pollution. In this study we used scanning electron microscopy to characterize biodiversity of organisms on the surface of 68 small floating plastics (length range = 1.7–24.3 mm, median = 3.2 mm) from Australia-wide coastal and oceanic, tropical to temperate sample collections. Diatoms were the most diverse group of plastic colonizers, represented by 14 genera. We also recorded ‘epiplastic’ coccolithophores (7 genera), bryozoans, barnacles (Lepas spp.), a dinoflagellate (Ceratium), an isopod (Asellota), a marine worm, marine insect eggs (Halobates sp.), as well as rounded, elongated, and spiral cells putatively identified as bacteria, cyanobacteria, and fungi. Furthermore, we observed a variety of plastic surface microtextures, including pits and grooves conforming to the shape of microorganisms, suggesting that biota may play an important role in plastic degradation. This study highlights how anthropogenic millimeter-sized polymers have created a new pelagic habitat for microorganisms and invertebrates. The ecological ramifications of this phenomenon for marine organism dispersal, ocean productivity, and biotransfer of plastic-associated pollutants, remains to be elucidated. PMID:24941218

Groundwater Modeling in Coastal Arid Regions Under the Influence of Marine Saltwater Intrusion

Science.gov (United States)

Walther, Marc; Kolditz, Olaf; Grundmann, Jens; Liedl, Rudolf

2010-05-01

The optimization of an aquifer's "safe yield", especially within agriculturally used regions, is one of the fundamental tasks for nowaday's groundwater management. Due to the limited water ressources in arid regions, conflict of interests arise that need to be evaluated using scenario analysis and multicriterial optimization approaches. In the context of the government-financed research project "International Water Research Alliance Saxony" (IWAS), the groundwater quality for near-coastal, agriculturally used areas is investigated under the influence of marine saltwater intrusion. Within the near-coastal areas of the study region, i.e. the Batinah plains of Northern Oman, an increasing agricultural development could be observed during the recent decades. Simultaneously, a constant lowering of the groundwater table was registered, which is primarily due to the uncontrolled and unsupervised mining of the aquifers for the local agricultural irrigation. Intensively decreased groundwater levels, however, cause an inversion of the hydraulic gradient which is naturally aligned towards the coast. This, in turn,leads to an intrusion of marine saltwater flowing inland, endangering the productivity of farms near the coast. Utilizing the modeling software package OpenGeoSys, which has been developed and constantly enhanced by the Department of Environmental Informatics at the Helmholtz Centre for Environmental Research Leipzig (UFZ; Kolditz et al., 2008), a three-dimensional, density-dependent model including groundwater flow and mass transport is currently being built up. The model, comprehending three selected coastal wadis of interest, shall be used to investigate different management scenarios. The main focus of the groundwater modelling are the optimization of well positions and pumping schemes as well as the coupling with a surface runoff model, which is also used for the determination of the groundwater recharge due to wadi runoff downstream of retention dams. Based on

Sponge species composition, abundance, and cover in marine lakes and coastal mangroves in Berau, Indonesia

NARCIS (Netherlands)

Becking, L.E.; Cleary, D.F.R.; Voogd, de N.J.

2013-01-01

We compared the species composition, abundance, and cover of sponges in 2 marine lakes (Kakaban Lake and Haji Buang Lake) and adjacent coastal mangroves on the islands of Kakaban and Maratua in the Berau region of Indonesia. We recorded a total of 115 sponge species, 33 of which were restricted to

75 FR 9158 - Atlantic Coastal Fisheries Cooperative Management Act Provisions; Coastal Sharks Fishery

Science.gov (United States)

2010-03-01

... Coastal Fisheries Cooperative Management Act Provisions; Coastal Sharks Fishery AGENCY: National Marine... Commission's Interstate Fishery Management Plan (ISFMP) for Coastal Sharks. Subsequently, the Commission... New Jersey failed to carry out its responsibilities under the Coastal Sharks ISFMP, and if the...

Isolation and characterization of extracellular polysaccharides from the epipelic diatoms Cylindrotheca closterium and Navicula salinarum

NARCIS (Netherlands)

Staats, N.; de Winder, B.; Stal, L.J.; Mur, L.R.

1999-01-01

The production and composition of extracellular polymeric substances (EPS) in axenic batch cultures of the benthic marine epipelic diatoms Navicula salinarum and Cylindrotheca closterium were investigated. EPS was secreted into the medium and the bulk was loosely associated with the cells. Neither

Rio de la Plata river: as paleoenvironmental focus using diatoms as proxies

International Nuclear Information System (INIS)

Perez, L; Garcia-Rodriguez, F; Hanebuth, T.

2012-01-01

The objective of this study is the reconstruction of the environmental history of the Rio de la Plata system in relation to the anthropogenic impact and historical changes in the flow with emphasis on salinity variations during the late Holocene. For this reason it was analyzed the composition of diatoms (grouped in freshwater (D), saline (S) and marine (M))

Biodiversity protection and sustainable management of coastal areas: The Marine Protected Area of Egadi Islands

International Nuclear Information System (INIS)

Donati, Stefano

2015-01-01

The Marine Protected Area of Egadi Islands, northwest coast of Sicily Island, is the largest area in the Mediterranean Sea, stretching over with its 53,992 hectares. Established in 1991, since 2001 it is managed by the Municipality of Favignana on behalf of the Italian Ministry for the Environment, Land and Sea. The Egadi’s archipelago is located in the Strait of Sicily, and includes the islands of Favignana, Levanzo, Marettimo and the islets of Formica and Maraone. The institutional mission of the Marine Protected Area is the protection and enhancement of the marine environment, environmental education, awareness and information of users, research and monitoring, integrated management of the coastal zone, and the promotion of sustainable development, with particular reference to the eco-compatibility of tourism [it

Marine Battlefields

DEFF Research Database (Denmark)

Harðardóttir, Sara

as they are an important food source for various marine animals. For both phytoand zooplankton predation is a major cause of mortality, and strategies for protection or avoidance are important for survival. Diatoms of the genera Nitzschia and Pseudo-nitzschia are known to produce a neuro-toxin, domoic acid (DA). Despite......Phytoplankton species are photosynthetic organisms found in most aquatic habitats. In the ocean, phytoplankton are tremendously important because they produce the energy that forms the base of the marine food web. Zooplankton feed on phytoplankton and mediate the energy to higher trophic levels...

Influence of elevated temperature and pCO2 on the marine periphytic diatom Navicula distans and its associated organisms in culture

Digital Repository Service at National Institute of Oceanography (India)

Baragi, L.V.; Khandeparker, L.; Anil, A.C.

are available for diatoms (Sett et al., 2014; Torstensson et al., 2013). Diatoms are the major primary producers and dominate the fouling community in the shallow water photic system. Fouling diatoms are: (a) a source of primary production for higher... (picoperiphyte and heterotrophic bacteria). Materials and methods Culture conditions Navicula distans, a pennate periphytic diatom, was isolated from a biofilm developed on a glass slide submerged in the waters of Dona Paula Bay located along the west coast...

Assessing habitat risk from human activities to inform coastal and marine spatial planning: a demonstration in Belize

International Nuclear Information System (INIS)

Arkema, Katie K; Wood, Spencer A; Ruckelshaus, Mary; Verutes, Gregory; Rosenthal, Amy; Bernhardt, Joanna R; Clarke, Chantalle; Rosado, Samir; Canto, Maritza; McField, Melanie; De Zegher, Joann

2014-01-01

Integrated coastal and ocean management requires transparent and accessible approaches for understanding the influence of human activities on marine environments. Here we introduce a model for assessing the combined risk to habitats from multiple ocean uses. We apply the model to coral reefs, mangrove forests and seagrass beds in Belize to inform the design of the country’s first Integrated Coastal Zone Management (ICZM) Plan. Based on extensive stakeholder engagement, review of existing legislation and data collected from diverse sources, we map the current distribution of coastal and ocean activities and develop three scenarios for zoning these activities in the future. We then estimate ecosystem risk under the current and three future scenarios. Current levels of risk vary spatially among the nine coastal planning regions in Belize. Empirical tests of the model are strong—three-quarters of the measured data for coral reef health lie within the 95% confidence interval of interpolated model data and 79% of the predicted mangrove occurrences are associated with observed responses. The future scenario that harmonizes conservation and development goals results in a 20% reduction in the area of high-risk habitat compared to the current scenario, while increasing the extent of several ocean uses. Our results are a component of the ICZM Plan for Belize that will undergo review by the national legislature in 2015. This application of our model to marine spatial planning in Belize illustrates an approach that can be used broadly by coastal and ocean planners to assess risk to habitats under current and future management scenarios. (letter)

Diatomeas marinas de aguas costeras de la provincia de Buenos Aires (Argentina.: III Géneros potencialmente nocivos Asterionellopsis, Cerataulina, Ceratoneis y Leptocylindrus Marine diatoms from Buenos Aires coastal waters (Argentina: Ill Potentially harmful genus Asterionellopsis,Cerataulina, Ceratoneis y Leptocylindrus

Directory of Open Access Journals (Sweden)

INÉS SUNESEN

2007-12-01

Full Text Available El presente trabajo está abocado al estudio morfológico, taxonómico y distribucional de las especies de diatomeas pertenecientes a los géneros Asterionellopsis, Cerataulina, Ceratoneis y Leptocylindrus halladas en aguas costeras marinas de la provincia de Buenos Aires, Argentina. Las muestras planctónicas fueron colectadas en San Clemente del Tuyú, Santa Teresita, La Lucila del Mar, Mar de Ajó, Nueva Atlantis, Pinamar y Villa Gesell, entre noviembre de 1994 y septiembre de 2000. Material sin tratar y tratado fue analizado con microscopio óptico y microscopio electrónico de barrido. Seis taxa correspondientes a los géneros mencionados fueron determinados, de los cuales Cerataulina dentata es citada por primera vez para Argentina y Leptocylindrus minimus es citada por primera vez para el área costera de la provincia de Buenos Aires. Todas las especies reportadas como nocivas no toxígenas para otras áreas geográficas fueron encontradas. Cerataulina pelágica, Ceratoneis closterium y Leptocylindrus minimus, componentes ocasionales del plancton del área siempre en bajas densidades, no fueron nunca asociadas a episodios de floración. Asterionellopsis glacialis, componente habitual del plancton, fue causante de discoloraciones nocivas para el turismo y las actividades recreacionalesThe present work is devoted to the morphological, taxonomic, and distributional study of the diatom species belonging to the genera Asterionellopsis, Cerataulina, Ceratoneis and Leptocylindrus found in the marine coastal waters of Buenos Aires Province, Argentina. Planktonic samples were collected from November 1994 to September 2000 at San Clemente del Tuyú, Santa Teresita, La Lucila del Mar, Mar de Ajó, Nueva Atlantis, Pinamar and Villa Gesell. Raw and cleaned samples were analysed with light and scanning electron microscopy. Six taxa of the mentioned genera were determined, of which Cerataulina dentata is reported for the first time for Argentina and

Diatom stratigraphy and long-term dissolved silica concentrations in the Baltic Sea

Science.gov (United States)

Olli, Kalle; Clarke, Annemarie; Danielsson, Åsa; Aigars, Juris; Conley, Daniel J.; Tamminen, Timo

2008-10-01

In many parts of the world coastal waters with anthropogenic eutrophication have experienced a gradual depletion of dissolved silica (DSi) stocks. This could put pressure on spring bloom diatom populations, e.g. by limiting the intensity of blooms or by causing shifts in species composition. In addition, eutrophication driven enhanced diatom growth is responsible for the redistribution of DSi from the water phase to the sediments, and changes in the growth conditions may be reflected in the sediment diatom stratigraphy. To test for changes in diatom communities we have analyzed four sediment cores from the Baltic Sea covering approximately the last 100 years. The sediment cores originate from the western Gulf of Finland, the Kattegat, the Baltic Proper and the Gulf of Riga. Three out of the four cores reveal only minor changes in composition of diatom assemblages, while the Gulf of Riga core contains major changes, occurring after the second World War. This area is set apart from the other Baltic Sea basins by a high frequency of low after spring bloom DSi concentrations (< 2 µmol L - 1 ) during a relatively well defined time period from 1991-1998. In 1991 to 1993 a rapid decline of DSi spring concentrations and winter stocks (down to 5 µmol L - 1 ) in the Gulf was preceded by exceptionally intense diatom spring blooms dominated by the heavily silicified species Thalassiosira baltica (1991-1992; up to 5.5 mg ww L - 1 ). T. baltica has been the principal spring bloom diatom in the Gulf of Riga since records began in 1975. DSi consumption and biomass yield experiments with cultured T. baltica suggest that intense blooms can potentially exhaust the DSi stock of the water column and exceed the annual Si dissolution in the Gulf of Riga. The phytoplankton time series reveals another exceptional T. baltica bloom period in 1981-1983 (up to 8 mg L - 1 ), which, however, took place before the regular DSi measurements. These periods may be reflected in the conspicuous

Heavy metals in marine coastal sediments: assessing sources, fluxes, history and trends.

Science.gov (United States)

Frignani, Mauro; Bellucci, Luca Giorgio

2004-01-01

Examples are presented from the Adriatic Sea, the Ligurian Sea and the Venice Lagoon to illustrate different approaches to the study of anthropogenic metals in marine coastal sediments. These examples refer to studies of areal distribution and transport mechanisms, individuation of the sources, sediment dating, chronology of the fluxes, present and past trends. In particular, some of the findings achieved in studying the Venice Lagoon are discussed from the point of view of anthropogenic changes both in sediment composition and contaminant fluxes.

Feeding ecology of juvenile marine fish in a shallow coastal lagoon of southeastern Mexico

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Daniel Arceo-Carranza

2015-09-01

Full Text Available Many species of marine fish use coastal lagoons during early stages of their life cycles due to the protection provided by their turbid waters and complex structure of the environment, such as mangroves and mudflats, and the availability of food derived from the high productivity of these sites. In this study, we analyzed the diet of six species of juvenile marine fishes that use a karstic lagoon system in the northwest portion of the Yucatan Peninsula, Mexico. Through stomach contents analysis we determined the trophic differences among Caranx latus, Oligoplites saurus, Trachinotus falcatus, Synodus foetens, Lutjanus griseus, and Strongylura notata. C. latus, O. saurus, S. foetens, and S. notate, which are ichthyophagous species (>80% by number. L. griseus feeds mainly on crustaceans (>55% and fish (35%, while T. falcatus feeds on mollusks (>50% bivalves, >35% gastropods. The analysis of similarities (ANOSIM showed differences in the diet of all species. Cluster analysis, based on the Bray-Curtis similarity matrix revealed three groups; one characterized by the ichthyophagous guild (S. notata, S. foetens, C. latus, and O. saurus, other group formed by the crustacean consumers (L. griseus, and the third, composed by the mollusk feeder (T. falcatus. Species of the ichthyophagous guild showed overlap in their diets, which under conditions of low prey abundance may trigger competition, hence affecting juvenile stages of these marine species that use coastal lagoons to feed and grow.

Location, Location, Location: Management Uses of Marine Benthic Biogeographical Information in Coastal Waters of the Northeastern USA

Science.gov (United States)

Ecosystem-based management practices, along with coastal and marine spatial planning, have been adopted as foundational principles for ocean management in the United States. The success of these practices depends in large measure on a solid foundation of biogeographical informati...

Megacities and large urban agglomerations in the coastal zone: interactions between atmosphere, land, and marine ecosystems.

Science.gov (United States)

von Glasow, Roland; Jickells, Tim D; Baklanov, Alexander; Carmichael, Gregory R; Church, Tom M; Gallardo, Laura; Hughes, Claire; Kanakidou, Maria; Liss, Peter S; Mee, Laurence; Raine, Robin; Ramachandran, Purvaja; Ramesh, R; Sundseth, Kyrre; Tsunogai, Urumu; Uematsu, Mitsuo; Zhu, Tong

2013-02-01

Megacities are not only important drivers for socio-economic development but also sources of environmental challenges. Many megacities and large urban agglomerations are located in the coastal zone where land, atmosphere, and ocean meet, posing multiple environmental challenges which we consider here. The atmospheric flow around megacities is complicated by urban heat island effects and topographic flows and sea breezes and influences air pollution and human health. The outflow of polluted air over the ocean perturbs biogeochemical processes. Contaminant inputs can damage downstream coastal zone ecosystem function and resources including fisheries, induce harmful algal blooms and feedback to the atmosphere via marine emissions. The scale of influence of megacities in the coastal zone is hundreds to thousands of kilometers in the atmosphere and tens to hundreds of kilometers in the ocean. We list research needs to further our understanding of coastal megacities with the ultimate aim to improve their environmental management.

Chiral separation of a diketopiperazine pheromone from marine diatoms using supercritical fluid chromatography.

Science.gov (United States)

Frenkel, Johannes; Wess, Carsten; Vyverman, Wim; Pohnert, Georg

2014-03-01

The proline derived diketopiperazine has been identified in plants, insects and fungi with unknown function and was recently also reported as the first pheromone from a diatom. Nevertheless the stereochemistry and enantiomeric excess of this natural product remained inaccessible using direct analytical methods. Here we introduce a chiral separation of this metabolite using supercritical fluid chromatography/mass spectrometry. Several chromatographic methods for chiral analysis of the diketopiperazine from the diatom Seminavis robusta and synthetic enantiomers have been evaluated but neither gas chromatography nor high performance liquid chromatography on different chiral cyclodextrin phases were successful in separating the enantiomers. In contrast, supercritical fluid chromatography achieved baseline separation within four minutes of run time using amylose tris(3,5-dimethylphenylcarbamate) as stationary phase and 2-propanol/CO2 as mobile phase. This very rapid chromatographic method in combination with ESI mass spectrometry allowed the direct analysis of the cyclic dipeptide out of the complex sea water matrix after SPE enrichment. The method could be used to determine the enantiomeric excess of freshly released pheromone and to follow the rapid degradation observed in diatom cultures. Initially only trace amounts of c(d-Pro-d-Pro) were found besides the dominant c(l-Pro-l-Pro) in the medium. However the enantiomeric excess decreased upon pheromone degradation within few hours indicating that a preferential conversion and thus inactivation of the l-proline derived natural product takes place. Copyright © 2014 Elsevier B.V. All rights reserved.

Influence of fishing activity over the marine debris composition close to coastal jetty.

Science.gov (United States)

Farias, Eduardo G G; Preichardt, Paulo R; Dantas, David V

2018-04-23

Worldwide, the marine debris emissions have been provoking impacts in ecosystems, generating massive mortality of different species with commercial interest. In South America, we have a lack of studies to verify the marine debris composition in transitional environments such as adjacent regions of coastal jetties. These are hydraulic engineering constructions used to maintain the navigation channel access between the sea-estuarine interface and are also used by teleost fishes, crustaceans, and mollusks like artificial shelters (reefs), being excellent fishing grounds. Therefore, the present study was devoted to qualitatively evaluate the composition of marine debris in an internal jetty portion of a Laguna Estuarine System (LES) located in South America (Brazil). Six hundred freediving were conducted to collect marine debris in the study region. The in situ campaigns were performed in 2016 during all spring season (sand substrata) in four distinct zones with 26,400 m 2 each one covering almost all adjacent jetty extension, to evaluate possible spatial changes in the marine debris composition. All material obtained was identified, measured, weighed, and ordered in eight groups, with six groups being related to the fishing activity and two groups related to the tourism/community in the study region. So, it was possible to observe possible relations between the marine debris distribution to artisanal and recreational local fishing. After 600 freediving sampling efforts, 2142 marine debris items were obtained, totaling close to 100 kg of solid waste removed from the inner portion of the coastal jetty. Notably, 1752 units (50 kg) of fishing leads were collected being this item the main marine debris residue found in the four sampled areas, corresponding to nearly 50% of the total weight of the collected waste. Ninety-eight percent of marine debris were derived from the local fishing activities, and just 2% were derived from tourism/community. Considering the total

Isolation and Characterization of Silaffin that Catalyze Biosilica Formation from Marine Diatom Chaetoceros gracilis

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AGNES IMELDA MANURUNG

2007-09-01

Full Text Available The method of making silica in industries requires extreme conditions. The finding of proteins involved in the formation of biosilica from diatoms, has opened up an alternative way of production. Chaetoceros gracilis is one of the diatoms, which is potential in producing silaffin protein. This study aimed to isolate and to characterize the protein. We also analyzed the protein activity toward tetraethoxyorthosilicate (TEOS substrate in in vitro reaction. Diatom biomass was harvested and further kept in 2% SDS/100 mM EDTA solution. Protein isolation was conducted by dissolving the silica and separating the protein by soaking in 2 M HF/8 M NH4F. Protein concentration was analyzed using Bradford method and the molecular weight was estimated through SDS-PAGE. Protein activity was observed by reacting it with TEOS substrate to form silica polymer and measured by colorimetric molibdate assay. Protein concentration was 1.20 mg/ml and appeared filamentous. The apparent molecular weights consisted of 12, 23, 42, 44 kDa. These protein was able to polymerize the silica at room temperature within 10 min. As much as 85.65 μmol TEOS was polymerized per 1.4 × 106 silaffin protein per min. SEM analysis showed the formation of spherical, aggregate biosilica.

Isolation and Characterization of Silaffin that Catalyze Biosilica Formation from Marine Diatom Chaetoceros gracilis

Directory of Open Access Journals (Sweden)

AGNES IMELDA MANURUNG

2007-09-01

Full Text Available The method of making silica in industries requires extreme conditions. The finding of proteins involved in the formation of biosilica from diatoms, has opened up an alternative way of production. Chaetoceros gracilis is one of the diatoms, which is potential in producing silaffin protein. This study aimed to isolate and to characterize the protein. We also analyzed the protein activity toward tetraethoxyorthosilicate (TEOS substrate in in vitro reaction. Diatom biomass was harvested and further kept in 2% SDS/100 mM EDTA solution. Protein isolation was conducted by dissolving the silica and separating the protein by soaking in 2 M HF/8 M NH4F. Protein concentration was analyzed using Bradford method and the molecular weight was estimated through SDS-PAGE. Protein activity was observed by reacting it with TEOS substrate to form silica polymer and measured by colorimetric molibdate assay. Protein concentration was 1.20 mg/ml and appeared filamentous. The apparent molecular weights consisted of 12, 23, 42, 44 kDa. These protein was able to polymerize the silica at room temperature within 10 min. As much as 85.65 mol TEOS was polymerized per 1.4 x 106 silaffin protein per min. SEM analysis showed the formation of spherical, aggregate biosilica.

NODC Standard Format Marine Birds from Coastal Alaska and Puget Sound Data (1975-1980): Specimen and Feeding Studies (F031) (NODC Accession 0014154)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Marine Bird Specimen and Feeding Studies (F031) is one of a group of seven datasets related to Marine Birds from Coastal Alaska and Puget Sound Data (1975 -1980)....

Hypernatremia in Dice snakes (Natrix tessellata) from a coastal population: implications for osmoregulation in marine snake prototypes.

Science.gov (United States)

Brischoux, François; Kornilev, Yurii V

2014-01-01

The widespread relationship between salt excreting structures (e.g., salt glands) and marine life strongly suggests that the ability to regulate salt balance has been crucial during the transition to marine life in tetrapods. Elevated natremia (plasma sodium) recorded in several marine snakes species suggests that the development of a tolerance toward hypernatremia, in addition to salt gland development, has been a critical feature in the evolution of marine snakes. However, data from intermediate stage (species lacking salt glands but occasionally using salty environments) are lacking to draw a comprehensive picture of the evolution of an euryhaline physiology in these organisms. In this study, we assessed natremia of free-ranging Dice snakes (Natrix tessellata, a predominantly fresh water natricine lacking salt glands) from a coastal population in Bulgaria. Our results show that coastal N. tessellata can display hypernatremia (up to 195.5 mmol x l(-1)) without any apparent effect on several physiological and behavioural traits (e.g., hematocrit, body condition, foraging). More generally, a review of natremia in species situated along a continuum of habitat use between fresh- and seawater shows that snake species display a concomitant tolerance toward hypernatremia, even in species lacking salt glands. Collectively, these data suggest that a physiological tolerance toward hypernatremia has been critical during the evolution of an euryhaline physiology, and may well have preceded the evolution of salt glands.

Hypernatremia in Dice snakes (Natrix tessellata from a coastal population: implications for osmoregulation in marine snake prototypes.

Directory of Open Access Journals (Sweden)

François Brischoux

Full Text Available The widespread relationship between salt excreting structures (e.g., salt glands and marine life strongly suggests that the ability to regulate salt balance has been crucial during the transition to marine life in tetrapods. Elevated natremia (plasma sodium recorded in several marine snakes species suggests that the development of a tolerance toward hypernatremia, in addition to salt gland development, has been a critical feature in the evolution of marine snakes. However, data from intermediate stage (species lacking salt glands but occasionally using salty environments are lacking to draw a comprehensive picture of the evolution of an euryhaline physiology in these organisms. In this study, we assessed natremia of free-ranging Dice snakes (Natrix tessellata, a predominantly fresh water natricine lacking salt glands from a coastal population in Bulgaria. Our results show that coastal N. tessellata can display hypernatremia (up to 195.5 mmol x l(-1 without any apparent effect on several physiological and behavioural traits (e.g., hematocrit, body condition, foraging. More generally, a review of natremia in species situated along a continuum of habitat use between fresh- and seawater shows that snake species display a concomitant tolerance toward hypernatremia, even in species lacking salt glands. Collectively, these data suggest that a physiological tolerance toward hypernatremia has been critical during the evolution of an euryhaline physiology, and may well have preceded the evolution of salt glands.

Development of management tools for accidental radiological contamination of the French coastal areas - Development of management tools for accidental radiological contamination in the French marine coastal areas

Energy Technology Data Exchange (ETDEWEB)

Duffa, C.; Charmasson, S. [IRSN/PRP-ENV/SESURE/LERCM - Antenne de Radioecologie Marine, Centre Ifremer, Zone portuaire de Bregaillon, 13507 La Seyne sur Mer (France); Bailly du Bois, P.; Fievet, B. [IRSN/PRP-ENV/SERIS/LRC (France); Couvez, C.; Renaud, P. [IRSN/PRP-ENV/SESURE/DIR (France); Didier, D. [IRSN/PRP-CRI/SESUC/BMTA (France)

2014-07-01

The Fukushima nuclear accident led to the most important accidental release of artificial radionuclides into the sea. This accident has underlined the importance of being able to adequately reproduce the fate of radioactive releases and to estimate their consequences for the marine environment. For its Crisis Centre, the French Institute for Radioprotection and Nuclear Safety (IRSN) has operational tools, in order to help experts and decision makers in case of any atmospheric accidental release and terrestrial environment contamination. The on-going project aims to develop tools to manage any marine contamination of the French coastal areas. We should be able to evaluate and anticipate the marine post-accidental situation: contaminated areas localization and contamination levels, and possible consequences. Many sites has be considered as potential source terms into the sea: the Coastal Nuclear Power Plants, the La Hague reprocessing Plant, the Brest and Toulon Military Harbours as home-ports of nuclear powered vessels, and different river mouths (Rhone River, Gironde, Loire, Seine) that could be contaminated by upstream accidental release. To achieve this goal, two complementary approaches are developed: Marine sheets and a dedicated modelling tool (STERNE). - Marine sheets aim to summarize marine environment characteristics for the different sites, identify potential stakes for human protection such as aquaculture areas, beaches, or industrial water intakes, and ecological stakes. Whenever possible, a local climatology (main currents depending on meteorological or tide conditions) that could be a support to first environmental measurement strategy is proposed. A list of available local contacts for any operational management is also provided. - The modelling tool, STERNE (Simulation du Transport et du transfert d'Elements Radioactifs dans l'environNEment marin), must predict radionuclide dispersion and contamination of water, marine species and sediments

Event driven software package for the database of Integrated Coastal and Marine Area Management (ICMAM) (Developed in 'C')

Digital Repository Service at National Institute of Oceanography (India)

Sadhuram, Y.; Murty, T.V.R.; Chandramouli, P.; Murthy, K.S.R.

