scholarly journals Nutrient ratios in marine particulate organic matter are predicted by the population structure of well-adapted phytoplankton

2020 ◽  
Vol 6 (29) ◽  
pp. eaaw9371 ◽  
Author(s):  
Shlomit Sharoni ◽  
Itay Halevy
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Nutrient Deficiency ◽  
Laboratory Culture ◽  
Taxonomic Composition ◽  
Nutrient Ratios ◽  
Common Assumption ◽  
Mechanistic Basis ◽  
Physiological Acclimation ◽  
Insight Into

A common assumption of a constant nitrogen-to-phosphorus ratio (N:P) of 16:1 in marine particulate organic matter (POM) appears to be invalidated by observations of major spatial variations in N:P. Two main explanations have been proposed. The first attributes the N:P variability to changes in the community composition of well-adapted phytoplankton. The second proposes that variability arises from physiological acclimation involving intracellular adjustments of nutrient allocation under nutrient deficiency. Using a model of phytoplankton physiology, observational datasets, and a review of laboratory culture results, we assess the mechanistic basis of N:P variability. We find that the taxonomic composition of well-adapted phytoplankton best explains observed variations in POM N:P. Furthermore, we show that acclimation to nutrient deficiency may be safely neglected when considering the effects of ecology on POM N:P. These findings provide insight into the controls on global variability in POM composition and average phytoplankton physiological performance in the oceans.

scholarly journals Insight into removals of PARAFAC components from dissolved and particulate organic matter in wastewater treatment process by two-dimensional correlation and structure equation modeling

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Benxin Yu ◽  
Dongping Liu ◽  
Jian Wang ◽  
Yingxue Sun
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Particulate Organic Matter ◽  
Structural Equation ◽  
Treatment Process ◽  
Treatment Plant ◽  
Equation Modeling ◽  
Two Dimensional ◽  
Wastewater Treatment Process ◽  
Insight Into

Abstract Background Most particulate organic matter (POM) cannot be directly degraded in the conventional wastewater treatment, which should be transformed into dissolved organic matter (DOM) through a hydrolysis process. However, non-hydrolyzed POM in the biological treatment can limit treated efficiencies for the wastewater treatment plants (WWTPs) facilities. Hence an operational tool is indispensable for insight into removals of DOM and POM factions in the WWTP. In this study, excitation-emission matrix fluorescence spectroscopy (EEM) combined parallel factor analysis (PARAFAC), two-dimensional correlation (2D-COS) and structural equation modeling (SEM) was employed to evaluate removals of DOM and POM in a wastewater treatment plant. Results Four fluorescence components were identified in DOM and POM substances from the WWTP by EEM combined with PARAFAC, i.e., tyrosine-like (TYLF), tryptophan-like (TRLF), microbial byproduct-like (MBLF), and fulvic acid-like (FALF). In A2/O process, the TYLF and TRLF of DOM were removed to a larger extent than those of MBLF and FALF in anaerobic tank, while TYLF and MBLF of POM were removed to a great extent than those of TRLF and FALF in primary sedimentation and aerobic tanks. By the 2D-COS, a decreasing variation order of DOM fractions in the wastewater treatment process was UV-FALF → MBLF2 → Vis-FALF → TRLF → TYLF, while the decreasing order of POM fractions was Vis-FALF → UV-FALF → MBLF2 → TYLF → MBLF1 → TRLF. SEM revealed that TRLF and TYLF of DOM were degraded by anaerobic microorganism, and TRLF could be transformed partially into FALF. However, TRFL and TYLF of POM were discomposed by aerobic microorganism. Conclusions The 2D-COS and SEM can be practicable tools as EEM-PARAFAC for monitoring DOM and POM in the WWTP. The study could present a theoretical support to improving the retrofit of WWTP and formulating emission standards for organic pollutants.

