Michele Giani - Academia.edu (original) (raw)

Papers by Michele Giani

36th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 2023)

Marine Biology

Shallow-water hydrothermal vents are extreme environments characterized by high temperatures, low... more Shallow-water hydrothermal vents are extreme environments characterized by high temperatures, low pH, and high CO2 concentrations; therefore, they are considered as suitable laboratories for studying the effect of global changes on marine microbes. We hypothesized a direct effect of vents on prokaryotic community structure and functioning in the Panarea Island’s hydrothermal system. Sampling was conducted along a 9-station transect characterized by three active emission points. The water column was stratified with a thermocline at 25 m depth and a deep chlorophyll maximum between 50 and 100 m. Prokaryotic abundance ranged from 0.2 to 1.5 × 109 cells L−1, prokaryotic carbon production from 2.4 to 75.4 ng C L−1 h−1, and exoenzymatic activities degrading proteins, phosphorylated compounds, and polysaccharides were on the order of 4–28, 2–31 and 0.2–4.16 nM h−1, respectively. While microbial abundance and production were shaped by the water column's physical structure, alkaline phos...

Il tempo del pianeta Terra e il tempo dell’uomo: Le geoscienze fra passato e futuro, 2019

Frontiers in Marine Science

Ocean acidification (OA) is a serious consequence of climate change with complex organism-to-ecos... more Ocean acidification (OA) is a serious consequence of climate change with complex organism-to-ecosystem effects that have been observed through field observations but are mainly derived from experimental studies. Although OA trends and the resulting biological impacts are likely exacerbated in the semi-enclosed and highly populated Mediterranean Sea, some fundamental knowledge gaps still exist. These gaps are at tributed to both the uneven capacity for OA research that exists between Mediterranean countries, as well as to the subtle and long-term biological, physical and chemical interactions that define OA impacts. In this paper, we systematically analyzed the different aspects of OA research in the Mediterranean region based on two sources: the United Nation’s International Atomic Energy Agency’s (IAEA) Ocean Acidification International Coordination Center (OA-ICC) database, and an extensive survey. Our analysis shows that 1) there is an uneven geographic capacity in OA research, a...

Frontiers in Marine Science

The Antarctic continental shelf is known as a critical anthropogenic CO2 (Cant) sink due to its c... more The Antarctic continental shelf is known as a critical anthropogenic CO2 (Cant) sink due to its cold waters, high primary productivity, and unique circulation, which allow it to sequester large amounts of organic and inorganic carbon into the deep ocean. However, climate change is currently causing significant alteration to the Antarctic marine carbon cycle, with unknown consequences on the Cant uptake capacity, making model-based estimates of future ocean acidification of polar regions highly uncertain. Here, we investigated the marine carbonate system in the Ross Sea in order to assess the current anthropogenic carbon content and how physical–biological processes can control the Cant sequestration along the shelf-slope continuum. The Winter Water mass generated from convective events was characterized by high Cant level (28 µmol kg−1) as a consequence of the mixed layer break-up during the cold season, whereas old and less-ventilated Circumpolar Deep Water entering the Ross Sea re...

SAME - 11th Symposium on Aquatic Microbial Ecology, 2009

In this paper we investigated, for two years and with a bi-monthly frequency, how physical, chemi... more In this paper we investigated, for two years and with a bi-monthly frequency, how physical, chemical, and biological processes affect the marine carbonate system in a coastal area characterized by high alkalinity riverine discharge (Gulf of Trieste, northern Adriatic Sea, Mediterranean Sea).

A joint mesocosm experiment took place in February/March 2013 in the bay of Villefranche in Franc... more A joint mesocosm experiment took place in February/March 2013 in the bay of Villefranche in France as part of the european MedSeA project. Nine mesocosms (52 m**3) were deployed over a 2 weeks period and 6 different levels of pCO2 and 3 control mesocosms (about 450 µatm), were used, in order to cover the range of pCO2 anticipated for the end of the present century. During this experiment, the potential effects of these perturbations on chemistry, planktonic community composition and dynamics including: eucaryotic and prokaryotic species composition, primary production, nutrient and carbon utilization, calcification, diazotrophic nitrogen fixation, organic matter exudation and composition, micro-layer composition and biogas production were studied by a group of about 25 scientists from 8 institutes and 6 countries. This is one of the first mesocosm experiments conducted in oligotrophic waters. A blog dedicated to this experiment can be viewed at: http://medseavillefranche2013.obs-vlfr.fr.