National Institute of Oceanography (NIO, RC, Visakhapatnam, India) had taken up the Integrated Coastal and Marine Area Management (ICMAM) project funded by Department of Ocean Development (DOD), New Delhi, India. The main objective of this project...

Detection of a Planktothrix agardhii Bloom in Portuguese Marine Coastal Waters

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Catarina Churro

2017-12-01

Full Text Available Cyanobacteria blooms are frequent in freshwaters and are responsible for water quality deterioration and human intoxication. Although, not a new phenomenon, concern exists on the increasing persistence, scale, and toxicity of these blooms. There is evidence, in recent years, of the transfer of these toxins from inland to marine waters through freshwater outflow. However, the true impact of these blooms in marine habitats has been overlooked. In the present work, we describe the detection of Planktothrix agardhii, which is a common microcystin producer, in the Portuguese marine coastal waters nearby a river outfall in an area used for shellfish harvesting and recreational activities. P. agardhii was first observed in November of 2016 in seawater samples that are in the scope of the national shellfish monitoring system. This occurrence was followed closely between November and December of 2016 by a weekly sampling of mussels and water from the sea pier and adjacent river mouth with salinity ranging from 35 to 3. High cell densities were found in the water from both sea pier and river outfall, reaching concentrations of 4,960,608 cells·L−1 and 6810.3 × 106 cells·L−1 respectively. Cultures were also established with success from the environment and microplate salinity growth assays showed that the isolates grew at salinity 10. HPLC-PDA analysis of total microcystin content in mussel tissue, water biomass, and P. agardhii cultures did not retrieve a positive result. In addition, microcystin related genes were not detected in the water nor cultures. So, the P. agardhii present in the environment was probably a non-toxic strain. This is, to our knowledge, the first report on a P. agardhii bloom reaching the sea and points to the relevance to also monitoring freshwater harmful phytoplankton and related toxins in seafood harvesting and recreational coastal areas, particularly under the influence of river plumes.

Large centric diatoms allocate more cellular nitrogen to photosynthesis to counter slower RUBISCO turnover rates

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Yaping eWu

2014-12-01

Full Text Available Diatoms contribute ~40% of primary production in the modern ocean and encompass the largest cell size range of any phytoplankton group. Diatom cell size influences their nutrient uptake, photosynthetic light capture, carbon export efficiency, and growth responses to increasing pCO2. We therefore examined nitrogen resource allocations to the key protein complexes mediating photosynthesis across six marine centric diatoms, spanning 5 orders of magnitude in cell volume, under past, current and predicted future pCO2 levels, in balanced growth under nitrogen repletion. Membrane bound photosynthetic protein concentrations declined with cell volume in parallel with cellular concentrations of total protein, total nitrogen and chlorophyll. Larger diatom species, however, allocated a greater fraction (by 3.5 fold of their total cellular nitrogen to the soluble RUBISCO carbon fixation complex than did smaller species. Carbon assimilation per unit of RUBISCO large subunit (C RbcL-1 s-1 decreased with cell volume, from ~8 to ~2 C RbcL-1 s-1 from the smallest to the largest cells. Whilst a higher allocation of cellular nitrogen to RUBISCO in larger cells increases the burden upon their nitrogen metabolism, the higher RUBISCO allocation buffers their lower achieved RUBISCO turnover rate to enable larger diatoms to maintain carbon assimilation rates per total protein comparable to small diatoms. Individual species responded to increased pCO2, but cell size effects outweigh pCO2 responses across the diatom species size range examined. In large diatoms a higher nitrogen cost for RUBISCO exacerbates the higher nitrogen requirements associated with light absorption, so the metabolic cost to maintain photosynthesis is a cell size-dependent trait.

Spring molybdenum enrichment in scallop shells: a potential tracer of diatom productivity in temperate coastal environments (Brittany, NW France)

Science.gov (United States)

Barats, A.; Amouroux, D.; Pécheyran, C.; Chauvaud, L.; Thébault, J.; Donard, O. F. X.

2010-01-01

Skeletal molybdenum/calcium ([Mo]/[Ca])shell ratios were examined in shells of the Great Scallop Pecten maximus collected in temperate coastal environments of Western Europe (42 to 49° N). These ratios were determined by quantitative LA-ICP-MS analyses of daily striae taken every third day (i.e. a temporal resolution of 3 days) in 36 flat valves (2-years old; 3 shells/year). Variations of ([Mo]/[Ca])shell ratios were significant and reproducible for scallops from the same population, from different years (1998-2004) and temperate coastal locations (NW France). The [Mo]/[Ca])shell ratios exhibit typical profiles characterized by a background content, below the detection limit for this method (<0.003 μmol/mol) for most of the shell growth period, which is punctuated by a significant transient enrichment (0.031-2.1 μmol/mol) mainly occurring from May to June. The Bay of Brest (France) was investigated in particular because of its long term observations on scallop communities, environmental variables, and high resolution analyses of dissolved Mo in bottom seawater in 2000. In 2000, dissolved Mo exhibited a significant increase in concentration just preceding the maximum ([Mo]/[Ca])shell ratio. Both the intense monitoring survey in 2000 and over the 7-year period indicates that the ([Mo]/[Ca])shell maximum is directly influenced by spring changes of environmental conditions at the sediment water interface (SWI), occurring subsequent to the intense and periodic spring bloom. Spring maxima of ([Mo]/[Ca])shell ratios are closely correlated to the extent of silicic acid and nitrate depletion in seawater between winter and late spring (r2=0.878 and 0.780, p<0.05, n=6) that reflects diatom uptake and productivity in the Bay of Brest. The Mo inputs in bottom waters and subsequent shell enrichment are thus suggested to be directly or indirectly influenced by such biogenic material input at the SWI. The [Mo]/[Ca])shell records thus reveal unexpected biogeochemical cycles of

Contrasting Physiological and Proteomic Adaptations to Iron and/or Copper Limitation in Two Strains of the Same Open Ocean Diatom Thalassiosira oceanica

Science.gov (United States)

Schuback, N.; Hippmann, A.; Maldonado, M. T.; Allen, A. E.; McCrow, J.; Foster, L. J.; Green, B. R.; Alami, M.

2016-02-01

Iron plays a significant role in controlling marine primary productivity. Despite that extremely low dissolved iron (Fe) concentrations are found in Fe-limited regions, some phytoplankton are able to survive and thrive. Two strains of the model oceanic diatom Thalassiosira oceanica, TO 1003 and TO 1005, have both been used in previous studies to characterize adaptations to iron limitation. These studies have shown that T. oceanica has lowered its Fe requirements and increased its Fe acquisition efficiency compared to coastal counterparts. Both strategies may impose a higher cellular copper (Cu) demand. However, the underlying biochemical adaptations in these oceanic diatoms remain unknown. Recently, the genome, as well as the first proteomic and transcriptomic analyses of T. oceanica 1005 grown under different Fe levels, were published. To further our understanding of the interplay between Fe- and Cu- physiology in open ocean diatoms, we examined an array of physiological responses to varying degrees of Fe-, Cu- and Fe/Cu co-limitation in both strains. We also determined the differential expression of proteins using stable isotope labeling and LC-MS/MS proteomic analysis. The two strains, TO 1003 and TO 1005, need markedly different metal concentrations in the media. TO1003 requires 30% less Cu to sustain its optimal growth and less than 1/10th of the minimum Cu that is needed by TO 1005 to survive. In contrast, TO 1005 is able to grow with less Fe available in the media. The physiological and proteomic responses of these two strains when acclimated to low Fe and/or Cu concentrations will be presented. The evolutionary implications will be discussed.

Towards a representative periphytic diatom sample

Directory of Open Access Journals (Sweden)

2007-01-01

Full Text Available The need to acquire a representative periphytic diatom sample for river water quality monitoring has been recognised in the development of existing diatom indices, important in the development and employment of diatom monitoring tools for the Water Framework Directive. In this study, a nested design with replication is employed to investigate the magnitude of variation in diatom biomass, composition and Trophic Diatom Index at varying scales within a small chalk river. The study shows that the use of artificial substrates may not result in diatom communities that are typical of the surrounding natural substrates. Periphytic diatom biomass and composition varies between artificial and natural substrates, riffles and glides and between two stretches of the river channel. The study also highlights the existence of high variation in diatom frustule frequency and biovolume at the individual replicate scale which may have implications for the use of diatoms in routine monitoring.

Impact of multispecies diatom bloom on plankton community structure in Sundarban mangrove wetland, India

International Nuclear Information System (INIS)

Biswas, Sejuti Naha; Rakshit, Dibyendu; Sarkar, Santosh Kumar; Sarangi, Ranjit Kumar; Satpathy, Kamala Kanta

2014-01-01

Highlights: • A multispecies algal bloom was studied in coastal regions of Sundarban wetland. • Sharp changes in plankton community structure and hydrological parameters observed. • Chlorophyll a showed highest cell density (11.4 × 10 5 cells l −1 ) during bloom phase. • MODIS Aqua derived chlorophyll maps have been interpreted. - Abstract: A multispecies bloom caused by the centric diatoms, viz. Coscinodiscus radiatus, Chaetoceros lorenzianus and the pennate diatom Thalassiothrix frauenfeldii was investigated in the context of its impact on phytoplankton and microzooplankton (the loricate ciliate tintinnids) in the coastal regions of Sagar Island, the western part of Sundarban mangrove wetland, India. Both number (15–18 species) and cell densities (12.3 × 10 3 cells l −1 to 11.4 × 10 5 cells l −1 ) of phytoplankton species increased during peak bloom phase, exhibiting moderately high species diversity (H′ = 2.86), richness (R′ = 6.38) and evenness (E′ = 0.80). The diatom bloom, which existed for a week, had a negative impact on the tintinnid community in terms of drastic changes in species diversity index (1.09–0.004) and population density (582.5 × 10 3 to 50 × 10 3 ind m −3 ). The bloom is suggested to have been driven by the aquaculture activities and river effluents resulting high nutrient concentrations in this region. An attempt has been made to correlate the satellite remote sensing-derived information to the bloom conditions. MODIS-Aqua derived chlorophyll maps have been interpreted

The relationship between Holocene cultural site distribution and marine terrace uplift on the coast fringing Coastal Range, Taiwan

Science.gov (United States)

Yang, Hsiaochin; Chen, Wenshan

2013-04-01

According to the collision of Philippine Sea plate and Eurasia plate, a series of left-lateral active faults with reverse sense exists in the Longitudinal Valley of east Taiwan. The Holocene marine terraces along the east coast of the Coastal Range in Taiwan are well known for their very rapid uplift and record tectonic history of this active collision boundary. The Holocene marine terrace sequence resulting from successive sea level change and tectonic activation is subdivided into several steps where the highest and oldest terrace, back to ca 13,000yr BP, reaches up to ca 80 m above sea level, and the lower terraces are mostly erosional ones, overlain by less than 1m thick coral beds in situ. The uplift of the coast is very high, ranging from 5 to 10 m/ka. According to the fabrics of potsherds and geochronological data, the prehistoric cultures in eastern Taiwan could be classified into three stages: Fushan (ca 5000-3500yr BP), Peinan/Chilin (ca3500-2000yr BP), Kweishan (ca2000-1000 yr BP) and Jinpu (ca 1000-400yr BP) cultural assemblages respectively. A great difference exists between the various cultural stage, not only the pottery making techniques, but also the distributions of archaeological sites. Combined with the dynamic geomorphic evolution of marine terraces and the distribution of prehistoric culture sites on the east coast of the Coastal Range, a coastal migration trend could be established.

Marine Science

African Journals Online (AJOL)

sustainable coastal development in the region, as well as contributing to the ... between humans and the coastal and marine environment. ... exploitation for timber, fuel wood, aquaculture, urban. Abstract. Given the high dependence of coastal communities on natural resources, mangrove conservation is a challenge in.

Coastal upwelling linked to toxic Pseudo-nitzschia australis blooms in Los Angeles coastal waters, 2005-2007

KAUST Repository

Schnetzer, Astrid; Jones, Burton; Schaffner, Rebecca A.; Cetinić, Ivona; Fitzpatrick, Elizabeth; Miller, Peter E.; Seubert, Erica L.; Caron, David A.

2013-01-01

Harmful algal blooms dominated by the diatom Pseudo-nitzschia spp. have become a perennial but variable event within surface waters near the greater Los Angeles area. Toxic blooms during spring seasons from 2005 to 2007 varied strongly in their overall toxicity and duration. Differences in bloom dynamics were linked to differences in storm-induced river discharge following episodic rain events and coastal upwelling, both major coastal processes that led to the injection of nutrients into coastal surface waters. Heavy river runoff during early 2005, a record-rainfall year, favored a phytoplankton community mainly comprised of algal taxa other than Pseudo-nitzschia. The spring bloom during 2005 was associated with low domoic acid surface concentrations and minor contributions of (mainly) P. delicatissima to the diatom assemblage. In contrast, highly toxic P. australis-dominated blooms during spring seasons of 2006 and 2007 were linked to strong upwelling events. River discharge quotas in 2006 and 2007, in contrast to 2005, fell well below annual averages for the region. Surface toxin levels were linked to colder, more saline (i.e. upwelled) water over the 3-year study, but no such consistent relationship between domoic acid levels and other physiochemical parameters, such as macronutrient concentrations or nutrient ratios, was observed. © The Author 2013. Published by Oxford University Press. All rights reserved.

Coastal upwelling linked to toxic Pseudo-nitzschia australis blooms in Los Angeles coastal waters, 2005-2007

KAUST Repository

Schnetzer, Astrid

2013-06-10

Harmful algal blooms dominated by the diatom Pseudo-nitzschia spp. have become a perennial but variable event within surface waters near the greater Los Angeles area. Toxic blooms during spring seasons from 2005 to 2007 varied strongly in their overall toxicity and duration. Differences in bloom dynamics were linked to differences in storm-induced river discharge following episodic rain events and coastal upwelling, both major coastal processes that led to the injection of nutrients into coastal surface waters. Heavy river runoff during early 2005, a record-rainfall year, favored a phytoplankton community mainly comprised of algal taxa other than Pseudo-nitzschia. The spring bloom during 2005 was associated with low domoic acid surface concentrations and minor contributions of (mainly) P. delicatissima to the diatom assemblage. In contrast, highly toxic P. australis-dominated blooms during spring seasons of 2006 and 2007 were linked to strong upwelling events. River discharge quotas in 2006 and 2007, in contrast to 2005, fell well below annual averages for the region. Surface toxin levels were linked to colder, more saline (i.e. upwelled) water over the 3-year study, but no such consistent relationship between domoic acid levels and other physiochemical parameters, such as macronutrient concentrations or nutrient ratios, was observed. © The Author 2013. Published by Oxford University Press. All rights reserved.

Silicon Isotopes of Marine Pore Water: Tracking the Destiny of Marine Biogenic Opal

Science.gov (United States)

Cassarino, L.; Hendry, K. R.

2017-12-01

Silicon isotopes (δ30Si) are a powerful tool for the studying of the past and present silicon cycles, which is closely linked to the carbon cycle. Siliceous phytoplankton, such as diatoms, as one of the major conveyors of carbon to marine sediments. δ30Si from fossil diatoms has been shown to represent past silicic acid (DSi) utilization in the photic zone, since the lighter isotope is preferentially incorporated in their skeleton, the frustule. This assumes that species in the sediments depict past blooms and that frustules are preserved in their initial state during burial. Here we present new silicon isotopes data of sea water and pore water of deep marine sediments from two contrasted environments, the Equatorial Atlantic and West Antarctic Peninsula. δ30Si and DSi concentration, of both sea water and pore water, are negatively correlated. Marine biogenic opal dissolution can be tracked using δ30Si signature of pore water as lighter signals and high DSi concentrations are associated with the biogenic silica. Our data enhances post depositional and diagenesis processes during burial with a clear highlight on the sediment water interface exchanges.

Phosphorus physiological ecology and molecular mechanisms in marine phytoplankton.

Science.gov (United States)

Lin, Senjie; Litaker, Richard Wayne; Sunda, William G

2016-02-01

Phosphorus (P) is an essential nutrient for marine phytoplankton and indeed all life forms. Current data show that P availability is growth-limiting in certain marine systems and can impact algal species composition. Available P occurs in marine waters as dissolved inorganic phosphate (primarily orthophosphate [Pi]) or as a myriad of dissolved organic phosphorus (DOP) compounds. Despite numerous studies on P physiology and ecology and increasing research on genomics in marine phytoplankton, there have been few attempts to synthesize information from these different disciplines. This paper is aimed to integrate the physiological and molecular information on the acquisition, utilization, and storage of P in marine phytoplankton and the strategies used by these organisms to acclimate and adapt to variations in P availability. Where applicable, we attempt to identify gaps in our current knowledge that warrant further research and examine possible metabolic pathways that might occur in phytoplankton from well-studied bacterial models. Physical and chemical limitations governing cellular P uptake are explored along with physiological and molecular mechanisms to adapt and acclimate to temporally and spatially varying P nutrient regimes. Topics covered include cellular Pi uptake and feedback regulation of uptake systems, enzymatic utilization of DOP, P acquisition by phagotrophy, P-limitation of phytoplankton growth in oceanic and coastal waters, and the role of P-limitation in regulating cell size and toxin levels in phytoplankton. Finally, we examine the role of P and other nutrients in the transition of phytoplankton communities from early succession species (diatoms) to late succession ones (e.g., dinoflagellates and haptophytes). © 2015 Phycological Society of America.

Faster recovery of a diatom from UV damage under ocean acidification.

Science.gov (United States)

Wu, Yaping; Campbell, Douglas A; Gao, Kunshan

2014-11-01

Diatoms are the most important group of primary producers in marine ecosystems. As oceanic pH declines and increased stratification leads to the upper mixing layer becoming shallower, diatoms are interactively affected by both lower pH and higher average exposures to solar ultraviolet radiation. The photochemical yields of a model diatom, Phaeodactylum tricornutum, were inhibited by ultraviolet radiation under both growth and excess light levels, while the functional absorbance cross sections of the remaining photosystem II increased. Cells grown under ocean acidification (OA) were less affected during UV exposure. The recovery of PSII under low photosynthetically active radiation was much faster than in the dark, indicating that photosynthetic processes were essential for the full recovery of photosystem II. This light dependent recovery required de novo synthesized protein. Cells grown under ocean acidification recovered faster, possibly attributable to higher CO₂ availability for the Calvin cycle producing more resources for repair. The lower UV inhibition combined with higher recovery rate under ocean acidification could benefit species such as P.tricornutum, and change their competitiveness in the future ocean. Copyright © 2014 Elsevier B.V. All rights reserved.

Interactions of marine plankton with transuranic elements. II

International Nuclear Information System (INIS)

Fisher, N.S.; Bjerregaard, P.; Huynh-Ngoc, L.; Harvey, G.R.

1983-01-01

To assess the significance of naturally occurring dissolved organic matter (DOM) on complexation of transuranic elements in seawater, a series of bioassay experiments was conducted in which the effect of DOM on the accumulation of 241 Am, 237 Pu(III-IV), and 237 Pu(V-VI) by the marine diatom Thalassiosira pseudonana was measured. EDTA at 0.3 μM complexed both metals substantially, resulting in reduced radio-isotope uptake by the diatom; the greatest effect was on Pu(III-IV). In contrast, there was no apparent complexation of either element by equimolar concentrations of marine fulvic (MFA) or humic acids (MHA), naturally occurring photooxidizable DOM (uncharacterized), or diatom exudates, as none of these materials reduced isotope uptake; on the contrary, there were indications that some of this DOM enhanced transuranic bioaccumulation in the diatom slightly. Subsequent experiments showed this enhancement was probably due to complexation of transition metals by the DOM, leading to fewer ambient ions 'competing' for binding sites on the cells; 241 Am uptake rates were negatively correlated (r = -0.846, P<.01) with ΣASV-labile Cu + Zn + Cd + Pb. These experiments suggest that naturally occurring DOM may not appreciably complex Am or Pu or greatly affect their bioavailability in the sea. (Auth.)

Effects of different levels of UV-B radiation on marine epilithic communities: a short-term microcosm study

Directory of Open Access Journals (Sweden)

R. A. Danilov

2000-12-01

Full Text Available Epilithic communities from brackish coastal water of the east coast of Sweden were studied in order to reveal their responses to different levels of UV-B radiation. The experiment was conducted for seven days in an indoor microcosm system. The epilithic communities were exposed daily to different doses of UV-B radiation: 1, 3, 5 and 7 hours, respectively. The intensity of the UV-B radiation used was similar to that in natural environments. After seven days clear shifts both in species composition and community structure were observed. All species of diatoms showed negative correlation with enhanced levels of UV-B. On the other hand, abundance of cyanobacteria was positively correlated with enhanced levels of UV-B (Calothrix aeruginea, R=0.49;Oscillatoria amphibia, R=0.93; Pseudanabaena mucicola, R=0.26. Communities dominated by diatoms and green algae at the initial stage of the experiment did show a drastic decrease in diatom abundance under UV-B stress and finally became dominated by cyanobacteria. Among green algae the abundance of Cladophora sericea correlated positively (R=0.33 with enhanced exposure to UV-B, while Monoraphidium-species exhibited negative correlation to UV-B. Otherwise, no significant correlation between other green algae species identified and UV-B stress could be detected. We conclude that UV-B radiation, even at lower levels, is capable to induce severe changes to marine epilithic communities. The trends revealed in the present study predict a shift from communities dominated by diatoms and green algae to those dominated by cyanobacteria.

Attraction Pheromone of The Benthic Diatom Seminavis robusta: Studies on Structure-Activity Relationships.

Science.gov (United States)

Lembke, Christine; Stettin, Daniel; Speck, Franziska; Ueberschaar, Nico; De Decker, Sam; Vyverman, Wim; Pohnert, Georg

2018-04-01

Recently the first pheromone of a marine diatom was identified to be the diketopiperazine (S,S)-diproline. This compound facilitates attraction between mating partners in the benthic diatom Seminavis robusta. Interestingly, sexualized S. robusta cells are attracted to both the natural pheromone (S,S)-diproline as well as to its enantiomer (R,R)-diproline. Usually stereospecificity is a prerequisite for successful substrate-receptor interactions, and especially pheromone perception is often highly enantioselective. Here we introduce a structure-activity relationship study, to learn more about the principles of pheromone reception in diatoms. We analyzed the activity of nine different diketopiperazines in attraction and interference assays. The pheromone diproline itself, as well as a pipecolic acid derived diketopiperazine with two expanded aliphatic ring systems, showed the highest attractivity. Hydroxylatoin of the aliphatic rings abolished any bioactivity. Diketopiperazines derived from acyclic amino acids were not attrative as well. All stereoisomers of both the diproline and the pipecolic acid derived diketopiperazine were purified by enantioselective high-performance liquid chromatography, and application in bioactivity tests confirmed that attraction pheromone perception in this diatom is indeed not stereospecific. However, the lack of activity of diketopiperazines derived from acyclic amino acids suggests a specificity that prevents misguidance to sources of other naturally occurring diketopiperazines.

International cooperation for integrated management of coastal regions

International Nuclear Information System (INIS)

Bosc, E.; Houlbreque, F.; Boisson, F.; Scholten, J.; Betti, M.

2010-01-01

Coastal zones which comprise < 20% of the earth surface are one of the most dynamic areas of the world. Housing more than 50% of the earth's population, the coastal zones are affected by natural and anthropogenic induced pressures which challenge the sustainability of the coastal environment and its resources. Most of the environmental pressures originate from outside the coastal zones thus requiring an inter-regional approach for coastal environmental assessments. It is one of the missions of the Marine Environment Laboratories (MEL) of the International Atomic Energy Agency to assist Member States in coastal zone management by applying nuclear and isotopic techniques. These techniques are used in many ways at MEL to enhance the understanding of marine ecosystems and to improve their management and protection. The article gives an overview of MEL's current marine coastal projects and research activities. (author)

Accumulation of Mercury (Hg) and Methyl Mercury (Me Hg) Concentrations In Selected Marine Biota From Manjung Coastal Area

International Nuclear Information System (INIS)

Anisa Abdullah; Zaini Hamzah; Ahmad Saat; Ahmad Saat; Abd Khalik Wood; Masitah Alias

2015-01-01

Level of mercury (Hg) and methyl mercury (Me Hg) in marine ecosystem has been intensively studied as these toxic substances could be accumulated in the marine biota. This study is focusing on the Hg and Me Hg content in marine biota in Manjung coastal area. This area has high potential being affected by rapid socio-economic development of Manjung area such as heavy industrial activities (coal fired power plant, iron foundries, port development and factories), agricultural runoff, waste and toxic discharge, quarries, housing constructions. It may has a potential risk when released into the atmosphere and dispersed on the surface of water and continue deposited at the bottom of the water and sediment and being absorbed by marine biota. The concentrations of Hg and Me Hg in marine ecosystem can be adversely affect human health when it enters the food chain. In this study, five species of marine biota including Johnius dussumieri (Ikan Gelama), Pseudorhombus malayanus (Ikan Sebelah), Arius maculatus (Ikan Duri), Portunus pelagicus (Ketam Renjong) and Charybdis natator (Ketam Salib) were collected during rainy and dry seasons. Measurements were carried out using inductively coupled plasma mass spectrometry (ICP-MS) technique. The Hg concentrations for dry and rainy season are in the range 65.13-102.12 μg/ kg and 75.75-106.10 μg/ kg respectively, while for MeHg concentrations for dry and rainy seasons are in the range 4.35-6.26 μg/ kg and 5.42-6.46 μg/ kg, respectively. These results are below the limit set by Malaysia Food Act (1983). Generally, marine biota from the Manjung coastal area is safe to consume due to low value of ingestion dose rate and health risk index (HRI) for human health. (author)

Marine natural hazards in coastal zone: observations, analysis and modelling (Plinius Medal Lecture)

Science.gov (United States)

Didenkulova, Ira

2010-05-01

Giant surface waves approaching the coast frequently cause extensive coastal flooding, destruction of coastal constructions and loss of lives. Such waves can be generated by various phenomena: strong storms and cyclones, underwater earthquakes, high-speed ferries, aerial and submarine landslides. The most famous examples of such events are the catastrophic tsunami in the Indian Ocean, which occurred on 26 December 2004 and hurricane Katrina (28 August 2005) in the Atlantic Ocean. The huge storm in the Baltic Sea on 9 January 2005, which produced unexpectedly long waves in many areas of the Baltic Sea and the influence of unusually high surge created by long waves from high-speed ferries, should also be mentioned as examples of regional marine natural hazards connected with extensive runup of certain types of waves. The processes of wave shoaling and runup for all these different marine natural hazards (tsunami, coastal freak waves, ship waves) are studied based on rigorous solutions of nonlinear shallow-water theory. The key and novel results presented here are: i) parameterization of basic formulas for extreme runup characteristics for bell-shape waves, showing that they weakly depend on the initial wave shape, which is usually unknown in real sea conditions; ii) runup analysis of periodic asymmetric waves with a steep front, as such waves are penetrating inland over large distances and with larger velocities than symmetric waves; iii) statistical analysis of irregular wave runup demonstrating that wave nonlinearity nearshore does not influence on the probability distribution of the velocity of the moving shoreline and its moments, and influences on the vertical displacement of the moving shoreline (runup). Wave runup on convex beaches and in narrow bays, which allow abnormal wave amplification is also discussed. Described analytical results are used for explanation of observed extreme runup of tsunami, freak (sneaker) waves and ship waves on different coasts

Methodology for assessing the concentrations of the primary marine aerosol in coastal areas

International Nuclear Information System (INIS)

Barsanti, P.; Briganti, G.; Cappelletti, A.; Marri, P.