Indirect Effects of Detritus Manipulations in a Montane Stream

1991 ◽  
Vol 48 (5) ◽  
pp. 776-783 ◽  
Author(s):  
John S. Richardson ◽  
William E. Neill
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Trophic Group ◽  
Stream Channels ◽  
Organic Matter Production ◽  
Common Assumption ◽  
Matter Production ◽  
High Loading Rate ◽  
Ecosystem Theory ◽  
Larvae Density

To evaluate the common assumption in stream ecosystem theory that fine-particle feeders can indirectly benefit from coarse-particle detritus consumed by detritivores, we manipulated whole-leaf detritus in replicated experimental stream channels. Elevated input rates of detritus resulted in significantly higher densities of collectors and moderate but nonsignificantly higher densities of predators. When collectors were analyzed as filterers and gatherers separately, there were significantly higher densities of both groups at a high loading rate of leaves. The net rates of colonization for each trophic group did not differ significantly with respect to treatment, which suggests that the increased densities of collectors observed under high leaf input rates were due to increased survival of larvae. Density of no single taxon increased significantly in response to coarse particulate organic matter inputs; rather, most species showed moderate increases. Species richness showed no treatment effect. Increases in collector density may result indirectly from increased fine particulate organic matter production due to feeding by shredders. Predaceous species which responded were small taxa and were probably predators on collectors. These effects were observed over a period of less than 5 mo and demonstrate the potential strength of the interactions.

scholarly journals Varying influence of phytoplankton biodiversity and stoichiometric plasticity on bulk particulate stoichiometry across ocean basins

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Michael W. Lomas ◽  
Steven E. Baer ◽  
Celine Mouginot ◽  
Kristina X. Terpis ◽  
Debra A. Lomas ◽  
...  
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Nutrient Content ◽  
Taxonomic Composition ◽  
Nitrogen And Phosphorus ◽  
Elemental Ratios ◽  
Carbon Cycles ◽  
The North ◽  
Suspended Particulate ◽  
Stoichiometric Ratios

AbstractConcentrations and elemental ratios of suspended particulate organic matter influence many biogeochemical processes in the ocean, including patterns of phytoplankton nutrient limitation and links between carbon, nitrogen and phosphorus cycles. Here we present direct measurements of cellular nutrient content and stoichiometric ratios for discrete phytoplankton populations spanning broad environmental conditions across several ocean basins. Median cellular carbon-to-phosphorus and nitrogen-to-phosphorus ratios were positively correlated with vertical nitrate-to-phosphate flux for all phytoplankton groups and were consistently higher for cyanobacteria than eukaryotes. Light and temperature were inconsistent predictors of stoichiometric ratios. Across nutrient-rich and phosphorus-stressed biomes in the North Atlantic, but not in the nitrogen-stressed tropical North Pacific, we find that a combination of taxonomic composition and environmental acclimation best predict bulk particulate organic matter composition. Our findings demonstrate the central role of plankton biodiversity and plasticity in controlling linkages between ocean nutrient and carbon cycles in some regions.

scholarly journals Stable C and N Isotope Composition of Suspended Particulate Organic Matter in the Neva Estuary: The Role of Abiotic Factors, Productivity, and Phytoplankton Taxonomic Composition

2020 ◽  
Vol 8 (12) ◽  
pp. 959 ◽  
Author(s):  
Mikhail S. Golubkov ◽  
Vera N. Nikulina ◽  
Alexei V. Tiunov ◽  
Sergey M. Golubkov
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Abiotic Factors ◽  
Taxonomic Composition ◽  
Isotopic Ratios ◽  
Abiotic Factor ◽  
Δ13c And Δ15n ◽  
Neva Estuary ◽  
Suspended Particulate ◽  
Suspended Particulate Organic Matter