Three culture experiment on the diatom Thalassiosira rotula were conducted within two 2L-photobio... more Three culture experiment on the diatom Thalassiosira rotula were conducted within two 2L-photobioreactors under controlled conditions of light and temperature (20 ± 0.02 °C). During each experiment, diatoms were simultaneously grown in the two bioreactors filled respectively with different media. In one of the two bioreactor microalgae were grown in a natural seawater (NAT) medium, whereas in the second one an artificial seawater medium (ASW) was used. ASW medium was artificially prepared, to reach a modified isotopic composition of DIC using an industrial compressed CO2, and at each experiment a different initial DIC concentration was tested to verify if carbon availability would affect phytoplankton algal metabolism. For NAT medium, a sterile-filtered Adriatic Sea water was used and a natural DIC concentration used. During the experiments, the evolution of T. rotula abundance was investigated, together with the variation of the isotopic composition of dissolved inorganic carbon, p...

A joint mesocosm experiment took place in June/July 2012 in Corsica (bay of Calvi, Stareso statio... more A joint mesocosm experiment took place in June/July 2012 in Corsica (bay of Calvi, Stareso station;http://www.stareso.com/) as part of the european MedSeA project. Nine mesocosms (52 m**3) were deployed over a 20 days period and 6 different levels of pCO2 and 3 control mesocosms (about 450 µatm), were used, in order to cover the range of pCO2 anticipated for the end of the present century. During this experiment, the potential effects of these perturbations on chemistry, planktonic community composition and dynamics including: eucaryotic and prokaryotic species composition, primary production, nutrient and carbon utilization, calcification, diazotrophic nitrogen fixation, organic matter exudation and composition, micro-layer composition and biogas production were studied by a group of about 25 scientists from 8 institutes and 6 countries. This is one of the first mesocosm experiments conducted in oligotrophic waters. A blog dedicated to this experiment can be viewed at: http://medseastareso2012.wordpress.com/.

36th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 2023)

Marine Biology

Shallow-water hydrothermal vents are extreme environments characterized by high temperatures, low... more Shallow-water hydrothermal vents are extreme environments characterized by high temperatures, low pH, and high CO2 concentrations; therefore, they are considered as suitable laboratories for studying the effect of global changes on marine microbes. We hypothesized a direct effect of vents on prokaryotic community structure and functioning in the Panarea Island’s hydrothermal system. Sampling was conducted along a 9-station transect characterized by three active emission points. The water column was stratified with a thermocline at 25 m depth and a deep chlorophyll maximum between 50 and 100 m. Prokaryotic abundance ranged from 0.2 to 1.5 × 109 cells L−1, prokaryotic carbon production from 2.4 to 75.4 ng C L−1 h−1, and exoenzymatic activities degrading proteins, phosphorylated compounds, and polysaccharides were on the order of 4–28, 2–31 and 0.2–4.16 nM h−1, respectively. While microbial abundance and production were shaped by the water column's physical structure, alkaline phos...

Il tempo del pianeta Terra e il tempo dell’uomo: Le geoscienze fra passato e futuro, 2019

Frontiers in Marine Science

Ocean acidification (OA) is a serious consequence of climate change with complex organism-to-ecos... more Ocean acidification (OA) is a serious consequence of climate change with complex organism-to-ecosystem effects that have been observed through field observations but are mainly derived from experimental studies. Although OA trends and the resulting biological impacts are likely exacerbated in the semi-enclosed and highly populated Mediterranean Sea, some fundamental knowledge gaps still exist. These gaps are at tributed to both the uneven capacity for OA research that exists between Mediterranean countries, as well as to the subtle and long-term biological, physical and chemical interactions that define OA impacts. In this paper, we systematically analyzed the different aspects of OA research in the Mediterranean region based on two sources: the United Nation’s International Atomic Energy Agency’s (IAEA) Ocean Acidification International Coordination Center (OA-ICC) database, and an extensive survey. Our analysis shows that 1) there is an uneven geographic capacity in OA research, a...

