Internship – Ocean Acidification International Coordination Centre

Published 21 March 2023 Jobs Leave a Comment

Duty Station: Monaco

Duration of Appointment/Start: 1 year, Summer 2023

Application Deadline: 24 April 2023

Main Purpose

The main purpose of this internship will be to provide support to the IAEA’s Ocean Acidification International Coordination Centre (OA-ICC) for its numerous activities and initiatives in the areas of communication, capacity building, and science. The internship will be carried out in the Radioecology Laboratory (REL) of the IAEA’s Marine Environment Laboratories in Monaco. The laboratory is engaged in applied research on the accumulation and transfer of contaminants in freshwater, coastal and marine ecosystems and associated biota.

Tasks / Key Results Expected

  • Provide support to the OA-ICC in communication activities including drafting quarterly
    newsletters, web stories, and updating the OA-ICC website and news stream.
  • Participate in OA-ICC meetings and support the team in day-to-day activities.
  • Assist the OA-ICC in the organization of capacity building activities including the organization of training courses.

Knowledge, Skills and Abilities

  • Knowledge, Skills and Abilities
  • Strong ability to work in an international environment and as part of a team.
  • Good knowledge of Marine Ecology.
  • Knowledge of ocean acidification is an asset.
  • Experience in drafting communication material is an asset.
  • Strong analytical skills: ability to articulate, conceptualize, plan and execute ideas is an asset.

Qualifications and Experience

  • University degree in Environmental Science, Marine Biology, Ecology or a related field.
  • Experience working in an international organization is an asset.
  • Good written and spoken English essential; fluency in any other IAEA official language (Arabic, Chinese, French, Russian, Spanish) an asset.

Applicant Eligibility

  • Candidates must be a U.S. Citizen, be a minimum of 20 years of age and have completed at least three years of full-time studies at a university or equivalent institution towards the completion of a first degree.
  • Candidates may apply up to one year after the completion of a bachelor’s, master’s or doctorate degree.
  • Candidates must not have previously participated in the IAEA’s internship programme.
  • Excellent written and spoken English essential; fluency in any other IAEA official language (Arabic, Chinese, French, Russian) an asset.
  • Candidates must attach two signed letters of recommendation to their application.

How to Apply: https://anl.box.com/v/HowToApply-Intern

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Acclimatization in a changing environment: linking larval and juvenile performance in the quahog Mercenaria mercenaria

Published 30 March 2023 Science Leave a Comment
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Marine invertebrates in coastal communities are currently experiencing unprecedented, rapid environmental change. These symptoms of climate change and ocean acidification are projected to worsen faster than can be accommodated by evolutionary processes like adaptation via natural selection, necessitating investigations of alternative mechanisms that facilitate adaptive responses to environmental change. This dissertation posits that in the absence of adaptation, early development (larval) exposure to stressors can increase population tolerance by leveraging existing variation in the energy metabolism and host-microbial interactions. Focusing specifically on resiliency to acidification (low pH), hypoxia (low dissolved oxygen), and elevated temperature stress in the clam, Mercenaria mercenaria, this dissertation uses a combination of laboratory and field experiments in conjunction with next-generation sequencing and physiological assays to investigate the relationship between host health, microbial community structure, and environmental change.

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The evolution of coral reef under changing climate: a scientometric review

Published 30 March 2023 Science Leave a Comment
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Simple Summary

Coral reefs are vital ecosystems with high biodiversity and ecological services for coastal communities. Climate change is accelerating, with detrimental consequences on coral reefs and related communities, but it is challenging to keep up with the literature given its current rapid expansion. The current review foresees three future trends in the area of coral reefs and climate change, including (i) incorporating future scenarios, (ii) climate-induced temperature changes, and (iii) adaptation strategies, which are expected to move society closer to the following Sustainable Development Goal: 13 Climate Action.