2009-01-01

European and Italian regulations (DM 60/2002) fix for atmospheric particulate matter PM10 the threshold of 50 μg/m 3 as limit not to be exceeded more than 35 times per year (24 hour mean); unfortunately, such prescriptions do not distinguish anthropic contributions from natural ones (sea salt, Saharan sand, coastal erosion, volcanic ashes, etc.). The aim of this study is to set up a methodology in order to estimate sea salt emissions, both from open sea and surf zone, and to model atmospheric dispersion of marine aerosols. The proposed methodology, applied to the coastal zone between Massa Carrara and Viareggio (Tuscany, Italy), shows specific open sea emissions are generally very low in comparison with the surf zone ones: they are not negligible only with strong winds, but such meteorological conditions are neither persistent nor very frequent in the selected area. On the contrary, sea surf contributions are much more strong (at least 1 order of magnitude), peak-shaped and persistent then the first ones, and can lead to high PM10 concentration fields up to few kilometres inland. The comparison between model outputs and observations, in two points placed at 2000 and 4000 m from the shoreline, has shown an amount of sea salt in total PM10 even greater then 70% in mass. The existence of a surf zone, which can persist many hours or days even after a storm, can produce both elevated PM concentrations and gradients, mainly for light winds perpendicular to the shoreline. This work, supported by MINNI Project (www.minni.org), is suitable for other coastal areas as well and it is aimed to furnish an overview of marine particulate production and atmospheric dispersion processes; it is the starting point of an experimental investigation program, supported by institutional air quality authorities [it

226Ra-210Pb-210Po Levels in Marine Biota and Surface Coastal Sediments from the Red Sea, Sudan

International Nuclear Information System (INIS)

Sirelkhatim, D.A.; Sam, A.K.; Hassona, R.K.

2003-01-01

This paper presents data on 226 Ra, 210 Pb and 210 Po activity concentration levels in multicellular marine algae, molluscs, coral as well as in surface marine sediments collected from the shallower waters of the fringing reefs area extending towards north and south (Flamingo bay) of Port sudan harbour. The analyses were performed adopting a simple time efficient method combining alpha-spectrometry, liquid scintillation and Cerenkov counting technique. Generally speaking, surface sediments from this coastal region are poor in their radioactivity content in contrast to similar data reported from different coastal areas around the globe. There is surface enrichment of 210 Pb and 210 Po with respect to their progenitor 226 Ra as it is evident from the activity ratios of 210 Pb/ 226 Ra (3.03±1.79) and 210 Po/ 226 Ra (2.23±1.56). Among marine plants and animals investigated, the green algae species, Halimeda, and coral species, Favites, show substantial concentration of radium at 8.2 Bq/KXg and 21.9 Bq/KXg dry weight, respectively

Polonium-210 and Lead-210 in marine biota from a coastal region with high natural radioactivity

International Nuclear Information System (INIS)

Zafrul Kabir, M.; Deeba, Farah; Hossain, Sushmita; Fharim, Massoud; Md Moniruzzaman; Carvalho, Fernando P.; Oliveira, João M.; Malta, M.; Silva, L.

2013-01-01

Coastal sediments and marine fish from a region with high natural radioactivity in Cox Bazar Bangladesh, were analyzed in order to investigate the levels of naturally occurring radionuclides. Sediment from the sea shore in high ambient radiation dose rate areas contained naturally occurring radionuclides at high concentrations. These sediments displayed 226 Ra, 232 Th and 235 U activity concentrations of 2184 ± 88 Bq kg -1 dry weight (d.w.), 3808 ± 200 Bq kg -1 (d.w.) and 123 ± 15 Bq kg -1 (d.w.), respectively. In contrast with these high values, radionuclide concentrations in sand from other areas of the Cox's Bazar coast were as low as 42 ± 3, 70 ± 4 and < 8 Bq kg -1 (d.w.) for the same radionuclides, respectively, which are comparable to concentrations determined in many coastal areas elsewhere. The presence of sand deposits with high concentration of uranium series radionuclides could potentially originate high accumulation of alpha emitting radionuclides such as 210 Po in marine biota, and food chain transfer to man. 210 Po is a major contributor to the radiation dose both in marine organisms and sea food consumers. Determination of 210 Po in marine fish and shrimp from the area lead to concentration values ranging from 4.5±0.3 to 124±3 Bq kg -1 (d.w.) in fish and 82.9±1.6 Bq kg -1 (d.w.) in shrimp. Similar concentrations are commonly reported in marine biota from several regions. Therefore, in spite of the deposits of heavy mineral sands containing high concentrations of radionuclides such as 210 Pb and 210 Po no significant raise in the accumulation of these radionuclides in biota seems to occur, which suggests that radionuclides are tightly bound in sediment grains and are not significantly bioavailable. (author)

Skeletonema (Bacillariophyceae) in Indian waters: A reappraisal

Digital Repository Service at National Institute of Oceanography (India)

Naik, R.K.; Sarno, D.; Kooistra, W.H.C.F.; DeCosta, P.M.; Anil, A.C.

The planktonic diatom genus Skeletonema is common in Indian coastal waters. Recent taxonomic studies have uncovered high diversity in this genus, and it is expected that several species occur also in the highly diverse marine habitats along...

Front-Eddy Influence on Water Column Properties, Phytoplankton Community Structure, and Cross-Shelf Exchange of Diatom Taxa in the Shelf-Slope Area off Concepción (˜36-37°S)

Science.gov (United States)

Morales, Carmen E.; Anabalón, Valeria; Bento, Joaquim P.; Hormazabal, Samuel; Cornejo, Marcela; Correa-Ramírez, Marco A.; Silva, Nelson

2017-11-01

In eastern boundary current systems (EBCSs), submesoscale to mesocale variability contributes to cross-shore exchanges of water properties, nutrients, and plankton. Data from a short-term summer survey and satellite time series (January-February 2014) were used to characterize submesoscale variability in oceanographic conditions and phytoplankton distribution across the coastal upwelling and coastal transition zones north of Punta Lavapié, and to explore cross-shelf exchanges of diatom taxa. A thermohaline front (FRN-1) flanked by a mesoscale anticyclonic intrathermocline eddy (ITE-1), or mode-water eddy, persisted during the time series and the survey was undertaken during a wind relaxation event. At the survey time, ITE-1 contributed to an onshore intrusion of warm oceanic waters (southern section) and an offshore advection of cold coastal waters (northern section), with the latter forming a cold, high chlorophyll-a filament. In situ phytoplankton and diatom biomasses were highest at the surface in FRN-1 and at the subsurface in ITE-1, whereas values in the coastal zone were lower and dominated by smaller cells. Diatom species typical of the coastal zone and species dominant in oceanic waters were both found in the FRN-1 and ITE-1 interaction area, suggesting that this mixture was the result of both offshore and onshore advection. Overall, front-eddy interactions in EBCSs could enhance cross-shelf exchanges of coastal and oceanic plankton, as well as sustain phytoplankton growth in the slope area through localized upward injections of nutrients in the frontal zone, combined with ITE-induced advection and vertical nutrient inputs to the surface layer.

Diatom-inspired templates for 3D replication: natural diatoms versus laser written artificial diatoms

International Nuclear Information System (INIS)

Belegratis, M R; Schmidt, V; Nees, D; Stadlober, B; Hartmann, P

2014-01-01

The diatoms are ubiquitous, exist in large numbers and show a great diversity of features on their porous silica structures. Therefore, they inspire the fabrication of nanostructured templates for nanoimprint processes (NIL), where large structured areas with nanometer precision are required. In this study, two approaches regarding the respective challenges and potential exploitations are followed and discussed: the first one takes advantage of a template that is directly made of natural occurring diatoms. Here, two replication steps via soft lithography are needed to obtain a template which is subsequently used for NIL. The second approach exploits the technical capabilities of the precise 3D laser lithography (3DLL) based on two-photon polymerization of organic materials. This method enables the fabrication of arbitrary artificial diatom-inspired micro- and nanostructures and the design of an inverse structure. Therefore, only one replication step is needed to obtain a template for NIL. In both approaches, a replication technique for true 3D structures is shown. (paper)

An integrative analysis of post-translational histone modifications in the marine diatom Phaeodactylum tricornutum

KAUST Repository

Veluchamy, Alaguraj; Rastogi, Achal; Lin, Xin; Lombard, Bé rangè re; Murik, Omer; Thomas, Yann; Dingli, Florent; Rivarola, Maximo; Ott, Sandra; Liu, Xinyue; Sun, Yezhou; Rabinowicz, Pablo D.; McCarthy, James; Allen, Andrew E.; Loew, Damarys; Bowler, Chris; Tirichine, Leï la

2015-01-01

in global biogeochemical cycles. Dissecting chromatin-mediated regulation of genes in diatoms will help understand the ecological success of these organisms in contemporary oceans. Results: Here, we use high resolution mass spectrometry to identify a full

Fine-grained visual marine vessel classification for coastal surveillance and defense applications

Science.gov (United States)

Solmaz, Berkan; Gundogdu, Erhan; Karaman, Kaan; Yücesoy, Veysel; Koç, Aykut

2017-10-01

The need for capabilities of automated visual content analysis has substantially increased due to presence of large number of images captured by surveillance cameras. With a focus on development of practical methods for extracting effective visual data representations, deep neural network based representations have received great attention due to their success in visual categorization of generic images. For fine-grained image categorization, a closely related yet a more challenging research problem compared to generic image categorization due to high visual similarities within subgroups, diverse applications were developed such as classifying images of vehicles, birds, food and plants. Here, we propose the use of deep neural network based representations for categorizing and identifying marine vessels for defense and security applications. First, we gather a large number of marine vessel images via online sources grouping them into four coarse categories; naval, civil, commercial and service vessels. Next, we subgroup naval vessels into fine categories such as corvettes, frigates and submarines. For distinguishing images, we extract state-of-the-art deep visual representations and train support-vector-machines. Furthermore, we fine tune deep representations for marine vessel images. Experiments address two scenarios, classification and verification of naval marine vessels. Classification experiment aims coarse categorization, as well as learning models of fine categories. Verification experiment embroils identification of specific naval vessels by revealing if a pair of images belongs to identical marine vessels by the help of learnt deep representations. Obtaining promising performance, we believe these presented capabilities would be essential components of future coastal and on-board surveillance systems.

Large variation in the Rubisco kinetics of diatoms reveals diversity among their carbon-concentrating mechanisms

Science.gov (United States)

Young, Jodi N.; Heureux, Ana M.C.; Sharwood, Robert E.; Rickaby, Rosalind E.M.; Morel, François M.M.; Whitney, Spencer M.

2016-01-01

While marine phytoplankton rival plants in their contribution to global primary productivity, our understanding of their photosynthesis remains rudimentary. In particular, the kinetic diversity of the CO2-fixing enzyme, Rubisco, in phytoplankton remains unknown. Here we quantify the maximum rates of carboxylation (k cat c), oxygenation (k cat o), Michaelis constants (K m) for CO2 (K C) and O2 (K O), and specificity for CO2 over O2 (SC/O) for Form I Rubisco from 11 diatom species. Diatom Rubisco shows greater variation in K C (23–68 µM), SC/O (57–116mol mol−1), and K O (413–2032 µM) relative to plant and algal Rubisco. The broad range of K C values mostly exceed those of C4 plant Rubisco, suggesting that the strength of the carbon-concentrating mechanism (CCM) in diatoms is more diverse, and more effective than previously predicted. The measured k cat c for each diatom Rubisco showed less variation (2.1–3.7s−1), thus averting the canonical trade-off typically observed between K C and k cat c for plant Form I Rubisco. Uniquely, a negative relationship between K C and cellular Rubisco content was found, suggesting variation among diatom species in how they allocate their limited cellular resources between Rubisco synthesis and their CCM. The activation status of Rubisco in each diatom was low, indicating a requirement for Rubisco activase. This work highlights the need to better understand the correlative natural diversity between the Rubisco kinetics and CCM of diatoms and the underpinning mechanistic differences in catalytic chemistry among the Form I Rubisco superfamily. PMID:27129950

Convergence of marine megafauna movement patterns in coastal and open oceans

KAUST Repository

Sequeira, A. M. M.; Rodrí guez, J. P.; Eguí luz, V. M.; Harcourt, R.; Hindell, M.; Sims, D. W.; Duarte, C. M.; Costa, D. P.; Ferná ndez-Gracia, J.; Ferreira, L. C.; Hays, G. C.; Heupel, M. R.; Meekan, M. G.; Aven, A.; Bailleul, F.; Baylis, A. M. M.; Berumen, Michael L.; Braun, C. D.; Burns, J.; Caley, M. J.; Campbell, R.; Carmichael, R. H.; Clua, E.; Einoder, L. D.; Friedlaender, Ari; Goebel, M. E.; Goldsworthy, S. D.; Guinet, C.; Gunn, J.; Hamer, D.; Hammerschlag, N.; Hammill, M.; Hü ckstä dt, L. A.; Humphries, N. E.; Lea, M.-A.; Lowther, A.; Mackay, A.; McHuron, E.; McKenzie, J.; McLeay, L.; McMahon, C. R.; Mengersen, K.; Muelbert, M. M. C.; Pagano, A. M.; Page, B.; Queiroz, N.; Robinson, P. W.; Shaffer, S. A.; Shivji, M.; Skomal, G. B.; Thorrold, S. R.; Villegas-Amtmann, S.; Weise, M.; Wells, R.; Wetherbee, B.; Wiebkin, A.; Wienecke, B.; Thums, M.

2018-01-01

The extent of increasing anthropogenic impacts on large marine vertebrates partly depends on the animals' movement patterns. Effective conservation requires identification of the key drivers of movement including intrinsic properties and extrinsic constraints associated with the dynamic nature of the environments the animals inhabit. However, the relative importance of intrinsic versus extrinsic factors remains elusive. We analyze a global dataset of ∼2.8 million locations from >2,600 tracked individuals across 50 marine vertebrates evolutionarily separated by millions of years and using different locomotion modes (fly, swim, walk/paddle). Strikingly, movement patterns show a remarkable convergence, being strongly conserved across species and independent of body length and mass, despite these traits ranging over 10 orders of magnitude among the species studied. This represents a fundamental difference between marine and terrestrial vertebrates not previously identified, likely linked to the reduced costs of locomotion in water. Movement patterns were primarily explained by the interaction between species-specific traits and the habitat(s) they move through, resulting in complex movement patterns when moving close to coasts compared with more predictable patterns when moving in open oceans. This distinct difference may be associated with greater complexity within coastal microhabitats, highlighting a critical role of preferred habitat in shaping marine vertebrate global movements. Efforts to develop understanding of the characteristics of vertebrate movement should consider the habitat(s) through which they move to identify how movement patterns will alter with forecasted severe ocean changes, such as reduced Arctic sea ice cover, sea level rise, and declining oxygen content.

Convergence of marine megafauna movement patterns in coastal and open oceans

KAUST Repository

Sequeira, A. M. M.

2018-02-26

The extent of increasing anthropogenic impacts on large marine vertebrates partly depends on the animals\\' movement patterns. Effective conservation requires identification of the key drivers of movement including intrinsic properties and extrinsic constraints associated with the dynamic nature of the environments the animals inhabit. However, the relative importance of intrinsic versus extrinsic factors remains elusive. We analyze a global dataset of ∼2.8 million locations from >2,600 tracked individuals across 50 marine vertebrates evolutionarily separated by millions of years and using different locomotion modes (fly, swim, walk/paddle). Strikingly, movement patterns show a remarkable convergence, being strongly conserved across species and independent of body length and mass, despite these traits ranging over 10 orders of magnitude among the species studied. This represents a fundamental difference between marine and terrestrial vertebrates not previously identified, likely linked to the reduced costs of locomotion in water. Movement patterns were primarily explained by the interaction between species-specific traits and the habitat(s) they move through, resulting in complex movement patterns when moving close to coasts compared with more predictable patterns when moving in open oceans. This distinct difference may be associated with greater complexity within coastal microhabitats, highlighting a critical role of preferred habitat in shaping marine vertebrate global movements. Efforts to develop understanding of the characteristics of vertebrate movement should consider the habitat(s) through which they move to identify how movement patterns will alter with forecasted severe ocean changes, such as reduced Arctic sea ice cover, sea level rise, and declining oxygen content.

Impact of Late Holocene climate variability and anthropogenic activities on Biscayne Bay (Florida, U.S.A.): evidence from diatoms

Science.gov (United States)

Wachnicka, Anna; Gaiser, Evelyn; Wingard, Lynn; Briceño, Henry; Harlem, Peter

2013-01-01

Shallow marine ecosystems are experiencing significant environmental alterations as a result of changing climate and increasing human activities along coasts. Intensive urbanization of the southeast Florida coast and intensification of climate change over the last few centuries changed the character of coastal ecosystems in the semi-enclosed Biscayne Bay, Florida. In order to develop management policies for the Bay, it is vital to obtain reliable scientific evidence of past ecological conditions. The long-term records of subfossil diatoms obtained from No Name Bank and Featherbed Bank in the Central Biscayne Bay, and from the Card Sound Bank in the neighboring Card Sound, were used to study the magnitude of the environmental change caused by climate variability and water management over the last ~ 600 yr. Analyses of these records revealed that the major shifts in the diatom assemblage structures at No Name Bank occurred in 1956, at Featherbed Bank in 1966, and at Card Sound Bank in 1957. Smaller magnitude shifts were also recorded at Featherbed Bank in 1893, 1942, 1974 and 1983. Most of these changes coincided with severe drought periods that developed during the cold phases of El Niño Southern Oscillation (ENSO), Atlantic Multidecadal Oscillation (AMO) and Pacific Decadal Oscillation (PDO), or when AMO was in warm phase and PDO was in the cold phase. Only the 1983 change coincided with an unusually wet period that developed during the warm phases of ENSO and PDO. Quantitative reconstructions of salinity using the weighted averaging partial least squares (WA-PLS) diatom-based salinity model revealed a gradual increase in salinity at the three coring locations over the last ~ 600 yr, which was primarily caused by continuously rising sea level and in the last several decades also by the reduction of the amount of freshwater inflow from the mainland. Concentration of sediment total nitrogen (TN), total phosphorus (TP) and total organic carbon (TOC) increased in the

Marine pollution

International Nuclear Information System (INIS)

Albaiges, J.

1989-01-01

This book covers the following topics: Transport of marine pollutants; Transformation of pollutants in the marine environment; Biological effects of marine pollutants; Sources and transport of oil pollutants in the Persian Gulf; Trace metals and hydrocarbons in Syrian coastal waters; and Techniques for analysis of trace pollutants

Advancing satellite-based solar power forecasting through integration of infrared channels for automatic detection of coastal marine inversion layer

Energy Technology Data Exchange (ETDEWEB)

Kostylev, Vladimir; Kostylev, Andrey; Carter, Chris; Mahoney, Chad; Pavlovski, Alexandre; Daye, Tony [Green Power Labs Inc., Dartmouth, NS (Canada); Cormier, Dallas Eugene; Fotland, Lena [San Diego Gas and Electric Co., San Diego, CA (United States)

2012-07-01

The marine atmospheric boundary layer is a layer or cool, moist maritime air with the thickness of a few thousand feet immediately below a temperature inversion. In coastal areas as moist air rises from the ocean surface, it becomes trapped and is often compressed into fog above which a layer of stratus clouds often forms. This phenomenon is common for satellite-based solar radiation monitoring and forecasting. Hour ahead satellite-based solar radiation forecasts are commonly using visible spectrum satellite images, from which it is difficult to automatically differentiate low stratus clouds and fog from high altitude clouds. This provides a challenge for cloud motion tyracking and cloud cover forecasting. San Diego Gas and Electric {sup registered} (SDG and E {sup registered}) Marine Layer Project was undertaken to obtain information for integration with PV forecasts, and to develop a detailed understanding of long-term benefits from forecasting Marine Layer (ML) events and their effects on PV production. In order to establish climatological ML patterns, spatial extent and distribution of marine layer, we analyzed visible and IR spectrum satellite images (GOES WEST) archive for the period of eleven years (2000 - 2010). Historical boundaries of marine layers impact were established based on the cross-classification of visible spectrum (VIS) and infrared (IR) images. This approach is successfully used by us and elsewhere for evaluating cloud albedo in common satellite-based techniques for solar radiation monitoring and forecasting. The approach allows differentiation of cloud cover and helps distinguish low laying fog which is the main consequence of marine layer formation. ML occurrence probability and maximum extent inland was established for each hour and day of the analyzed period and seasonal/patterns were described. SDG and E service area is the most affected region by ML events with highest extent and probability of ML occurrence. Influence of ML was the

Environmental perverse incentives in coastal monitoring.

Science.gov (United States)

Gibbs, Mark T

2013-08-15

It can be argued that the intensity of monitoring of coastal marine environments lags behind the equivalent terrestrial environments. This results in a paucity of long-term time series of key environmental parameters such as turbidity. This lack of management information of the sources and sinks, and causes and impacts of stressors to the coastal marine environment, along with a lack of co-ordination of information collection is compromising the ability of environmental impact assessments of major coastal developments to discriminate between local and remote anthropogenic impacts, and natural or background processes. In particular, the quasi outsourcing of the collection of coastal information can lead to a perverse incentive whereby in many cases nobody is actively or consistently monitoring the coastal marine environment effectively. This is particularly the case with regards to the collection of long-term and whole-of-system scale data. This lack of effective monitoring can act to incentivise poor environmental performance. Copyright © 2013 Elsevier Ltd. All rights reserved.

Tsunami induced transportation of the coastal marine sediments to distant onshore regions: Some indications from foraminiferal and microbenthic studies of new Wandoor region (Andaman & Nicobar)

Digital Repository Service at National Institute of Oceanography (India)

Khare, N.; Chaturvedi, S.K.; Ingole, B.S.

regions near New Wandoor (Andaman and Nicobar) suggested the areal extent of marine transgression due to tsunami waves on December 26, 2004. There is a need to investigate coastal marine sediments with multi-disciplinary approach to understnd impact...

The transcription factor bZIP14 regulates the TCA cycle in the diatom Phaeodactylum tricornutum.

Science.gov (United States)

Matthijs, Michiel; Fabris, Michele; Obata, Toshihiro; Foubert, Imogen; Franco-Zorrilla, José Manuel; Solano, Roberto; Fernie, Alisdair R; Vyverman, Wim; Goossens, Alain

2017-06-01

Diatoms are amongst the most important marine microalgae in terms of biomass, but little is known concerning the molecular mechanisms that regulate their versatile metabolism. Here, the pennate diatom Phaeodactylum tricornutum was studied at the metabolite and transcriptome level during nitrogen starvation and following imposition of three other stresses that impede growth. The coordinated upregulation of the tricarboxylic acid (TCA) cycle during the nitrogen stress response was the most striking observation. Through co-expression analysis and DNA binding assays, the transcription factor bZIP14 was identified as a regulator of the TCA cycle, also beyond the nitrogen starvation response, namely in diurnal regulation. Accordingly, metabolic and transcriptional shifts were observed upon overexpression of bZIP14 in transformed P. tricornutum cells. Our data indicate that the TCA cycle is a tightly regulated and important hub for carbon reallocation in the diatom cell during nutrient starvation and that bZIP14 is a conserved regulator of this cycle. © 2017 The Authors.

Widespread detection of a brominated flame retardant, hexabromocyclododecane, in expanded polystyrene marine debris and microplastics from South Korea and the Asia-Pacific coastal region

International Nuclear Information System (INIS)

Jang, Mi; Shim, Won Joon; Han, Gi Myung; Rani, Manviri; Song, Young Kyoung; Hong, Sang Hee

2017-01-01

The role of marine plastic debris and microplastics as a carrier of hazardous chemicals in the marine environment is an emerging issue. This study investigated expanded polystyrene (EPS, commonly known as styrofoam) debris, which is a common marine debris item worldwide, and its additive chemical, hexabromocyclododecane (HBCD). To obtain a better understanding of chemical dispersion via EPS pollution in the marine environment, intensive monitoring of HBCD levels in EPS debris and microplastics was conducted in South Korea, where EPS is the predominant marine debris originate mainly from fishing and aquaculture buoys. At the same time, EPS debris were collected from 12 other countries in the Asia-Pacific region, and HBCD concentrations were measured. HBCD was detected extensively in EPS buoy debris and EPS microplastics stranded along the Korean coasts, which might be related to the detection of a quantity of HBCD in non-flame-retardant EPS bead (raw material). The wide detection of the flame retardant in sea-floating buoys, and the recycling of high-HBCD-containing EPS waste inside large buoys highlight the need for proper guidelines for the production and use of EPS raw materials, and the recycling of EPS waste. HBCD was also abundantly detected in EPS debris collected from the Asia-Pacific coastal region, indicating that HBCD contamination via EPS debris is a common environmental issue worldwide. Suspected tsunami debris from Alaskan beaches indicated that EPS debris has the potential for long-range transport in the ocean, accompanying the movement of hazardous chemicals. The results of this study indicate that EPS debris can be a source of HBCD in marine environments and marine food web. - Highlights: • A brominated flame retardant, HBCD, was assessed in EPS debris and microplastics. • HBCD was widely detected in EPS debris from the Asia-Pacific coastal region. • Additive HBCD are dispersed via EPS pollution in marine environments. • EPS debris can be a

A review of the influence of biogeography, riverine linkages, and marine connectivity on fish assemblages in evolving lagoons and lakes of coastal southern Africa.