Frontiers in Marine Science

The Antarctic continental shelf is known as a critical anthropogenic CO2 (Cant) sink due to its c... more The Antarctic continental shelf is known as a critical anthropogenic CO2 (Cant) sink due to its cold waters, high primary productivity, and unique circulation, which allow it to sequester large amounts of organic and inorganic carbon into the deep ocean. However, climate change is currently causing significant alteration to the Antarctic marine carbon cycle, with unknown consequences on the Cant uptake capacity, making model-based estimates of future ocean acidification of polar regions highly uncertain. Here, we investigated the marine carbonate system in the Ross Sea in order to assess the current anthropogenic carbon content and how physical–biological processes can control the Cant sequestration along the shelf-slope continuum. The Winter Water mass generated from convective events was characterized by high Cant level (28 µmol kg−1) as a consequence of the mixed layer break-up during the cold season, whereas old and less-ventilated Circumpolar Deep Water entering the Ross Sea re...

SAME - 11th Symposium on Aquatic Microbial Ecology, 2009

In this paper we investigated, for two years and with a bi-monthly frequency, how physical, chemi... more In this paper we investigated, for two years and with a bi-monthly frequency, how physical, chemical, and biological processes affect the marine carbonate system in a coastal area characterized by high alkalinity riverine discharge (Gulf of Trieste, northern Adriatic Sea, Mediterranean Sea).

A joint mesocosm experiment took place in February/March 2013 in the bay of Villefranche in Franc... more A joint mesocosm experiment took place in February/March 2013 in the bay of Villefranche in France as part of the european MedSeA project. Nine mesocosms (52 m**3) were deployed over a 2 weeks period and 6 different levels of pCO2 and 3 control mesocosms (about 450 µatm), were used, in order to cover the range of pCO2 anticipated for the end of the present century. During this experiment, the potential effects of these perturbations on chemistry, planktonic community composition and dynamics including: eucaryotic and prokaryotic species composition, primary production, nutrient and carbon utilization, calcification, diazotrophic nitrogen fixation, organic matter exudation and composition, micro-layer composition and biogas production were studied by a group of about 25 scientists from 8 institutes and 6 countries. This is one of the first mesocosm experiments conducted in oligotrophic waters. A blog dedicated to this experiment can be viewed at: http://medseavillefranche2013.obs-vlfr.fr.

Three culture experiment on the diatom Thalassiosira rotula were conducted within two 2L-photobio... more Three culture experiment on the diatom Thalassiosira rotula were conducted within two 2L-photobioreactors under controlled conditions of light and temperature (20 ± 0.02 °C). During each experiment, diatoms were simultaneously grown in the two bioreactors filled respectively with different media. In one of the two bioreactor microalgae were grown in a natural seawater (NAT) medium, whereas in the second one an artificial seawater medium (ASW) was used. ASW medium was artificially prepared, to reach a modified isotopic composition of DIC using an industrial compressed CO2, and at each experiment a different initial DIC concentration was tested to verify if carbon availability would affect phytoplankton algal metabolism. For NAT medium, a sterile-filtered Adriatic Sea water was used and a natural DIC concentration used. During the experiments, the evolution of T. rotula abundance was investigated, together with the variation of the isotopic composition of dissolved inorganic carbon, p...

A joint mesocosm experiment took place in June/July 2012 in Corsica (bay of Calvi, Stareso statio... more A joint mesocosm experiment took place in June/July 2012 in Corsica (bay of Calvi, Stareso station;http://www.stareso.com/) as part of the european MedSeA project. Nine mesocosms (52 m**3) were deployed over a 20 days period and 6 different levels of pCO2 and 3 control mesocosms (about 450 µatm), were used, in order to cover the range of pCO2 anticipated for the end of the present century. During this experiment, the potential effects of these perturbations on chemistry, planktonic community composition and dynamics including: eucaryotic and prokaryotic species composition, primary production, nutrient and carbon utilization, calcification, diazotrophic nitrogen fixation, organic matter exudation and composition, micro-layer composition and biogas production were studied by a group of about 25 scientists from 8 institutes and 6 countries. This is one of the first mesocosm experiments conducted in oligotrophic waters. A blog dedicated to this experiment can be viewed at: http://medseastareso2012.wordpress.com/.