Quantification of the effects of ocean acidification on sediment microbial communities in the environment: the importance of ecosystem approaches

Ocean warming and ocean acidification (OA) are direct consequences of climate change and affect coral reefs worldwide. While the effect of ocean warming manifests itself in increased frequency and severity of coral bleaching, the effects of ocean acidification on corals are less clear. In particular, long-term effects of OA on the bacterial communities associated with corals are largely unknown. In this study, we investigated the effects of ocean acidification on the resident and active microbiome of long-term aquaria-maintained Stylophora pistillata colonies by assessing 16S rRNA gene diversity on the DNA (resident community) and RNA level (active community). Coral colony fragments of S. pistillata were kept in aquaria for 2 years at four different pCO2 levels ranging from current pH conditions to increased acidification scenarios (i.e., pH 7.2, 7.4, 7.8, and 8). We identified 154 bacterial families encompassing 2,047 taxa (OTUs) in the resident and 89 bacterial families including 1,659 OTUs in the active communities. Resident communities were dominated by members of Alteromonadaceae, Flavobacteriaceae, and Colwelliaceae, while active communities were dominated by families Cyclobacteriacea and Amoebophilaceae. Besides the overall differences between resident and active community composition, significant differences were seen between the control (pH 8) and the two lower pH treatments (7.2 and 7.4) in the active community, but only between pH 8 and 7.2 in the resident community. Our analyses revealed profound differences between the resident and active microbial communities, and we found that OA exerted stronger effects on the active community. Further, our results suggest that rDNA- and rRNA-based sequencing should be considered complementary tools to investigate the effects of environmental change on microbial assemblage structure and activity.

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Comments on Ice Acidification: A review of the effects of ocean acidification on sea ice microbial communities

10.5194/bg-2017-111-rc3 ◽

2017 ◽

Author(s):

Anonymous

Keyword(s):

Sea Ice ◽

Ocean Acidification ◽

Microbial Communities

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Ice Acidification: A review of the effects of ocean acidification on sea ice microbial communities

10.5194/bg-2017-111 ◽

2017 ◽

Author(s):

Andrew McMinn

Keyword(s):

Sea Ice ◽

Ocean Acidification ◽

Microbial Communities ◽

Co2 Concentration ◽

Marine Phytoplankton ◽

Ice Algae ◽

Sea Ice Algae ◽

Co2 Concentrations ◽

Ocean Properties ◽

Short Time

Abstract. Sea ice algae are naturally exposed to a wider range of pH and CO2 concentrations than marine phytoplankton. While climate change and ocean acidification (OA) will impact pelagic communities, their effects on sea ice microbial communities remains unclear. Sea ice contains several distinct microbial communities, which are exposed to differing environmental conditions depending on their depth within the ice. Bottom communities mostly experience relatively benign bulk ocean properties, while interior brine and surface communities experience much greater extremes. Most OA studies have examined the impacts on single sea ice algae species in culture. Although some studies examined the effects of OA alone, most also examined the effects of OA and either light, nutrients or temperature. With few exceptions, increased CO2 concentration caused either no change or an increase in growth and/or photosynthesis. In situ studies of brine and surface algae also demonstrated a wide tolerance to increased and decreased pH and showed increased growth at higher CO2 concentrations. The short time period of most experiments (

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Reviews and syntheses: Ice acidification, the effects of ocean acidification on sea ice microbial communities

Biogeosciences ◽

10.5194/bg-14-3927-2017 ◽

2017 ◽

Vol 14 (17) ◽

pp. 3927-3935 ◽

Cited By ~ 8

Author(s):

Andrew McMinn

Keyword(s):

Sea Ice ◽

Ocean Acidification ◽

Microbial Communities ◽

Full Range ◽

Co2 Concentration ◽

Ice Algae ◽

Single Strain ◽

Sea Ice Algae ◽

Co2 Concentrations ◽

Negative Impacts

Abstract. Sea ice algae, like some coastal and estuarine phytoplankton, are naturally exposed to a wider range of pH and CO2 concentrations than those in open marine seas. While climate change and ocean acidification (OA) will impact pelagic communities, their effects on sea ice microbial communities remain unclear. Sea ice contains several distinct microbial communities, which are exposed to differing environmental conditions depending on their depth within the ice. Bottom communities mostly experience relatively benign bulk ocean properties, while interior brine and surface (infiltration) communities experience much greater extremes. Most OA studies have examined the impacts on single sea ice algae species in culture. Although some studies examined the effects of OA alone, most examined the effects of OA and either light, nutrients or temperature. With few exceptions, increased CO2 concentration caused either no change or an increase in growth and/or photosynthesis. In situ studies on brine and surface algae also demonstrated a wide tolerance to increased and decreased pH and showed increased growth at higher CO2 concentrations. The short time period of most experiments (< 10 days), together with limited genetic diversity (i.e. use of only a single strain), however, has been identified as a limitation to a broader interpretation of the results. While there have been few studies on the effects of OA on the growth of marine bacterial communities in general, impacts appear to be minimal. In sea ice also, the few reports available suggest no negative impacts on bacterial growth or community richness. Sea ice ecosystems are ephemeral, melting and re-forming each year. Thus, for some part of each year organisms inhabiting the ice must also survive outside of the ice, either as part of the phytoplankton or as resting spores on the bottom. During these times, they will be exposed to the full range of co-stressors that pelagic organisms experience. Their ability to continue to make a major contribution to sea ice productivity will depend not only on their ability to survive in the ice but also on their ability to survive the increasing seawater temperatures, changing distribution of nutrients and declining pH forecast for the water column over the next centuries.