Science.gov (United States)

Whitfield, Alan K; Weerts, Steven P; Weyl, Olaf L F

2017-09-01

The Holocene evolution of eight South African coastal lakes and lagoons is examined and related to changes in fish composition over that period. Historical and current connectivity with riverine and marine environments are the primary determinants of present-day fish assemblages in these systems. A small and remarkably consistent group of relict estuarine species have persisted in these coastal lakes and lagoons. The loss or reduction of connectivity with the sea has impacted on the diversity of marine fishes in all eight study systems, with no marine fishes occurring in those water bodies where connectivity has been completely broken (e.g. Sibaya, Groenvlei). In systems that have retained tenuous linkages with the sea (e.g., Verlorenvlei, Wilderness lakes), elements of the marine fish assemblage have persisted, especially the presence of facultative catadromous species. Freshwater fish diversity in coastal lakes and lagoons is a function of historical and present biogeography and salinity. From a freshwater biogeography perspective, the inflowing rivers of the four temperate systems reviewed here contain three or fewer native freshwater fishes, while the subtropical lakes that are fed by river systems contain up to 40 freshwater fish species. Thus, the significantly higher fish species diversity in subtropical versus temperate coastal lakes and lagoons comes as no surprise. Fish species diversity has been increased further in some systems (e.g., Groenvlei) by alien fish introductions. However, the impacts of fish introductions and translocations have not been studied in the coastal lakes and lagoons of South Africa. In these closed systems, it is probable that predation impacts on small estuarine fishes are significant. The recent alien fish introductions is an example of the growing threats to these systems during the Anthropocene, a period when human activities have had significant negative impacts and show potential to match the changes recorded during the

Integrated coastal area management: The case of India

Digital Repository Service at National Institute of Oceanography (India)

Swamy, G.N.

ofindustries, shipping, ports, fishing, mining, urbanisation and tourism. All these affect the coastal areas. Coastal zone takes the brunt of industrial pressure, environmental degradation, marine life depletion, socia-economic conflicts and security threats... first. Marine life depletes affecting the sustainable fish catch and the marine food chain. Socio-economic conflicts between the industry-oriented society and the marine/agrarian society lead to new legal tangles and ethnic upheavals. Security threats...

Geochemical and diatom records of recent changes in depositional environment of a tropical wetland, central west coast of India

Digital Repository Service at National Institute of Oceanography (India)

Pande, A.; Nayak, G.N.; Prasad, V.; PrakashBabu, C

size, total organic carbon, total nitrogen, carbon/nitrogen ratio (TOC/TN), selected metals and pH) and diatom records The sub-channel (S-61) represents river environment which opens into main channel (S-60) which represents marine environment being...

Transparent Exopolymeric Particles (TEP Selectively Increase Biogenic Silica Dissolution From Fossil Diatoms as Compared to Fresh Diatoms

Directory of Open Access Journals (Sweden)

Jordan Toullec

2018-03-01

Full Text Available Diatom production is mainly supported by the dissolution of biogenic silica (bSiO2 within the first 200 m of the water column. The upper oceanic layer is enriched in dissolved and/or colloidal organic matter, such as exopolymeric polysaccharides (EPS and transparent exopolymeric particles (TEP excreted by phytoplankton in large amounts, especially at the end of a bloom. In this study we explored for the first time the direct influence of TEP-enriched diatom excretions on bSiO2 dissolution. Twelve dissolution experiments on fresh and fossil diatom frustules were carried out on seawater containing different concentrations of TEP extracted from diatom cultures. Fresh diatom frustules were cleaned from the organic matter by low ash temperature, and fossil diatoms were made from diatomite powder. Results confirm that newly formed bSiO2 dissolved at a faster rate than fossil diatoms due to a lower aluminum (Al content. Diatom excretions have no effect on the dissolution of the newly formed bSiO2 from Chaetoceros muelleri. Reversely, the diatomite specific dissolution rate constant and solubility of the bSiO2 were positively correlated to TEP concentrations, suggesting that diatom excretion may provide an alternative source of dSi when limitations arise.

Novel adenosine 3',5'-cyclic monophosphate dependent protein kinases in a marine diatom

International Nuclear Information System (INIS)

Lin, P.P.C.; Volcani, B.E.

1989-01-01

Two novel adenosine 3',5'-cyclic monophosphate (cAMP) dependent protein kinases have been isolated from the diatom Cylindrotheca fusiformis. The kinases, designated I and II, are eluted from DEAE-Sephacel at 0.10 and 0.15 M NaCl. They have a high affinity for cAMP and are activated by micromolar cAMP. They exhibit maximal activity at 5 mM Mg 2+ and pH 8 with the preferred phosphate donor ATP and phosphate acceptor histone H1. They phosphorylate sea urchin sperm histone H1 on a single serine site in the sequence Arg-Lys-Gly-Ser( 32 P)-Ser-Asn-Ala-Arg and have an apparent M r of 75,000 as determined by gel filtration and sucrose density sedimentation. In the kinase I preparation a single protein band with an apparent M r of about 78,000 is photolabeled with 8-azido[ 32 P]cAMP and is also phosphorylated with [γ- 32 P]ATP in a cAMP-dependent manner, after autoradiography following sodium dodecyl sulfate gel electrophoresis. The rate of phosphorylation of the 78,000-dalton band is independent of the enzyme concentration. The results indicate that (i) these diatom cAMP-dependent protein kinases are monomeric proteins, possessing both the cAMP-binding regulatory and catalytic domains on the same polypeptide chain, (ii) the enzymes do not dissociate into smaller species upon activation by binding cAMP, and (iii) self-phosphorylation of the enzymes by an intrapeptide reaction is cAMP dependent. The two diatom cAMP kinases are refractory to the heat-stable protein kinase modulator from rabbit muscle, but they respond differently to proteolytic degradation and to inhibition by arachidonic acid and several microbial alkaloids

Determination of Ra natural isotopes in marine samples from Itamaraca coastal regions; Determinacao de isotopos naturais de Ra em amostras costeiras da regiao de Itamaraca (PE)

Energy Technology Data Exchange (ETDEWEB)

Silveira, Patricia B.; Valentim, Eliane; Lima, Ricardo A. [Centro Regional de Ciencias Nucleares (CRCN), Recife, PE (Brazil)]. E-mail: pbrandao@cnen.gov.br; Medeiros, Carmem [Pernambuco Univ., Recife, PE (Brazil). Dept. de Oceanografia; Oliveira, Joselene [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

2005-07-01

Groundwater plays an important role in the transport of nutrients and pollutants to the coastal marine environment s and other surfaces water. Concentrations of {sup 223}Ra, {sup 224}Ra and {sup 226}Ra in marine water of the Itamaraca coastal region, PE, were measured during the winter of 2004, aiming to investigate the presence of radionuclides as a tracer of submarine groundwater discharges (SGD) in the environment studied. Measurements of temperature, salinity and nutrients were also carried out. (author)

Long-term trends in eutrophication and nutrients in the coastal zone

DEFF Research Database (Denmark)

Clarke, Anne-Marie; Weckström, Kaarina; Conley, Daniel

2006-01-01

We used high-resolution paleoecological records of environmental change to study the rate and magnitude of eutrophication over the last century in two contrasting coastal ecosystems. A multiproxy approach using geochemical and biological indicators and diatom-based transfer functions provides...

Radiological assessment of coastal marine sediment and water samples, Karachi coast, Pakistan

International Nuclear Information System (INIS)

Qureshi, R.M.; Mashiatullah, A.; Akram, M.; Sajjad, M.I.; Shafiq, M.; Javed, T.; Aslam, M.

1999-04-01

Concentrations of selective natural radionuclides (/sup 226/Ra, /sup 228/Ra, /sup 40/K) in shallow marine coastal sediments and sea water off Karachi coast, Pakistan, were measured with a hyper pure germanium (HPGe) gamma spectrometer. Sediment and water samples were collected from polluted Layari and Malire River downstream (pre-out fall), Gizri Creek, Layari River out fall in Karachi harbor, Karachi Harbor/ Manora Channel Mains, as well as from open sea (South-East Coast and North-West Coast) within the 10m depth contour. No artificial radionuclides (e.g. /sup 60/Co, /sup 137/Cs and /sup 134/Cs were detected in both water and sediment samples at any of these locations. The activity of /sup 226/Ra in coastal river sediments is found below its limit of detection (<18.35 Bqkg/sup -1/). Activity of /sup 228/Ra in sediments off Karachi Coast ranges between 11.80 +- 3.60 to 37.27+- 4.31 Bqkg/sup -1/. The highest activity was found south of Nuclear Power Station (KANUPP) and the lowest activity was found in the vicinity of Oyster Rocks (open sea). The /sup 226/Ra activity ranges from 19.40+- 5.88 to 67.14 +- 10.02 Bqkg/sup -1/. The activity of /sup 228/Ra in sediments of Manora Channel, South-east Coast of Karachi and the North west coast of Karachi are also in agreement with the IAEA marine sediment standard namely: IAEA-135 (/sup 228/Ra = 36.7 +- 3 Bqkg/sup -1/). The activity of /sup 226/Ra for the South East Coast of Karachi and the North west coast of Karachi are also in agreement with the IAEA marine sediment standard namely: IAEA 135(/sup 226/Ra=23.9 +- 1.1 Bqkg/sup -1/) and Pacific Ocean sediment standard namely: IAEA-368 (/sup 226/Ra=21.4+- 1.1 Bqkg/sup -1/). The /sup 40/K activity in sea sediments varies from 197.7+- 44.24 to 941.90 +- 39.00 Bqkg-1). The highest activity is observed in the vicinity of Oyster Rocks (open sea) along the Clifton coast (South-East Cost of Karachi) and the lowest activity is found south of Nuclear Power Station (KANUPP) along the

Microplastics in mussels along the coastal waters of China

International Nuclear Information System (INIS)

Li, Jiana; Qu, Xiaoyun; Su, Lei; Zhang, Weiwei; Yang, Dongqi; Kolandhasamy, Prabhu; Li, Daoji; Shi, Huahong

2016-01-01

Microplastic has been confirmed as an emerging pollutant in marine environments. One of the primary environmental risks of microplastics is their bioavailability for aquatic organisms. Bivalves are of particular interest because their extensive filter-feeding activity exposes them directly to microplastics present in the water column. In the present study, we investigated microplastic pollution in mussels (Mytilus edulis) from 22 sites along 12,400 mile coastlines of China in 2015. The number of total microplastics varied from 0.9 to 4.6 items/g and from 1.5 to 7.6 items/individual. M. edulis contained more microplastics (2.7 items/g) in wild groups than that (1.6 items/g) in farmed groups. The abundance of microplastics was 3.3 items/g in mussels from the areas with intensive human activities and significantly higher than that (1.6 items/g) with less human activities. The most common microplastics were fibers, followed by fragments. The proportion of microplastics less than 250 μm in size arranged from 17% to 79% of the total microplastics. Diatom was distinguished from microplastics in mussels for the first time using Scanning Electron Microscope. Our results suggested that the numbers of microplastic kept within a relatively narrow range in mussels and were closely related to the contamination of the environments. We proposed that mussels could be used as a potential bioindicator of microplastic pollution of the coastal environment. - Highlights: • Microplastics varied from 0.9 to 4.6 items/g in Mytilus edulis. • M. edulis contained more microplastics in wild groups than farmed groups. • The most common microplastics were fibers. • Diatom was distinguished from microplastics in mussels. • Mussels could be used as a potential bioindicator of microplastic. - Microplastics varied from 0.9 to 4.6 items/g in wild and farmed Mytilus edulis from 22 sites along the coastal waters of China.

Dynamics of short-term acclimation to UV radiation in marine diatoms.

Science.gov (United States)

Fouqueray, Manuela; Mouget, Jean-Luc; Morant-Manceau, Annick; Tremblin, Gérard

2007-11-12

In order to investigate the dynamics of the acclimation of marine diatoms to ultraviolet radiation (UVR), Amphora coffeaeformis, Odontella aurita and Skeletonema costatum were exposed for 5 h per day to a combination of UVA and UVB (UVBR/UVAR ratio 4.5%) with a total UVR daily dose of 110 kJ m(-2), which is equivalent to that observed in the natural environment. This treatment was applied in the middle of the photoperiod and was repeated on five successive days. During the UVR treatment, chlorophyll fluorescence parameters were monitored, damage and repair constants were calculated from effective quantum yield values (phi(PSII)), and rapid light curves (electron transport rate versus irradiance curves using short light steps of different intensity) were plotted to determine the maximum relative electron transport rate (rETR(max)) and maximum light use efficiency (alpha). In all species the growth rate was lower than control from day 1-3, but increased thereafter, except for S. costatum. The cellular chlorophyll a content increased significantly with repeated daily exposure to UVR for A. coffeaeformis only. In all species, the fluorescence parameters (F(m), the maximum fluorescence level measured in the dark, phi(PSII), rETR(max) and alpha) decreased during UVR exposure, in contrast to F(0) (the minimum fluorescence level measured in the dark). The response to UVR stress was species-specific. S. costatum was very sensitive, and failed to survive for more than three days, whereas A. coffeaeformis and O. aurita were able to acclimate to UVR stress. These two species used different strategies. In A. coffeaeformis, the repair constant was lower than the damage constant, but phi(PSII) values returned to baseline values at the beginning of each experimental day, indicating that an effective active recovery process occurred after stress. In O. aurita, the repair processes took place during the stress, and could account for the UVR tolerance of this species.

Effect of Engineered Nanoparticles on Exopolymeric Substances Release from Marine Phytoplankton

OpenAIRE

Chiu, Meng-Hsuen; Khan, Zafir A.; Garcia, Santiago G.; Le, Andre D.; Kagiri, Agnes; Ramos, Javier; Tsai, Shih-Ming; Drobenaire, Hunter W.; Santschi, Peter H.; Quigg, Antonietta; Chin, Wei-Chun

2017-01-01

Engineered nanoparticles (ENPs), products from modern nanotechnologies, can potentially impact the marine environment to pose serious threats to marine ecosystems. However, the cellular responses of marine phytoplankton to ENPs are still not well established. Here, we investigate four different diatom species (Odontella mobiliensis, Skeletonema grethae, Phaeodactylum tricornutum, Thalassiosira pseudonana) and one green algae (Dunaliella tertiolecta) for their extracellular polymeric substance...

Egyptian coastal regions development through economic diversity for its coastal cities

Directory of Open Access Journals (Sweden)

Tarek AbdeL-Latif

2012-12-01

This study examines the structure of the coastal cities industry, the main types, the impacts (economic, environmental, and social of coastal cities, and the local trends in development in the Egyptian coastal cities and its regions. It will also analyze coastal and marine tourism in several key regions identified because of the diversity of life they support, and the potential destruction they could face. This paper confirms that economic diversification in coastal cities is more effective than developments in only one economic sector, even if this sector is prominent and important.

Coastal erosion as a source of mercury into the marine environment along the Polish Baltic shore.

Science.gov (United States)

Bełdowska, Magdalena; Jędruch, Agnieszka; Łęczyński, Leszek; Saniewska, Dominika; Kwasigroch, Urszula

2016-08-01

The climate changes in recent years in the southern Baltic have been resulting in an increased frequency of natural extreme phenomena (i.e. storms, floods) and intensification of abrasion processes, which leads to introduction of large amounts of sedimentary deposits into the marine environment. The aim of this study was to determine the mercury load introduced to the Baltic Sea with deposits crumbling off the cliffs-parts of the coast that are the most exposed to abrasion. The studies were carried out close to five cliffs located on the Polish coast in the years 2011-2014. The results show that coastal erosion could be an important Hg source into the marine environment. This process is the third most important route, after riverine and precipitation input, by which Hg may enter the Gulf of Gdańsk. In the Hg budget in the gulf, the load caused by erosion (14.3 kg a(-1)) accounted for 80 % of the wet deposition and was 50 % higher than the amount of mercury introduced with dry deposition. Although the Hg concentration in the cliff deposits was similar to the natural background, due to their large mass, this problem could be significant. In addition, the preliminary studies on the impact of coastal erosion on the Hg level in the marine ecosystem have shown that this process may be one of the Hg sources into the trophic chain.

Isolation and partial chemical analysis of exopolysaccharides from cultivated marine diatom Coscinodiscus wailesii (Coscinodiscales, Bacillariophyta); Isolamento e analise quimica parcial de exopolissacarideos da diatomacea marinha cultivada Coscinodiscus wailesii (Coscinodiscales, Bacillariophyta)

Energy Technology Data Exchange (ETDEWEB)

Marson-Ascencio, Poliana G.; Ascencio, Sergio Donizeti [Universidade Federal do Tocantins, Palmas, TO (Brazil); Baggio, Selma Faria Zawadzki, E-mail: polianamarson@uft.edu.br [Universidade Federal do Parana, Curitiba, PR (Brazil). Centro Politecnico. Dept. de Bioquimica e Biologia Molecular

2012-07-01

The marine diatom Coscinodiscus wailesii has attracted ecological interest because their blooms affect fishing areas. The aim of this work was the isolation, extraction and partial chemical characterization of soluble exopolysaccharide and bound exopolysaccharide from C. wailesii. Cultures were grown in Guillards f/2 medium under controlled conditions of temperature, aeration, photo period and light intensity. Percentage of carbohydrate, uronic acids, sulfates groups and cellular lipids was determined. Ion exchange chromatography of exopolysaccharides produced three fractions whose partial chemical structures were disclosed using {sup 13}C NMR and methylation techniques. (author)

Trophic Cascading of Medusae on the Relationships between Copepods and Diatoms in a Subtropical Coastal Ecosystem

Directory of Open Access Journals (Sweden)

Jia-Lu Chung

2009-01-01

Full Text Available To investigate the spatial and temporal variation of phytoplankton and copepods, eight seasonal cruises (January 2005 ~ Oc to ber 2006 were conducted in a subtropical coast site that encom passed 19 sampling stations. The results in dicated that the temperature (18.4 - 29.7°C varied more than 10°C seasonally, while nutrient concentrations (ni trate: 0.4 - 6.3 mM, phosphate: 0.1 - 0.8 mM, and silicate 2.1 - 12.1 mM were in versely corre lated with temperature. Diatoms (2792 - 1602437 cells m-3 constituted > 90% of the phytoplankton as semblages and dinoflagellates (226 - 10029 cells m-3 represented only ~10% of the algaebiomass. Copepod abun dance (8 - 1031 ind. m-3 varied positively with that of diatom and tempeature. Therelative abundance of Temora spp. (1 - 712 ind. m-3 varied from 69% in summer; that of Paracalanus spp. (0.1 - 176 ind. m-3 were > 25% in spring and au tumn and Calanus spp. (0.5 - 24 ind. m-3 dom i nated in win ter and spring, but ac counted for only ~10% of the to tal copepods. Both di a tom den sity and copepod abun dance were positively correlated with temperature, indicating these two plank tongroups were left bot tom-up control. The copepod abun dance positively co-aried with diatoms in 2005, but not in 2006. Fur ther sea son-to-sea son analysis showed that the diatomvs. copepodratios changed positively only when the medusa abun dance changed greatly (> 40-fold between consecutive sea sons. During periods when the medusa abundance varied less than 10-fold between seasons, there is no relationship between the ratios and the medusa abun dance. This study suggests that the stability of the medusa abundance from season to season could be important in regulating the ecological linkage between diatoms and their predators ¡V copepods.

Sedimentation of phytoplankton during a diatom bloom : Rates and mechanisms

DEFF Research Database (Denmark)

Kiørboe, Thomas; Hansen, J.L.S.; Alldredge, A.L.

1996-01-01

Phytoplankton blooms are uncoupled from grazing and are normally terminated by sedimentation. There are several potential mechanisms by which phytoplankton cells may settle out of the photic zone: sinking of individual cells or chains, coagulation of cells into aggregates with high settling...... velocities, settling of cells attached to marine snow aggregates formed from discarded larvacean houses or pteropod feeding webs, and packaging of cells into rapidly falling zooplankton fecal pellets. We quantified the relative significance of these different mechanisms during a diatom bloom in a temperate...... to marine snow aggregates formed from discarded larvacean houses, whereas settling of unaggregated cells was insignificant. Formation rates of phytoplankton aggregates by physical coagulation was very low, and losses by this mechanism were much less than 0.07 d(-1); phytoplankton aggregates were neither...

Constrains in gamma spectrometry analysis of fallout 137Cs in coastal marine environment of Arabian sea in India

International Nuclear Information System (INIS)

Sartandel, S.J.; Jha, S.K.; Puranik, V.D.

2012-01-01

In this study, an accurate faster gamma spectrometry method for measuring the low level activity concentrations of 137 Cs using in situ pre-concentration technique on copper ferrocyanide cartridge was standardized. Due to unavailability of reference standard in the copper ferrocyanide matrix, efficiency calibration curves were plotted using RGU and RGTh reference standards. To harmonize the difference in density of standard and sample the required density correction factors for photo peak efficiency were generated. The in situ pre-concentration technique followed by gamma-ray spectrometry was applied for activity determination in surface seawater from eight locations in the coastal marine environment of Arabian Sea. The mean activity concentration of 137 Cs ranged between 0.71 and 0.91 Bq/m 3 . Higher activity concentrations were observed at location with latitude, longitude of 21.6 deg N, 69.57 deg E as compared to concentration observed at location with latitude, longitude 16.98 deg N, 73.25 deg E. The observed concentrations were found to be in range of data reported in Asia-Pacific Marine radioactive database (ASPARMARD). The results will fill up the gaps in the existing database. The generated data will be useful for monitoring fresh input of anthropogenic radionuclide into coastal marine environment for post Fukushima environmental assessment. (author)

Marine Mammal Sighting and Census data from Coastal Alaska from 1985-05-05 to 1985-06-13 (NODC Accession 8600633)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Marine Mammal Sighting and Census data were collected from Coastal Alaska. Data were collected by Alaska Department of Fish and Game from 05 May 1985 to 13 June...

Sustaining anti-littering behavior within coastal and marine environments: Through the macro-micro level lenses.

Science.gov (United States)

Beeharry, Yashna Devi; Bekaroo, Girish; Bokhoree, Chandradeo; Phillips, Michael Robert; Jory, Neelakshi

2017-06-30

Being regarded as a problem of global dimensions, marine litter has been a growing concern that affects human beings, wildlife and the economic health of coastal communities to varying degrees. Due to its involvement with human behavior, marine littering has been regarded as a cultural matter encompassing macro and micro level aspects. At the micro or individual level, behavior and behavioral motivation of an individual are driven by perception of that person while at the macro or societal level, aspects including policies and legislations influence behavior. This paper investigates marine littering through the macro-micro level lenses in order to analyze and recommend how anti-littering behavior can be improved and sustained. Using Coleman's model of micro-macro relations, research questions are formulated and investigated through a social survey. Results showed important differences in perceptions among participating groups and to address key issues, potential actions are proposed along with a framework to sustain anti-littering behavior. Copyright © 2017 Elsevier Ltd. All rights reserved.

Spatio-temporal distribution of the dominant Diatom and Dinoflagellate species in the Bay of Tunis (SW Mediterranean Sea

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O. DALY YAHIA-KEFI

2005-06-01

Full Text Available Microphytoplankton composition and its relationships with hydrology and nutrient distributions were investigated over 24 months (December 1993 - November 1995 in the Bay of Tunis ( SW Mediterranean Sea. A new index, the ‘Specific Preference Index’ (SPI obtained by computing the median value of each parameter weighed by the numerical value of each species density was developed. Using this index, the relationships between each species and temperature, salinity and major nutrients were analysed. The distribution of chlorophyll a did not show a clear correlation with microplankton abundance suggesting that other factors contribute to chlorophyll concentration, such as smaller phytoplankton size fractions or detritus. The winter-spring diatom blooms did not show a regular pattern during both years. High nutrient inputs in late summer, associated with mild meteorological conditions, contributed to the development of a large diatom bloom in autumn 1995 where significant silicate depletion was witnessed. Generally, diatoms were more stenotherm than dinoflagellates in the Bay, whereas dinoflagellates were more stenohaline than diatoms. The statistical analyses showed that the two species, Bellerochea horologicalis , and Lithodesmioides polymorpha, var., tunisiense, appeared in a wide range of environmental conditions. An excess of phosphateversus nitrate appeared to be associated with red tides of, Gymnodinium spp, whereas Peridinium quinquecorne, showed the opposite. Phosphate concentrations appear to be crucial in this coastal environment, where diatom blooms are often limited by low silicate availability.

Organization of marine phenology data in support of planning and conservation in ocean and coastal ecosystems

Science.gov (United States)

Thomas, Kathryn A.; Fornwall, Mark D.; Weltzin, Jake F.; Griffis, R.B.

2014-01-01

Among the many effects of climate change is its influence on the phenology of biota. In marine and coastal ecosystems, phenological shifts have been documented for multiple life forms; however, biological data related to marine species' phenology remain difficult to access and is under-used. We conducted an assessment of potential sources of biological data for marine species and their availability for use in phenological analyses and assessments. Our evaluations showed that data potentially related to understanding marine species' phenology are available through online resources of governmental, academic, and non-governmental organizations, but appropriate datasets are often difficult to discover and access, presenting opportunities for scientific infrastructure improvement. The developing Federal Marine Data Architecture when fully implemented will improve data flow and standardization for marine data within major federal repositories and provide an archival repository for collaborating academic and public data contributors. Another opportunity, largely untapped, is the engagement of citizen scientists in standardized collection of marine phenology data and contribution of these data to established data flows. Use of metadata with marine phenology related keywords could improve discovery and access to appropriate datasets. When data originators choose to self-publish, publication of research datasets with a digital object identifier, linked to metadata, will also improve subsequent discovery and access. Phenological changes in the marine environment will affect human economics, food systems, and recreation. No one source of data will be sufficient to understand these changes. The collective attention of marine data collectors is needed—whether with an agency, an educational institution, or a citizen scientist group—toward adopting the data management processes and standards needed to ensure availability of sufficient and useable marine data to understand

Marine Jurisdiction Boundaries

Data.gov (United States)

Department of Homeland Security — The NOAA Coastal Services Center's Marine Jurisdiction dataset was created to assist in marine spatial planning and offshore alternative energy sitting. This is a...

C5 glycolipids of heterocystous cyanobacteria track symbiont abundance in the diatom Hemiaulus hauckii across the tropical North Atlantic

Science.gov (United States)

Bale, Nicole J.; Villareal, Tracy A.; Hopmans, Ellen C.; Brussaard, Corina P. D.; Besseling, Marc; Dorhout, Denise; Sinninghe Damsté, Jaap S.; Schouten, Stefan

2018-03-01

Diatom-diazotroph associations (DDAs) include marine heterocystous cyanobacteria found as exosymbionts and endosymbionts in multiple diatom species. Heterocysts are the site of N2 fixation and have thickened cell walls containing unique heterocyst glycolipids which maintain a low oxygen environment within the heterocyst. The endosymbiotic cyanobacterium Richelia intracellularis found in species of the diatom genus Hemiaulus and Rhizosolenia makes heterocyst glycolipids (HGs) which are composed of C30 and C32 diols and triols with pentose (C5) moieties that are distinct from limnetic cyanobacterial HGs with predominantly hexose (C6) moieties. Here we applied a method for analysis of intact polar lipids to the study of HGs in suspended particulate matter (SPM) and surface sediment from across the tropical North Atlantic. The study focused on the Amazon plume region, where DDAs are documented to form extensive surface blooms, in order to examine the utility of C5 HGs as markers for DDAs as well as their transportation to underlying sediments. C30 and C32 triols with C5 pentose moieties were detected in both marine SPM and surface sediments. We found a significant correlation between the water column concentration of these long-chain C5 HGs and DDA symbiont counts. In particular, the concentrations of both the C5 HGs (1-(O-ribose)-3,27,29-triacontanetriol (C5 HG30 triol) and 1-(O-ribose)-3,29,31-dotriacontanetriol (C5 HG32 triol)) in SPM exhibited a significant correlation with the number of Hemiaulus hauckii symbionts. This result strengthens the idea that long-chain C5 HGs can be applied as biomarkers for marine endosymbiotic heterocystous cyanobacteria. The presence of the same C5 HGs in surface sediment provides evidence that they are effectively transported to the sediment and hence have potential as biomarkers for studies of the contribution of DDAs to the paleo-marine N cycle.

