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Implementing UN SDG 14.4: minimize and address the impacts of ocean acidification (text & video)

Published 28 June 2021 Presentations Closed

On World Ocean Day 2021, we explored how nations around the world step up and build a sustainable ocean economy in the face of cumulative ocean change. This broadly attended event co-hosted by The Ocean Foundation, the OA Alliance, and IAEA Ocean Acidification International Coordinating Center brought to you Ambassador Peter Thomson, United Nations Secretary-General’s Special Envoy for the Ocean, Dr. Peter Swarzenski from International Atomic Energy Agency (IAEA) OA International Coordination Centre, and speakers from around the globe from the Pacific Coast of North America, through New Zealand, to Lebanon and Argentina.

In 2021, it is imperative that governments and civil society continue to advance the suite of science and policy actions that will be needed to support food security and sovereignty, increase the resilience of marine ecosystems, and build a sustainable ocean economy in the face of future change.

This is reflected in the UN Sustainable Development Goal Agenda and target SDG 14.3, to “Minimize and address the impacts of ocean acidification.” As the science, research, and observed impacts of ocean acidification continue to grow, there is a continued need for increased knowledge exchange and expertise on the substance and process for developing local, regional, and national responses in the face of cumulative ocean change.

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Le CSM invité au Collège de France à donner une conférence (in French)

Published 28 June 2021 Presentations , Web sites and blogs Closed

Le Dr Sylvie Tambutté (Directeur de Recherche de l’équipe Physiologie et biochimie du CSM) lors de son allocution à la conférence sur ‘Le cycle du carbone dans l’océan’ au Collège de France le 18 juin 2021.

Le Dr Sylvie Tambutté, responsable de l’équipe de Physiologie corallienne a été invitée à donner une conférence au Collège de France le 18 Juin dernier. Le colloque était organisé par le Professeur Edouard Bard, titulaire de la Chaire “Évolution du climat et de l’océan” du Collège de France. La thématique portait sur « Le cycle du carbone dans l’océan » et huit orateurs ont présenté des séminaires sur des sujets incluant la perspective paléoclimatique, les flux de carbone, la modélisation biogéochimique ou encore le changement climatique et ses impacts sur l’océan.
C’est sur un aspect biologique que le Dr Tambutté est intervenu en exposant les impacts de l’acidification sur les organismes benthiques calcifiants. Après avoir introduit les bases du sujet, elle a pu aborder les résultats récents des recherches de son équipe montrant comment l’acidification impacte le processus de calcification chez les coraux de l’organisme jusqu’aux cellules et aux gènes.

Conférence du Dr S. Tambutté : “L’acidification de l’océan et les impacts sur les organismes benthiques calcifiant “

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Documents

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Cellular level response of the bivalve Limecola balthica to seawater acidification due to potential CO2 leakage from a sub-seabed storage site in the southern Baltic Sea: TiTank experiment at representative hydrostatic pressure

Published 28 June 2021 Science Closed
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Highlights

  • Cellular level responses of L. balthica to acidification caused by CO2 was tested 9 ATM pressure.
  • The bivalve is tolerant to medium-term severe environmental hypercapnia.
  • Seawater pH 7.0 induced effects on radical defence mechanisms (GPx, GST, CAT).
  • pH 6.3 caused increased cellular oxidative stress (MDA) and detoxification (tGST).