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Contrasting effects of ocean acidification on the microbial food web under different trophic conditions

ICES Journal of Marine Science ◽

10.1093/icesjms/fsv130 ◽

2015 ◽

Vol 73 (3) ◽

pp. 670-679 ◽

Cited By ~ 44

Author(s):

M. M. Sala ◽

F. L. Aparicio ◽

V. Balagué ◽

J. A. Boras ◽

E. Borrull ◽

...

Keyword(s):

Ocean Acidification ◽

Microbial Communities ◽

Heterotrophic Bacteria ◽

Phytoplankton Bloom ◽

Extracellular Enzyme ◽

Nutrient Concentrations ◽

Leucine Incorporation ◽

Negative Effects ◽

Trophic Conditions ◽

Positive Effects

AbstractWe investigated the effects of an increase in dissolved CO2 on the microbial communities of the Mediterranean Sea during two mesocosm experiments in two contrasting seasons: winter, at the peak of the annual phytoplankton bloom, and summer, under low nutrient conditions. The experiments included treatments with acidification and nutrient addition, and combinations of the two. We followed the effects of ocean acidification (OA) on the abundance of the main groups of microorganisms (diatoms, dinoflagellates, nanoeukaryotes, picoeukaryotes, cyanobacteria, and heterotrophic bacteria) and on bacterial activity, leucine incorporation, and extracellular enzyme activity. Our results showed a clear stimulation effect of OA on the abundance of small phytoplankton (pico- and nanoeukaryotes), independently of the season and nutrient availability. A large number of the measured variables showed significant positive effects of acidification in summer compared with winter, when the effects were sometimes negative. Effects of OA were more conspicuous when nutrient concentrations were low. Our results therefore suggest that microbial communities in oligotrophic waters are considerably affected by OA, whereas microbes in more productive waters are less affected. The overall enhancing effect of acidification on eukaryotic pico- and nanophytoplankton, in comparison with the non-significant or even negative response to nutrient-rich conditions of larger groups and autotrophic prokaryotes, suggests a shift towards medium-sized producers in a future acidified ocean.

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Ocean acidification alters the diversity and structure of oyster associated microbial communities

Limnology and Oceanography Letters ◽

10.1002/lol2.10214 ◽

2021 ◽

Author(s):

Andrea Unzueta‐Martínez ◽

Alan M. Downey‐Wall ◽

Louise P. Cameron ◽

Justin B. Ries ◽

Katie E. Lotterhos ◽

...

Keyword(s):

Ocean Acidification ◽

Microbial Communities

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Ocean acidification reduces growth and grazing impact of Antarctic heterotrophic nanoflagellates

Biogeosciences ◽

10.5194/bg-17-4153-2020 ◽

2020 ◽

Vol 17 (16) ◽

pp. 4153-4171

Author(s):

Stacy Deppeler ◽

Kai G. Schulz ◽

Alyce Hancock ◽

Penelope Pascoe ◽

John McKinlay ◽

...

Keyword(s):

Ocean Acidification ◽

Food Web ◽

Microbial Communities ◽

Heterotrophic Bacteria ◽

Trophic Levels ◽

Heterotrophic Nanoflagellates ◽

Grazing Impact ◽

Antarctic Marine ◽

Morphological Differences ◽

Organic Matter Recycling

Abstract. High-latitude oceans have been identified as particularly vulnerable to ocean acidification if anthropogenic CO2 emissions continue. Marine microbes are an essential part of the marine food web and are a critical link in biogeochemical processes in the ocean, such as the cycling of nutrients and carbon. Despite this, the response of Antarctic marine microbial communities to ocean acidification is poorly understood. We investigated the effect of increasing fCO2 on the growth of heterotrophic nanoflagellates (HNFs), nano- and picophytoplankton, and prokaryotes (heterotrophic Bacteria and Archaea) in a natural coastal Antarctic marine microbial community from Prydz Bay, East Antarctica. At CO2 levels ≥634 µatm, HNF abundance was reduced, coinciding with increased abundance of picophytoplankton and prokaryotes. This increase in picophytoplankton and prokaryote abundance was likely due to a reduction in top-down control of grazing HNFs. Nanophytoplankton abundance was elevated in the 634 µatm treatment, suggesting that moderate increases in CO2 may stimulate growth. The taxonomic and morphological differences in CO2 tolerance we observed are likely to favour dominance of microbial communities by prokaryotes, nanophytoplankton, and picophytoplankton. Such changes in predator–prey interactions with ocean acidification could have a significant effect on the food web and biogeochemistry in the Southern Ocean, intensifying organic-matter recycling in surface waters; reducing vertical carbon flux; and reducing the quality, quantity, and availability of food for higher trophic levels.

