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M. Fabiano - One of the best experts on this subject based on the ideXlab platform.

  • Particulate Organic Matter Composition in A Semi-Enclosed Marine System
    Chemistry and Ecology, 2001
    Co-Authors: Antonio Mazzola, M. Fabiano, Antonio Pusceddu, Gianluca Sarà
    Abstract:

    Abstract Spatial and temporal changes in the biochemical composition of Particulate Organic Matter in a semi-enclosed marine system (Stagnone di Marsala, Mediterranean Sea) were studied, on a monthly basis, from January to December 1994, in order to assess nutritional value of suspended particles for benthic suspension feeders. According to previous findings, the study site displayed a strong oligotrophy. Chlorophyll-a accounted for a very low fraction of the total suspended Matter pool (0.1%), whereas at least 75% of POC was of detrital/heterotrophic origin. POC: PON ratio values indicate that bacterioplankton biomass accounted for a significant fraction of the total POC pool, displaying values comparable to those of the phytoplankton biomass (phytoplankton to bacterial biomass ratio was about (1). Temporal and spatial changes in the biochemical composition of Particulate Organic Matter were rather limited and related to its sources, the main of which is represented by detrital particles released by the ...

  • Spatial and Temporal Distribution of Particulate Organic Matter in the Ross Sea
    Ross Sea Ecology, 2000
    Co-Authors: M. Fabiano, Paolo Povero, Cristina Misic
    Abstract:

    Spatial distribution and biochemical composition of Particulate Organic Matter (POM) were studied in relation to ice melting of the Ross Sea (Antarctica) during the austral spring and summer 1994 (from 14 Nov to 15 Dec 1994). POM distribution, characterized by areas with different amounts and biochemical composition of Organic particles, was strongly influenced by ice melting. POM, mostly of phytoplankton origin, showed a large detrital component. On average, proteins accounted for the largest fraction of POM (40–80%), followed by carbohydrates (10–40%) and lipids (5–35%). POM vertical distribution was characterised by a concentration decrease between 20- and 60-m depth. Particulate Organic Matter in the surface layer and in the deep layer differed in quantitative and qualitative biochemical composition. POC and PON concentrations ranged, in the surface layer, between 36–256 and 3–41 µg |-1, respectively, and in the deep layer between 16–50 and 1–7 μg |-1, respectively. Changes in chemical composition were related to microbial ectoenzymatic activity. Degradation processes lead to a strong decrease in the protein fraction, as a result of the activity of protein degrading ectoenzymes, mainly leucine aminopeptidase, which showed the highest activities (>30 nmol |−1h-1) in the surface layer.The Ross Sea system acts as a retentive system since a large part of the Organic Matter is remineralized within the water column. POM spatial variation is considered within the frame of biochemical composition changes induced by ice-melting processes and compared with previous observations in the Ross Sea.

  • Particulate Organic Matter and Nutrient Utilization in the Mixed Layer of the Ross Sea
    Ross Sea Ecology, 2000
    Co-Authors: Paolo Povero, M. Fabiano, G. Catalano
    Abstract:

    The relationship between Particulate Organic Matter, nutrient depletion and vertical stability were studied in different areas of the Ross Sea during the Antarctic spring and summer. In the upper mixed layer, identified in relation to the vertical stability index E[Z(UML)], a significant relationship between the vertical stability index and nutrient depletion was found. A similar relationship was also observed between Particulate Matter distribution and composition vs. nutrient utilization. Data analysis showed that stations could be divided into different groups with differing characteristics. Summer stations in the western and central areas of the Ross Sea and in the coastal zone of Terra Nova Bay were affected by ice melting and showed strong stratification (E[Z(UML)] > 25), higher biomass and nutrient depletion values (average values of POC = 236 µg |-1; PON = 40 µg |-1; ΔNW, ΔPW, ΔSiW = 7, 0.7, 23 mmol m-3, respectively). Another group of stations in the northern-central area of the Ross Sea was characterized by low nutrient utilization (ΔNW, ΔPW, ΔSiW 180 µg |-1 and PON > 29 µg |-1) and with phytoplankton assemblages dominated by diatoms and/or Phaeocystis antarctica. The degree of stabilization, but also sedimentation rates and grazing pressure played an important role in the development, accumulation and spatial variability of Particulate Organic Matter in the Ross Sea areas.