Assessment of the environmental status of the coastal and marine aquatic environment in Europe: A plea for adaptive management

NARCIS (Netherlands)

Laane, R.W.P.M.; Slijkerman, D.M.E.; Vethaak, A.D.; Schobben, J.H.M.

2012-01-01

Policymakers and managers have a very different philosophy and approach to achieving healthy coastal and marine ecosystems than scientists. In this paper we discuss the evolution of the assessment of the chemical status in the aquatic environment and the growing rift between the political intention

Active Marine Station Metadata

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Active Marine Station Metadata is a daily metadata report for active marine bouy and C-MAN (Coastal Marine Automated Network) platforms from the National Data...

The Coastal Ocean Prediction Systems program: Understanding and managing our coastal ocean

International Nuclear Information System (INIS)

1990-01-01

This document is a compilation of summaries of papers presented at the Coastal Ocean Prediction Systems workshop. Topics include; marine forecasting, regulatory agencies and regulations, research and application models, research and operational observing, oceanic and atmospheric data assimilation, and coastal physical processes

Spatial and temporal characteristics of PM2.5 acidity during autumn in marine and coastal area of Bohai Sea, China, based on two-site contrast

Science.gov (United States)

Zhou, Ming; Zhang, Yufen; Han, Yan; Wu, Jianhui; Du, Xiang; Xu, Hong; Feng, Yinchang; Han, Suqin

2018-04-01

In-situ pH of atmospheric particulate, defined as the pH value of aqueous phase in ambient aerosol, has been reported to have significant influence on the formation progress of secondary aerosol, especially through the heterogeneous pathway. In this study, PM2.5 samples were collected in the marine and costal area of Bohai Sea from September 8th to October 8th in 2013, with daytime and nighttime separated. Eight water-soluble ions including SO42 -, NO3-, Cl-, NH4+, K+, Ca2 +, Na+ and Mg2 + were analyzed by ion chromatography. The in-situ pH of PM2.5 was estimated using Aerosol Inorganics Model II, with meteorological parameters (temperature and relative humidity) and basic chemical composition data (concentrations of water-soluble ions) serving as input. Five indicators were conjunctively applied to describe the spatial and temporal characteristics of PM2.5 acidity over Bohai Sea during autumn. As a result, strong acidity was found in both marine and coastal area. Marine area had a stronger acidity under a more NH4+-deficiency and humid condition. And the difference of PM2.5 acidity between daytime and nighttime was more obvious in coastal area than that in marine area, with stronger acidity observed during the daytime. Local SO2 emission was identified as an important factor influencing the diurnal variation of aerosol acidity. Meanwhile, sulfurous species were identified as a mixture of NH4HSO4 and H2SO4 in marine area while a mixture of NH4HSO4 and (NH4)2SO4 in the coastal area. Analysis in the impact of aerosol acidity on nitrate formation has indicated that heterogeneous pathways were important in nitrate formation in coastal area of Bohai Sea as well as the homogeneous pathways.

Dispersal kernel estimation: A comparison of empirical and modelled particle dispersion in a coastal marine system

Science.gov (United States)

Hrycik, Janelle M.; Chassé, Joël; Ruddick, Barry R.; Taggart, Christopher T.

2013-11-01

Early life-stage dispersal influences recruitment and is of significance in explaining the distribution and connectivity of marine species. Motivations for quantifying dispersal range from biodiversity conservation to the design of marine reserves and the mitigation of species invasions. Here we compare estimates of real particle dispersion in a coastal marine environment with similar estimates provided by hydrodynamic modelling. We do so by using a system of magnetically attractive particles (MAPs) and a magnetic-collector array that provides measures of Lagrangian dispersion based on the time-integration of MAPs dispersing through the array. MAPs released as a point source in a coastal marine location dispersed through the collector array over a 5-7 d period. A virtual release and observed (real-time) environmental conditions were used in a high-resolution three-dimensional hydrodynamic model to estimate the dispersal of virtual particles (VPs). The number of MAPs captured throughout the collector array and the number of VPs that passed through each corresponding model location were enumerated and compared. Although VP dispersal reflected several aspects of the observed MAP dispersal, the comparisons demonstrated model sensitivity to the small-scale (random-walk) particle diffusivity parameter (Kp). The one-dimensional dispersal kernel for the MAPs had an e-folding scale estimate in the range of 5.19-11.44 km, while those from the model simulations were comparable at 1.89-6.52 km, and also demonstrated sensitivity to Kp. Variations among comparisons are related to the value of Kp used in modelling and are postulated to be related to MAP losses from the water column and (or) shear dispersion acting on the MAPs; a process that is constrained in the model. Our demonstration indicates a promising new way of 1) quantitatively and empirically estimating the dispersal kernel in aquatic systems, and 2) quantitatively assessing and (or) improving regional hydrodynamic

Sources of atmospheric methane from coastal marine wetlands

International Nuclear Information System (INIS)

Harriss, R.C.; Sebacher, D.I.; Bartlett, K.B.; Bartlett, D.S.

1982-01-01

Biological methanogenesis in wetlands is believed to be one of the major sources of global tropospheric methane. The present paper reports measurements of methane distribution in the soils, sediments, water and vegetation of coastal marine wetlands. Measurements, carried out in the salt marshes Bay Tree Creek in Virginia and Panacea in northwest Florida, reveal methane concentrations in soils and sediments to vary with depth below the surface and with soil temperature. The fluxes of methane from marsh soils to the atmosphere at the soil-air interface are estimated to range from -0.00067 g CH 4 /sq m per day (methane sink) to 0.024 g CH 4 /sq m per day, with an average value of 0.0066 g CH 4 /sq m per day. Data also demonstrate the important role of tidal waters percolating through marsh soils in removing methane from the soils and releasing it to the atmosphere. The information obtained, together with previous studies, provides a framework for the design of a program based on in situ and remote sensing measurements to study the global methane cycle

Meteorological and oceanographic data collected from the National Data Buoy Center Coastal-Marine Automated Network (C-MAN) and moored (weather) buoys

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The National Data Buoy Center (NDBC) established the Coastal-Marine Automated Network (C-MAN) for the National Weather Service in the early 1980's. NDBC has...

Distribution of Epilithic Diatoms in Estuaries of the Korean Peninsula in Relation to Environmental Variables

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Ha-Kyung Kim

2015-11-01

Full Text Available This study explores the relationships between environmental factors and the distribution of epilithic diatoms in 161 estuaries of three coastal areas on the Korean peninsula. We investigated epilithic diatoms, water quality, and land use in the vicinities of the estuaries during the months of May 2012, 2013 and 2014, because Korea is relatively free from the influences of rainfall at that time of year. We recorded 327 diatom taxa from the study sites, and the assemblage was dominated by members of the Naviculaceae. Bacillariaceae accounted for the largest proportion of diatoms, and Nitzschia inconspicua (18% and N. frustulum (9.6% were the most dominant species. A cluster analysis based on epilithic diatom abundance suggested that the epilithic diatom communities of Korean estuaries can be classified into four large groups (G according to geography, as follows: Ia—the East Sea watershed, Ib—the eastern watershed of the South Sea, IIa—the West Sea watershed, and IIb—the western watershed of the South Sea. The former two groups, Ia and Ib, showed higher proportions of forest land cover and use, higher species occurrence, lower salinity, lower turbidity, and lower concentrations of nutrients than the latter two groups, while the latter groups, IIa and IIb, had higher proportions of agricultural land cover and use, higher electrical conductivity, higher turbidity, higher concentrations of nutrients, and lower species occurrence. The environmental factors underlying the distribution of epilithic diatoms, representative of each region, are as follows: dissolved oxygen and forest land cover and use for Reimeria sinuate and Rhoicosphenia abbreviate of the East Sea (ES, salinity and turbidity for Tabularia fasciculate of the West Sea (WS, and biochemical oxygen demand (BOD and nutrients for Cyclotella meneghiniana of the WS. On the other hand, the most influential environmental factors affecting the occurrence of indicator species showing the

Response of phytoplankton and enhanced biogeochemical activity to an episodic typhoon event in the coastal waters of Japan

Science.gov (United States)

Tsuchiya, Kenji; Kuwahara, Victor S.; Yoshiki, Tomoko M.; Nakajima, Ryota; Shimode, Shinji; Kikuchi, Tomohiko; Toda, Tatsuki

2017-07-01

Daily field surveys were conducted at a coastal-shelf station in Sagami Bay, Japan after the passage of typhoon Malou in 2010 to evaluate the after-effect of a typhoon passage on the physical-chemical environment, phytoplankton bloom formation and microbial processes within and below the euphotic layer. The passage of Malou induced an abrupt decrease in salinity and increased loading of nutrients to the euphotic layer. Dinoflagellates dominated the phytoplankton community at the surface, whereas diatoms dominated below the surface just after the passage of Malou. Four days later, the dominant dinoflagellate taxa at the surface changed from Protoperidinium spp. to Prorocentrum spp. and Ceratium spp., indicating a dinoflagellate community succession from heterotrophic to autotrophic functional groups. Five days after passage, the dominant phytoplankton taxa shifted from dinoflagellates to diatom groups of Chaetoceros spp. and Cerataulina spp. throughout the water column. Below the euphotic layer, there were increases in diatom frustules, mainly composed of Chaetoceros spp. and Cerataulina spp., bacterial abundance and NH4+ concentrations. Diatom carbon biomass contributed to approximately half of particulate organic carbon (POC) below the euphotic layer, suggesting a significant contribution of diatoms to POC sinking flux after the passage of a typhoon. Bacterial abundance was positively correlated to both phaeopigment concentrations (p affect biogeochemical activities within and below the euphotic layer in temperate coastal waters.

Centennial-scale variations in diatom productivity off Peru over the last 3000 years

Science.gov (United States)

Fleury, Sophie; Crosta, Xavier; Schneider, Ralph; Blanz, Thomas; Ther, Olivier; Martinez, Philippe; Kim, Jung-Hyun

2016-04-01

The Peruvian coastal upwelling is one of the most productive systems in the global ocean, with important impacts on the carbon cycle. Primary productivity there displays strong variations at the inter-annual to decadal timescales. However, down-core investigations rarely reach sufficient temporal resolution to assess the response of productivity to climatic variations at these timescales beyond the instrumental and historical periods. We here analyzed diatom assemblages, sea-surface temperatures, nitrogen and organic carbon contents on a laminated sediment core from the Peruvian continental shelf to trace variations in regional productivity over the last 3000 years. Our record provides evidence for different climatic and oceanic conditions with more humid and less productive conditions older than 2500 Cal years BP and drier and more productive conditions younger than 2500 Cal years BP. The last 2500 years also present much stronger centennial-scale variability with the occurrence of six intervals with higher total diatom abundances and stronger percentages in upwelling-related diatom species, representative of intensified productivity, congruent to lower percentages in benthic diatoms, indicative of reduced rainfall. These six periods were synchronous to intervals of enhanced Walker circulation, suggesting a strong imprint of the Pacific zonal circulation on productivity variations off Peru. Our record also demonstrates that SSTs did not vary in phase with productivity, arguing against the idea of regional SSTs controlled by the upwelling intensity, but were rather in agreement to SST records off southern Chile, suggesting that Peruvian SSTs variations were largely controlled by oceanic currents at southern high latitudes.

Metal concentrations and mobility in marine sediment and groundwater in coastal reclamation areas: A case study in Shenzhen, China

International Nuclear Information System (INIS)

Chen Kouping; Jiao, Jiu J.

2008-01-01

The concentrations of metals in the buried marine sediment and groundwater were differently affected by land reclamation. Nine metals (V, Cr, Mn, Co, Ni, Cu, Zn, Cd and Pb) in sediment and coastal groundwater from reclamation areas in Shenzhen were examined. The gradually decreased concentrations (V, Cr, Mn, Ni, Cu, Zn) in sediment and relatively higher concentrations (V, Cr, Mn, Co, Ni, Cu and Cd) in groundwater within reclamation areas were observed. The increase of V, Cr, Mn, Ni, Cu and Cd concentrations in groundwater within reclamation areas subsequently after land reclamation should be resulted from the mobilization of these metals accumulated in the sediment. These metals appear to be easily mobilized from solid phase to solution phase after reclamation. The physico-chemical changes such as reduction in pH and salinity in water environment induced by land reclamation appear to be responsible for metal mobility in the sediment-groundwater system. - Metals in coastal groundwater and marine sediment are affected by land reclamation

How marine debris ingestion differs among megafauna species in a tropical coastal area.

Science.gov (United States)

Di Beneditto, Ana Paula Madeira; Awabdi, Danielle Rodrigues

2014-11-15

The marine debris ingested by megafauna species (Trichiurus lepturus, Chelonia mydas, Pontoporia blainvillei, and Sotalia guianensis) was recorded in a coastal area of southeastern Brazil (21-23°S). Marine debris was recorded in all species, mainly consisting of plastic material (flexible and hard plastics - clear, white, and colored- and nylon filaments). The 'pelagic predators' T. lepturus and S. guianesis showed the lowest percent frequencies of debris ingestion (0.7% and 1.3%, respectively), followed by the 'benthic predator' P. blainvillei (15.7%) and the 'benthic herbivorous C. mydas (59.2%). The debris found in C. mydas stomachs was opportunistically ingested during feeding activities on local macroalgal banks. In the study area, the benthic environment accumulates more anthropogenic debris than the pelagic environment, and benthic/demersal feeders are more susceptible to encounters and ingestion. The sub-lethal effects observed in C. mydas, such as intestinal obstruction due to hardened fecal material, should be considered a local conservation concern. Copyright © 2014 Elsevier Ltd. All rights reserved.

Methylamine as a nitrogen source for microorganisms from a coastal marine environment.

Science.gov (United States)

Taubert, Martin; Grob, Carolina; Howat, Alexandra M; Burns, Oliver J; Pratscher, Jennifer; Jehmlich, Nico; von Bergen, Martin; Richnow, Hans H; Chen, Yin; Murrell, J Colin

2017-06-01

Nitrogen is a key limiting resource for biomass production in the marine environment. Methylated amines, released from the degradation of osmolytes, could provide a nitrogen source for marine microbes. Thus far, studies in aquatic habitats on the utilization of methylamine, the simplest methylated amine, have mainly focussed on the fate of the carbon from this compound. Various groups of methylotrophs, microorganisms that can grow on one-carbon compounds, use methylamine as a carbon source. Non-methylotrophic microorganisms may also utilize methylamine as a nitrogen source, but little is known about their diversity, especially in the marine environment. In this proof-of-concept study, stable isotope probing (SIP) was used to identify microorganisms from a coastal environment that assimilate nitrogen from methylamine. SIP experiments using 15 N methylamine combined with metagenomics and metaproteomics facilitated identification of active methylamine-utilizing Alpha- and Gammaproteobacteria. The draft genomes of two methylamine utilizers were obtained and their metabolism with respect to methylamine was examined. Both bacteria identified in these SIP experiments used the γ-glutamyl-methylamide pathway, found in both methylotrophs and non-methylotrophs, to metabolize methylamine. The utilization of 15 N methylamine also led to the release of 15 N ammonium that was used as nitrogen source by other microorganisms not directly using methylamine. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Tropical land-sea couplings: Role of watershed deforestation, mangrove estuary processing, and marine inputs on N fluxes in coastal Pacific Panama.

Science.gov (United States)

Valiela, Ivan; Elmstrom, Elizabeth; Lloret, Javier; Stone, Thomas; Camilli, Luis

2018-07-15

We review data from coastal Pacific Panama and other tropical coasts with two aims. First, we defined inputs and losses of nitrogen (N) mediating connectivity of watersheds, mangrove estuaries, and coastal sea. N entering watersheds-mainly via N fixation (79-86%)-was largely intercepted; N discharges to mangrove estuaries (3-6%), small compared to N inputs to watersheds, nonetheless significantly supplied N to mangrove estuaries. Inputs to mangrove estuaries (including watershed discharges, and marine inputs during flood tides) were matched by losses (mainly denitrification and export during ebb tides). Mangrove estuary subsidies of coastal marine food webs take place by export of forms of N [DON (62.5%), PN (9.1%), and litter N (12.9%)] that provide dissimilative and assimilative subsidies. N fixation, denitrification, and tidal exchanges were major processes, and DON was major form of N involved in connecting fluxes in and out of mangrove estuaries. Second, we assessed effects of watershed forest cover on connectivity. Decreased watershed forest cover lowered N inputs, interception, and discharge into receiving mangrove estuaries. These imprints of forest cover were erased during transit of N through estuaries, owing to internal N cycle transformations, and differences in relative area of watersheds and estuaries. Largest losses of N consisted of water transport of energy-rich compounds, particularly DON. N losses were similar in magnitude to N inputs from sea, calculated without considering contribution by intermittent coastal upwelling, and hence likely under-estimated. Pacific Panama mangrove estuaries are exposed to major inputs of N from land and sea, which emphasizes the high degree of bi-directional connectivity in these coupled ecosystems. Pacific Panama is still lightly affected by human or global changes. Increased deforestation can be expected, as well as changes in ENSO, which will surely raise watershed-derived loads of N, as well as significantly

Luminescence properties of a nanoporous freshwater diatom.

Science.gov (United States)

Goswami, Bondita; Choudhury, Amarjyoti; Buragohain, Alak K

2012-01-01

Freshwater diatom frustules show special optical properties. In this paper we observed luminescence properties of the freshwater diatom Cyclotella meneghiniana. To confirm the morphological properties we present scanning electron microscopy (SEM) images. X-ray diffraction (XRD) studies were carried out to visualize the structural properties of the frustules, confirming that silica present in diatom frustules crystallizes in an α-quartz structure. Study of the optical properties of the silica frustules of diatoms using ultra-violet-visible (UV-vis) spectroscopy and photoluminescence spectroscopy confirmed that the diatom C. meneghiniana shows luminescence in the blue region of the electromagnetic spectrum when irradiated with UV light. This property of diatoms can be exploited to obtain many applications in day-to-day life. Also, using time-resolved photoluminescence spectroscopy (TRPL) it was confirmed that this species of diatom shows bi-exponential decay. Copyright © 2011 John Wiley & Sons, Ltd.

Marine snow derived from abandoned larvacean houses: Sinking rates, particle content and mechanisms of aggregate formation

DEFF Research Database (Denmark)

Hansen, J.L.S.; Kiørboe, Thomas; Alldredge, A.L.

1996-01-01

The dynamics and formation mechanisms of marine snow aggregates from abandoned larvacean houses were examined by laboratory experiments and field sampling during a spring diatom bloom in a shallow fjord on the west coast of the USA. Intact aggregates were sampled both from sediment traps and dire......The dynamics and formation mechanisms of marine snow aggregates from abandoned larvacean houses were examined by laboratory experiments and field sampling during a spring diatom bloom in a shallow fjord on the west coast of the USA. Intact aggregates were sampled both from sediment traps...

The kelp highway hypothesis: marine ecology, the coastal migration theory, and the peopling of the Americas

Science.gov (United States)

Erlandson, Jon M.; Graham, Michael H.; Bourque, Bruce J.; Corbett, Debra; Estes, James A.; Steneck, Robert S.

2007-01-01

In this article, a collaborative effort between archaeologists and marine ecologists, we discuss the role kelp forest ecosystems may have played in facilitating the movement of maritime peoples from Asia to the Americas near the end of the Pleistocene. Growing in cool nearshore waters along rocky coastlines, kelp forests offer some of the most productive habitats on earth, with high primary productivity, magnified secondary productivity, and three-dimensional habitat supporting a diverse array of marine organisms. Today, extensive kelp forests are found around the North Pacific from Japan to Baja California. After a break in the tropicswhere nearshore mangrove forests and coral reefs are highly productivekelp forests are also found along the Andean Coast of South America. These Pacific Rim kelp forests support or shelter a wealth of shellfish, fish, marine mammals, seabirds, and seaweeds, resources heavily used historically by coastal peoples. By about 16,000 years ago, the North Pacific Coast offered a linear migration route, essentially unobstructed and entirely at sea level, from northeast Asia into the Americas. Recent reconstructions suggest that rising sea levels early in the postglacial created a highly convoluted and island-rich coast along Beringia's southern shore, conditions highly favorable to maritime hunter-gatherers. Along with the terrestrial resources available in adjacent landscapes, kelp forests and other nearshore habitats sheltered similar suites of food resources that required minimal adaptive adjustments for migrating coastal peoples. With reduced wave energy, holdfasts for boats, and productive fishing, these linear kelp forest ecosystems may have provided a kind of kelp highway for early maritime peoples colonizing the New World.

Journal of Biosciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Biosciences. LOCHNER. Articles written in Journal of Biosciences. Volume 43 Issue 1 March 2018 pp 59-74 Article. Thalassiosira mala italic> (Bacillariophyta), a potentially harmful, marine diatom from Chilka Lake and other coastal localities of Odisha, India: Nomenclature, frustule morphology ...

Marine ecology

International Nuclear Information System (INIS)

Anon.

1977-01-01

Studies on marine ecology included marine pollution; distribution patterns of Pu and Am in the marine waters, sediments, and organisms of Bikini Atoll and the influence of physical, chemical, and biological factors on their movements through marine biogeochemical systems; transfer and dispersion of organic pollutants from an oil refinery through coastal waters; transfer of particulate pollutants, including sediments dispersed during construction of offshore power plants; and raft culture of the mangrove oysters

Marine Pollution and Ecotoxicology

Digital Repository Service at National Institute of Oceanography (India)

Sarkar, A.

. Heavy metals Editorial Guest The special issue of Environment International has come up with selected papers presented in the International workshop on Marine Pollution and Ecotoxicology held at the National Institute of Oceanography, Dona Paula, Goa... presented in this special issue are classified into five sections namely, Coastal water quality, Heavy metals, Trace metals, Persistent organic pollutants and Ecotoxicology. 1. Coastal water quality assessment The pollution of the marine environment has...

Evolution of Hierarchical Structure and Spatial Pattern of Coastal Cities in China – Based on the Data of Distribution of Marine-Related Enterprises

Directory of Open Access Journals (Sweden)

Wang Lili

2017-11-01

Full Text Available In this paper, a comprehensive research of the evolution of the hierarchical structure and spatial pattern of coastal cities in China was conducted based on the data of distribution of the headquarters and subsidiaries of marine-related enterprises in 1995, 2005 and 2015 using the city network research method proposed by Taylor. The results of the empirical research showed: China’s coastal city network had an obvious hierarchical characteristics of “national coastal cityregional coastal city-sub-regional coastal city-local coastal city”, in the 20 years of development process, the hierarchies of coastal cities in China showed a hierarchical progressive evolution; in past 20 years, the spatial pattern and network structure of coastal cities in China tended to be complete, and the city network was more uniform, forming a “three tiers and three urban agglomerations” network structure; the strength of connection among the cities was obviously strengthened, and the efficiency of urban spatial connection was improved overall.

Dissolved inorganic carbon and alkalinity fluxes from coastal marine sediments: Model estimates for different shelf environments and sensitivity to global change

NARCIS (Netherlands)

Krumins, V.; Gehlen, M.; Arndt, S.; Van Cappellen, P.; Regnier, P.

2013-01-01

We present a one-dimensional reactive transport model to estimate benthic fluxes of dissolved inorganic carbon (DIC) and alkalinity (AT) from coastal marine sediments. The model incorporates the transport processes of sediment accumulation, molecular diffusion, bioturbation and bioirrigation,

Late Quaternary landscape evolution of northeastern Amazonia from pollen and diatom records

Directory of Open Access Journals (Sweden)

DARCILÉA F. CASTRO

2013-03-01

Full Text Available The main goal of this study was to reconstruct the Late Pleistocene-Holocene floristic composition in an area of the northern Brazilian Amazonia, comparing the results with other Amazonian localities in order to discuss the factors that have influenced phytophysiognomic changes over this time period. The work in eastern Marajó Island at the mouth of the Amazonas River was approached based on analysis of 98 pollen and diatom samples from core data distributed along a proximal to distal transect of a paleoestuarine system. The results indicated high concentration of Rhizophora, associated with arboreal pollen grains typical of the modern Amazonian rainforest during the last 40,000 cal yrs BP. Pollen composition also included wetland herbs. Diatoms were dominated by marine and fresh water taxa. Wetland forest, mangrove and, subordinately herbs remained constant during most of the latest Pleistocene-early/middle Holocene. At 5,000 cal yrs BP, there was a distinguished change from forest and mangrove to wet grassland savanna due to sea level fluctuation. As marine influence decreased, the estuary gave rise to fresh water lacustrine and swamp environments, with establishment of herbaceous campos. A main conclusion from this study is that solely the occurrence of herbaceous savanna can not be used as a definitive indicator of past dry climates in Amazonian areas.

ANALYSIS OF SEA WATER POLLUTION IN COASTAL MARINE DISTRICT TUBAN TO THE QUALITY STANDARDS OF SEA WATER WITH USING STORET METHOD

Directory of Open Access Journals (Sweden)

Perdana Ixbal Spanton

2017-05-01

Full Text Available The sea water is a component that interacts with the terrestrial environment, where sewage from the land will lead to the sea. Waste containing these pollutants will enter into coastal waters and marine ecosystems. Partially soluble in water, partially sinks to the bottom and was concentrated sediment, and partly into the body tissues of marine organisms. This study was conducted to determine the level of pollution of sea water on the coast in the district of Tuban. This research was conducted in the Coastal Water Tuban, East Java. The main material used in research on Analysis of Water Pollution in Coastal Sea on Tuban. The method used in this research is using storet method and compared to the quality standards of the Environment Decree No. 51 in 2004. Based on the analysis of testing at five sampling point’s seawater around Bodies Tuban, obtained by sea water quality measurement results either in physics, chemistry, and microbiology varied. The level of pollution of sea water around Coastal Tuban obtained by using Storet Method average value of analysis is -4.2 included in class B are lightly blackened, while using values obtained Pollution Index average pollution index of 3.60 is included in the category lightly blackened. Keywords: Analysis of the pollution level of seawater on the coast in Tuban, Quality Standards of Sea Water, Storet Method.

NODC Standard Format Marine Birds from Coastal Alaska and Puget Sound Data (1974-1982): Feeding Flock (F037) (NODC Accession 0014157)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Feeding Flock (F037) is one of a group of seven datasets related to Marine Birds from Coastal Alaska and Puget Sound Data (1974 -1982). Each dataset uses the NODC...

Marine litter from beach-based sources: Case study of an Eastern Mediterranean coastal town.

Science.gov (United States)

Portman, Michelle E; Brennan, Ruth E

2017-11-01

Marine litter has been a serious and growing problem for some decades now. Yet, there is still much speculation among researchers, policy makers and planners about how to tackle marine litter from land-based sources. This paper provides insights into approaches for managing marine litter by reporting and analyzing survey results of litter dispersal and makeup from three areas along an Arab-Israeli coastal town in view of other recent studies conducted around the Mediterranean Sea. Based on our results and analysis, we posit that bathing beach activities should be a high priority for waste managers as a point of intervention and beach-goers must be encouraged to take a more active role in keeping beaches clean. Further, plastic fragments on the beach should be targeted as a first priority for prevention (and cleanup) of marine litter with plastic bottle caps being a high priority to be targeted among plastics. More survey research is needed on non-plastic litter composition for which amounts and geographic dispersal in the region vary greatly from place to place along Mediterranean shores. In general, findings of this study lead us to recommend exploring persuasive beach trash can design coupled with greater enforcement for short term waste management intervention while considering the local socio-economic and institutional context further for long-term efforts. Copyright © 2017 Elsevier Ltd. All rights reserved.

