Phytoplankton: below the salt at the global table

1986 ◽  
Vol 60 (3) ◽  
pp. 545-554 ◽  
Author(s):  
Helen Tappan
Keyword(s):  
Marine Ecosystem ◽  
Nutrient Retention ◽  
Plant Litter ◽  
Plant Evolution ◽  
Marine Phytoplankton ◽  
Nitrogen And Phosphorus ◽  
Major Increase ◽  
Abundance And Diversity ◽  
Time Of Origin ◽  
Terrestrial Biomass

The abundance and diversity of marine phytoplankton and the geologic timing of its major innovations and extinctions show a broad but inverse relationship to stages of terrestrial plant evolution. Successively, the first appearance of land plants, and the later major increases in global live terrestrial biomass and dead biomass in the form of plant litter, peat, coal, and soil humus, increased the retention on land of carbon, nitrogen, and phosphorus, and decreased the amount of these nutrients that was transported by rivers to the seas. Each major increase in terrestrial nutrient retention resulted in extensive changes in the marine ecosystem, as it adapted to the new conditions. From its time of origin in the early Paleozoic, the terrestrial biota figuratively occupied the position at the head of the table, and only the unutilized nutrient excess trickled down to the oceanic phytoplankton and its dependent food web.

scholarly journals Bounds on Biomass Estimates and Energetic Consequences of Ctenophora in the Northeast U.S. Shelf Ecosystem

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Michael D. Ford ◽  
Jason S. Link
Keyword(s):  
Feeding Strategy ◽  
Marine Ecosystem ◽  
High Energy ◽  
Gelatinous Zooplankton ◽  
Squalus Acanthias ◽  
High Energy Density ◽  
Spiny Dogfish ◽  
Sampling Device ◽  
Large Marine Ecosystem ◽  
Major Increase

Previous descriptions have noted that the stomach samples of spiny dogfish, Squalus acanthias, showed a major increase in the overall occurrence and hence implied abundance of Ctenophora. This apparent and persistent gelatinous zooplankton outbreak is increasingly more common in the world’s oceans. We briefly explore the energetic ramifications of ctenophores in the spiny dogfish diet, inferring that the presence of gelatinous zooplankton represents an ambient feeding strategy. Relative to other prey, ctenophores are not a high energy density prey item. However, given varying assumptions of the amount of ctenophores consumed, they may be an important staple in the diet of spiny dogfish. We also examine the utility of using spiny dogfish as a gelatinous zooplankton sampling device. Using five calculation methodologies, we provide bounds on potential abundance and biomass estimates of ctenophores in the Northeast U.S. shelf ecosystem. We then contextualize these findings relative to the implications for the Northeast U.S. and any large marine ecosystem.

The effect of riparian restoration on channel complexity and soil nutrients

2017 ◽  
Vol 68 (11) ◽  
pp. 2041 ◽  
Author(s):  
J. Patrick Laceby ◽  
Nina E. Saxton ◽  
Kate Smolders ◽  
Justine Kemp ◽  
Stephen J. Faggotter ◽  
...  
Keyword(s):  
Soil Nutrients ◽  
Riparian Vegetation ◽  
Soil Nutrient ◽  
Nutrient Retention ◽  
River Channel ◽  
Channel Width ◽  
Riparian Restoration ◽  
Nitrogen And Phosphorus ◽  
Elemental Geochemistry ◽  
Channel Complexity

Restoration of riparian vegetation may reduce nutrient and sediment contamination of waterways while potentially enhancing stream channel complexity. Accordingly, the present study used a paired-site approach to investigate the effects of mature regrowth riparian vegetation on river channel morphology and soil nutrients (i.e. nitrogen and phosphorus), comparing four sites of degraded (pasture) and reforested reaches. A revised rapid assessment of riparian condition (RARC) was used to validate the site pairings. Riparian soil nutrient and elemental geochemistry were compared between paired sites, along with two parameters of channel width complexity and two for channel slope complexity. The RARC analysis confirmed the validity of the paired site design. The elemental geochemistry results indicated that underlying geology may affect the paired site analyses. Reaches with mature regrowth vegetation had greater channel width complexity but no difference in their riverbed slope complexity. In addition, degraded reaches had higher soil nutrient (i.e. nitrogen and phosphorus) concentrations, potentially indicative of the greater nutrient retention of pasture grass sites compared with mature regrowth forested reaches with less ground cover. Overall, the present study indicates that restoring mature regrowth riparian vegetation may increase river channel width complexity, although it may require canopy management to optimise the nutrient retention potential necessary to maximise the effect of riparian restoration strategies on freshwater environments.

