The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Carla Pruzzo - One of the best experts on this subject based on the ideXlab platform.
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benthic ecology of vibrio spp and pathogenic vibrio species in a coastal mediterranean Environment la spezia gulf italy
Microbial Ecology, 2009Co-Authors: Luigi Vezzulli, Elisabetta Pezzati, Mariapaola Moreno, Luigi Pane, Mauro Fabiano, Carla PruzzoAbstract:We carried out a 16-month in situ study to investigate the ecology of Vibrio spp. and pathogenic Vibrio species in coastal sediments of the Mediterranean Sea, employing multiple-regression analysis to reveal the major Environmental factors controlling their occurrence in the benthic Environment. In addition, association between vibrios and sediment-inhabiting meiofauna, which is a major component of benthic ecosystems, was investigated. Culturable and total Vibrio spp. estimates by most-probable-number technique coupled with standard polymerase chain reaction (PCR) and real-time PCR methods, respectively, were at least one order of magnitude higher in sediment than in seawater. In addition, potential human pathogenic species Vibrio cholerae, Vibrio vulnificus and Vibrio parahaemolyticus occurred in the sediment with V. parahaemolyticus being the most frequently found. In the Pelagic Environment, 60% of total variance in culturable Vibrio data was explained by sea surface temperature (40%), salinity (13%) and organic matter concentration (7%). In the benthic Environment, sea surface temperature was the only factor that significantly affected culturable Vibrio occurrence although it explained only 25% of total variance, suggesting that additional unexplored factors may play a role as well. No correlation was found between culturable Vibrio spp. concentrations and the abundance of harpacticoid copepods in the sediment whilst a negative correlation was found between Vibrio spp. and nematode abundance which accounted for almost 90% of the total meiofaunal density. Taxonomic analysis revealed that selective bacterial feeders accounted for nearly 50% of the total nematode community and included genera such as Terschellingia, Molgolaimus and Halalaimus, suggesting that top-down control by nematode grazing may be an important factor affecting Vibrio occurrence in these sediments. It is concluded that the benthic marine Environment may function as a reservoir of Vibrio spp. and potential pathogenic vibrios whose ecological features appeared substantially different from the ones recognised in the Pelagic Environment.
William F Gilly - One of the best experts on this subject based on the ideXlab platform.
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behavioral ecology of jumbo squid dosidicus gigas in relation to oxygen minimum zones
Deep-sea Research Part Ii-topical Studies in Oceanography, 2013Co-Authors: Julia S Stewart, John C Field, Unai Markaida, William F GillyAbstract:Abstract Habitat utilization, behavior and food habits of the jumbo or Humboldt squid, Dosidicus gigas, were compared between an area recently inhabited in the northern California Current System (CCS) and a historically established area of residence in the Gulf of California (GOC). Low dissolved oxygen concentrations at midwater depths define the oxygen minimum zone (OMZ), an important Environmental feature in both areas. We analyzed vertical diving behavior and diet of D. gigas and hydrographic properties of the water column to ascertain the extent to which squid utilized the OMZ in the two areas. The upper boundary of the OMZ has been shoaling in recent decades in the CCS, and this phenomenon has been proposed to vertically compress the Pelagic Environment inhabited by aerobic predators. A shoaling OMZ will also bring mesoPelagic communities into a depth range with more illumination during daytime, making these organisms more vulnerable to predation by visual predators (i.e. jumbo squid). Because the OMZ in the GOC is considerably shallower than in the CCS, our study provides insight into the behavioral plasticity of jumbo squid and how they may respond to a shoaling OMZ in the CCS. We propose that shoaling OMZs are likely to be favorable to jumbo squid and could be a key indirect factor behind the recent range expansion of this highly migratory predator.
Luigi Vezzulli - One of the best experts on this subject based on the ideXlab platform.
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benthic ecology of vibrio spp and pathogenic vibrio species in a coastal mediterranean Environment la spezia gulf italy
Microbial Ecology, 2009Co-Authors: Luigi Vezzulli, Elisabetta Pezzati, Mariapaola Moreno, Luigi Pane, Mauro Fabiano, Carla PruzzoAbstract:We carried out a 16-month in situ study to investigate the ecology of Vibrio spp. and pathogenic Vibrio species in coastal sediments of the Mediterranean Sea, employing multiple-regression analysis to reveal the major Environmental factors controlling their occurrence in the benthic Environment. In addition, association between vibrios and sediment-inhabiting meiofauna, which is a major component of benthic ecosystems, was investigated. Culturable and total Vibrio spp. estimates by most-probable-number technique coupled with standard polymerase chain reaction (PCR) and real-time PCR methods, respectively, were at least one order of magnitude higher in sediment than in seawater. In addition, potential human pathogenic species Vibrio cholerae, Vibrio vulnificus and Vibrio parahaemolyticus occurred in the sediment with V. parahaemolyticus being the most frequently found. In the Pelagic Environment, 60% of total variance in culturable Vibrio data was explained by sea surface temperature (40%), salinity (13%) and organic matter concentration (7%). In the benthic Environment, sea surface temperature was the only factor that significantly affected culturable Vibrio occurrence although it explained only 25% of total variance, suggesting that additional unexplored factors may play a role as well. No correlation was found between culturable Vibrio spp. concentrations and the abundance of harpacticoid copepods in the sediment whilst a negative correlation was found between Vibrio spp. and nematode abundance which accounted for almost 90% of the total meiofaunal density. Taxonomic analysis revealed that selective bacterial feeders accounted for nearly 50% of the total nematode community and included genera such as Terschellingia, Molgolaimus and Halalaimus, suggesting that top-down control by nematode grazing may be an important factor affecting Vibrio occurrence in these sediments. It is concluded that the benthic marine Environment may function as a reservoir of Vibrio spp. and potential pathogenic vibrios whose ecological features appeared substantially different from the ones recognised in the Pelagic Environment.