Abstract

Understanding of biological responses of marine fauna to seawater acidification due to potential CO2 leakage from sub-seabed storage sites has improved recently, providing support to CCS environmental risk assessment. Physiological responses of benthic organisms to ambient hypercapnia have been previously investigated but rarely at the cellular level, particularly in areas of less common geochemical and ecological conditions such as brackish water and/or reduced oxygen levels. In this study, CO2-related responses of oxygen-dependent, antioxidant and detoxification systems as well as markers of neurotoxicity and acid-base balance in the Baltic clam Limecola balthica from the Baltic Sea were quantified in 50-day experiments. Experimental conditions included CO2 addition producing pH levels of 7.7, 7.0 and 6.3, respectively and hydrostatic pressure 900 kPa, simulating realistic seawater acidities following a CO2 seepage accident at the potential CO2-storage site in the Baltic. Reduced pH interfered with most biomarkers studied, and modifications to lactate dehydrogenase and malate dehydrogenase indicate that aerobiosis was a dominant energy production pathway. Hypercapnic stress was most evident in bivalves exposed to moderately acidic seawater environment (pH 7.0), showing a decrease of glutathione peroxidase activity, activation of catalase and suppression of glutathione S-transferase activity likely in response to enhanced free radical production. The clams subjected to pH 7.0 also demonstrated acetylcholinesterase activation that might be linked to prolonged impact of contaminants released from sediment. The most acidified conditions (pH 6.3) stimulated glutathione and malondialdehyde concentration in the bivalve tissue suggesting potential cell damage. Temporal variations of most biomarkers imply that after a 10-to-15-day initial phase of an acute disturbance, the metabolic and antioxidant defence systems recovered their capacities.

Continue reading ‘Cellular level response of the bivalve Limecola balthica to seawater acidification due to potential CO2 leakage from a sub-seabed storage site in the southern Baltic Sea: TiTank experiment at representative hydrostatic pressure’

Effects of ocean acidification on larval Atlantic surfclam (Spisula solidissima) from Long Island Sound in Connecticut

Published 28 June 2021 Science Closed
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The Atlantic surfclam (Spisula solidissima) supports a $29.2-million fishery on the northeastern coast of the United States. Increasing global carbon dioxide (CO2) in the atmosphere has resulted in a decrease in ocean pH, known as ocean acidification (OA), in Atlantic surfclam habitat. The effects of OA on larval Atlantic surfclam were investigated for 28 d by using 3 different levels of partial pressure of CO2 (ρCO2): low (344 μatm), medium (821 μatm), and high (1243 μatm). Samples were taken to examine growth, shell height, time to metamorphosis, survival, and lipid concentration. Larvae exposed to a medium ρCO2 level had a hormetic response with significantly greater shell height and growth rates and a higher percentage that metamorphosed by day 28 than larvae exposed to the high- and low-level treatments. No significant difference in survival was observed between treatments. Although no significant difference was found in lipid concentration, Atlantic surfclam did have a similar hormetic response for concentrations of phospholipids, sterols, and triacylglycerols and for the ratio of sterols to phospholipids, indicating that larvae may have a homeoviscous adaptation to OA at medium ρCO2 levels. Our results indicate that larval Atlantic surfclam have some tolerance to slightly elevated ρCO2 concentrations but that, at high ρCO2 levels, they may be susceptible to OA.

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Chapter 13 – the future of Atlantic walrus in a rapidly warming Arctic

Published 28 June 2021 Science Closed
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The walrus (Odobenus rosmarus) is classified as a focal ecosystem component of the Arctic, defined as a biological element that is considered central to the functioning of an ecosystem, is of major importance to Arctic residents and/or is likely to be a good proxy for short- and long-term changes in the environment. The Arctic is undergoing large-scale environmental changes due to rapid global warming, including a marked reduction of sea ice in several areas inhabited by walruses. This chapter reviews how walruses already have been affected by global warming, or likely will be in the future. Specifically, we review the effects on walruses of projected changes in sea ice cover, marine productivity, ocean acidification, predation, pathogens and ultraviolet radiation, whereas changes in human activity patterns are discussed elsewhere in this volume. We find that, while the Pacific walrus seems to experience negative effects of warming and decrease in sea ice, the Atlantic walruses may be less affected; also in comparison to other ice-associated pinnipeds. Hence, we concur with previous assessments that the walrus is likely to survive into the future; at least in areas where human disturbance is minimal, and suitable terrestrial haul-outs are close enough to their feeding grounds.

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Ocean acidification impairs the physiology of symbiotic phyllosoma larvae of the lobster Thenus australiensis and their ability to detect cues from jellyfish

Published 25 June 2021 Science Closed
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Highlights

  • Ocean acidification (OA) under delta (∆) pH = – 0.3 (pH ~7.7), but not ∆pH = – 0.1 (pH ~ 7.9) relative to the present (~8.0 pH), reduced the survival, respiration and moulting of phyllosomas of T. australiensis.
  • OA under pH ~7.7 adversely affected the attraction of T. australiensis phyllosomas to jellyfish cues.
  • The majority of individual metabolites of phyllosomas were suppressed even in mild pH ~ 7.9.
  • The interaction between phyllosoma and jellyfish may be impaired under pH ~7.7.