Knowledge of carbon and nitrogen isotopic ratios in organic matter and their changes is important when studying nutrient cycles in aquatic ecosystems. Relationships between δ13C and δ15N values of suspended particulate organic matter (POM), water temperature, salinity, pH, redox potential, chlorophyll a concentration, primary production, and biomasses of different taxonomic groups of phytoplankton in the Neva Estuary were statistically analyzed. We tested the hypothesis that the studied physicochemical and biogeochemical characteristics, as well as the species composition of phytoplankton and its productivity, can be significant predictors of changes in the isotopic ratios of suspended particulate organic matter in estuaries. In the Neva Estuary, δ13CPOM (−16.8–−27.6‰) and δ15NPOM (2.3–7.3‰) changed synchronously. Statistical analysis showed that for both isotopes, the photosynthetic activity and taxonomic composition of phytoplankton are important. For 13CPOM, the second most important factor was water salinity, which was apparently associated with the transition of algae from CO2 to HCO3 consumption during photosynthesis in estuarine waters. For 15NPOM changes, the most important abiotic factor was pH. The study showed that the dependences of POM isotopic ratios on environmental variables obtained for continental and oceanic waters are also valid in transitional zones such as the Neva Estuary.

scholarly journals Assessing the role of canopy cover on the colonization of phytotelmata by aquatic invertebrates: an experiment with the tank-bromeliad Aechmea lingulata

2016 ◽  
Author(s):  
Juliana V. Rangel ◽  
Rosângela E.S. Araújo ◽  
Cinthia G. Casotti ◽  
Larissa C. Costa ◽  
Walace P. Kiffer Jr. ◽  
...  
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Aquatic Invertebrates ◽  
Canopy Cover ◽  
Taxonomic Composition ◽  
Organic Detritus ◽  
Invertebrate Communities ◽  
Small Influence ◽  
Colonization Process ◽  
Tank Bromeliad

<p>The presence of canopy cover may influence the amount of organic detritus and stored water in bromeliad tanks and, consequently, the colonization of these ecosystems by aquatic invertebrates. The aim of this study was to determine the effects of canopy cover on the colonization of the tank-bromeliad<em> Aechmea lingulata </em>in the restinga, an ecosystem composed of a variety of plant communities in the sandy coastal plains of Brazil. We hypothesized that the taxonomic composition of invertebrate communities would differ between bromeliads covered and not covered by a dense canopy (shaded and unshaded bromeliads). Prior to the beginning of the experiment, bromeliads of similar size were carefully washed to remove all organisms and organic detritus, and their tanks were filled with 1.0 L of spring water. On days 7, 14, 21, 30, 45, 60 and 90, four bromeliad tanks of each shade treatment were sampled to determine invertebrate communities, stored water and organic detritus. Average daily values of water temperature and light intensity were higher in unshaded than in shaded bromeliads. The amount of fine particulate organic matter (FPOM) and stored water did not differ between treatments, but the amount of coarse particulate organic matter (CPOM) was higher in shaded bromeliads. Ostracoda, Hydracarina and Oligochaeta were the most abundant taxa in bromeliad tanks. Among insects, Culicidae, Chironomidae and Ceratopogonidae were the most representative. Invertebrate colonization occurred quickly and values of abundance were higher in unshaded bromeliads compared to shaded bromeliads. The values for biomass and richness did not differ between treatments or colonization times, and the taxonomic composition of invertebrate communities was similar throughout the experiment. Our results showed that canopy cover had a small influence on the colonization of tanks of <em>A. lingulata</em> in restinga, not corroborating the proposed hypothesis. These findings were likely due to the lack of variation in environmental conditions that are relevant to the colonization process, such as stored water and FPOM. However, because the amounts of CPOM were higher in shaded bromeliads, the taxonomic composition of invertebrate communities could have differed if typical shredders were present.</p>

Relating particulate organic matter-nitrogen (POM-N) and non-POM-N with pulse crop residues, residue management and cereal N uptake

Agronomie ◽  
2002 ◽  
Vol 22 (7-8) ◽  
pp. 777-787 ◽  
Author(s):  
Graeme D. Schwenke ◽  
Warwick L. Felton ◽  
David F. Herridge ◽  
Dil F. Khan ◽  
Mark B. Peoples
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Crop Residues ◽  
N Uptake ◽  
Residue Management ◽  
Pulse Crop