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Effects of Ocean Acidification, Hypoxia, and Warming on the Gut Microbiota of the Thick Shell Mussel Mytilus coruscus Through 16S rRNA Gene Sequencing

Frontiers in Marine Science ◽

10.3389/fmars.2021.736338 ◽

2021 ◽

Vol 8 ◽

Author(s):

Fahim Ullah Khan ◽

Yueyong Shang ◽

Xueqing Chang ◽

Hui Kong ◽

Amina Zuberi ◽

...

Keyword(s):

Community Structure ◽

Gut Microbiota ◽

Ocean Acidification ◽

Microbial Communities ◽

16S Rrna Gene Sequencing ◽

Low Ph ◽

Rrna Gene ◽

Linear Discriminant ◽

Mytilus Coruscus ◽

Marine Mussels

Gut microbiota play a very important role in the health of the host, such as protecting from pathogens and maintaining homeostasis. However, environmental stressors, such as ocean acidification, hypoxia, and warming can affect microbial communities by causing alteration in their structure and relative abundance and by destroying their network. The study aimed to evaluate the combined effects of low pH, low dissolved oxygen (DO) levels, and warming on gut microbiota of the mussel Mytilus coruscus. Mussels were exposed to two pH levels (8.1, 7.7), two DO levels (6, 2 mg L−1), and two temperature levels (20, 30°C) for a total of eight treatments for 30 days. The experiment results showed that ocean acidification, hypoxia, and warming affected the community structure, species richness, and diversity of gut microbiota. The most abundant phyla noted were Proteobacteria, Bacteroidetes, and Firmicutes. Principal coordinate analysis (PCoA) revealed that ocean acidification, hypoxia, and warming change microbial community structure. Low pH, low DO, and increased temperature can cause shifting of microbial communities toward pathogen dominated microbial communities. Linear discriminant analysis effect size (LEfSe) showed that the significantly enriched biomarkers in each group are significantly different at the genus level. Phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) analysis revealed that the gut microbiome of the mussels is associated with many important functions, such as amino acid transport and metabolism, transcription, energy production and conservation, cell wall, membrane and envelope biogenesis, and other functions. This study highlights the complexity of interaction among pH, DO, and temperature in marine organisms and their effects on the gut microbiota and health of marine mussels.

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Polar opposites; bacterioplankton susceptibility and mycoplankton resistance to ocean acidification

10.1101/2020.02.03.933325 ◽

2020 ◽

Author(s):

Storme Zaviar de Scally ◽

Samuel Chaffron ◽

Thulani Peter Makhalanyane

Keyword(s):

Community Structure ◽

Microbial Community ◽

Southern Ocean ◽

Ocean Acidification ◽

Microbial Communities ◽

Enzyme Activities ◽

Experimental Manipulation ◽

Trophic Levels ◽

Community Interactions ◽

Nitrogen Acquisition

ABSTRACTMicroorganisms form the basis of ocean ecosystems yet the effects of perturbations such as decreasing pH on microbial community structure, interactions and functionality remain compared to multicellular organisms. Using an experimental manipulation of Southern Ocean seawater, we subjected bacterioplankton and mycoplankton to artificial pH decreases, which are predicted to occur in the future. We show that acidification led to substantial increases of bacterioplankton diversity, while in contrast it had no effect on mycoplankton diversity. Our analyses revealed a loss of putative keystone taxa and a decrease in predicted community interactions as a response to lower pH levels. Bacterioplankton shifted from generalist to specialist community members, suggesting a specific stress response to unfavourable conditions. In addition, enzyme activities involved in nitrogen acquisition were lower at reduced pH levels, suggesting altered organic matter cycling in a more acidic ocean. Our findings suggest that bacterioplankton and mycoplankton may respond differentially to future ocean acidification, with potentially negative impacts on community structure and biogeochemical cycling in the Southern Ocean.IMPORTANCEOceans absorb the majority of anthropogenically produced CO2, the consequence of which is ocean acidification, a phenomenon already negatively impacting key marine organisms. Marine microbial communities form the basis of ocean food webs by generating nutrients for higher trophic levels, yet the response of these key microbial drivers to acidification remains unclear. This knowledge deficit is particularly true for understudied marine ecosystems such as the Southern Ocean. Using a mesocosm approach, we found that acidification severely impacts microbial community stability, by altering bacterioplankton community structure, reducing network complexity, and augmenting enzyme activities associated with nitrogen acquisition. This study adds to our understanding of the effects of ocean acidification on microbial communities, particularly within an environment expected to be largely effected by future anthropogenically driven climate change.

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