Abstract

Ocean acidification (OA) can alter the behaviour and physiology of marine fauna and impair their ability to interact with other species, including those in symbiotic and predatory relationships. Phyllosoma larvae of lobsters are symbionts to many invertebrates and often ride and feed on jellyfish, however OA may threaten interactions between phyllosomas and jellyfish. Here, we tested whether OA predicted for surface mid-shelf waters of Great Barrier Reef, Australia, under ∆ pH = −0.1 (pH ~7.9) and ∆pH = −0.3 (pH ~7.7) relative to the present pH (~8.0) (P) impaired the survival, moulting, respiration, and metabolite profiles of phyllosoma larvae of the slipper lobster Thenus australiensis, and the ability of phyllosomas to detect chemical cues of fresh jellyfish tissue. We discovered that OA was detrimental to survival of phyllosomas with only 20% survival under ∆pH = −0.3 compared to 49.2 and 45.3% in the P and ∆pH = −0.1 treatments, respectively. The numbers of phyllosomas that moulted in the P and ∆pH = −0.1 treatments were 40% and 34% higher, respectively, than those in the ∆pH = −0.3 treatment. Respiration rates varied between pH treatments, but were not consistent through time. Respiration rates in the ∆pH = −0.3 and ∆pH = −0.1 treatments were initially 40% and 22% higher, respectively, than in the P treatment on Day 2 and then rates varied to become 26% lower (∆pH = −0.3) and 17% (∆pH = −0.1) higher towards the end of the experiment. Larvae were attracted to jellyfish tissue in treatments P and ∆pH = −0.1 but avoided jellyfish at ∆pH = −0.3. Moreover, OA conditions under ∆pH = −0.1 and ∆pH = −0.3 levels reduced the relative abundances of 22 of the 34 metabolites detected in phyllosomas via Nuclear Magnetic Resonance (NMR) spectroscopy. Our study demonstrates that the physiology and ability to detect jellyfish tissue by phyllosomas of the lobster T. australiensis may be impaired under ∆pH = −0.3 relative to the present conditions, with potential negative consequences for adult populations of this commercially important species.

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Seasonal dynamics of the carbonate system under complex circulation schemes on a large continental shelf: the northern South China Sea

Published 25 June 2021 Science Closed
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Highlights

  • 1. The NSCS shelf carbonate system shows strong seasonality with two distinct regimes between the inner-shelf and the mid-outer shelf.
  • 2. The seasonal dynamics of sea surface pCO2 and Ωarag on the mid-outer shelf highlight the influence of temperature effect and the seasonal cycle of mixed layer depth (MLD), while the Pearl River Plume has a profound effect in summer on the mid-shelf.
  • 3. The spatial dynamics of sea surface pCO2 and Ωarag on the inner-shelf feature the influence of China Coastal Current (CCC) in winter and coastal upwelling in summer.

Abstract

Based on large-scale surveys conducted during all four seasons from 2009-2011, we investigated the carbonate systems on the northern South China Sea (NSCS) shelf featuring much higher variations in both seasonality and spatiality on its inner-shelf (< 40 m) as compared to the areas on the mid-outer shelf (> 40 m). The most notable forcing on the mid-outer shelf include the intrusion of Kuroshio water leading to high surface salinity and high total alkalinity (TA) in winter, the impact of which is however limited to the northeastern part of the NSCS. The Pearl River Plume (PRP), a prominent feature in summer also has profound impact on the carbonate system on the mid-outer shelf. On the inner-shelf, the carbonate system was much more dynamic, featuring complex modulations by coastal upwelling associated with relatively high dissolved inorganic carbon (DIC) and TA in summer, and the China Coastal Current (CCC) of high DIC in winter, spring and fall. In addition, the influences of coastal plume water from local rivers were identifiable on the inner-shelf in both winter and spring.