  • Particulate Organic Matter composition in Terra Nova Bay (Ross Sea, Antarctica) during summer 1990
    Antarctic Science, 1996
    Co-Authors: M. Fabiano, Paolo Povero, Roberto Danovaro
    Abstract:

    Particulate Organic Matter was collected in the coastal waters of Terra Nova Bay during the Oceanographic Campaign of the Italian Antarctic Research Programme in summer (January–February) 1990. Particulate Matter composition was analysed for Organic carbon and nitrogen, carbohydrates, proteins, lipids, nucleic acids (DNA and RNA) and ATP. A vertical stratification was evident in the study area, and resulted from prior melting of the pack ice. Suspended Organic Matter in the mixed layer and below the mixed layer differed in quantitative and qualitative composition. Except for ATP, all the biochemical components showed higher concentrations in the mixed layer than in the deeper waters. The Particulate Organic Matter in Terra Nova Bay was mostly detrital and of algal origin.

  • A Functional Approach to the Assessment of the Nutritional Value of Particulate Organic Matter
    Chemistry and Ecology, 1996
    Co-Authors: Cristina Misic, M. Fabiano
    Abstract:

    Abstract Organic Matter lability can be determined with different approaches, based on the quantitative and qualitative estimate of its nutritional value. the C/N ratio and the Particulate Organic Matter (as the sum of protein, carbohydrate and lipid bulks) vs total suspended Matter (POM/TSM) deal with a quantitative assessment of the Organic Matter bulk, while other indices such as proteins/carbohydrates ratio (PRT/CHO) may give also qualitative information. Gordon (1970) proposed a functional approach, based on Organic carbon decrease after enzymatic digestion. Coupling Gordon's approach with the evaluation of the main biochemical components (proteins, carbohydrates and lipids) contained in the Particulate Organic Matter, a simple method to assess lability and nutritional value of Organic substrates is proposed. Water samples were collected at the surface and close to the bottom in a shallow coastal station (10 m depth) in the Marconi Gulf (Ligurian Sea, NW Mediterranean). the difference between “total ...

Y. Onda - One of the best experts on this subject based on the ideXlab platform.

  • Particulate Organic Matter in rivers of Fukushima An unexpected carrier phase for radiocesiums
    Science of the Total Environment, 2017
    Co-Authors: M. Naulier, F. Eyrolle-boyer, P. Boyer, J.-m. Métivier, Y. Onda
    Abstract:

    The role of Particulate Organic Matter in radiocesium transfers from soils to rivers was investigated in areas contaminated by the Fukushima Daiichi Nuclear Power Plant accident. Suspended and deposited sediments, filtered water, macro Organic debris and dead leaves were sampled along the six most contaminated coastal river catchments of the Fukushima prefecture in the early autumns 2013 and 2014. Radiocesium concentrations of river samples and total Organic carbon concentrations in suspended and deposited sediments were measured. Radiocesium concentrations of suspended and deposited sediments were significantly correlated to 137Cs inventories in soils and total Organic carbon. The distributions of radiocesium between the Organic and mineral phases of both types of sediment were assessed by using a modelling approach. The results suggest that, during the early autumn season, the Organic fraction was the main phase that carried the radiocesiums in deposited sediments and in suspended sediments for suspended loads andlt; 25 mg·L− 1. For higher suspended loads like those occurring during typhoon periods, the mineral fraction was the main carrier phase. Thus, high apparent distribution coefficient values noted by various authors in Fukushima could be attributed to the high radiocesium contents of Particulate Organic Matter. Since it is well known that Organic compounds generally do not significantly adsorb radiocesium onto specific sites, several hypotheses are suggested 1) Radiocesiums may have been absorbed into Organic components at the early stage of atmospheric radioactive deposits and/or later due to biomass recycling and 2) Those elements would be partly carried by glassy hot particles together with Organic Matter transported by rivers in Fukushima. Both hypotheses would lead to conserve the amount of radiocesiums associated with particles during their transfers from the contaminated areas to the marine environment. Finally, such Organically bound radiocesium would lead to significant deliveries of bioavailable radiocesium for living organisms at Fukushima. © 2016 Elsevier B.V.

