Role of filtering and biodeposition by Adamussium colbecki in circulation of organic matter in Terra Nova Bay (Ross Sea, Antarctica)

1998 ◽  
Vol 17 (1-4) ◽  
pp. 411-424 ◽  
Author(s):  
M. Chiantore ◽  
R. Cattaneo-Vietti ◽  
G. Albertelli ◽  
C. Misic ◽  
M. Fabiano
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. 645-653 ◽  
Author(s):  
Marta Guidetti ◽  
Stefania Marcato ◽  
Mariachiara Chiantore ◽  
Tomaso Patarnello ◽  
Giancarlo Albertelli ◽  
...  

The endemic Antarctic scallop Adamussium colbecki (Mollusca: Bivalvia) represents a key species in the Ross Sea littoral benthic ecosystem, locally reaching very high densities. This species has an annual gametogenic cycle, with a summer spawning event, and a pelagic larval behaviour. This paper aims at describing population structure and genetic polymorphism (using AFLP) of the large populations inhabiting the Ross Sea (Terra Nova Bay and McMurdo Sound) in order to investigate possible genetic exchange between A. colbecki in these areas. In Terra Nova Bay, size-frequency distributions show, generally, the dominance of large individuals, although site related differences are found in the abundance of smaller size classes (less than 40 mm), suggesting that recruitment is not a regular event. All McMurdo sites are characterized by large individuals and, at least during this sampling period, recruitment is completely absent. Nuclear DNA analyses show that the largest differences are found at the largest scale (between McMurdo Sound and Terra Nova Bay), but all populations sampled, even at a smaller spatial scale, have a well-settled genetic structure, notwithstanding the pelagic larval strategy. The panmixia hypothesis has therefore to be rejected for this species.


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

Polar Biology ◽  
2008 ◽  
Vol 32 (3) ◽  
pp. 311-323 ◽  
Author(s):  
Olga Mangoni ◽  
Maria Saggiomo ◽  
Monica Modigh ◽  
Giulio Catalano ◽  
Adriana Zingone ◽  
...  

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.


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