The transcriptome and proteome of the diatom Thalassiosira pseudonana reveal a diverse phosphorus stress response.

Directory of Open Access Journals (Sweden)

Sonya T Dyhrman

Full Text Available Phosphorus (P is a critical driver of phytoplankton growth and ecosystem function in the ocean. Diatoms are an abundant class of marine phytoplankton that are responsible for significant amounts of primary production. With the control they exert on the oceanic carbon cycle, there have been a number of studies focused on how diatoms respond to limiting macro and micronutrients such as iron and nitrogen. However, diatom physiological responses to P deficiency are poorly understood. Here, we couple deep sequencing of transcript tags and quantitative proteomics to analyze the diatom Thalassiosira pseudonana grown under P-replete and P-deficient conditions. A total of 318 transcripts were differentially regulated with a false discovery rate of <0.05, and a total of 136 proteins were differentially abundant (p<0.05. Significant changes in the abundance of transcripts and proteins were observed and coordinated for multiple biochemical pathways, including glycolysis and translation. Patterns in transcript and protein abundance were also linked to physiological changes in cellular P distributions, and enzyme activities. These data demonstrate that diatom P deficiency results in changes in cellular P allocation through polyphosphate production, increased P transport, a switch to utilization of dissolved organic P through increased production of metalloenzymes, and a remodeling of the cell surface through production of sulfolipids. Together, these findings reveal that T. pseudonana has evolved a sophisticated response to P deficiency involving multiple biochemical strategies that are likely critical to its ability to respond to variations in environmental P availability.

Diatoms from a peat bog on the Pešter plateau (southwestern Serbia: New records for diatom flora of Serbia

Directory of Open Access Journals (Sweden)

Vidaković Danijela

2016-01-01

Full Text Available The distribution of diatoms was studied in three types of diatom communities (epiphytes, benthos and plankton of a peat bog on the Pešter plateau. The observed diatom flora inhabited all investigated communities, comprising in total 250 taxa in 53 genera. Among them, 45 taxa were new records for the Serbian diatom flora. Identified taxa belonged to different groups of algae, however alkaliphile diatoms were dominant. New ecological data for Encyonopsis minuta, Pinnularia isostauron and P. marchica are presented here. All the diatoms were documented by light micrographs, and brief notes on their morphology, distribution and ecology are provided. [Projekat Ministarstva nauke Republike Srbije, br. TR 037009

Ocean acidification modulates expression of genes and physiological performance of a marine diatom

Science.gov (United States)

Li, Y.; Zhuang, S.; Wu, Y.; Ren, H.; Cheng, F.; Lin, X.; Wang, K.; Beardall, J.; Gao, K.

2015-09-01

Ocean Acidification (OA) is known to affect various aspects of the physiological performance of diatoms, but there is little information on the underlining molecular mechanisms involved. Here, we show that in the model diatom Phaeodactylum tricornutum expression of the genes related to light harvesting, carbon acquisition and carboxylation, nitrite assimilation and ATP synthesis are modulated by OA. Growth and photosynthetic carbon fixation were enhanced by elevated CO2 (1000 μatm) under both constant indoor and fluctuating outdoor light regimes. The genetic expression of nitrite reductase (NiR) was up-regulated by OA regardless of light levels and/or regimes. The transcriptional expression of fucoxanthin chlorophyll a/c protein (lhcf type (FCP)) and mitochondrial ATP synthase (mtATP synthase) genes were also enhanced by OA, but only under high light intensity. OA treatment decreased the expression of β-carbonic anhydrase (β-CA) along with down-regulation of CO2 concentrating mechanisms (CCMs). Additionally, the genes for these proteins (NiR, FCP, mtATP synthase, β-CA) showed diel expressions either under constant indoor light or fluctuating sunlight. Thus, OA enhanced photosynthetic and growth rates by stimulating nitrogen assimilation and indirectly by down-regulating the energy-costly inorganic carbon acquisition process.

Biofilm and Diatom Succession on Polyethylene (PE) and Biodegradable Plastic Bags in Two Marine Habitats: Early Signs of Degradation in the Pelagic and Benthic Zone?

Science.gov (United States)

Eich, Andreas; Mildenberger, Tobias; Laforsch, Christian; Weber, Miriam

2015-01-01

The production of biodegradable plastic is increasing. Given the augmented littering of these products an increasing input into the sea is expected. Previous laboratory experiments have shown that degradation of plastic starts within days to weeks. Little is known about the early composition and activity of biofilms found on biodegradable and conventional plastic debris and its correlation to degradation in the marine environment. In this study we investigated the early formation of biofilms on plastic shopper bags and its consequences for the degradation of plastic. Samples of polyethylene and biodegradable plastic were tested in the Mediterranean Sea for 15 and 33 days. The samples were distributed equally to a shallow benthic (sedimentary seafloor at 6 m water depth) and a pelagic habitat (3 m water depth) to compare the impact of these different environments on fouling and degradation. The amount of biofilm increased on both plastic types and in both habitats. The diatom abundance and diversity differed significantly between the habitats and the plastic types. Diatoms were more abundant on samples from the pelagic zone. We anticipate that specific surface properties of the polymer types induced different biofilm communities on both plastic types. Additionally, different environmental conditions between the benthic and pelagic experimental site such as light intensity and shear forces may have influenced unequal colonisation between these habitats. The oxygen production rate was negative for all samples, indicating that the initial biofilm on marine plastic litter consumes oxygen, regardless of the plastic type or if exposed in the pelagic or the benthic zone. Mechanical tests did not reveal degradation within one month of exposure. However, scanning electron microscopy (SEM) analysis displayed potential signs of degradation on the plastic surface, which differed between both plastic types. This study indicates that the early biofilm formation and composition

Biofilm and Diatom Succession on Polyethylene (PE and Biodegradable Plastic Bags in Two Marine Habitats: Early Signs of Degradation in the Pelagic and Benthic Zone?

Directory of Open Access Journals (Sweden)

Andreas Eich

Full Text Available The production of biodegradable plastic is increasing. Given the augmented littering of these products an increasing input into the sea is expected. Previous laboratory experiments have shown that degradation of plastic starts within days to weeks. Little is known about the early composition and activity of biofilms found on biodegradable and conventional plastic debris and its correlation to degradation in the marine environment. In this study we investigated the early formation of biofilms on plastic shopper bags and its consequences for the degradation of plastic. Samples of polyethylene and biodegradable plastic were tested in the Mediterranean Sea for 15 and 33 days. The samples were distributed equally to a shallow benthic (sedimentary seafloor at 6 m water depth and a pelagic habitat (3 m water depth to compare the impact of these different environments on fouling and degradation. The amount of biofilm increased on both plastic types and in both habitats. The diatom abundance and diversity differed significantly between the habitats and the plastic types. Diatoms were more abundant on samples from the pelagic zone. We anticipate that specific surface properties of the polymer types induced different biofilm communities on both plastic types. Additionally, different environmental conditions between the benthic and pelagic experimental site such as light intensity and shear forces may have influenced unequal colonisation between these habitats. The oxygen production rate was negative for all samples, indicating that the initial biofilm on marine plastic litter consumes oxygen, regardless of the plastic type or if exposed in the pelagic or the benthic zone. Mechanical tests did not reveal degradation within one month of exposure. However, scanning electron microscopy (SEM analysis displayed potential signs of degradation on the plastic surface, which differed between both plastic types. This study indicates that the early biofilm formation

Proceedings of a Coastal and Marine Spatial Planning Workshop for the Western United States

Science.gov (United States)

Thorsteinson, Lyman; Hirsch, Derrick; Helweg, David; Dhanju, Amardeep; Barmenski, Joan; Ferrero, Richard

2011-01-01

Recent scientific and ocean policy assessments demonstrate that a fundamental change in our current management system is required to achieve the long-term health of our ocean, coasts, and Great Lakes in order to sustain the services and benefits they provide to society. The present (2011) species- and sector-centric way we manage these ecosystems cannot account properly for cumulative effects, sustaining multiple ecosystem services, and holistically and explicitly evaluating the tradeoffs associated with proposed alternative and multiple human uses. A transition to an ecosystem-based approach to management and conservation of coastal and marine resources is needed. Competing uses and activities such as commerce, recreation, cultural practices, energy development, conservation, and national security are increasing pressure for new and expanded resource usage in coastal marine ecosystems. Current management efforts use a sector-by-sector approach that mostly focuses on a limited range of tools and outcomes [for example, oil and gas leases, fishery management plans, and Marine Protected Areas (MPAs)]. A comprehensive, ecosystem-based, and proactive approach to planning and managing these uses and activities is needed. Further, scientific understanding and information are essential to achieve an integrated decision-making process that includes knowledge of ecosystem services, existing and possible future conditions, and potential consequences of natural and anthropogenic events. Because no single government agency has executive authority for coastal or ocean resources, conflicting objectives around competing uses abound. In recent years, regional- and state-level initiatives in Coastal and Marine Spatial Planning (CMSP) have emerged to coordinate management activities. In some respects, the components and steps of the overall CMSP process are similar to how existing ocean resources are regulated and managed. For example, the Bureau of Ocean Energy Management Regulation

Journal of Biosciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Biosciences. JAMES A NIENOW. Articles written in Journal of Biosciences. Volume 43 Issue 1 March 2018 pp 59-74 Article. Thalassiosira mala italic> (Bacillariophyta), a potentially harmful, marine diatom from Chilka Lake and other coastal localities of Odisha, India: Nomenclature, frustule ...

Socio-ecological studies on marine fishing villages in the selective south coastal districts of Andhra Pradesh.

Science.gov (United States)

Jacob, M Jaya Kumar; Rao, P Brahmaji

2016-12-01

Coasts are an amazing gift of nature. Industrialization, infrastructure development, urbanisation, tourism, mechanized fishing, disposal of industrial and urban wastes and effluents, are all ringing the death-knell of the sensitive coastal ecosystems of recently separated State of Andhra Pradesh. These modern interventions have been violent, disregarding both nature's rejuvenating mechanisms, and the symbiotic relationship that exist between the coast and traditional marine fishing communities. Modern fishing tecnologies using mechanized trawlers and small meshed nets lead directly to overexploitation, which is not sustainable. It is evident that fish have to breed successfully and need to have time to grow if the yield has to be used sustainably. Multiple pressures and excessive technological invasion on these marine fishing villages had created an environment in which life has become physically and mentally unhealthy. The focus of this paper is to emphasize that investing in large-scale industrial fishing, building bigger boats, and giving subsidies for pursuing deep sea fishing would be a waste of resources as the fish hauls in these selelctive districts i.e. Krishna, Guntur, Prakasam and Nellore coastal communities have dropped off alarmingly in recent years. It is essential and crucial to focus research and scientific analysis and establish awareness and education to provide a means of distinguishing responses between improvements in quality of ecosystem and those of damages. The study is to elaborate that long-term ecological gains cannot be sacrificed for short-term economic gains that unfortunately lead to environmental damage. Investigating coastal regulations, policies, and their implementation is an urgent social need for the sake of socio-ecological safety and security of coasts and host communities. Copyright © 2015 Elsevier Inc. All rights reserved.

Effect of diatom morphology on the small-scale behavior of the copepod Temora stylifera (Dana, 1849)

KAUST Repository

Mahadik, Gauri A.

2017-05-12

We explored the small-scale behavior of the calanoid copepod Temora stylifera in relation to the diatoms Chaetoceros socialis, Leptocylindrus aporus, Leptocylindrus danicus and Pseudo-nitzschia calliantha offered as monospecific diets at similar carbon concentrations. These four diatoms are characterized by distinct size, shape and colony forming ability and are important components of the autumnal bloom co-occurring with the seasonal peak of T. stylifera abundance in Mediterranean coastal waters. High-speed video recordings showed that T. stylifera acquired cells in a suspension feeding mode while creating feeding currents. Copepod behavior was quantified in terms of feeding, motion, and grooming activities. T. stylifera spent more time in hovering than cruising in presence of all diets. The solitary L. aporus and P. calliantha elicited longer feeding bouts, lower appendage beat frequency and shorter grooming events compared to the colonial L. danicus and C. socialis. Overall the present results indicate that the behavioral responses of T. stylifera to different diatom diets were species-specific. The observed behavioral plasticity may help T. stylifera to adjust rapidly to changes in the food environment and this can be advantageous in exploiting short-lived phytoplankton blooms.

Effect of diatom morphology on the small-scale behavior of the copepod Temora stylifera (Dana, 1849)

KAUST Repository

Mahadik, Gauri A.; Castellani, Claudia; Mazzocchi, Maria Grazia

2017-01-01

We explored the small-scale behavior of the calanoid copepod Temora stylifera in relation to the diatoms Chaetoceros socialis, Leptocylindrus aporus, Leptocylindrus danicus and Pseudo-nitzschia calliantha offered as monospecific diets at similar carbon concentrations. These four diatoms are characterized by distinct size, shape and colony forming ability and are important components of the autumnal bloom co-occurring with the seasonal peak of T. stylifera abundance in Mediterranean coastal waters. High-speed video recordings showed that T. stylifera acquired cells in a suspension feeding mode while creating feeding currents. Copepod behavior was quantified in terms of feeding, motion, and grooming activities. T. stylifera spent more time in hovering than cruising in presence of all diets. The solitary L. aporus and P. calliantha elicited longer feeding bouts, lower appendage beat frequency and shorter grooming events compared to the colonial L. danicus and C. socialis. Overall the present results indicate that the behavioral responses of T. stylifera to different diatom diets were species-specific. The observed behavioral plasticity may help T. stylifera to adjust rapidly to changes in the food environment and this can be advantageous in exploiting short-lived phytoplankton blooms.

A marine eutrophication impacts assessment method in LCIA coupling coastal ecosystems exposure to nitrogen and species sensitivity to hypoxia

DEFF Research Database (Denmark)

Cosme, Nuno Miguel Dias; Koski, Marja; Hauschild, Michael Zwicky

Characterisation modelling in Life Cycle Impact Assessment (LCIA) aims at quantifying potential impacts of anthropogenic emissions. It delivers substance-specific Characterisation Factors (CF) expressing ecosystem responses to marginal increments in emitted quantities. Nitrogen (N) emissions from e.......g. agriculture and industry enrich coastal marine ecosystems. Excessive algal growth and dissolved oxygen (DO) depletion typify the resulting marine eutrophication. LCIA modelling frameworks typically encompass fate, exposure and effect in the environment. The present novel method couples relevant marine...... biological processes of ecosystem’s N exposure (Exposure Factor, XF) with the sensitivity of select species to hypoxia (Effect Factor, EF). The XF converts N-inputs into a sinking carbon flux from planktonic primary production and DO consumed by bacterial respiration in bottom waters, whereas EF builds...

Evolution of a Holsteinian (MIS 11c) palaeolake based on a 12-ka-long diatom record from Dethlingen (northern Germany)

NARCIS (Netherlands)

Koutsodendris, A.; Lotter, A.F.; Kirilova, E.P.|info:eu-repo/dai/nl/304838071; Verhagen, F.; Brauer, A.; Pross, J.

2013-01-01

To provide insights into the long-term evolution of aquatic ecosystems without human interference, we hereevaluate a decadal- to centennial-scale-resolution diatom record spanning about 12 ka of the Holsteinian inter-glacial (Marine Isotope Stage 11c). Using a partially varved sediment core from the

Tinted windows: The presence of the UV absorbing compounds called mycosporine-like amino acids embedded in the frustules of marine diatoms

Science.gov (United States)

Ingalls, Anitra E.; Whitehead, Kenia; Bridoux, Maxime C.

2010-01-01

Diatom frustule-bound organic compounds presumably play an important role in biomineralization and constitute an important pool of organic matter preserved in diatom frustule-rich sediments. In this study, detailed analysis of diatom frustule-bound organic matter in opal-rich Southern Ocean plankton and sediments revealed for the first time the presence of low molecular weight, UV light absorbing compounds called mycosporine-like amino acids (MAAs). Chemically cleaned diatom frustule-derived biosilica was dissolved in HF, releasing bound or entrapped organic compounds that were subsequently characterized using liquid chromatography with UV-Vis and electrospray ionization mass spectrometry (LC/PDA/ESI-MS). Palythine ([M+H] + = 245), porphyra-334 ([M+H] + = 347) and shinorine ([M+H] + = 333) were the most abundant MAAs detected in HF digests of plankton and sediment. Traces of asterina ([M+H] + = 289), palythinol ([M+H] + = 303) and palythinic acid ([M+H] + = 329) were also detected. MAAs in cleaned HF digested frustules were up to two orders of magnitude more abundant than methanol extractable MAAs. MAAs are substituted with acid hydrolysable amino acid residues. Our results suggest that MAAs, and not proteins, could be responsible for the high proportion of the amino acids glycine and threonine found in hydrolysates of HF digested diatom-rich environmental samples. Total MAAs accounted for 3-27% of the carbon and 2-18% of total nitrogen in the frustules undergoing various chemical cleaning treatments. This is the first report of MAAs in close association with a mineral phase and we hypothesize that the mineral matrix could stabilize these compounds, thereby enhancing photoprotection against the harmful effects of UV light. The presence of frustule-bound MAAs in sediment cores further suggests the possibility that they could be used in compound-specific isotope analysis of diatom-bound organic matter and as indicators of past solar irradiance.

In hot water: the future of Australia's coastal and marine ecosystems

International Nuclear Information System (INIS)

Richardson, Anthony J; Poloczanska, Elvira

2007-01-01

Full text: Full text: Marine ecosystems are extremely important economically and ecologically to Australia in terms of tourism, coastal defence, resources, and ecosystem services such as nutrient cycling and waste disposal. Australia is also a globally important repository of biodiversity. Here we describe the observed and potential future impacts of climate change on Australia's marine diversity. Climate simulations project oceanic warming, an increase in stratification, a strengthening of the Eastern Australian Current, increased ocean acidification, a rise in sea level, and altered storm and rainfall regimes, which taken collectively will fundamentally change marine ecosystems. There has already been widespread bleaching of tropical corals, poleward shifts of temperate fish and plankton populations, and a decline in cold-water giant kelp off Tasmania. Future changes are likely to be even more dramatic and have considerable economic and ecological consequences, especially in 'hot spots' of climate change such as theTasman Sea and the Great Barrier Reef area. Corals are likely to bleach more frequently and decline in abundance in response to both warming and ocean acidification. Planktonic animals with calcium carbonate shells, such as winged pteropod snails and coccolithophorid phytoplankton, are likely to decline as increased ocean acidification impairs their ability to maintain carbonate body structures. The projected high warming off south-east Australia is of particular concern. Marine ecosystems in this region are already stressed by high metal concentrations, sewage pollution, and overfishing, and climate models project that this region will warm more than anywhere else in the Southern Hemisphere this century because of enhanced southerly penetration of the East Australian Current. Venomous jellyfish and harmful algal blooms, which are major threats to human health, will potentially extend further south and occur more frequently. Temperate species

Effects of pulsed nutrient inputs on phytoplankton assemblage structure and blooms in an enclosed coastal area

Science.gov (United States)

Spatharis, Sofie; Tsirtsis, George; Danielidis, Daniel B.; Chi, Thang Do; Mouillot, David

2007-07-01

The response of phytoplankton assemblage structure to terrestrial nutrient inputs was examined for the Gulf of Kalloni in the Northern Aegean Sea, a productive semi-enclosed coastal marine ecosystem. The study was focused on a typical annual cycle, and emphasis was placed on the comparative analysis between blooms developing after significant nutrient inputs from the watershed, and naturally occurring blooms. Baseline information was collected on a monthly basis from a network of stations located in the oligotrophic open sea and the interior and more productive part of the embayment. Intensive sampling was also carried out along a gradient in the vicinity of a river which was the most important source of freshwater and nutrient input for the Gulf. Phytoplankton assemblage structure was analyzed from 188 samples using diversity indices (Shannon and Average Taxonomic Distinctness), multivariate plotting methods (NMDS), multivariate statistics (PERMANOVA), and canonical correspondence analysis (CCA). Three characteristic assemblages were recognized: (1) an autumn assemblage developed under nutrient depleted conditions, having low diversity due to the dominance of two small diatoms, (2) a winter bloom of the potentially toxic species Pseudo-nitzschia calliantha occurring immediately after a nutrient peak and characterized by very low diversity, and (3) a naturally occurring early summer bloom of centric diatoms with relatively high diversity. The results of the study support the view that moderate nutrient inputs may have a beneficial effect on the functioning of coastal ecosystems, stimulating the taxonomic diversity through the growth of different taxonomic groups and taxa. On the other hand, a sudden pulse of high nutrient concentrations may greatly affect the natural succession of organisms, have a negative effect on the diversity through the dominance of a single species, and can increase the possibility of a harmful algal bloom development.

A novel marine nitrite-oxidizing Nitrospira species from Dutch coastal North Sea water

Directory of Open Access Journals (Sweden)

Suzanne Caroline Marianne Haaijer

2013-03-01

Full Text Available Marine microorganisms are important for the global nitrogen cycle, but marine nitrifiers, especially aerobic nitrite-oxidizers, remain largely unexplored. To increase the number of cultured representatives of marine nitrite-oxidizing bacteria (NOB, a bioreactor cultivation approach was adopted to first enrich nitrifiers and ultimately nitrite oxidizers from Dutch coastal North Sea water. With solely ammonia as the substrate an active nitrifiying community consisting of novel marine Nitrosomonas aerobic ammonia oxidizers (AOB and Nitrospina and Nitrospira NOB was obtained which converted a maximum of 2 mmoles of ammonia per liter per day. Switching the feed of the culture to nitrite as a sole substrate resulted in a Nitrospira NOB dominated community (approximately 80% of the total microbial community based on FISH and metagenomic data converting a maximum of 3 mmoles of nitrite per liter per day. Phylogenetic analyses based on the 16S rRNA gene indicated that the Nitrospira enriched from the North Sea is a novel Nitrospira species with Nitrospira marina as the next taxonomically described relative (94% 16S rRNA sequence identity. Transmission electron microscopy analysis revealed a cell plan typical for Nitrospira species. The cytoplasm contained electron light particles that might represent glycogen storage. A large periplasmic space was present which was filled with electron dense particles. Nitrospira-targeted PCR analyses demonstrated the presence of the enriched Nitrospira species in a time series of North Sea genomic DNA samples. The availability of this new Nitrospira species enrichment culture facilitates further in-depth studies such as determination of physiological constraints, and comparison to other NOB species.

Petroleum hydrocarbon concentrations in marine sediments along Nagapattinam - Pondicherry coastal waters, Southeast coast of India.

Science.gov (United States)

Kamalakannan, K; Balakrishnan, S; Sampathkumar, P

2017-04-15

In this present study, petroleum hydrocarbons were statistically analyzed in three different coastal sediment cores viz., (N1, P1 and P2) from the Southeast coast of Tamil Nadu, India to examine the viability of PHCs. The significant positive relationship between mud (silt+clay+sand) and PHC unveiled that high specific surface of area of mud content raise the level of PHCs. Cluster analysis was used to discriminate the sediment samples based on their degree of contamination. The present study shows that instead of expensive and destructive PHC chemical methods, magnetic susceptibility is found to be a suitable, cheap and rapid method for detailed study of PHC in marine sediments. This baseline PHCs data can be used for regular ecological monitoring and effective management for the mining and tourism related activities in the coastal ecosystem. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Marine organic geochemistry in industrially affected coastal areas in Greece: Hydrocarbons in surface sediments

Science.gov (United States)

Hatzianestis, Ioannis

2015-04-01

Hydrocarbons are abundant components of the organic material in coastal zones. Their sources are mainly anthropogenic, but several natural ones have also been recognized. Among hydrocarbons, the polycyclic aromatic ones (PAHs) have received special attention since they considered as hazardous environmental chemicals and are included in priority pollutant lists. The purpose of this study was to investigate the distribution, sources and transport pathways of hydrocarbons in marine areas in Greece directly influenced from the operation of major industrial units in the coastal zone by using a molecular marker approach, characteristic compositional patterns and related indices and also to evaluate their potential toxicity. Thirty two surface sediment samples were collected from three marine areas: a) Antikyra bay in Korinthiakos gulf, affected from the operation of an alumina and production plant b) Larymna bay in Noth Evoikos, affected from the operation of a nickel production plant and c) Aliveri bay in South Evoikos Gulf, affected from a cement production plant. In all the studied areas aquaculture and fishing activities have been also developed in the coastal zone. High aliphatic hydrocarbon (AHC) concentrations (~500 μg/g), indicating significant petroleum related inputs, were measured only in Antikyra bay. In all the other samples, AHC values were below 100 μg/g. N-alkanes were the most prominent resolved components (R) with an elevated odd to even carbon number preference, revealing the high importance of terrestrial inputs in the study areas. The unresolved complex mixture (UCM) was the major component of the aliphatic fraction (UCM/R > 4), indicating a chronic oil pollution. A series of hopanes were also identified, with patterns characteristic of oil-derived hydrocarbons, further confirming the presence of pollutant inputs from fossil fuel products. Extremely high PAH concentrations (> 100,000 ng/g) were found in the close vicinity of the alumina production

Environmental monitoring and assessment of antibacterial metabolite producing actinobacteria screened from marine sediments in south coastal regions of Karnataka, India.

Science.gov (United States)

Skariyachan, Sinosh; Garka, Shruthi; Puttaswamy, Sushmitha; Shanbhogue, Shobitha; Devaraju, Raksha; Narayanappa, Rajeswari

2017-06-01

Assessment of the therapeutic potential of secondary metabolite producing microorganisms from the marine coastal areas imparts scope and application in the field of environmental monitoring. The present study aims to screen metabolites with antibacterial potential from actionbacteria associated with marine sediments collected from south coastal regions of Karnataka, India. The actinobacteria were isolated and characterized from marine sediments by standard protocol. The metabolites were extracted, and antibacterial potential was analyzed against eight hospital associated bacteria. The selected metabolites were partially characterized by proximate analysis, SDS-PAGE, and FTIR-spectroscopy. The antibiogram of the test clinical isolates revealed that they were emerged as multidrug-resistant strains (P ≤ 0.05). Among six actinobacteria (IS1-1S6) screened, 100 μl -1 metabolite from IS1 showed significant antibacterial activities against all the clinical isolates except Pseudomonas aeruginosa. IS2 demonstrated antimicrobial potential towards Proteus mirabilis, Streptococcus pyogenes, and Escherichia coli. The metabolite from IS3 showed activity against Strep. pyogenes and E. coli. The metabolites from IS4, IS5, and IS6 exhibited antimicrobial activities against Ps. aeruginosa (P ≤ 0.05). The two metabolites that depicted highest antibacterial activities against the test strains were suggested to be antimicrobial peptides with low molecular weight. These isolates were characterized and designated as Streptomyces sp. strain mangaluru01 and Streptomyces sp. mangaloreK01 by 16S ribosomal DNA (rDNA) sequencing. This study suggests that south coastal regions of Karnataka, India, are one of the richest sources of antibacterial metabolites producing actinobacteria and monitoring of these regions for therapeutic intervention plays profound role in healthcare management.