  • Particulate Organic Matter in rivers of Fukushima: An unexpected carrier phase for radiocesiums.
    Science of The Total Environment, 2017
    Co-Authors: M. Naulier, F. Eyrolle-boyer, P. Boyer, J.-m. Métivier, Y. Onda
    Abstract:

    The role of Particulate Organic Matter in radiocesium transfers from soils to rivers was investigated in areas contaminated by the Fukushima Daiichi Nuclear Power Plant accident. Suspended and deposited sediments, filtered water, macro Organic debris and dead leaves were sampled along the six most contaminated coastal river catchments of the Fukushima prefecture in the early autumns 2013 and 2014. Radiocesium concentrations of river samples and total Organic carbon concentrations in suspended and deposited sediments were measured. Radiocesium concentrations of suspended and deposited sediments were significantly correlated to 137Cs inventories in soils and total Organic carbon. The distributions of radiocesium between the Organic and mineral phases of both types of sediment were assessed by using a modelling approach. The results suggest that, during the early autumn season, the Organic fraction was the main phase that carried the radiocesiums in deposited sediments and in suspended sediments for suspended loads

Paolo Povero - One of the best experts on this subject based on the ideXlab platform.

  • Spatial and Temporal Distribution of Particulate Organic Matter in the Ross Sea
    Ross Sea Ecology, 2000
    Co-Authors: M. Fabiano, Paolo Povero, Cristina Misic
    Abstract:

    Spatial distribution and biochemical composition of Particulate Organic Matter (POM) were studied in relation to ice melting of the Ross Sea (Antarctica) during the austral spring and summer 1994 (from 14 Nov to 15 Dec 1994). POM distribution, characterized by areas with different amounts and biochemical composition of Organic particles, was strongly influenced by ice melting. POM, mostly of phytoplankton origin, showed a large detrital component. On average, proteins accounted for the largest fraction of POM (40–80%), followed by carbohydrates (10–40%) and lipids (5–35%). POM vertical distribution was characterised by a concentration decrease between 20- and 60-m depth. Particulate Organic Matter in the surface layer and in the deep layer differed in quantitative and qualitative biochemical composition. POC and PON concentrations ranged, in the surface layer, between 36–256 and 3–41 µg |-1, respectively, and in the deep layer between 16–50 and 1–7 μg |-1, respectively. Changes in chemical composition were related to microbial ectoenzymatic activity. Degradation processes lead to a strong decrease in the protein fraction, as a result of the activity of protein degrading ectoenzymes, mainly leucine aminopeptidase, which showed the highest activities (>30 nmol |−1h-1) in the surface layer.The Ross Sea system acts as a retentive system since a large part of the Organic Matter is remineralized within the water column. POM spatial variation is considered within the frame of biochemical composition changes induced by ice-melting processes and compared with previous observations in the Ross Sea.

  • Particulate Organic Matter and Nutrient Utilization in the Mixed Layer of the Ross Sea
    Ross Sea Ecology, 2000
    Co-Authors: Paolo Povero, M. Fabiano, G. Catalano
    Abstract:

    The relationship between Particulate Organic Matter, nutrient depletion and vertical stability were studied in different areas of the Ross Sea during the Antarctic spring and summer. In the upper mixed layer, identified in relation to the vertical stability index E[Z(UML)], a significant relationship between the vertical stability index and nutrient depletion was found. A similar relationship was also observed between Particulate Matter distribution and composition vs. nutrient utilization. Data analysis showed that stations could be divided into different groups with differing characteristics. Summer stations in the western and central areas of the Ross Sea and in the coastal zone of Terra Nova Bay were affected by ice melting and showed strong stratification (E[Z(UML)] > 25), higher biomass and nutrient depletion values (average values of POC = 236 µg |-1; PON = 40 µg |-1; ΔNW, ΔPW, ΔSiW = 7, 0.7, 23 mmol m-3, respectively). Another group of stations in the northern-central area of the Ross Sea was characterized by low nutrient utilization (ΔNW, ΔPW, ΔSiW 180 µg |-1 and PON > 29 µg |-1) and with phytoplankton assemblages dominated by diatoms and/or Phaeocystis antarctica. The degree of stabilization, but also sedimentation rates and grazing pressure played an important role in the development, accumulation and spatial variability of Particulate Organic Matter in the Ross Sea areas.