Julia S Stewart - One of the best experts on this subject based on the ideXlab platform.
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behavioral ecology of jumbo squid dosidicus gigas in relation to oxygen minimum zones
Deep-sea Research Part Ii-topical Studies in Oceanography, 2013Co-Authors: Julia S Stewart, John C Field, Unai Markaida, William F GillyAbstract:Abstract Habitat utilization, behavior and food habits of the jumbo or Humboldt squid, Dosidicus gigas, were compared between an area recently inhabited in the northern California Current System (CCS) and a historically established area of residence in the Gulf of California (GOC). Low dissolved oxygen concentrations at midwater depths define the oxygen minimum zone (OMZ), an important Environmental feature in both areas. We analyzed vertical diving behavior and diet of D. gigas and hydrographic properties of the water column to ascertain the extent to which squid utilized the OMZ in the two areas. The upper boundary of the OMZ has been shoaling in recent decades in the CCS, and this phenomenon has been proposed to vertically compress the Pelagic Environment inhabited by aerobic predators. A shoaling OMZ will also bring mesoPelagic communities into a depth range with more illumination during daytime, making these organisms more vulnerable to predation by visual predators (i.e. jumbo squid). Because the OMZ in the GOC is considerably shallower than in the CCS, our study provides insight into the behavioral plasticity of jumbo squid and how they may respond to a shoaling OMZ in the CCS. We propose that shoaling OMZs are likely to be favorable to jumbo squid and could be a key indirect factor behind the recent range expansion of this highly migratory predator.
Nicholas J Shackleton - One of the best experts on this subject based on the ideXlab platform.
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Response of the Pelagic Environment to palaeoclimatic changes in the central Mediterranean Sea during the Late Quaternary
Marine Geology, 2020Co-Authors: Laura Sbaffi, Forese Carlo Wezel, Nejib Kallel, Martine Paterne, Isabel Cacho, Patrizia Ziveri, Nicholas J ShackletonAbstract:Three central Mediterranean deep-sea cores have been studied to reconstruct the palaeoclimatic history of the basin over the time interval 34-0 kyr BP. The intensity and duration of the climatic events that occurred in the Mediterranean Sea during the last glacial-postglacial transition were estimated by observing compositional changes in the planktonic foraminifera and calcareous nannoplankton (coccolithophores) assemblages, together with a reconstruction of sea surface temperatures (using the Modern Analogue Techmque and
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response of the Pelagic Environment to palaeoclimatic changes in the central mediterranean sea during the late quaternary
Marine Geology, 2001Co-Authors: Laura Sbaffi, Forese Carlo Wezel, Nejib Kallel, Martine Paterne, Isabel Cacho, Patrizia Ziveri, Nicholas J ShackletonAbstract:Abstract Three central Mediterranean deep-sea cores have been studied to reconstruct the palaeoclimatic history of the basin over the time interval 34–0 kyr bp . The intensity and duration of the climatic events that occurred in the Mediterranean Sea during the last glacial-postglacial transition were estimated by observing compositional changes in the planktonic foraminifera and calcareous nannoplankton (coccolithophores) assemblages, together with a reconstruction of sea surface temperatures (using the Modern Analogue Technique and U 37 k′ index), the δ 18 O signal and pteropod fluxes. The application of two independent and well established techniques for the determination of the past SST led to a number of considerations about the accuracy and efficacy of the use of such methodologies in the Mediterranean Sea, notoriously dominated by local factors and characterised by a number of independent Environments. The recognition of millennial to centennial climatic instabilities, in both the SST and microfossil records, was possible because of the high resolution of the study. A succession of nine main biozones and six sub-zones, based on the major changes in the planktonic foraminifera records, has been recognised and compared with GRIP and GISP2 ice cores δ 18 O values and with records from four other studies from the central Mediterranean Sea. During the early phase of the Holocene, a period characterised by relatively higher temperatures and lighter δ 18 O values has been recognised as being coeval with the ‘Climatic Optimum’ (between 10.5 and 6.1 kyr bp , calendar age). This interval was characterised by an abrupt drop in the pteropods relative abundances and fluxes. The pteropodal fossil assemblage may have been affected by a possible event of selective dissolution of the aragonite driven by the shoaling of the ACD. A coeval change in the position of the pycnocline may have been responsible for a strong relative increase in abundance of Neogloboquadrina pachyderma r.c., and a decrease in the abundance of Globorotalia inflata in the western sector of the Mediterranean Sea.