Such distinction between inner-shelf and mid-outer shelf in the dynamics of DIC, the partial pressure of CO2 (pCO2) and saturation state index of aragonite (Ωarag) is also obvious. On the mid-outer shelf, the salinity normalized DIC (nDIC) fluctuated seasonally between 1974±9 and 2001±9 µmol kg-1. The decline of nDIC from winter to spring and spring to summer mainly results from CO2 outgassing, while the increase in nDIC from summer to fall and from fall to winter is due to entrainment of the carbon-enriched subsurface water. The pCO2 increases from a minimum of 344±9 μatm in winter to a maximum of 387±14 μatm in spring, which is in phase with temperature changes and the fluctuations of nDIC. The Ωarag ranged 3.28-3.68 with the highest value in summer but lowest value in winter, which is consistent with the seasonal cycles of the nDIC. Nearshore on the inner-shelf influenced by the CCC water in winter and the mid-outer shelf influenced by the PRP in summer, the spatial dynamics of sea surface pCO2 and Ωarag are modulated by both temperature and the water mass mixing between CCC, PRP, and shelf waters. Here, the high biological uptake sustained by nutrients in the CCC and PRP drawdown the pCO2 and augmented the Ωarag, while the CO2 sequestration enhanced the sea surface pCO2 but drawdown the Ωarag.

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Seasonal and spatial controls on the eutrophication-induced acidification in the Pearl River Estuary

Published 25 June 2021 Science Closed
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Abstract

Our understanding of eutrophication-induced acidification in estuaries and coastal oceans is complicated by the seasonally and spatially changing interactions between physical and biochemical drivers. By combining the conservative mixing method and a physical-biogeochemical model, we present the seasonal and spatial dynamical analysis of eutrophication-induced acidification in the Pearl River Estuary in the northern South China Sea. In summer, the widespread eutrophication-induced acidification is regulated by two distinct physical drivers, which are the strengthened stratification in the hypoxia zone and the high turbidity in the Lingdingyang Bay. In the hypoxia zone, eutrophication-induced acidification is controlled by the combined effect of benthic remineralization and stratification, while it is dominantly regulated by local biochemical processes (nitrification and respiration) of the whole water column in other regions of the estuary. In winter with the enhanced vertical mixing, the eutrophication-induced acidification is still active in the Lingdingyang Bay, and its strength has largely decreased compared with summer condition. While for the hypoxia zone, the eutrophication-induced acidification peaks in summer and disappears in winter.

Plain Language Summary

Eutrophication in estuaries has accelerated the ocean acidification, which induced a negative impact on marine ecosystem. In the estuary, physical and biochemical processes lead to difficulties in understanding and evaluating the impact of eutrophication-induced acidification. High-resolution and coupled oceanographic models can reproduce the biogeochemical cycles in the marine system and present an integrated framework to understand ocean acidification. We revealed two distinct types of eutrophication-induced acidification in the estuary by using an oceanographic model. The model results show that these two types of eutrophication-induced acidification are regulated by different physical processes that are water stratification and turbidity, which result in their unique seasonal evolution patterns.

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Scientist spotlight: Dr. Ana Franco, postdoctoral fellow, UBC

Published 25 June 2021 Web sites and blogs Closed

Dr. Ana Franco is a Postdoctoral Fellow at the University of British Columbia with Professor Phil Tortell in the MEOPAR project OxyNet: A network to examine ocean deoxygenation trends and impacts. She is also an expert in ocean acidification, having worked on the topic since her undergraduate degree. Dr. Franco shares with us her expertise, research, and past experiences that led her to become an expert in ocean acidification and oceanography.

A woman with brown hair and glasses smiles at the camera

Dr. Ana Franco

What is your background?

At the end of my bachelor studies in oceanography, almost by chance, I had the opportunity to participate as an undergrad in an ocean acidification (OA) cruise in the Pacific coast of Canada-US-Mexico. I had never participated in a cruise or had heard about OA before (this was 2007). I’m not even sure that I understood English very well at the time, but there I go to spend 30+ days immersed in ocean acidification science of the highest quality. Intimidating! The science from that cruise was a turning point for OA research (Feely et al., 2008), but the main result, from my own personal perspective, is that I haven’t stopped researching ocean acidification since then.