[Research advances in heavy metals pollution ecology of diatom].

Science.gov (United States)

Ding, Teng-Da; Ni, Wan-Min; Zhang, Jian-Ying

2012-03-01

Diatom, due to its high sensitivity to environmental change, is one of the bio-indicators of aquatic ecosystem health, and some typical diatom species have been applied to indicate the heavy metals pollution of water body. With the focus on the surface water heavy metals pollution, this paper reviewed the research advances in the toxic effect of heavy metals pollution on diatom, biosorption and bioaccumulation of heavy metals by diatom, ecological adaptation mechanisms of diatom to heavy metals pollution, and roles of diatom as bio-indicator and in ecological restoration of heavy metals pollution. The growth tendency of diatom and the morphological change of frustule under heavy metals pollution as well as the differences in heavy metals biosorption and bioaccumulation by diatom, the ecological adaptation mechanisms of diatom on heavy metals surface complexation and ion exchange, and the roles of diatom as bio-indicator and in ecological restoration of heavy metals polluted water body were also discussed. This review could provide scientific evidences for the prevention of aquatic ecosystems heavy metals pollution and related early warning techniques.

Mapping of Florida's Coastal and Marine Resources: Setting Priorities Workshop

Science.gov (United States)

Robbins, Lisa; Wolfe, Steven; Raabe, Ellen

2008-01-01

The importance of mapping habitats and bioregions as a means to improve resource management has become increasingly clear. Large areas of the waters surrounding Florida are unmapped or incompletely mapped, possibly hindering proper management and good decisionmaking. Mapping of these ecosystems is among the top priorities identified by the Florida Oceans and Coastal Council in their Annual Science Research Plan. However, lack of prioritization among the coastal and marine areas and lack of coordination of agency efforts impede efficient, cost-effective mapping. A workshop on Mapping of Florida's Coastal and Marine Resources was sponsored by the U.S. Geological Survey (USGS), Florida Department of Environmental Protection (FDEP), and Southeastern Regional Partnership for Planning and Sustainability (SERPPAS). The workshop was held at the USGS Florida Integrated Science Center (FISC) in St. Petersburg, FL, on February 7-8, 2007. The workshop was designed to provide State, Federal, university, and non-governmental organizations (NGOs) the opportunity to discuss their existing data coverage and create a prioritization of areas for new mapping data in Florida. Specific goals of the workshop were multifold, including to: * provide information to agencies on state-of-the-art technology for collecting data; * inform participants of the ongoing mapping programs in waters off Florida; * present the mapping needs and priorities of the State and Federal agencies and entities operating in Florida; * work with State of Florida agencies to establish an overall priority for areas needing mapping; * initiate discussion of a unified classification of habitat and bioregions; * discuss and examine the need to standardize terminology and data collection/storage so that data, in particular habitat data, can be shared; 9 identify opportunities for partnering and leveraging mapping efforts among agencies and entities; * identify impediments and organizational gaps that hinder collection

Sampler collection gadget for epilithic diatoms.

Science.gov (United States)

Salomoni, S E; Torgan, L C; Rocha, O

2007-11-01

This work present a new gadget for sampling epilithic diatoms from both lentic and lotic enviroments. The sampler consists of a polystyrene cylinder, left to float on the surface of the water, to which stone substrates are attached. This epilithic diatom sampler (EDS) can be used to detect spatial and temporal richness and density variation in the study of the diatom community, as well as in water quality monitoring.

Marine habitat mapping at Labuan Marine Park, Federal Territory of Labuan, Malaysia

Science.gov (United States)

Mustajap, Fazliana; Saleh, Ejria; Madin, John; Hamid, Shahimah Abdul

2015-06-01

Marine habitat mapping has recently become essential in coastal marine science research. It is one of the efforts to understand marine ecosystems, and thus to protect them. Habitat mapping is integral to marine-related industries such as fisheries, aquaculture, forestry and tourism. An assessment of marine habitat mapping was conducted at Labuan Marine Park (LMP), a marine protected area in the Federal Territory of Labuan. It is surrounded by shallow water within its islands (Kuraman, Rusukan Kecil and Rusukan Besar) with an area of 39.7 km2. The objectives of the study are to identify the substrate and types of marine habitat present within the park. Side scan sonar (SSS) (Aquascan TM) was used to determine the substrates and habitat while ground truthings were done through field observation and SCUBA diving survey. Seabed classification and marine habitat was based on NOAA's biogeography program. Three substrate types (sand, rock, silt) were identified in this area. The major marine habitats identified are corals, macro algae and small patches of sea grass. The study area is an important refuge for spawning and juvenile fish and supports the livelihood of the coastal communities on Labuan Island. Therefore, proper management is crucial in order to better maintain the marine protected area. The findings are significant and provide detailed baseline information on marine habitat for conservation, protection and future management in LMP.

Ecological Significance of Marine Microzooplankton

Digital Repository Service at National Institute of Oceanography (India)

Godhantaraman, N.

). Studies concerning microzooplankton in marine coastal, estuarine and brackish-water systems along tropical Indian waters are limited. Hence, in the following sections, I provide the results obtained by the research conducted in the tropical Vellar... estuarine systems, southeast coast of India. This was one of the first comprehensive studies on microzooplankton in India. There are also comparative accounts of microzooplankton researches from my studies in Japanese coastal marine waters. Microzooplankton...

Depositional Architecture of Late Pleistocene-Holocene Coastal Alluvial-fan System in the Coastal Range, Taiwan

Science.gov (United States)

Chen, S. T.; Chen, W. S.

2016-12-01

Since late Pleistocene, the Coastal Range (Philippine Sea plate) collided and overridden on the Central Range (Eurasian Plate) along the Longitudinal Valley Fault. Therefore, the Coastal Range is exposed widely the late Pleistocene-Holocene marine and fluvial terraces caused by the tectonic uplift. Based on the estimation of paleosea-level elevations (Δh), depositional paleodepth, altitude distribution of Holocene deposits (D), altitude of outcrops (H), and 14C dating of marine deposits (t), the uplift rate (=(Δh+H +d-D)/t) is about 5-10 mm/yr in the southern Coastal Range. In this study, we suggest through field logging that the deposits can be divided into alluvial, foreshore (intertidal), shoreface, and offshore environments. In Dulan area in the southern Coastal Range, the uplift rate was 6-7 mm/yr during 16,380-10,000 cal yr BP and 3-4 mm/yr after 7,000 cal yr BP. Results from the Dulan Coastal alluvial-fan system can be divided into five depositional stages: (1) 16,380-14,300 cal yr BP: The rate of global sea level rise (SLR) has averaged about 6-7 mm/yr, similar to the tectonic uplift rate. In this stage, the bedrock was eroded and formed a wide wave-cut platform. (2) 14,300-10,000 cal yr BP: SLR of about 14 mm/yr that was faster than tectonic uplift rate of 6-7 mm/yr. As a result of transgression, the beach-lagoon deposits about 5 m thick were unconformably overlain on the wave-cut platform. (3) 10,000-8,200 cal yr BP: The ongoing sea level rise (SLR: 11 mm/yr), the lagoon deposits were overlain by an offshore slump deposits representing a gradual deepening of the depositional environment. (4) 8,200-7,930 cal yr BP (SLR: 6-7 mm/yr): The tectonic uplift rate may occur at similar SLR. The alluvial-fan deposits have prograded over the shallow marine deposits. (5) After 7,000 cal yr BP (SLR: 1-0 mm/yr): SLR was much slower than tectonic uplift rate of 3-4 mm/yr. Thus, Holocene marine terraces are extensively developed in the coastal region, showing that the

Weddellian marine/coastal vertebrates diversity from a basal horizon (Ypresian, Eocene of the Cucullaea I Allomember, La Meseta formation, Seymour (Marambio Island, Antarctica

Directory of Open Access Journals (Sweden)

Marcelo A. Reguero

2013-06-01

Full Text Available The La Meseta Formation crops out in Seymour/Marambio Island, Weddell Sea, northeast of the Antarctic Peninsula and contains one of the world's most diverse assemblages of Weddellian marine/coastal verte-brates of Early Eocene (Ypresian age. The La Meseta Formation is composed of poorly consolidated, marine sandstones and siltstones which were deposited in a coastal, deltaic and/or estuarine environment. It includes marine invertebrates and vertebrates as well as terrestrial vertebrates and plants. The highly fossiliferous basal horizon (Cucullaeashell bed, Telm 4 of Sadler 1988 of the CucullaeaI Allomember is a laterally extensive shell bed with sandy matrix. The fish remains, including 35 species from 26 families, of the Ypresian Cucullaeabed represent one of the most abundant and diverse fossil vertebrate faunas yet recorded in southern latitudes. Stratigraphic distribution and phylogenetic relationships of the Weddellian sphenisciforms are consistent with a first radiation of this group in the Early Eocene. The first inquestionable archaeocete from Antarctica is recorded in this unit and is referred to a new taxon.

Grazer-induced chain lenght plasticity reduces grazing risk in a marine diatom

DEFF Research Database (Denmark)

Bergkvist, Johanna; Thor, Peter; Jakobsen, Hans Henrik

2012-01-01

. marinoi was exposed to chemical cues from caged A. tonsa without physical contact with the responding cells. The reductions in chain length significantly reduced copepod grazing; grazing rates on chains (four cells or more) were several times higher compared to that of single cells. This suggests...... that chain length plasticity is a means for S. marinoi to reduce copepod grazing. In contrast, chain length was not suppressed in cultures exposed to the microzooplankton grazer Gyrodinium dominans. Size-selective predation may have played a key role in the evolution of chain formation and chain length...... plasticity in diatoms...

Contributions of Pakistan in the IAEA/RCA/UNDP regional project on management of marine coastal environment and its pollution

International Nuclear Information System (INIS)

Qureshi, R.M.; Mashiatullah, A.; Fazil, M.; Ahmad, E.; Tasneem, M.A.; Khan, H.A.; Sajjad, M.I.

2002-01-01

The International Atomic Energy Agency (IAEA), Vienna, launched a five years (duration: 1998 - 2002) Joint Project on 'Better Management of the Environment and Industrial Growth Through Isotope and Radiation Technology (RAS/97/030)' in co-operation with the RCA (Regional Co-operative Agreement) office, Vienna, and United Nations Development Programme (UNDP). The Marine Sub-project entitled 'Management of Marine Coastal Environment and its Pollution (RAS/8/083)' is 'Output 1.2' of this joint project. Pakistan is very actively participating in activities of the IAEA/RCA/UNDP Marine Sub-Project that were planned in two Project Formulation Meetings (PFMs) held at Manila, Philippines, during 1998. In Pakistan, various activities of the national marine pollution project are being administered by the nuclear institute namely, Pakistan Institute of Nuclear Science and Technology (PINSTECH), in collaboration with national end user institutions. To-date, Pakistan has significantly contributed in this project, both at national level and at RCA regional level. This paper highlights the progress and some accomplishments of Pakistan, up to the year 2001, for marine pollution studies related to the IAEA/RCA regional marine sub project. (author)

Biological Soil Crusts from Coastal Dunes at the Baltic Sea: Cyanobacterial and Algal Biodiversity and Related Soil Properties.

Science.gov (United States)

Schulz, Karoline; Mikhailyuk, Tatiana; Dreßler, Mirko; Leinweber, Peter; Karsten, Ulf

2016-01-01

Biological soil crusts (BSCs) are known as "ecosystem-engineers" that have important, multifunctional ecological roles in primary production, in nutrient and hydrological cycles, and in stabilization of soils. These communities, however, are almost unstudied in coastal dunes of the temperate zone. Hence, for the first time, the biodiversity of cyanobacterial and algal dominated BSCs collected in five dunes from the southern Baltic Sea coast on the islands Rügen and Usedom (Germany) was investigated in connection with physicochemical soil parameters. The species composition of cyanobacteria and algae was identified with direct determination of crust subsamples, cultural methods, and diatom slides. To investigate the influence of soil properties on species composition, the texture, pH, electrical conductivity, carbonate content, total contents of carbon, nitrogen, phosphorus, and the bioavailable phosphorus-fraction (PO4 (3-)) were analyzed in adjacent BSC-free surface soils at each study site. The data indicate that BSCs in coastal dunes of the southern Baltic Sea represent an ecologically important vegetation form with a surprisingly high site-specific diversity of 19 cyanobacteria, 51 non-diatom algae, and 55 diatoms. All dominant species of the genera Coleofasciculus, Lyngbya, Microcoleus, Nostoc, Hydrocoryne, Leptolyngbya, Klebsormidium, and Lobochlamys are typical aero-terrestrial cyanobacteria and algae, respectively. This first study of coastal sand dunes in the Baltic region provides compelling evidence that here the BSCs were dominated by cyanobacteria, algae, or a mixture of both. Among the physicochemical soil properties, the total phosphorus content of the BSC-free sand was the only factor that significantly influenced the cyanobacterial and algal community structure of BSCs in coastal dunes.

Sampler collection gadget for epilithic diatoms

Directory of Open Access Journals (Sweden)

SE. Salomoni

Full Text Available This work present a new gadget for sampling epilithic diatoms from both lentic and lotic enviroments. The sampler consists of a polystyrene cylinder, left to float on the surface of the water, to which stone substrates are attached. This epilithic diatom sampler (EDS can be used to detect spatial and temporal richness and density variation in the study of the diatom community, as well as in water quality monitoring.

Environmental impact of industrial wastes on marine area, case study: Port Sudan coastal area

International Nuclear Information System (INIS)

Abdalrahman, E. A. H.

2004-05-01

This study was carried out to determine the effect of the industrial wastes on marine environment in Port Sudan area. A very intensive study has been made to identify types of pollutions drained in seawater at study area of Red Sea coast. Samples were taken from three stations (1, 2 and 3) at study area and the following analysis were made: Temperature, salinity, hydrogen ion concentration, dissolved oxygen, biochemical oxygen demand, nutrient, oil and grease. The laboratory results revealed that wastes pollute the marine environment as the cooling water from studied industries which is drain into the seawater increases the degree of temperature approximately from 6 to 12 C degree above the allowed rate, the matter which was adverse effect on the environment and living marine creatures due to the sudden change of temperature degree. Also, it was found that the great amount of oil spills discharged into seawater due to many factors such as: cooling water, oil spills from ships and loading and discharging operations of crude oil ships. Accordingly these oils spills might have a deadly effect on living marine creatures, which have been mention in details through out this research. Hence, and to minimize this adverse effect of industrial wastes and others on the marine environment, may recommend to the following: Pretreatment to the industrial wastes should be taking before its draining into the Red Sea coastal area. Surveillance all ships into the port and observing loading and discharging operations as well as those ships in the regional waters and implementing the international maritime laws. Enlightenment the industrial administrators and manpower working with them about the severity which will definitely cause the marine environmental deterioration as a result of industrial wastes. To punish every one who violates the laws of environment protection. Thus, can be safeguarding the environment from pollutions and consequently develop the natural resources and proceed

A study of copper, lead and cadmium speciation in some estuarine and coastal marine waters

Energy Technology Data Exchange (ETDEWEB)

Batley, G E; Gardner, D

1978-07-01

The significance of the measured changes in heavy metal distribution for different sampled environments was ascertained. The potential of a heavy metal speciation scheme to reflect differences in marine metal distributions was evaluated in a study of soluble copper, lead, and cadmium speciation in water samples from Port Hacking Estuary and one coastal Pacific station in Australia. In all samples, the percentages of metals associated with colloidal matter were high40-60% of total copper, 45-75% of total lead, and 15-35% of total cadmium. (1 map, 26 references, 4 tables)

Toxic Diatom Aldehydes Affect Defence Gene Networks in Sea Urchins.

Directory of Open Access Journals (Sweden)

Stefano Varrella

Full Text Available Marine organisms possess a series of cellular strategies to counteract the negative effects of toxic compounds, including the massive reorganization of gene expression networks. Here we report the modulated dose-dependent response of activated genes by diatom polyunsaturated aldehydes (PUAs in the sea urchin Paracentrotus lividus. PUAs are secondary metabolites deriving from the oxidation of fatty acids, inducing deleterious effects on the reproduction and development of planktonic and benthic organisms that feed on these unicellular algae and with anti-cancer activity. Our previous results showed that PUAs target several genes, implicated in different functional processes in this sea urchin. Using interactomic Ingenuity Pathway Analysis we now show that the genes targeted by PUAs are correlated with four HUB genes, NF-κB, p53, δ-2-catenin and HIF1A, which have not been previously reported for P. lividus. We propose a working model describing hypothetical pathways potentially involved in toxic aldehyde stress response in sea urchins. This represents the first report on gene networks affected by PUAs, opening new perspectives in understanding the cellular mechanisms underlying the response of benthic organisms to diatom exposure.

Intrinsic bioremediation potential of a chronically polluted marine coastal area.

Science.gov (United States)

Catania, Valentina; Santisi, Santina; Signa, Geraldina; Vizzini, Salvatrice; Mazzola, Antonio; Cappello, Simone; Yakimov, Michail M; Quatrini, Paola

2015-10-15

A microbiological survey of the Priolo Bay (eastern coast of Sicily, Ionian Sea), a chronically polluted marine coastal area, was carried out in order to discern its intrinsic bioremediation potential. Microbiological analysis, 16S rDNA-based DGGE fingerprinting and PLFAs analysis were performed on seawater and sediment samples from six stations on two transects. Higher diversity and variability among stations was detected by DGGE in sediment than in water samples although seawater revealed higher diversity of culturable hydrocarbon-degrading bacteria. The most polluted sediment hosted higher total bacterial diversity and higher abundance and diversity of culturable HC degraders. Alkane- and PAH-degrading bacteria were isolated from all stations and assigned to Alcanivorax, Marinobacter, Thalassospira, Alteromonas and Oleibacter (first isolation from the Mediterranean area). High total microbial diversity associated to a large selection of HC degraders is believed to contribute to natural attenuation of the area, provided that new contaminant contributions are avoided. Copyright © 2015 Elsevier Ltd. All rights reserved.

Intraseasonal patterns in coastal plankton biomass off central Chile derived from satellite observations and a biochemical model

Science.gov (United States)

Gomez, Fabian A.; Spitz, Yvette H.; Batchelder, Harold P.; Correa-Ramirez, Marco A.

2017-10-01

Subseasonal (5-130 days) environmental variability can strongly affect plankton dynamics, but is often overlooked in marine ecology studies. We documented the main subseasonal patterns of plankton biomass in the coastal upwelling system off central Chile, the southern part of the Humboldt System. Subseasonal variability was extracted from temporal patterns in satellite data of wind stress, sea surface temperature, and chlorophyll from the period 2003-2011, and from a realistically forced eddy-resolving physical-biochemical model from 2003 to 2008. Although most of the wind variability occurs at submonthly frequencies (< 30 days), we found that the dominant subseasonal pattern of phytoplankton biomass is within the intraseasonal band (30-90 days). The strongest intraseasonal coupling between wind and plankton is in spring-summer, when increased solar radiation enhances the phytoplankton response to upwelling. Biochemical model outputs show intraseasonal shifts in plankton community structure, mainly associated with the large fluctuations in diatom biomass. Diatom biomass peaks near surface during strong upwelling, whereas small phytoplankton biomass peaks at subsurface depths during relaxation or downwelling periods. Strong intraseasonally forced changes in biomass and species composition could strongly impact trophodynamics connections in the ecosystem, including the recruitment of commercially important fish species such as common sardine and anchovy. The wind-driven variability of chlorophyll concentration was connected to mid- and high-latitude atmospheric anomalies, which resemble disturbances with frequencies similar to the tropical Madden-Julian Oscillation.

THE INNOVATIVE POLICY OPTIONS FOR COASTAL FISHERIES ECONOMIC DEVELOPMENT: A CASE OF KWANDANG BAY COASTAL ECOSYSTEM

Directory of Open Access Journals (Sweden)

Noel Taylor Moore

2017-07-01

Full Text Available Socio-environmental problems, such as climate change, pollution and habitat destruction, present serious challenges for fisheries economic development. The integration of interventions or investments within a coastal marine ecosystem, a defined spatial area, is considered important in the economic development of local communities leading to the planned outcomes of livelihoods, food security and conservation The coastal marine ecosystem, is the provider of products and services to the local economy adjacent to the ecosystem where the benefit flows, within that area, are interconnected. The roles of science, technology and innovation (STI are an integral part of these multi-dimensional interventions. Hence the need for an integrated approach for these interventions by government and/or through donor funded projects to enhance economic development of coastal communities. The policy framework proposed is therefore an STI perspective of the links between these intervention and investment options, based on a ‘fisheries economic development Hub’ (Hub and discussed using the multi-level perspective (MLP. The policy innovation proposal suggests an implementation strategy of a pilot project and analyses the selection and implications of a potential Indonesian site for the application of the Hub. This paper aims to introduce the MLP into the framework of coastal community-based fisheries economic development.   Key words: policy innovation. coastal marine ecosystem, fisheries economic development Hub, value chains, multi-level perspective (MLP

Vertical activity distribution of dissimilatory nitrate reduction in coastal marine sediments

DEFF Research Database (Denmark)

Behrendt, A.; de Beer, D.; Stief, P.

2013-01-01

The relative importance of two dissimilatory nitrate reduction pathways, denitrification (DEN) and dissimilatory nitrate reduction to ammonium (DNRA), was investigated in intact sediment cores from five different coastal marine field sites (Dorum, Aarhus Bight, Mississippi Delta, Limfjord...... reduction was clearly dominated by DEN (59-131% of the total NO3- reduced) rather than by DNRA, irrespective of the sedimentary inventories of electron donors such as organic carbon, sulfide, and iron. Highest ammonium production via DNRA, accounting for up to 8.9% of the total NO3- reduced, was found...... was detected accounting for 37-77% of the total NO3- reduced. These contradictory results might be explained by enhanced NO3- availability for DNRA bacteria in the sediment slurries compared to the core-incubated sediments in which diffusion of NO3- from the water column may only reach DEN bacteria...

Primary versus secondary and anthropogenic versus natural sources of aminium ions in atmospheric particles during nine coastal and marine campaigns

Science.gov (United States)

Xie, H.; Yao, X.

2017-12-01

In this study, size-segregated dimethylaminium (DMA+) and trimethylaminium (TMA+) in atmospheric particles were measured during four coastal campaigns in Qingdao, China and five campaigns cruising over marginal seas of China and the northwest Pacific Ocean. The measured averages of DMA+ and TMA+ in PM0.056-10 (the sum of chemical concentrations from 0.056 to 10 µm) during each campaign, ranged from 0.045 to 1.1 nmol m-3 and from 0.029 to 0.53 nmol m-3, respectively. Size distributions of DMA+ and TMA+ in coastal atmospheric particles suggested that primary combustion emissions featured by mass median aerodynamic diameter (MMAD) at 0.2 µm generally yielded appreciable contributions to their observed concentrations in PM0.056-10 and sometimes dominantly contributed. In the marine atmospheres, the 0.1-0.2 µm modes of DMA+ and TMA+ also existed and sometimes dominated while they were very likely derived from primary ocean-biogenic emissions. In most of the samples during nine campaigns, secondarily-formed DMA+ and TMA+ in droplet mode with MMAD at 0.3-2 µm dominantly contributed to DMA+ and TMA+ in PM0.056-10. Overall, our results suggested that DMA+ and TMA+ in the marine atmospheric particles overwhelmingly came from ocean biogenic sources while they were likely derived from complicated anthropogenic and natural sources at the coastal sites.

Colloquium on diatom-copepod interactions

DEFF Research Database (Denmark)

Paffenhofer, G.A.; Ianora, A.; Miralto, A.

2005-01-01

in situ were also addressed. During the plenary session, the most recent advances on this topic were presented. The plenary session was followed by 3 working groups on (1) production of aldehydes by phytoplankton, (2) toxic and nutritional effects of diatoms on zooplankton, and (3) the chemistry of diatom...

Controlling dynamics in diatomic systems

Indian Academy of Sciences (India)

WINTEC

Abstract. Controlling molecular energetics using laser pulses is exemplified for nuclear motion in two different diatomic systems. The problem of finding the optimized field for maximizing a desired quantum dynamical target is formulated using an iterative method. The method is applied for two diatomic sys- tems, HF and OH.

Spread, Behavior, and Ecosystem Consequences of Conventional Munitions Compounds in Coastal Marine Waters

Directory of Open Access Journals (Sweden)

Aaron J. Beck

2018-04-01

Full Text Available Coastal marine environments are contaminated globally with a vast quantity of unexploded ordnance and munitions from intentional disposal. These munitions contain organic explosive compounds as well as a variety of metals, and represent point sources of chemical pollution to marine waters. Most underwater munitions originate from World Wars at the beginning of the twentieth century, and metal munitions housings have been impacted by extensive corrosion over the course of the following decades. As a result, the risk of munitions-related contaminant release to the water column is increasing. The behavior of munitions compounds is well-characterized in terrestrial systems and groundwater, but is only poorly understood in marine systems. Organic explosive compounds, primarily nitroaromatics and nitramines, can be degraded or transformed by a variety of biotic and abiotic mechanisms. These reaction products exhibit a range in biogeochemical characteristics such as sorption by particles and sediments, and variable environmental behavior as a result. The reaction products often exhibit increased toxicity to biological receptors and geochemical controls like sorption can limit this exposure. Environmental samples typically show low concentrations of munitions compounds in water and sediments (on the order of ng/L and μg/kg, respectively, and ecological risk appears generally low. Nonetheless, recent work demonstrates the possibility of sub-lethal genetic and metabolic effects. This review evaluates the state of knowledge on the occurrence, fate, and effect of munition-related chemical contaminants in the marine environment. There remain a number of knowledge gaps that limit our understanding of munitions-related contaminant spread and effect, and the need for additional work is made all the more urgent by increasing risk of release to the environment.

