scholarly journals Ocean Acidification Induces Changes in Virus–Host Relationships in Mediterranean Benthic Ecosystems

2021 ◽  
Vol 9 (4) ◽  
pp. 769
Author(s):  
Michael Tangherlini ◽  
Cinzia Corinaldesi ◽  
Francesca Ape ◽  
Silvestro Greco ◽  
Teresa Romeo ◽  
...  

Acidified marine systems represent “natural laboratories”, which provide opportunities to investigate the impacts of ocean acidification on different living components, including microbes. Here, we compared the benthic microbial response in four naturally acidified sites within the Southern Tyrrhenian Sea characterized by different acidification sources (i.e., CO2 emissions at Ischia, mixed gases at Panarea and Basiluzzo and acidified freshwater from karst rocks at Presidiana) and pH values. We investigated prokaryotic abundance, activity and biodiversity, viral abundance and prokaryotic infections, along with the biochemical composition of the sediment organic matter. We found that, despite differences in local environmental dynamics, viral life strategies change in acidified conditions from mainly lytic to temperate lifestyles (e.g., chronic infection), also resulting in a lowered impact on prokaryotic communities, which shift towards (chemo)autotrophic assemblages, with lower organic matter consumption. Taken together, these results suggest that ocean acidification exerts a deep control on microbial benthic assemblages, with important feedbacks on ecosystem functioning.

2010 ◽  
Vol 1 (2) ◽  
pp. 235 ◽  
Author(s):  
Rosabruna La Ferla ◽  
Maurizio Azzaro ◽  
Giorgio Budillon ◽  
Carmela Caroppo ◽  
Franco Decembrini ◽  
...  

The distribution of the prokaryotic biomass (from both abundance and cell volume measurements) and microbial community respiration (by ETS activity) in the main water masses of the Southern Tyrrhenian Sea were studied. The data were collected from surface to the bottom depth (max 3600 m) in July and December 2005. Prokaryotic abundance and microbial respiration were higher in summer than late-autumn and decreased with depth in accordance with the water masses. The opposite was found for the prokaryotic cell volumes that increased with depth and were higher in December. The cell carbon content varied within the water masses and study periods (range 9–34 fg C cell−1) and overestimations and underestimations of biomass there would have been by using the routinely adopted conversion factor (20 fg C cell−1). The depth-integrated respiratory rates resulted comparable in the photic and aphotic layers. In July, 210 and 225 mg C m−2 day−1 in the euphotic and aphotic zones, respectively, were remineralized while in December, 112 and 134 mg C m−2 day−1, respectively, were. Speculations to quantify the carbon flow mediated by microbial community suggested the occurrence of different microbial behavior within the different water masses.


2018 ◽  
Vol 15 (1) ◽  
pp. 209-231 ◽  
Author(s):  
Stacy Deppeler ◽  
Katherina Petrou ◽  
Kai G. Schulz ◽  
Karen Westwood ◽  
Imojen Pearce ◽  
...  

Abstract. High-latitude oceans are anticipated to be some of the first regions affected by ocean acidification. Despite this, the effect of ocean acidification on natural communities of Antarctic marine microbes is still not well understood. In this study we exposed an early spring, coastal marine microbial community in Prydz Bay to CO2 levels ranging from ambient (343 µatm) to 1641 µatm in six 650 L minicosms. Productivity assays were performed to identify whether a CO2 threshold existed that led to a change in primary productivity, bacterial productivity, and the accumulation of chlorophyll a (Chl a) and particulate organic matter (POM) in the minicosms. In addition, photophysiological measurements were performed to identify possible mechanisms driving changes in the phytoplankton community. A critical threshold for tolerance to ocean acidification was identified in the phytoplankton community between 953 and 1140 µatm. CO2 levels  ≥ 1140 µatm negatively affected photosynthetic performance and Chl a-normalised primary productivity (csGPP14C), causing significant reductions in gross primary production (GPP14C), Chl a accumulation, nutrient uptake, and POM production. However, there was no effect of CO2 on C : N ratios. Over time, the phytoplankton community acclimated to high CO2 conditions, showing a down-regulation of carbon concentrating mechanisms (CCMs) and likely adjusting other intracellular processes. Bacterial abundance initially increased in CO2 treatments  ≥ 953 µatm (days 3–5), yet gross bacterial production (GBP14C) remained unchanged and cell-specific bacterial productivity (csBP14C) was reduced. Towards the end of the experiment, GBP14C and csBP14C markedly increased across all treatments regardless of CO2 availability. This coincided with increased organic matter availability (POC and PON) combined with improved efficiency of carbon uptake. Changes in phytoplankton community production could have negative effects on the Antarctic food web and the biological pump, resulting in negative feedbacks on anthropogenic CO2 uptake. Increases in bacterial abundance under high CO2 conditions may also increase the efficiency of the microbial loop, resulting in increased organic matter remineralisation and further declines in carbon sequestration.