In the years following the cruise I went on to work with inorganic carbon data from the tropical Pacific off Mexico for my bachelor and master’s thesis at the Universidad Autonoma de Baja California, in Ensenada, Mexico. During that time, I collected and analysed dissolved inorganic carbon and total alkalinity samples from one of the most intense oxygen minimum and carbon maximum zones. The objective was to establish a baseline for future ocean acidification research and sea-air carbon fluxes in this particularly undersampled region.

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Postdoctoral research assistant in evolutionary genetics and biochemistry of calcifying Ph (vacancy ID :150798)

Published 25 June 2021 Jobs Closed

Job Details

Earth Sciences, South Parks Road, Oxford Grade 7: £32,817 – £36,914 p.a

Calcifying phytoplankton, such as coccolithophores, are a fundamental component of the marine carbon cycle. Yet, we have little understanding how changing climate affects calcification and how it is going to evolve under the environmental pressure imposed by global warming and ocean acidification. Currently there is little mechanistic understanding of how energy and carbon flow between photosynthesis and calcification in coccolithophores, and how this dynamic coupling is affected by resource limitation and environmental stress. Our knowledge gap on the environmental sensitivity of the coupling between photosynthesis and calcification means that we still do not know whether coccolithophore calcification increases or decreases in response to ocean acidification, despite 20 years of research.

This project will take advantage of advances in cutting-edge evolutionary genomic and biogeochemical techniques that document and mechanistically interrogate the sensitivity of coccolithophore calcification rates to the environment. The project will focus on ubiquitous and highly abundant coccolithophore species, Emiliania huxleyi , that is a de-facto model system for calcifying phytoplankton. Sufficient globally distributed isolates of this species are now available in culture so that it is possible to gain an integrative insight of the evolutionary genetics, physiology and biochemistry control the calcite production, as well as its change over micro- and macro-evolutionary timescales.

The successful candidate will be responsible for identification of candidate genes responsible for distinct photosynthetic and calcification adaptations to the environment. These genes will be used in evolutionary genetic and functional analyses to understand how different environments select for increased or decreased calcification and how calcification has evolved over time. The work will involve detailing the diversity of resource allocation strategies within different Emiliania huxleyi strains by performing biochemical and metabolomic analyses on strains grown under a range of environmental stresses. The postholder will work at outlining the interface between genetic expression, and the generation of organic molecules that both fuel and shape the calcite. They will be required to develop, test and refine working hypotheses, and analyse data from a range of sources. They will be expected to manage their own academic research and administrative activities, to contribute ideas for this research project and others, and to represent the group and the project at external meetings/seminars.  

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Postdoctoral research assistant in biogeochemistry of calcifying nannoplankton (vacancy ID : 150797)

Published 25 June 2021 Jobs Closed

Job Details

Earth Sciences, South Parks Road, Oxford Grade 7: £32,817 – £36,914 p.a

Calcifying phytoplankton, such as coccolithophores, are a fundamental component of the marine carbon cycle. Yet, we have little understanding how changing climate affects calcification and how it is going to evolve under the environmental pressure imposed by global warming and ocean acidification. Currently there is little mechanistic understanding of how energy and carbon flow between photosynthesis and calcification in coccolithophores, and how this dynamic coupling is affected by resource limitation and environmental stress. Our knowledge gap on the environmental sensitivity of the coupling between photosynthesis and calcification means that we still do not know whether coccolithophore calcification increases or decreases in response to ocean acidification, despite 20 years of research.

PUCCA (Photosynthetic Underpinnings of Coccolithophore Calcification) will take advantage of advances in cutting-edge techniques that document and mechanistically interrogate the sensitivity of coccolithophore calcification rates to the environment. A new physiological model of carbon isotopic fractionation in coccolithophores allows the reconstruction of species-specific calcification rates from the sedimentary record. Additionally, methods have advanced that can extract and characterise biochemical molecules from fossils over a hundred million years old which will allow the interrogation of controlling environmental parameters.