The hidden seasonality of the rare biosphere in coastal marine bacterioplankton

KAUST Repository

Alonso-Sáez, Laura

2015-04-08

Summary: Rare microbial taxa are increasingly recognized to play key ecological roles, but knowledge of their spatio-temporal dynamics is lacking. In a time-series study in coastal waters, we detected 83 bacterial lineages with significant seasonality, including environmentally relevant taxa where little ecological information was available. For example, Verrucomicrobia had recurrent maxima in summer, while the Flavobacteria NS4, NS5 and NS2b clades had contrasting seasonal niches. Among the seasonal taxa, only 4 were abundant and persistent, 20 cycled between rare and abundant and, remarkably, most of them (59) were always rare (contributing <1% of total reads). We thus demonstrate that seasonal patterns in marine bacterioplankton are largely driven by lineages that never sustain abundant populations. A fewer number of rare taxa (20) also produced episodic \\'blooms\\', and these events were highly synchronized, mostly occurring on a single month. The recurrent seasonal growth and loss of rare bacteria opens new perspectives on the temporal dynamics of the rare biosphere, hitherto mainly characterized by dormancy and episodes of \\'boom and bust\\', as envisioned by the seed-bank hypothesis. The predictable patterns of seasonal reoccurrence are relevant for understanding the ecology of rare bacteria, which may include key players for the functioning of marine ecosystems. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

Variation partitioning of diatom species data matrices: Understanding the influence of multiple factors on benthic diatom communities in tropical streams

Energy Technology Data Exchange (ETDEWEB)

Bere, Taurai, E-mail: tbere2015@gmail.com; Mangadze, Tinotenda; Mwedzi, Tongai

2016-10-01

Elucidating the confounding influence of multiple environmental factors on benthic diatom communities is important in developing water quality predictive models for better guidance of stream management efforts. The objective of this study was to explore the relative impact of metal pollution and hydromorphological alterations in, addition to nutrient enrichment and organic pollution, on diatom taxonomic composition with the view to improve stream diatom-based water quality inference models. Samples were collected twice at 20 sampling stations in the tropical Manyame Catchment, Zimbabwe. Diatom, macroinvertebrate communities and environmental factors were sampled and analysed. The variations in diatom community composition explained by different categories of environmental factors were analysed using canonical correspondence analysis using variance partitioning (partial CCA). The following variations were explained by the different predictor matrices: nutrient levels and organic pollution - 10.4%, metal pollution - 8.3% and hydromorphological factors - 7.9%. Thus, factors other than nutrient levels and organic pollution explain additional significant variation in these diatom communities. Development of diatom-based stream water quality inference models that incorporate metal pollution and hydromorphological alterations, where these are key issues, is thus deemed necessary. - Highlights: • Confounding influences of multiple environmental factors on diatom communities are elucidated. • Variation explained: nutrients + organic pollution - 10.4%, metals - 8.3% and hydromorphological factors - 7.9%. • Calibration of existing or development of new indices may be necessary.

Variation partitioning of diatom species data matrices: Understanding the influence of multiple factors on benthic diatom communities in tropical streams

International Nuclear Information System (INIS)

Bere, Taurai; Mangadze, Tinotenda; Mwedzi, Tongai

2016-01-01

Elucidating the confounding influence of multiple environmental factors on benthic diatom communities is important in developing water quality predictive models for better guidance of stream management efforts. The objective of this study was to explore the relative impact of metal pollution and hydromorphological alterations in, addition to nutrient enrichment and organic pollution, on diatom taxonomic composition with the view to improve stream diatom-based water quality inference models. Samples were collected twice at 20 sampling stations in the tropical Manyame Catchment, Zimbabwe. Diatom, macroinvertebrate communities and environmental factors were sampled and analysed. The variations in diatom community composition explained by different categories of environmental factors were analysed using canonical correspondence analysis using variance partitioning (partial CCA). The following variations were explained by the different predictor matrices: nutrient levels and organic pollution - 10.4%, metal pollution - 8.3% and hydromorphological factors - 7.9%. Thus, factors other than nutrient levels and organic pollution explain additional significant variation in these diatom communities. Development of diatom-based stream water quality inference models that incorporate metal pollution and hydromorphological alterations, where these are key issues, is thus deemed necessary. - Highlights: • Confounding influences of multiple environmental factors on diatom communities are elucidated. • Variation explained: nutrients + organic pollution - 10.4%, metals - 8.3% and hydromorphological factors - 7.9%. • Calibration of existing or development of new indices may be necessary.

NODC Standard Format Marine Birds from Coastal Alaska and Puget Sound Data (1974-1982): Migratory Sea Bird Watch (F038) (NODC Accession 0014158)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Migratory Sea Bird Watch (F038) is one of a group of seven datasets related to Marine Birds from Coastal Alaska and Puget Sound Data (1974 -1982). Each dataset uses...

Are sunscreens a new environmental risk associated with coastal tourism?

Science.gov (United States)

Sánchez-Quiles, David; Tovar-Sánchez, Antonio

2015-10-01

The world coastal-zone population and coastal tourism are expected to grow during this century. Associated with that, there will be an increase in the use of sunscreens and cosmetics with UV-filters in their formulation, which will make coastal regions worldwide susceptible to the impact of these cosmetics. Recent investigations indicate that organic and inorganic UV-filters, as well as many other components that are constituents of the sunscreens, reach the marine environment--directly as a consequence of water recreational activities and/or indirectly from wastewater treatment plants (WWTP) effluents. Toxicity of organic and inorganic UV filters has been demonstrated in aquatic organism. UV-filters inhibit growth in marine phytoplankton and tend to bioaccumulate in the food webs. These findings together with coastal tourism data records highlight the potential risk that the increasing use of these cosmetics would have in coastal marine areas. Nevertheless, future investigations into distribution, residence time, aging, partitioning and speciation of their main components and by-products in the water column, persistence, accumulation and toxicity in the trophic chain, are needed to understand the magnitude and real impact of these emerging pollutants in the marine system. Copyright © 2015 Elsevier Ltd. All rights reserved.

226Ra chronology of a coastal marine sediment

International Nuclear Information System (INIS)

Koide, M.; Bruland, K.; Goldberg, E.D.

1976-01-01

Unsupported 226 Ra (tsub (1/2) = 1620 years) in marine sediments can provide a basis for measuring rates of accumulation of the order of centimeters per thousand years. The excess radium apparently enters the sediments incorporated in phytoplankton. The sensitivity of the method depends upon the initial value of the unsupported 226 Ra and of the value of 230 Th, a parent of 226 Ra, in the sedimentary components. 226 Ra dating was applied to a sediment taken from the slope of the San Clemente Basin in the Southern California coastal region. Rates of sedimentation over two half-lives of the nuclide were found to be either 5.2 or 5.3 cm/1000 years depending upon which of two models for the geochronology is used. One model assumes that the 230 Th brings to the deposit an amount of 226 Ra in equilibrium with it. The other is based upon the growth of the 226 Ra from the 230 Th in the sedimentary components. 238+239 Pu and 210 Pb levels in the upper strata indicated sedimentation rates of the order of 100-500 cm/1000 years, i.e. much faster accumulations. It is suggested that these derived rates are spurious and reflect bioturbative activities of surface-living organisms. (Auth.)

Cell volumes of marine phytoplankton from globally distributed coastal data sets

Digital Repository Service at National Institute of Oceanography (India)

Harrison, P.J; Zingone, A.; Mickelson, M.J; Lehtinen, S.; Ramaiah, N.; Kraberg, A.C; Sun, J; McQuatters-Gollop, A.; Jakobsen, H.H.

volumes are the single largest source of uncertainty in community phytoplankton carbon estimates and greatly exceeds the uncertainty associated with the different volume to carbon estimates. Small diatoms have 10 times more carbon density than large...

Diatom genomics: genetic acquisitions and mergers.

Science.gov (United States)

Nisbet, R Ellen R; Kilian, Oliver; McFadden, Geoffrey I

2004-12-29

Diatom algae arose by two-step endosymbiosis. The complete genome of the diatom Thalassiosira pseudonana has now been sequenced, allowing us to reconstruct the remarkable intracellular gene transfers that occurred during this convoluted cellular evolution.

Observed and projected impacts of climate change on marine fisheries, aquaculture, coastal tourism, and human health: an update

Directory of Open Access Journals (Sweden)

Lauren V Weatherdon

2016-04-01

Full Text Available The Intergovernmental Panel on Climate Change (IPCC Fifth Assessment Report (AR5 states that climate change and ocean acidification are altering the oceans at a rate that is unprecedented compared with the recent past, leading to multifaceted impacts on marine ecosystems, associated goods and services, and human societies. AR5 underlined key uncertainties that remain regarding how synergistic changes in the ocean are likely to affect human systems, and how humans are likely to respond to these events. As climate change research has accelerated rapidly following AR5, an updated synthesis of available knowledge is necessary to identify emerging evidence, and to thereby better inform policy discussions. This paper reviews the literature to capture corroborating, conflicting, and novel findings published following the cut-off date for contribution to AR5. Specifically, we highlight key scientific developments on the impacts of climate-induced changes in the ocean on key socioeconomic sectors, including fisheries, aquaculture and tourism. New evidence continues to support a climate-induced redistribution of benefits and losses at multiple scales and across coastal and marine socio-ecological systems, partly resulting from species and ecosystem range shifts and changes in primary productivity. New efforts have been made to characterize and value ecosystem services in the context of climate change, with specific relevance to ecosystem-based adaptation. Recent studies have also explored synergistic interactions between climatic drivers, and have found strong variability between impacts on species at different life stages. Although climate change may improve conditions for some types of freshwater aquaculture, potentially providing alternative opportunities to adapt to impacts on wild capture fisheries, ocean acidification poses a risk to shellfish fisheries and aquaculture. The risk of increased prevalence of disease under warmer temperatures is

Marine Phytophthora species can hamper conservation and restoration of vegetated coastal ecosystems.

Science.gov (United States)

Govers, Laura L; Man In 't Veld, Willem A; Meffert, Johan P; Bouma, Tjeerd J; van Rijswick, Patricia C J; Heusinkveld, Jannes H T; Orth, Robert J; van Katwijk, Marieke M; van der Heide, Tjisse

2016-08-31

Phytophthora species are potent pathogens that can devastate terrestrial plants, causing billions of dollars of damage yearly to agricultural crops and harming fragile ecosystems worldwide. Yet, virtually nothing is known about the distribution and pathogenicity of their marine relatives. This is surprising, as marine plants form vital habitats in coastal zones worldwide (i.e. mangrove forests, salt marshes, seagrass beds), and disease may be an important bottleneck for the conservation and restoration of these rapidly declining ecosystems. We are the first to report on widespread infection of Phytophthora and Halophytophthora species on a common seagrass species, Zostera marina (eelgrass), across the northern Atlantic and Mediterranean. In addition, we tested the effects of Halophytophthora sp. Zostera and Phytophthora gemini on Z. marina seed germination in a full-factorial laboratory experiment under various environmental conditions. Results suggest that Phytophthora species are widespread as we found these oomycetes in eelgrass beds in six countries across the North Atlantic and Mediterranean. Infection by Halophytophthora sp. Zostera, P. gemini, or both, strongly affected sexual reproduction by reducing seed germination sixfold. Our findings have important implications for seagrass ecology, because these putative pathogens probably negatively affect ecosystem functioning, as well as current restoration and conservation efforts. © 2016 The Author(s).

Picocyanobacteria Dominance in Deep Biomass Layers: Relation to Diatom Presence and Episodic Events.

Science.gov (United States)

Aguilar, C.; Cuhel, R. L.

2016-02-01

In Offshore Marine and Large Lake Waters, most of the biomass and the productivity of phytoplankton occur below surface observation capabilities. Sub-mixed layer phytoplankton populations develop, increase, persist, and decay in relation to physical structure such as pycnocline density gradients interacting with progressively changing light fields. Basin-scale meteorological events and persistence of major invasive species have also left marks on biogeochemical cycling and ecosystem function in Lake Michigan. Among the former are precipitation and turbulence alterations brought on by unusual winter ice cover and a century-scale flood during 2008. Dampened seasonal silicate cycling indicated a basin-wide reduction of diatom production following mussel establishment. Communities in Lake Michigan shifted from diatom and big cell-dominated to small cell picocyanobacteria-dominated phytoplankton. Picocyanobacteria were beneficiaries of profound oligotrophication of the ecosystem starting in 2003. Photosynthetic parameters of pre-2003 Deep Biomass populations dominated by diatoms were systematically different from the cyanobacterial epoch following quagga mussel establishment and increase in depth of 1% incident light to 50-60m. Deep cyanobacterial production has now often been on the same scale as overlying waters. Photophysiology changes in a smooth depth gradient in this clear water as opposed to previous abrupt transition to shade adaptation. Among these many physicochemical permutations, community structure has consistently been a tradeoff between diatoms and picocyanobacteria. Opposing fluctuations of biomass favor one or the other on seasonal time frames of sequential years, with a complete system reset between each (winter mixing). For the Great Flood example, diatom surface blooms increased light extinction and drove the deep biomass maximum up - as populations settled into the pycnocline they had already outcompeted the picocyanobacteria. The opposite was true

Marine mammals and contaminants in the diet of coastal feeding ...

African Journals Online (AJOL)

contamination resulting from diatom blooms (Scholin et al. 2000). Recent reproductive failures of reintroduced ... one condor population, birds released in the Ventana Wilderness area of central California, feeds on sea ... Although birds in that population have been mature enough to breed for the past 3-4 years (the oldest ...

Coupled states approximation for scattering of two diatoms

International Nuclear Information System (INIS)

Heil, T.G.; Green, S.; Kouri, D.J.

1978-01-01

The coupled states (CS) approximation is developed in detail for the general case of two colliding diatomic molecules. The high energy limit of the exact Lippmann-Schwinger equation is used to obtain the CS equations so that the sufficiency conditions of Kouri, Heil, and Shimoni apply. In addition, care is taken to ensure correct treatment of parity in the CS, as well as correct labeling of the CS by an effective orbital angular momentum. The analysis follows that given by Shimoni and Kouri for atom-diatom collisions where the coupled rotor angular momentum j 12 and projection lambda 12 replace the single diatom angular momentum j and projection lambda. The result is an expression for the differential scattering amplitude which is a generalization of the highly successful McGuire-Kouri differential scattering amplitude for atom-diatom collisions. Also, the opacity function is found to be a generalization of the Clebsch-Gordon weight atom-diatom expression of Shimoni and Kouri. The diatom-diatom CS body frame T matrix T/sup J/(j 1 'j 2 'j 12 'lambda 12 'vertical-bar j 1 j 2 j 12 lambda 12 ) is also found to be nondiagonal in lambda' 12 ,lambda 12 , just as in the atom-diatom case. The parity and identical molecule interchange symmetries are also considered in detail in both the exact close coupling and CS approximations. Symmetrized expressions for all relevant quantities are obtained, along with the symmetrized coupled equations one must solve. The properly labeled and symmetrized CS equations have not been derived before this present work. The present correctly labeled CS theory is tested computationally by applications to three different diatom-diatom potentials. First we carry out calculations for para-para, ortho-ortho, and ortho-para H 2 -H 2 collisions using the experimental potential of Farrar and Lee

The Behavior of Environmentally Friendly Corrosion Preventative Compounds in an Aggressive Coastal Marine Environment

Science.gov (United States)

Montgomery, Eliza L.; Calle, Luz Marina; Curran Jerome C.; Kolody, Mark R.

2013-01-01

The shift to use environmentally friendly technologies throughout future space-related launch programs prompted a study aimed at replacing current petroleum and solvent-based Corrosion Preventive Compounds (CPCs) with environmentally friendly alternatives. The work in this paper focused on the identification and evaluation of environmentally friendly CPCs for use in protecting flight hardware and ground support equipment from atmospheric corrosion. The CPCs, while a temporary protective coating, must survive in the aggressive coastal marine environment that exists throughout the Kennedy Space Center, Florida. The different protection behaviors of fifteen different soft film CPCs, both common petroleum-based and newer environmentally friendly types, were evaluated on various steel and aluminum substrates. The CPC and substrate systems were subjected to atmospheric testing at the Kennedy Space Center's Beachside Atmospheric Corrosion Test Site, as well as cyclic accelerated corrosion testing. Each CPC also underwent physical characterization and launch-related compatibility testing . The initial results for the fifteen CPC systems are reported : Key words: corrosion preventive compound, CPC, spaceport, environmentally friendly, atmospheric exposure, marine, carbon steel, aluminum alloy, galvanic corrosion, wire on bolt.

Speciated mercury at marine, coastal, and inland sites in New England – Part 1: Temporal variability

Directory of Open Access Journals (Sweden)

H. Mao

2012-06-01

Full Text Available A comprehensive analysis was conducted using long-term continuous measurements of gaseous elemental mercury (Hg⁰, reactive gaseous mercury (RGM, and particulate phase mercury (Hg^P at coastal (Thompson Farm, denoted as TF, marine (Appledore Island, denoted as AI, and elevated inland (Pac Monadnock, denoted as PM sites from the AIRMAP Observatories in southern New Hampshire, USA. Decreasing trends in background Hg⁰ were identified in the 7.5- and 5.5-yr records at TF and PM with decline rates of 3.3 parts per quadrillion by volume (ppqv yr⁻¹ and 6.3 ppqv yr⁻¹, respectively. Common characteristics at these sites were the reproducible annual cycle of Hg⁰ with its maximum in winter-spring and minimum in fall, comprised of a positive trend in the warm season (spring – early fall and a negative one in the cool season (late fall – winter. Year-to-year variability was observed in the warm season decline in Hg⁰ at TF varying from a minimum total (complete seasonal loss of 43 ppqv in 2009 to a maximum of 92 ppqv in 2005, whereas variability remained small at AI and PM. The coastal site TF differed from the other two sites with its exceptionally low levels (as low as below 50 ppqv in the nocturnal inversion layer possibly due to dissolution in dew water. Measurements of Hg⁰ at PM exhibited the smallest diurnal to annual variability among the three environments, where peak levels rarely exceeded 250 ppqv and the minimum was typically 100 ppqv. It should be noted that summertime diurnal patterns at TF and AI were opposite in phase indicating strong sink(s for Hg⁰ during the day in the marine boundary layer, which was consistent with the hypothesis of Hg⁰ oxidation by halogen radicals there. Mixing ratios of RGM in the coastal and marine boundary layers reached annual maxima in spring and minima in fall, whereas at PM levels were generally

Anaerobic Methane-Oxidizing Microbial Community in a Coastal Marine Sediment: Anaerobic Methanotrophy Dominated by ANME-3.

Science.gov (United States)

Bhattarai, Susma; Cassarini, Chiara; Gonzalez-Gil, Graciela; Egger, Matthias; Slomp, Caroline P; Zhang, Yu; Esposito, Giovanni; Lens, Piet N L

2017-10-01

The microbial community inhabiting the shallow sulfate-methane transition zone in coastal sediments from marine Lake Grevelingen (The Netherlands) was characterized, and the ability of the microorganisms to carry out anaerobic oxidation of methane coupled to sulfate reduction was assessed in activity tests. In vitro activity tests of the sediment with methane and sulfate demonstrated sulfide production coupled to the simultaneous consumption of sulfate and methane at approximately equimolar ratios over a period of 150 days. The maximum sulfate reduction rate was 5 μmol sulfate per gram dry weight per day during the incubation period. Diverse archaeal and bacterial clades were retrieved from the sediment with the majority of them clustered with Euryarchaeota, Thaumarcheota, Bacteroidetes, and Proteobacteria. The 16S rRNA gene sequence analysis showed that the sediment from marine Lake Grevelingen contained anaerobic methanotrophic Archaea (ANME) and methanogens as archaeal clades with a role in the methane cycling. ANME at the studied site mainly belong to the ANME-3 clade. This study provides one of the few reports for the presence of ANME-3 in a shallow coastal sediment. Sulfate-reducing bacteria from Desulfobulbus clades were found among the sulfate reducers, however, with very low relative abundance. Desulfobulbus has previously been commonly found associated with ANME, whereas in our study, ANME-3 and Desulfobulbus were not observed simultaneously in clusters, suggesting the possibility of independent AOM by ANME-3.

Marine environmental assessment in the Black Sea region- a case for the Turkish coastal zone

International Nuclear Information System (INIS)

Goektepe, G G.; Koeksal, G.; Osvath, I.

2001-01-01

'Marine Environmental Assessment of the Black Sea Region' Technical Cooperation Project, implemented by the International Atomic Energy Agency (IAEA) is presented. Environmental problems of the Black Sea eco-system and the current international efforts with regard to prevention of pollution are discussed. General aspects of the project are presented. A joint monitoring program initiated according to the work plan of the project among six Black Sea countries is outlined with emphasis on the monitoring program for the Turkish coastal zone. Concluding remarks are on the vital importance of sharing the scientific responsibility on the trans-boundary environmental problems

Effects of organic pollution on biological communities of marine biofilm on hard substrata

International Nuclear Information System (INIS)

Sanz-Lázaro, C.; Fodelianakis, S.; Guerrero-Meseguer, L.; Marín, A.; Karakassis, I.

2015-01-01

We examined the effect of organic enrichment on diatom and bacterial assemblages of marine epilithic biofilms on two locations in the Mediterranean, one situated in Spain and the other in Greece. Total organic carbon, total organic nitrogen, stable isotopes (δ 13 C and δ 15 N) and chlorophyll a indicated significant incorporation of organic wastes, increased primary production and trophic niche modifications on the biofilms close to the organic enrichment source. In Spain, where the organic load was higher than in Greece, diatom and, to some extent, bacterial assemblages varied following the organic enrichment gradient. The taxonomic richness of diatom and bacterial communities was not influenced by organic enrichment. Classical community parameters showed consistent patterns to organic pollution in both locations, whereas community assemblages were only influenced when organic pollution was greatest. The successional patterns of these communities were similar to other epilithic communities. The modification of community assemblages induced by organic pollution may affect ecological functions. - Highlights: • We examined the effect of organic enrichment on assemblages of marine biofilms. • Classical community parameters showed consistent patterns to organic pollution. • Diatom and bacterial assemblages were affected under high level of organic enrichment. • Successional patterns were similar to other communities inhabiting hard substrata. • Assemblage modifications induced by organic pollution may affect ecological functions. - Organic pollution modifies the assemblages of biofilm communities which may affect important ecological functions

Eco-biology of marine diatoms with emphasis on the influence of physico-chemical parameters

Digital Repository Service at National Institute of Oceanography (India)

Mitbavkar, S.

cell abundance of epipelic diatoms was high only during the morning low tide whereas in winter it was found to be the highest during the mid-morning high tide and continued to be so even during the following evening low tide. This ability... of microphytobenthos to migrate vertically within the surface sediment when their requirements are fulfilled may be considered as a form of behavioral photoacclimation, allowing cells to avoid potentially 166 damaging irradiance and temperature conditions (Kromkamp...

Cellular metabolic responses of the marine diatom Pseudo-nitzschia multiseries associated with cell wall formation.

Science.gov (United States)

Xu, Bin; Luo, Chun-Shan; Liang, Jun-Rong; Chen, Dan-Dan; Zhuo, Wen-Hao; Gao, Ya-Hui; Chen, Chang-Ping; Song, Si-Si

2014-08-01

In this study a comparative proteomics approach involving a mass spectrometric analysis of synchronized cells was employed to investigate the cellular-level metabolic mechanisms associated with siliceous cell wall formation in the pennate diatom Pseudo-nitzschia multiseries. Cultures of P. multiseries were synchronized using the silicate limitation method. Approximately 75% of cells were arrested at the G2+M phase of the cell cycle after 48 h of silicate starvation. The majority of cells progressed to new valve synthesis within 5h of silicon replenishment. We compared the proteome of P. multiseries at 0, 4, 5, and 6h of synchronization progress upon silicon replenishment using two-dimensional gel electrophoresis. Forty-eight differentially expressed protein spots were identified in abundance (greater than two-fold change; Pwall formation. The proteomic profile analysis suggests that P. multiseries most likely employs multiple synergistic biochemical mechanisms for cell wall formation. These results improve our understanding of the molecular mechanisms underlying silicon cell wall formation and enhance our understanding of the important role played by diatoms in silicon biogeochemical cycling. Copyright © 2013 Elsevier B.V. All rights reserved.

Applications of Diatoms as Potential Microalgae in Nanobiotechnology

Directory of Open Access Journals (Sweden)

Ahmad Yari Khosroushahi

2012-05-01

Full Text Available Introduction: Diatoms are single cell eukaryotic microalgae, which present in nearly every water habitat make them ideal tools for a wide range of applications such as oil explora­tion, forensic examination, environmental indication, biosilica pattern generation, toxicity testing and eutrophication of aqueous ecosystems. Methods: Essential information on diatoms were reviewed and discussed towards impacts of diatoms on biosynthesis and bioremediation. Results: In this review, we present the recent progress in this century on the application of diatoms in waste degradation, synthesis of biomaterial, biomineraliza­tion, toxicity and toxic effects of mineral elements evaluations. Conclusion: Diatoms can be considered as metal toxicity bioindicators and they can be applied for biomineralization, synthesis of biomaterials, and degradation of wastes.

High frequency monitoring of the coastal marine environment using the MAREL buoy.

Science.gov (United States)

Blain, S; Guillou, J; Tréguer, P; Woerther, P; Delauney, L; Follenfant, E; Gontier, O; Hamon, M; Leilde, B; Masson, A; Tartu, C; Vuillemin, R

2004-06-01

The MAREL Iroise data buoy provides physico-chemical measurements acquired in surface marine water in continuous and autonomous mode. The water is pumped 1.5 m from below the surface through a sampling pipe and flows through the measuring cell located in the floating structure. Technological innovations implemented inside the measuring cell atop the buoy allow a continuous cleaning of the sensor, while injection of chloride ions into the circuit prevents biological fouling. Specific sensors for temperature, salinity, oxygen and fluorescence investigated in this paper have been evaluated to guarantee measurement precision over a 3 month period. A bi-directional link under Internet TCP-IP protocols is used for data, alarms and remote-control transmissions with the land-based data centre. Herein, we present a 29 month record for 4 parameters measured using a MAREL buoy moored in a coastal environment (Iroise Sea, Brest, France). The accuracy of the data provided by the buoy is assessed by comparison with measurements of sea water weekly sampled at the same site as part of SOMLIT (Service d'Observation du Milieu LIToral), the French network for monitoring of the coastal environment. Some particular events (impact of intensive fresh water discharges, dynamics of a fast phytoplankton bloom) are also presented, demonstrating the worth of monitoring a highly variable environment with a high frequency continuous reliable system.

Stable isotopic techniques to address marine pollution: Karachi coast as a case study

International Nuclear Information System (INIS)

Ahmad, N.; Mashiatullah, A.; Javed, T.; Chaudhary, M.Z.; Fazil, M.; Khan, M.S.; Qureshi, R.M.

2011-01-01

Seawater of the coastal regions near heavily industrialized and thickly populated urbanized centers normally receive large quantities of domestic, agricultural and industrial sewage. Ocean systems generally appear to be unlimited in their ability to dilute these human discharges and industrial wastes. This limit is now being exceeded in coastal waters in the vicinity of many large industrial and heavy populated coastal zones, causing threat to marine coastal resources of these areas. Considering the increasing threats of the unplanned inventory of untreated wastes into the marine coastal environment, the strength of isotope tools (delta/sup 13/C) is used to understand the complex ecological systems in the marine coastal environment. This technique has been applied to study transport, behavior and fate of organic pollutants in marine coastal ecosystems of Karachi coast mainly as model studies. Carbon flow in heavily contaminated harbour channel (Manora Channel) , southeast and northwest coast have been investigated. The results indicate that shallow marine coastal waters tend to be depleted in /sup 13/C (TDIC) where polluted rivers through the coastal dwellings enter and get mixed with the seawater. Gradual increase in /sup 13/C (TDIC) are observed as the distance from pollution source is increased. Extremely depleted /sup 13/C/sub org/ was observed in sediment of Layari river out fall zone and Karachi fish harbor indicating input of domestic sewage through Layari river. Studies have proved that stable carbon isotope ratios of total dissolved inorganic carbon (TDIC) can be used as an effective tracer of sewage discharge and their transport in shallow marine environment. (author)

A review of the influence of biogeography, riverine linkages, and marine connectivity on fish assemblages in evolving lagoons and lakes of coastal southern Africa

CSIR Research Space (South Africa)

Whitfield, AK

2017-09-01