scholarly journals A model for variable phytoplankton stoichiometry based on cell protein regulation

2013 ◽  
Vol 10 (2) ◽  
pp. 3241-3279
Author(s):  
J. A. Bonachela ◽  
S. D. Allison ◽  
A. C. Martiny ◽  
S. A. Levin
Keyword(s):  
Physiological State ◽  
Single Point ◽  
Nutrient Content ◽  
Growth Conditions ◽  
Marine Phytoplankton ◽  
Cell Protein ◽  
Nitrogen And Phosphorus ◽  
Elemental Ratios ◽  
Regulatory Processes ◽  
Complex Interactions

Abstract. The elemental ratios of marine phytoplankton emerge from complex interactions between the biotic and abiotic components of the ocean, and reflect the plastic response of individuals to changes in their environment. The stoichiometry of phytoplankton is, thus, dynamic and dependent on the physiological state of the cell. We present a theoretical model for the dynamics of the carbon, nitrogen and phosphorus contents of a phytoplankton population. By representing the regulatory processes controlling nutrient uptake, and focusing on the relation between nutrient content and protein synthesis, our model qualitatively replicates existing experimental observations for nutrient content and ratios. The population described by our model takes up nutrients in proportions that match the input ratios for a broad range of growth conditions. In addition, there are two zones of single-nutrient limitation separated by a wide zone of co-limitation. Within the co-limitation zone, a single point can be identified where nutrients are supplied in an optimal ratio. The existence of a wide co-limitation zone affects the standard picture for species competing for nitrogen and phosphorus, which shows here a much richer pattern. However, additional comprehensive laboratory experiments are needed to test our predictions. Our model contributes to the understanding of the global cycles of oceanic nitrogen and phosphorus, as well as the elemental ratios of these nutrients in phytoplankton populations.

Age of the Cedarberg Formation, South Africa and early land plant evolution

1986 ◽  
Vol 123 (4) ◽  
pp. 445-454 ◽  
Author(s):  
J. Gray ◽  
J. N. Theron ◽  
A. J. Boucot
Keyword(s):  
South Africa ◽  
Land Plant ◽  
Plant Evolution ◽  
Marine Phytoplankton ◽  
Land Plants ◽  
Table Mountain ◽  
Plant Remains ◽  
First Occurrence ◽  
Land Plant Evolution ◽  
Early Land

AbstractThe first occurrence of Early Paleozoic land plants is reported from South Africa. The plant remains are small, compact tetrahedral spore tetrads. They occur abundantly in the Soom Shale Member of the Cedarberg Formation, Table Mountain Group. Marine? phytoplankton (sphaeromorphs or leiospheres) occur with the spore tetrads in all samples. Rare chitinozoans are found in half the samples. Together with similar spore tetrads from the Paraná Basin (Gray et al. 1985) these are the first well-documented records of Ashgill and/or earlier Llandovery land plants from the Malvinokaffric Realm, and from the African continent south of Libya. These spore tetrads have botanical, evolutionary, and biogeographic significance. Their size in comparison with spore tetrads from stratigraphic sections throughout eastern North America, suggests that an earliest Llandovery age is more probable for the Soom Shale Member, although a latest Ordovician age cannot be discounted. The age of the brachiopods in the overlying Disa Siltstone Member has been in contention for over a decade. Both Ashgillian and Early Llandovery ages have been proposed. The age of the underlying Soom Shale Member based on plant spores and trilobites (earliest Llandovery or latest Ashgillian) suggests that the Disa Siltstone Member is also likely to be of Early Llandovery age, although the distance between the Soom Shale Member spore-bearing locality and rocks to the south yielding abundant invertebrate body fossils at one locality is great enough to permit diachroneity.

scholarly journals The inhibitory effect of a non-yessotoxin-producing dinoflagellate, Lingulodinium polyedrum (Stein) Dodge, towards Vibrio vulnificus and Staphylococcus aureus

2016 ◽  
Vol 64 (2) ◽  
pp. 805 ◽  
Author(s):  
Sonia Quijano-Scheggia
Keyword(s):  
Growth Inhibition ◽  
Bacterial Resistance ◽  
Vibrio Vulnificus ◽  
High Growth ◽  
Inhibitory Effect ◽  
Marine Phytoplankton ◽  
Agar Culture ◽  
Lingulodinium Polyedrum ◽  
The Pacific ◽  
Abundance And Diversity