The successful candidate will be responsible for identifying which environmental parameter(s) drive the highest coccolithophore calcification rates during the Cenozoic, and across the modern ocean. As approaches, they will use ocean sediments as a recorder of coccolithophore stable isotope vital effects, extracted polysaccharides and other organic molecules, as a measure of the physiological sensitivity of calcification to different environmental regimes. They will also document how the sensitivity of calcification rates to environmental parameters is influenced by cellular resource allocation strategies using culture experiments of a range of strains of Emiliania huxleyi subjected to environmental limitation. These experiments will provide the foundation for calibrating organic molecules for the environmental impact on their structure and composition. 

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Ocean and climate ambition from COP25 to COP26 and beyond – International partnership on MPAs, biodiversity, and climate change (text & video)

Published 25 June 2021 Events Closed

Date: 29 June 2021

Time: 10:00 am

Register

A conversation about the International Partnership on MPAs, Biodiversity, and Climate Change, an alliance between the Nations of Chile, Costa Rica, France, United Kingdom, and the United States to dramatically scale up ocean and climate action during this decisive decade.

As the Earth’s temperature rises, climate change and ocean acidification are affecting species, ecosystems, and people around the world. Greenhouse gas reduction targets are critical to protecting the ocean. In addition, nature-based solutions marine protected areas (MPAs) are widely recognized as an effective, nature-based solution for climate change mitigation and conserving biodiversity. Global collaboration is key to achieving climate benefits provided by MPAs.   

What is the role of MPAs and MPA networks as nature-based solutions for biodiversity conservation and climate change mitigation, adaptation, and resilience? How are countries from the northern and southern hemispheres working together to solve one of the world’s most pressing issues?   

Join the Atlantic Council’s Global Energy Center and Adrienne Arsht Latin America Center, in partnership with the Wilson Center, Mission Blue, and the Chilean Embassy in the United States, on Tuesday, June 29, from 10:00 a.m. to 11:00 a.m. EDT, for a public discussion on the importance of the ocean in climate change and biodiversity negotiations. This event will also mark the launch of the International Partnership on MPAs, Biodiversity, and Climate Change, an alliance between ministries and marine protected area agencies from Chile, Costa Rica, France, United Kingdom, and the United States to dramatically scale up ocean and climate action during this decisive decade. Learn more at: www.mpabioclimate.org.

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Moderate nutrient concentrations are not detrimental to corals under future ocean conditions

Published 24 June 2021 Science Closed
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Under predicted future ocean conditions, reefs exposed to elevated nutrients will simultaneously experience ocean acidification and elevated temperature. We evaluated if moderate nutrients mitigate, minimize, or exacerbate negative effects of predicted future ocean conditions on coral physiology. For 30 days, Acropora millepora and Turbinaria reniformis were exposed to a fully factorial experiment of eight treatments including two seawater temperatures (26.4 °C and 29.8 °C), pCO2 levels (401 μatm pCO2 and 760 μatm pCO2), and nutrient concentrations (ambient: 0.40 μmol L−1 NO3− and 0.22 μmol L−1 PO43−, and moderate: 3.56 μmol L−1 NO3− and 0.31 μmol L−1 PO43−). Added nitrate was taken up by the algal endosymbionts and transferred to the coral hosts in both species, though to a much higher degree in A. millepora. When exposed to elevated temperature, elevated pCO2, or both, effects observed for chlorophyll a, calcification, biomass, and energy reserves were not compounded by the moderate nutrient concentrations in either species. Moderate nutrients enabled A. millepora to continue to meet daily metabolic demand via photosynthesis under predicted future ocean conditions and T. reniformis to greatly exceed daily metabolic demand via photosynthesis and heterotrophy. Our results suggest that balanced moderate nutrients are not detrimental to corals under predicted future ocean conditions and may even provide some benefits.