  • Particulate Organic Matter composition in Terra Nova Bay (Ross Sea, Antarctica) during summer 1990
    Antarctic Science, 1996
    Co-Authors: M. Fabiano, Paolo Povero, Roberto Danovaro
    Abstract:

    Particulate Organic Matter was collected in the coastal waters of Terra Nova Bay during the Oceanographic Campaign of the Italian Antarctic Research Programme in summer (January–February) 1990. Particulate Matter composition was analysed for Organic carbon and nitrogen, carbohydrates, proteins, lipids, nucleic acids (DNA and RNA) and ATP. A vertical stratification was evident in the study area, and resulted from prior melting of the pack ice. Suspended Organic Matter in the mixed layer and below the mixed layer differed in quantitative and qualitative composition. Except for ATP, all the biochemical components showed higher concentrations in the mixed layer than in the deeper waters. The Particulate Organic Matter in Terra Nova Bay was mostly detrital and of algal origin.

  • Distribution and composition of Particulate Organic Matter in the Ross Sea (Antarctica)
    Polar Biology, 1993
    Co-Authors: M. Fabiano, Paolo Povero, Roberto Danovaro
    Abstract:

    The biochemical composition and spatial distribution of Particulate Organic Matter (POM) were studied in the Ross Sea (Antarctica) in summer 1989 to assess the quantitative role of Organic carbon fractions in the cycling of Organic Matter in the water column. Large differences in chemical composition were observed between surface and deep layers. The results indicated that, despite large geographical differences, POM was quite homogeneous, of phytoplankton origin and mostly detrital. Different ratios were used to investigate the changes in biochemical composition of Particulate Organic Matter in relation to the ice-melting: C∶N (Organic carbon∶Organic nitrogen ratio) and C-POM∶POC (sum of carbohydrate, protein and lipid carbon∶total Organic carbon ratio) were used to analyse the percentage of refractory Organic material. PPRT∶PCHO (protein∶carbohydrate ratio) were used to establish POM “age” and RNA∶DNA ratios as a relative measure of Particulate activity; POC∶Chl a and N-PPRT∶Chl a ratios were used to estimate the autotrophic contribution to the suspended Particulate Organic Matter. Despite its low caloric value (5.3 Kcal g POM−1), an high caloric content in the photic layer (1.6 Kcal m−3 of POM and 2.5 Kcal m−3 of POC) was found thus indicating that a large amount of food was available to higher trophic levels.

Roberto Danovaro - One of the best experts on this subject based on the ideXlab platform.

  • Particulate Organic Matter composition in Terra Nova Bay (Ross Sea, Antarctica) during summer 1990
    Antarctic Science, 1996
    Co-Authors: M. Fabiano, Paolo Povero, Roberto Danovaro
    Abstract:

    Particulate Organic Matter was collected in the coastal waters of Terra Nova Bay during the Oceanographic Campaign of the Italian Antarctic Research Programme in summer (January–February) 1990. Particulate Matter composition was analysed for Organic carbon and nitrogen, carbohydrates, proteins, lipids, nucleic acids (DNA and RNA) and ATP. A vertical stratification was evident in the study area, and resulted from prior melting of the pack ice. Suspended Organic Matter in the mixed layer and below the mixed layer differed in quantitative and qualitative composition. Except for ATP, all the biochemical components showed higher concentrations in the mixed layer than in the deeper waters. The Particulate Organic Matter in Terra Nova Bay was mostly detrital and of algal origin.