<p>The increased bacterial resistance to antibiotics has caused global concern, prompting the search for new compounds. Because of their abundance and diversity, marine phytoplankton are an important potential source of such compounds. Research on dinoflagellates has led to the discovery of inhibitors of bacterial growth. The marine dinoflagellate <em>Lingulodinium polyedrum</em> blooms in different regions of the world, including Mexico, and is also known to regulate the growth of other species in coastal waters. Here, we investigate the taxonomy of this dinoflagellate and characterize the ability of its extracts to inhibit the growth of two bacteria of medical importance (<em>Vibrio</em> <em>vulnificus</em> and <em>Staphylococcus</em> <em>aureus</em>) on agar culture plates. Taxonomic characterization was performed by PCR and gene amplification of ITS, and confirmed that the species isolated off the Pacific coast of Mexico was <em>L.</em> <em>polyedrum</em>. To prove the inhibitory effect of <em>L. polyedrum</em> extracts, cultures were harvested by centrifugation. Pellets from three cellular abundances were extracted with water, methanol, hexane and chloroform. The experiments on <em>V. vulnificus</em> showed a high growth inhibition for the four extracts, ranging from 77 to 98%. Surprisingly, the growth inhibition was lower when the extracts originated from a higher <em>L. polyedrum</em> cell abundance, ranging from 0 to 34%. For <em>S. aureus</em>, the growth inhibition was also high, but not statistically different for all extracts and cell abundances, ranging from 62 to 99%. This shows promise for future pharmacological applications. Our Mexican strain of <em>L. polyedrum</em> did not produce any detectable yessotoxins.</p>

scholarly journals Surviving Starvation: Proteomic and Lipidomic Profiling of Nutrient Deprivation in the Smallest Known Free-Living Eukaryote

Metabolites ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 273
Author(s):  
Sarah F. Martin ◽  
Mary K. Doherty ◽  
Eliane Salvo-Chirnside ◽  
Seshu R. Tammireddy ◽  
Jiaxiuyu Liu ◽  
...  
Keyword(s):  
Model Organism ◽  
Carbon Assimilation ◽  
Phospholipid Metabolism ◽  
Marine Phytoplankton ◽  
Nitrogen And Phosphorus ◽  
Free Living ◽  
Betaine Lipids ◽  
Low Phosphorus ◽  
Adaptive Processes ◽  
Low Levels

Marine phytoplankton, comprising cyanobacteria, micro- and pico-algae are key to photosynthesis, oxygen production and carbon assimilation on Earth. The unicellular green picoalga Ostreococcus tauri holds a key position at the base of the green lineage of plants, which makes it an interesting model organism. O. tauri has adapted to survive in low levels of nitrogen and phosphorus in the open ocean and also during rapid changes in the levels of these nutrients in coastal waters. In this study, we have employed untargeted proteomic and lipidomic strategies to investigate the molecular responses of O. tauri to low-nitrogen and low-phosphorus environments. In the absence of external nitrogen, there was an elevation in the expression of ammonia and urea transporter proteins together with an accumulation of triglycerides. In phosphate-limiting conditions, the expression levels of phosphokinases and phosphate transporters were increased, indicating an attempt to maximise scavenging opportunities as opposed to energy conservation conditions. The production of betaine lipids was also elevated, highlighting a shift away from phospholipid metabolism. This finding was supported by the putative identification of betaine synthase in O. tauri. This work offers additional perspectives on the complex strategies that underpin the adaptive processes of the smallest known free-living eukaryote to alterations in environmental conditions.

scholarly journals A model for variable phytoplankton stoichiometry based on cell protein regulation

2013 ◽  
Vol 10 (6) ◽  
pp. 4341-4356 ◽  
Author(s):  
J. A. Bonachela ◽  
S. D. Allison ◽  
A. C. Martiny ◽  
S. A. Levin
Keyword(s):  
Physiological State ◽  
Single Point ◽  
Nutrient Content ◽  
Growth Conditions ◽  
Marine Phytoplankton ◽  
Cell Protein ◽  
Nitrogen And Phosphorus ◽  
Elemental Ratios ◽  
Regulatory Processes ◽  
Complex Interactions

Abstract. The elemental ratios of marine phytoplankton emerge from complex interactions between the biotic and abiotic components of the ocean, and reflect the plastic response of individuals to changes in their environment. The stoichiometry of phytoplankton is, thus, dynamic and dependent on the physiological state of the cell. We present a theoretical model for the dynamics of the carbon, nitrogen and phosphorus contents of a phytoplankton population. By representing the regulatory processes controlling nutrient uptake, and focusing on the relation between nutrient content and protein synthesis, our model qualitatively replicates existing experimental observations for nutrient content and ratios. The population described by our model takes up nutrients in proportions that match the input ratios for a broad range of growth conditions. In addition, there are two zones of single-nutrient limitation separated by a wide zone of co-limitation. Within the co-limitation zone, a single point can be identified where nutrients are supplied in an optimal ratio. When different species compete, the existence of a wide co-limitation zone implies a more complex pattern of coexistence and exclusion compared to previous model predictions. However, additional comprehensive laboratory experiments are needed to test our predictions. Our model contributes to the understanding of the global cycles of oceanic nitrogen and phosphorus, as well as the elemental ratios of these nutrients in phytoplankton populations.