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Alkalinity of diverse water samples can be altered by mercury preservation and borosilicate vial storage

Published 24 June 2021 Science Closed
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We compared the effects of preservation and storage methods on total alkalinity (AT) of seawater, estuarine water, freshwater, and groundwater samples stored for 0–6 months. Water samples, untreated or treated with HgCl2, 0.45 µm filtration, or filtration plus HgCl2, were stored in polypropylene or borosilicate glass vials for 0, 1, or 6 months. Mean AT of samples treated with HgCl2 was reduced by as much as 49.1 µmol kg−1 (1.3%). Borosilicate glass elevated AT, possibly due to dissolving silicates. There was little change in AT of control and filtered samples stored in polypropylene, except for untreated groundwater (~ 4.1% reduction at 6 months). HgCl2 concentrations of 0.02–0.05% reduced the AT of fresh, estuarine, and ground water samples by as much as 35.5 µmol kg−1 after 1 month, but had little effect on the AT of seawater. Adding glucose as a carbon source for microbial growth resulted in no AT changes in 0.45 µm-filtered samples. We suggest water samples intended for AT analyses can be filtered to 0.45 µm, and stored in polypropylene vials at 4 °C for at least 6 months. Borosilicate glassware and HgCl2 can be avoided to prevent analytical uncertainties and reduce risks related to use of Hg2+.

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Perse community lecture – ‘listening to shells’ (text & video)

Published 24 June 2021 Web sites and blogs Closed

We were pleased to welcome Liz Harper, Professor of Evolutionary Biology at the University of Cambridge’s Department of Earth Sciences, to give the latest online Perse Community Lecture.

Prof Harper provided an insight into evolutionary biology and climate change in her talk entitled Listening to Shells.

She explained the origin of molluscs and the variety of molluscs and brachiopods, as well as how fossils can help us to understand shells and how and why they adapted to suit the organism and environment.

Prof Harper reflected on the materials aspect of shells, using the example of nacre, the ‘wonder material’ of mother of pearl, which has unexpectedly remained unchanged over the past few eras, suggesting that evolutionary development has turned its back on one of the most successful materials.

She outlined that the development of lighter shell materials has enabled species to thrive within their specific habitats. However, ongoing ocean acidification does pose a threat to organisms that make a shell, given the current ocean surface pH of 8.1 is expected to decrease significantly due to climate change, especially those that lay down shells made of calcium carbonate, such as sea butterflies.

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2021 Northeast spring ecosystem monitoring cruise completed

Published 24 June 2021 Web sites and blogs Closed

Thanks to a combination of favorable weather and a well-run vessel, the 2021 Northeast spring ecosystem monitoring survey aboard NOAA Ship Gordon Gunter is complete.

Two men on deck at the rail of a ship watching a fine-mesh net array being hauled onboard by a winch.
Texas A & M student Joseph Losoya and crewman Dante Starks prepare to retrieve a bongo net array used to collect plankton aboard the NOAA Ship Gordon Gunter during the spring 2021 ecosystem monitoring cruise off the Northeastern United States. Credit NOAA Fisheries/Jerry Prezioso

During May, researchers returned to sea for the ecosystem monitoring cruise. This was the first ecosystem monitoring cruise since operations were stopped in 2020 to reduce risks posed by the COVID-19 pandemic. This one-year hiatus is the longest gap in sampling in the nearly 45-year record of oceanographic observations made on this recurring cruise. 

Scientists and crew aboard the NOAA Ship Gordon Gunter sampled at 106 stations. They achieved near-complete coverage of the survey area from Delaware through Southern New England. 

Fewer days were available for the cruise than originally planned, so the scientific crew dropped all stations south of Delaware Bay to accommodate the time available. Coverage was also reduced on the Scotian Shelf, in the northern Gulf of Maine, and on Georges Bank, when a fast-moving storm front passed through, making sampling impossible. Instead, the team moved into the western Gulf of Maine to keep working, and collected more mackerel eggs and larvae.

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Elevated pCO2 alters the interaction patterns and functional potentials of rearing seawater microbiota

Published 23 June 2021 Science Closed
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Highlights

  • More simplified and modularized bacterial networks of rearing seawater under elevated pCO2.
  • Changed abundances of CNPS cycling genes of seawater microbiome under elevated pCO2.
  • Changed C, N, and P chemistry of rearing seawater under elevated pCO2.
  • Seawater C, N, and P chemistry may be affected by future elevated pCO2 via seawater microbiome.