  • Distribution and composition of Particulate Organic Matter in the Ross Sea (Antarctica)
    Polar Biology, 1993
    Co-Authors: M. Fabiano, Paolo Povero, Roberto Danovaro
    Abstract:

    The biochemical composition and spatial distribution of Particulate Organic Matter (POM) were studied in the Ross Sea (Antarctica) in summer 1989 to assess the quantitative role of Organic carbon fractions in the cycling of Organic Matter in the water column. Large differences in chemical composition were observed between surface and deep layers. The results indicated that, despite large geographical differences, POM was quite homogeneous, of phytoplankton origin and mostly detrital. Different ratios were used to investigate the changes in biochemical composition of Particulate Organic Matter in relation to the ice-melting: C∶N (Organic carbon∶Organic nitrogen ratio) and C-POM∶POC (sum of carbohydrate, protein and lipid carbon∶total Organic carbon ratio) were used to analyse the percentage of refractory Organic material. PPRT∶PCHO (protein∶carbohydrate ratio) were used to establish POM “age” and RNA∶DNA ratios as a relative measure of Particulate activity; POC∶Chl a and N-PPRT∶Chl a ratios were used to estimate the autotrophic contribution to the suspended Particulate Organic Matter. Despite its low caloric value (5.3 Kcal g POM−1), an high caloric content in the photic layer (1.6 Kcal m−3 of POM and 2.5 Kcal m−3 of POC) was found thus indicating that a large amount of food was available to higher trophic levels.

M. Naulier - One of the best experts on this subject based on the ideXlab platform.

  • Particulate Organic Matter in rivers of Fukushima An unexpected carrier phase for radiocesiums
    Science of the Total Environment, 2017
    Co-Authors: M. Naulier, F. Eyrolle-boyer, P. Boyer, J.-m. Métivier, Y. Onda
    Abstract:

    The role of Particulate Organic Matter in radiocesium transfers from soils to rivers was investigated in areas contaminated by the Fukushima Daiichi Nuclear Power Plant accident. Suspended and deposited sediments, filtered water, macro Organic debris and dead leaves were sampled along the six most contaminated coastal river catchments of the Fukushima prefecture in the early autumns 2013 and 2014. Radiocesium concentrations of river samples and total Organic carbon concentrations in suspended and deposited sediments were measured. Radiocesium concentrations of suspended and deposited sediments were significantly correlated to 137Cs inventories in soils and total Organic carbon. The distributions of radiocesium between the Organic and mineral phases of both types of sediment were assessed by using a modelling approach. The results suggest that, during the early autumn season, the Organic fraction was the main phase that carried the radiocesiums in deposited sediments and in suspended sediments for suspended loads andlt; 25 mg·L− 1. For higher suspended loads like those occurring during typhoon periods, the mineral fraction was the main carrier phase. Thus, high apparent distribution coefficient values noted by various authors in Fukushima could be attributed to the high radiocesium contents of Particulate Organic Matter. Since it is well known that Organic compounds generally do not significantly adsorb radiocesium onto specific sites, several hypotheses are suggested 1) Radiocesiums may have been absorbed into Organic components at the early stage of atmospheric radioactive deposits and/or later due to biomass recycling and 2) Those elements would be partly carried by glassy hot particles together with Organic Matter transported by rivers in Fukushima. Both hypotheses would lead to conserve the amount of radiocesiums associated with particles during their transfers from the contaminated areas to the marine environment. Finally, such Organically bound radiocesium would lead to significant deliveries of bioavailable radiocesium for living organisms at Fukushima. © 2016 Elsevier B.V.

  • Particulate Organic Matter in rivers of Fukushima: An unexpected carrier phase for radiocesiums.
    Science of The Total Environment, 2017
    Co-Authors: M. Naulier, F. Eyrolle-boyer, P. Boyer, J.-m. Métivier, Y. Onda
    Abstract:

    The role of Particulate Organic Matter in radiocesium transfers from soils to rivers was investigated in areas contaminated by the Fukushima Daiichi Nuclear Power Plant accident. Suspended and deposited sediments, filtered water, macro Organic debris and dead leaves were sampled along the six most contaminated coastal river catchments of the Fukushima prefecture in the early autumns 2013 and 2014. Radiocesium concentrations of river samples and total Organic carbon concentrations in suspended and deposited sediments were measured. Radiocesium concentrations of suspended and deposited sediments were significantly correlated to 137Cs inventories in soils and total Organic carbon. The distributions of radiocesium between the Organic and mineral phases of both types of sediment were assessed by using a modelling approach. The results suggest that, during the early autumn season, the Organic fraction was the main phase that carried the radiocesiums in deposited sediments and in suspended sediments for suspended loads