2011 ◽  
Vol 109 (2-3) ◽  
pp. 342-350 ◽  
Author(s):  
Anna Perdichizzi ◽  
Laura Pirrera ◽  
Daniela Giordano ◽  
Francesco Perdichizzi ◽  
Barbara Busalacchi ◽  
...  

2006 ◽  
Vol 262 (1) ◽  
pp. 337-348
Author(s):  
G. L. Piangiamore ◽  
O. Faggioni ◽  
M. S. Barbano

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Anna Perdichizzi ◽  
Laura Pirrera ◽  
Valeria Micale ◽  
Ugo Muglia ◽  
Paola Rinelli

The reproductive features of the giant red shrimp,Aristaeomorpha foliacea, were investigated in the southern Tyrrhenian sea by experimental trawl sampling. The annual length-frequency distribution showed a multimodal trend in females, ranging between 16 and 67 mm carapace length (CL), and a unimodal trend in males (18–45 mm CL). Mature males occurred in different proportions all year round, while females displayed seasonal maturity (June—September), with a peak in July. Six oocyte developmental stages were identified, the most advanced of which (Pv, postvitellogenic) had never been described before in this species. Ovary development followed a group-synchronous pattern, with the yolked oocyte stock clearly separated from the reservoir of unyolked oocytes, suggesting thatA. foliaceais a total spawner, with determinate fecundity. Based upon histological findings, a revision of macroscopic maturity staging employed in Mediterranean bottom trawl surveys (MEDITS) is proposed.


2016 ◽  
Vol 64 (spe2) ◽  
pp. 117-136 ◽  
Author(s):  
Paulo Antunes Horta ◽  
Pablo Riul ◽  
Gilberto M. Amado Filho ◽  
Carlos Frederico D. Gurgel ◽  
Flávio Berchez ◽  
...  

Abstract Rhodolith beds are important marine benthic ecosystems, representing oases of high biodiversity among sedimentary seabed environments. They are found frequently and abundantly, acting as major carbonate 'factories' and playing a key role in the biogeochemical cycling of carbonates in the South Atlantic. Rhodoliths are under threat due to global change (mainly related to ocean acidification and global warming) and local stressors, such as fishing and coastal run-off. Here, we review different aspects of the biology of these organisms, highlighting the predicted effects of global change, considering the additional impact of local stressors. Ocean acidification (OA) represents a particular threat that can reduce calcification or even promote the decalcification of these bioengineers, thus increasing the eco-physiological imbalance between calcareous and fleshy algae. OA should be considered, but this together with extreme events such as heat waves and storms, as main stressors of these ecosystems at the present time, will worsen in the future, especially if possible interactions with local stressors like coastal pollution are taken into consideration. Thus, in Brazil there is a serious need for starting monitoring programs and promote innovative experimental infrastructure in order to improve our knowledge of these rich environments, optimize management efforts and enhance the needed conservation initiatives.


Eos ◽  
2019 ◽  
Vol 100 ◽  
Author(s):  
Terri Cook

Researchers have identified a previously unknown volcanic-intrusive complex that originated through the melting of mantle material at the northern edge of the Ionian slab.


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