Short-term variations in particulate matter flux in Terra Nova Bay, Ross Sea

1997 ◽  
Vol 9 (2) ◽  
pp. 143-149 ◽  
Author(s):  
Mauro Fabiano ◽  
Mariachiara Chiantore ◽  
Paolo Povero ◽  
Riccardo Cattaneo-Vietti ◽  
Antonio Pusceddu ◽  
...  

As part of the Ross Sea Marginal Ice Zone Ecology Project (ROSSMIZE) the summer organic matter flux through the water column was measured at 40 m depth in Terra Nova Bay. Water samples and material from a sediment trap on the sea-bottom were analysed for their biochemical composition. A close coupling between biochemical composition of the organic matter in the water column and the material collected in the sediment trap was found, resulting from complex interactions between physical and biological processes. The physical processes are related to break-up and melting of the ice cover and occur mainly in the early summer season, whilst biological processes play a key role in mid summer and, from the evidence from faecal pellets, are related to the primary production and consumption processes.

1999 ◽  
Vol 11 (4) ◽  
pp. 415-418 ◽  
Author(s):  
Roberto Danovaro ◽  
Antonio Pusceddu ◽  
Simone Mirto ◽  
Mauro Fabiano

Meiofaunal community structure in coastal sediments of Terra Nova Bay (Ross Sea) was related to quantity and biochemical composition of sedimentary organic matter. The sediments were generally characterized by large amounts of chloropigments and labile compounds (dominated by proteins), indicating high inputs of primary organic matter. Meiofaunal densities were very high and comparable to those from the most productive areas worldwide. Sediments with high densities of the scallop had low meiofaunal densities especially in the top 2 cm, suggesting that scallop clapping contributed to meiofauna resuspension. However, it is not possible to exclude the probability that meiofauna are part of the scallop beds apparently have an important role in structuring meiofaunal communities with nematodes dominant where Adamussium colbecki is absent, and gastrotrichs dominant (44–51%) in A. colbecki beds, reaching the highest density reported so far.


2021 ◽  
pp. 103510
Author(s):  
Alessandro Cau ◽  
Claudia Ennas ◽  
Davide Moccia ◽  
Olga Mangoni ◽  
Francesco Bolinesi ◽  
...  

2020 ◽  
Vol 8 (9) ◽  
pp. 1273
Author(s):  
Renata Zaccone ◽  
Cristina Misic ◽  
Filippo Azzaro ◽  
Maurizio Azzaro ◽  
Giovanna Maimone ◽  
...  

The active prokaryotic communities proliferate in the ecosystems of the Antarctic Ocean, participating in biogeochemical cycles and supporting higher trophic levels. They are regulated by several environmental and ecological forcing, such as the characteristics of the water masses subjected to global warming and particulate organic matter (POM). During summer 2017, two polynyas in the Ross Sea were studied to evaluate key-microbiological parameters (the proteasic, glucosidasic, and phosphatasic activities, the microbial respiratory rates, the prokaryotic abundance and biomass) in relation to quantitative and qualitative characteristics of POM. Results showed significant differences in the epipelagic layer between two macro-areas (Terra Nova Bay and Ross Sea offshore area). Proteins and carbohydrates were metabolized rapidly in the offshore area (as shown by turnover times), due to high enzymatic activities in this zone, indicating fresh and labile organic compounds. The lower quality of POM in Terra Nova Bay, as shown by the higher refractory fraction, led to an increase in the turnover times of proteins and carbohydrates. Salinity was the physical constraint that played a major role in the distribution of POM and microbial activities in both areas.


2003 ◽  
Vol 15 (2) ◽  
pp. 175-188 ◽  
Author(s):  
A. ACCORNERO ◽  
C. MANNO ◽  
F. ESPOSITO ◽  
M.C. GAMBI