scholarly journals Emissions of nitrogen and phosphorus into rivers from agricultural land – selected controversial issues/ Ładunki azotu i fosforu wprowadzane do rzek z terenów rolniczych – wybrane dyskusyjne problemy

2014 ◽  
Vol 23 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Piotr Ilnicki
Keyword(s):  
Agricultural Land ◽  
Sewage Treatment ◽  
Nutrient Retention ◽  
Drainage Basins ◽  
Nitrogen And Phosphorus ◽  
Professional Literature ◽  
Nutrient Sources ◽  
Systems Model ◽  
Vistula River ◽  
Nutrient Emissions

Abstract The research methodology for determining the sources of nutrients responsible for the eutrophication of rivers and seas, as well as the extent of their load in particular drainage basins, has for many years been at the centre of vigorous discussion. In the Oder and Vistula river basin, apart from the calculation of monthly and annual loads of nitrogen and phosphorus, based on the discharge and chemical monitoring data of waters, the MONERIS (Modeling Nutrient Emissions in River Systems) model has also been applied in determining nutrient sources. This article, on the basis of a comprehensive review of the professional literature, shall cast a critical eye over six issues that have been at the centre of past robust discussion: 1) determining the balance of N and P in agriculture, 2) the effects of a significant improvement in sewage treatment, 3) impact of technology on agriculture, 4) determination of nutrient retention in drainage basins, 5) impact of tile drainage practices on the leaching of nutrients, 6) as well as the accuracy of calculations made according to the MONERIS model. It would appear that for practical purposes it is sufficient to determine given loads of N and P from the drainage basins of particular rivers, as well as to adjust the above mentioned model, or indeed - resign from the unproven methodology of determining nutrient sources in rivers.

scholarly journals Vegetation characteristics control local sediment and nutrient retention on but not underneath vegetation in floodplain meadows

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0252694
Author(s):  
Lena Kretz ◽  
Elisabeth Bondar-Kunze ◽  
Thomas Hein ◽  
Ronny Richter ◽  
Christiane Schulz-Zunkel ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Nutrient Retention ◽  
Leaf Size ◽  
Sediment Traps ◽  
Ecosystem Functions ◽  
Floodplain Management ◽  
Nitrogen And Phosphorus ◽  
Floodplain Vegetation ◽  
Vegetation Height ◽  
Vegetation Characteristics

Sediment and nutrient retention are essential ecosystem functions that floodplains provide and that improve river water quality. During floods, the floodplain vegetation retains sediment, which settles on plant surfaces and the soil underneath plants. Both sedimentation processes require that flow velocity is reduced, which may be caused by the topographic features and the vegetation structure of the floodplain. However, the relative importance of these two drivers and their key components have rarely been both quantified. In addition to topographic factors, we expect vegetation height and density, mean leaf size and pubescence, as well as species diversity of the floodplain vegetation to increase the floodplain’s capacity for sedimentation. To test this, we measured sediment and nutrients (carbon, nitrogen and phosphorus) both on the vegetation itself and on sediment traps underneath the vegetation after a flood at 24 sites along the River Mulde (Germany). Additionally, we measured biotic and topographic predictor variables. Sedimentation on the vegetation surface was positively driven by plant biomass and the height variation of the vegetation, and decreased with the hydrological distance (total R2 = 0.56). Sedimentation underneath the vegetation was not driven by any vegetation characteristics but decreased with hydrological distance (total R2 = 0.42). Carbon, nitrogen and phosphorus content in the sediment on the traps increased with the total amount of sediment (total R2 = 0.64, 0.62 and 0.84, respectively), while C, N and P on the vegetation additionally increased with hydrological distance (total R2 = 0.80, 0.79 and 0.92, respectively). This offers the potential to promote sediment and especially nutrient retention via vegetation management, such as adapted mowing. The pronounced signal of the hydrological distance to the river emphasises the importance of a laterally connected floodplain with abandoned meanders and morphological depressions. Our study improves our understanding of the locations where floodplain management has its most significant impact on sediment and nutrient retention to increase water purification processes.

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