Macrophyte-derived detritus in shallow coastal waters contributes to suspended particulate organic matter and increases growth rates of Mytilus edulis

2020 ◽  
Vol 644 ◽  
pp. 91-103
Author(s):  
D Bearham ◽  
MA Vanderklift ◽  
RA Downie ◽  
DP Thomson ◽  
LA Clementson
Keyword(s):  
Organic Matter ◽  
Mytilus Edulis ◽  
Particulate Organic Matter ◽  
Coastal Waters ◽  
Gill Tissue ◽  
Suspension Feeder ◽  
Food Sources ◽  
Suspension Feeders ◽  
Blue Mussels ◽  
Suspended Particulate

Benthic suspension feeders, such as bivalves, potentially have several different food sources, including plankton and resuspended detritus of benthic origin. We hypothesised that suspension feeders are likely to feed on detritus if it is present. This inference would be further strengthened if there was a correlation between δ13C of suspension feeder tissue and δ13C of particulate organic matter (POM). Since detritus is characterised by high particulate organic matter (POC):chl a ratios, we would also predict a positive correlation between POM δ13C and POC:chl a. We hypothesised that increasing depth and greater distance from shore would produce a greater nutritional reliance by experimentally transplanted blue mussels Mytilus edulis on plankton rather than macrophyte-derived detritus. After deployments of 3 mo duration in 2 different years at depths from 3 to 40 m, M. edulis sizes were positively correlated with POM concentrations. POC:chl a ratios and δ13C of POM and M. edulis gill tissue decreased with increasing depth (and greater distance from shore). δ13C of POM was correlated with δ13C of M. edulis. Our results suggest that detritus comprised a large proportion of POM at shallow depths (<15 m), that M. edulis ingested and assimilated carbon in proportion to its availability in POM, and that growth of M. edulis was higher where detritus was present and POM concentrations were higher.

Hydrolysis of organic wastewater particles in laboratory scale and pilot scale biofilm reactors under anoxic and aerobic conditions

1998 ◽  
Vol 38 (8-9) ◽  
pp. 179-188 ◽  
Author(s):  
K. F. Janning ◽  
X. Le Tallec ◽  
P. Harremoës
Keyword(s):  
Organic Matter ◽  
Mass Balance ◽  
Particulate Organic Matter ◽  
Removal Rate ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Synthetic Wastewater ◽  
Aerobic Conditions ◽  
Biofilm Reactors ◽  
Hydrolysis Of

Hydrolysis and degradation of particulate organic matter has been isolated and investigated in laboratory scale and pilot scale biofilters. Wastewater was supplied to biofilm reactors in order to accumulate particulates from wastewater in the filter. When synthetic wastewater with no organic matter was supplied to the reactors, hydrolysis of the particulates was the only process occurring. Results from the laboratory scale experiments under aerobic conditions with pre-settled wastewater show that the initial removal rate is high: rV, O2 = 2.1 kg O2/(m3 d) though fast declining towards a much slower rate. A mass balance of carbon (TOC/TIC) shows that only 10% of the accumulated TOC was transformed to TIC during the 12 hour long experiment. The pilot scale hydrolysis experiment was performed in a new type of biofilm reactor - the B2A® biofilter that is characterised by a series of decreasing sized granular media (80-2.5 mm). When hydrolysis experiments were performed on the anoxic pilot biofilter with pre-screened wastewater particulates as carbon source, a rapid (rV, NO3=0.7 kg NO3-N/(m3 d)) and a slowler (rV, NO3 = 0.3 kg NO3-N/(m3 d)) removal rate were observed at an oxygen concentration of 3.5 mg O2/l. It was found that the pilot biofilter could retain significant amounts of particulate organic matter, reducing the porosity of the filter media of an average from 0.35 to 0.11. A mass balance of carbon shows that up to 40% of the total incoming TOC accumulates in the filter at high flow rates. Only up to 15% of the accumulated TOC was transformed to TIC during the 24 hour long experiment.

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