Abstract

Mean oceanic CO2 values have already risen and are expected to rise further on a global scale. Elevated pCO2 (eCO2) changes the bacterial community in seawater. However, the ecological association of seawater microbiota and related geochemical functions are largely unknown. We provide the first evidence that eCO2 alters the interaction patterns and functional potentials of microbiota in rearing seawater of the swimming crab, Portunus trituberculatus. Network analysis showed that eCO2 induced a simpler and more modular bacterial network in rearing seawater, with increased negative associations and distinct keystone taxa. Using the quantitative microbial element cycling method, nitrogen (N) and phosphorus (P) cycling genes exhibited the highest increase after one week of eCO2 stress and were significantly associated with keystone taxa. However, the functional potential of seawater bacteria was decoupled from their taxonomic composition and strongly coupled with eCO2 levels. The changed functional potential of seawater bacteria contributed to seawater N and P chemistry, which was highlighted by markedly decreased NH3, NH4+-N, and PO43--P levels and increased NO2−-N and NO3−-N levels. This study suggests that eCO2 alters the interaction patterns and functional potentials of seawater microbiota, which lead to the changes of seawater chemical parameters. Our findings provide new insights into the mechanisms underlying the effects of eCO2 on marine animals from the microbial ecological perspective.

Continue reading ‘Elevated pCO2 alters the interaction patterns and functional potentials of rearing seawater microbiota’

Microbiome diversity and host immune functions may define the fate of sponge holobionts under future ocean conditions

Published 23 June 2021 Science Closed
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The sponge-associated microbial community contributes to the overall health and adaptive capacity of the sponge holobiont. This community is regulated by the environment, as well as the immune system of the host. However, little is known about the effect of environmental stress on the regulation of host immune functions and how this may, in turn, affect sponge-microbe interactions. In this study, we compared the microbiomes and immune repertoire of two sponge species, the demosponge, Neopetrosia compacta and the calcareous sponge, Leucetta chagosensis, under varying levels of acidification and warming stress. Neopetrosia compacta harbors a diverse bacterial assemblage and possesses a rich repertoire of scavenger receptors while L. chagosensis has a less diverse microbiome and an expanded range of pattern recognition receptors and proteins with immunological domains. Upon exposure to warming and acidification, the microbiome and host transcriptome of N. compacta remained stable, which correlated with high survival. In contrast, the bacterial community of L. chagosensis exhibited drastic restructuring and widespread downregulation of host immune-related pathways, which accompanied tissue necrosis and mortality. Differences in microbiome diversity and immunological repertoire of diverse sponge groups highlight the central role of host-microbe interactions in predicting the fate of sponges under future ocean conditions.

Continue reading ‘Microbiome diversity and host immune functions may define the fate of sponge holobionts under future ocean conditions’

Dialogue strengthens regional coordination for ocean acidification monitoring

Published 23 June 2021 Web sites and blogs Closed

Continue reading ‘Dialogue strengthens regional coordination for ocean acidification monitoring’

Postdoctoral research associate

Published 23 June 2021 Jobs Closed

Posting Number: req5768

Department: Geosciences

Department Website Link: www.geo.arizona.edu/Research

Location: Main Campus

Address: Tucson, AZ USA

Target Hire Date: 8/23/2021

Position Highlights:

We seek a postdoctoral researcher to work as part of a collaborative team to better understand the impact of heat stress and ocean acidification on calcification and skeletal geochemistry in corals from the Republic of the Marshall Islands. The postdoctoral researcher will be expected to collect and analyze coral skeletal density and geochemical data, interpret results in the context of simulated ocean evolution over the last millennium using coupled climate models, and synthesize results for presentations at conferences and publications in peer-reviewed journals. This is a year-to-year appointment renewable for up to 4 years contingent upon funding and performance.

Outstanding UA benefits include health, dental, vision, and life insurance; paid vacation, sick leave, and holidays; UA/ASU/NAU tuition reduction for the employee and qualified family members; access to UA recreation and cultural activities; and more!

The University of Arizona has been recognized for our innovative work-life programs. For more information about working at the University of Arizona and relocations services, please click here.

Duties & Responsibilities:

  • Collate and analyze coral density and geochemical data
  • Help design and participate in field work efforts
  • Incorporate data into a modeling framework
  • Interpret results and publish findings in peer-reviewed journals
Continue reading ‘Postdoctoral research associate’

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