Downward fluxes of particulate matter were investigated in the polynya of Terra Nova Bay (western Ross Sea) from February 1995 to December 1997. The main biological components were siliceous phytoplankton (diatoms, silicoflagellates and parmales), abundant faecal pellets of several types and zooplankton (mainly shelled pteropods). Vertical fluxes of particles occurred mainly through diatoms and faecal pellets in the first and second part of the summer, respectively. The highest fluxes were recurrently observed in late summer, when faeces contributed up to 100% of organic carbon. Unusually high fluxes were recorded in winter 1995, when faecal pellets accounted for 84.6% of the organic carbon. Peak fluxes were always driven by the sinking of faecal pellets, that hence appear to be the most efficient vector of export in the polynya of Terra Nova Bay. A major flux component was the pteropod Limacina helicina, which repeatedly sank in high amounts after the growing season. In April–June, L. helicina probably transported biogenic carbon to deep layers as a passive sinker. The inclusion of pteropods in flux estimates resulted in values that were up to 20 (for total mass), 25 (for organic matter) and 48 (for carbonate) times higher than the previously measured fluxes. Fluxes are known to be biased by swimmers, but ultimately attention must be paid to a possible erroneous categorization of some zooplankton as swimmers to avoid severe underestimation of fluxes of total mass (up to 95% in our study), organic matter (up to 96%) and carbonate (up to 100%).


2006 ◽  
Vol 18 (4) ◽  
pp. 603-613 ◽  
Author(s):  
Paolo Povero ◽  
Michela Castellano ◽  
Nicoletta Ruggieri ◽  
Luis S. Monticelli ◽  
Vincenzo Saggiomo ◽  
...  

The northern Victoria Land coastal marine environment was investigated during the late summer 2004, within the framework of the Latitudinal Gradient Project (LGP), to describe the physical, chemical and biological patterns of the water column and their relationship with the pelagic and benthic compartments, and to determine to what extent they change with latitude. A latitudinal gradient from Cape Adare to the Terra Nova Bay–Cape Russell area was determined on the basis of abiotic and trophic factors. Cape Adare had lower values of organic matter (particulate organic carbon < 150 μg l−1) available for the benthic communities, but this organic matter had good trophic quality. In Terra Nova Bay the particulate organic matter was quantitatively higher (organic carbon > 400 μg l−1), presumably reaching the bottom via faecal pellets, but was more detrital, although its nutritive value was still high (carbon protein content nearly 40%), as confirmed by the great quantity of phytopigments in the sediments (> 4.0 μg g−1). The benthic communities changed with latitude as well, partially reflecting the environmental and trophic gradient, but also showing a large within-area variability (except for the Cape Adare area), due to a complex array of variables that did not change with latitude.


Polar Biology ◽  
2000 ◽  
Vol 23 (4) ◽  
pp. 288-293 ◽  
Author(s):  
Antonio Pusceddu ◽  
Antonio Dell'Anno ◽  
Mauro Fabiano

2010 ◽  
Vol 23 (1) ◽  
pp. 43-56 ◽  
Author(s):  
Stefano Cozzi ◽  
Carolina Cantoni

AbstractConcentration and isotope composition of particulate organic matter were analysed from five coastal sites on the annual fast ice and in the underlying water column at Terra Nova Bay. The highest increases of POC (< 2767 μM C) and PON (< 420 μM N) were reached in bottom ice and the unconsolidated platelet layer, linked with a large accumulation of nutrients and dissolved organic matter. Isotope POM composition in ice habitats was highly varied (δ13CPOC: -30.7 to -15.0‰, δ15NPON: 1.8–9.9‰). Constant negative δ13CPOC (> -29.3‰) and positive δ15NPON (< 9.4‰) values characterized the upper ice horizons, indicating the prevalence of aged detritus in these assemblages. By contrast, isotope composition (δ13CPOC: -15.0 to -29.7‰, δ15NPON: 1.8–9.6‰) and POC/PON ratios (6.2–12.6) changed markedly in bottom ice and interstitial water, even on short time scales, because of the combined effects of internal growth and mixing among freshly produced biomass. Sea ice breakout caused a large settling of particulates in the water column. It changed δ13CPOC (from 7.9 to 1.8‰) and δ15NPON (7.9–1.8‰) values in suspended particulate matter, indicating that inputs from fast ice strongly affect the isotopic signature of the particulate assemblage Antarctic coastal waters.


1996 ◽  
Vol 8 (1) ◽  
pp. 7-13 ◽  
Author(s):  
M. Fabiano ◽  
P. Povero ◽  
R. Danovaro

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.


Sign in / Sign up

Export Citation Format

Share Document