Abstract

In this scientometric review, we employ the Web of Science Core Collection to assess current publications and research trends regarding coral reefs in relation to climate change. Thirty-seven keywords for climate change and seven keywords for coral reefs were used in the analysis of 7743 articles on coral reefs and climate change. The field entered an accelerated uptrend phase in 2016, and it is anticipated that this phase will last for the next 5 to 10 years of research publication and citation. The United States and Australia have produced the greatest number of publications in this field. A cluster (i.e., focused issue) analysis showed that coral bleaching dominated the literature from 2000 to 2010, ocean acidification from 2010 to 2020, and sea-level rise, as well as the central Red Sea (Africa/Asia), in 2021. Three different types of keywords appear in the analysis based on which are the (i) most recent (2021), (ii) most influential (highly cited), and (iii) mostly used (frequently used keywords in the article) in the field. The Great Barrier Reef, which is found in the waters of Australia, is thought to be the subject of current coral reef and climate change research. Interestingly, climate-induced temperature changes in “ocean warming” and “sea surface temperature” are the most recent significant and dominant keywords in the coral reef and climate change area.

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Sediment-seawater exchange altered adverse effects of ocean acidification towards marine microalgae

Published 30 March 2023 Science Leave a Comment
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Highlights

  • Five marine microalgal species showed different sensitivities to OA.
  • OA promoted algal growth except I. galbana after introducing sediments.
  • N, P and Fe released from sediments mitigated OA-induced toxicity to E. huxleyi.
  • OA-induced algal community instability was alleviated by the presence of sediments.

Abstract

Ocean acidification (OA) exhibits high threat to marine microalgae. However, the role of marine sediment in the OA-induced adverse effect towards microalgae is largely unknown. In this work, the effects of OA (pH 7.50) on the growth of individual and co-cultured microalgae (Emiliania huxleyi, Isochrysis galbana, Chlorella vulgaris, Phaeodactylum tricornutum, and Platymonas helgolandica tsingtaoensis) were systematically investigated in the sediment-seawater systems. OA inhibited E. huxleyi growth by 25.21 %, promoted P. helgolandica (tsingtaoensis) growth by 15.49 %, while did not cause any effect on the other three microalgal species in the absence of sediment. In the presence of the sediment, OA-induced growth inhibition of E. huxleyi was significantly mitigated, because the released chemicals (N, P and Fe) from seawater-sediment interface increased the photosynthesis and reduced oxidative stress. For P. tricornutum, C. vulgaris and P. helgolandica (tsingtaoensis), the growth was significantly increased in the presence of sediment in comparison with those under OA alone or normal seawater (pH 8.10). For I. galbana, the growth was inhibited when the sediment was introduced. Additionally, in the co-culturing system, C. vulgaris and P. tricornutum were the dominant species, while OA increased the proportions of dominant species and decreased the community stability as indicated by Shannon and Pielou’s indexes. After the introduction of sediment, the community stability was recovered, but remained lower than that under normal condition. This work demonstrated the role of sediment in the biological responses to OA, and could be helpful for better understanding the impact of OA on marine ecosystems.

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The threat of ocean acidification: what you need to know (audio & video)

Published 30 March 2023 Presentations , Resources , Web sites and blogs Leave a Comment
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Ocean acidification is a topic that has been gaining more attention in recent years, and for good reason. It is a serious threat to the health and well-being of our oceans, and ultimately to the survival of countless species that call the ocean home.

In this video, we will explore what ocean acidification is, how it occurs, and the impacts it has on the environment. We will also discuss the primary drivers of ocean acidification, including the burning of fossil fuels and other human activities that release carbon dioxide into the atmosphere.

Through stunning visuals and clear explanations, we will delve into the science behind ocean acidification and why it is such a critical issue. We will also examine what steps can be taken to mitigate its effects and preserve the health of our oceans for future generations.

Whether you are a student, scientist, or concerned citizen, this video will provide a comprehensive overview of ocean acidification and its implications. Join us on this journey to understand one of the greatest challenges facing our planet today.

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A framework to evaluate preparedness for ocean acidification

Published 29 March 2023 Press releases Leave a Comment
How to prepare for ocean acidification, a framework

A vibrant coral reef in the Maldives. Credit: Luiz Rocha, California Academy of Sciences.

In a paper published today in the journal Environmental Research Letters, an international research team composed of scientists affiliated with more than a dozen institutions, including the California Academy of Sciences, propose a first-of-its-kind framework for governments around the world to evaluate their preparedness for—and guide future policies to address—ocean acidification, among the most dire threats to marine ecosystems.

“Ocean acidification is one of climate change’s silent killers,” says Rebecca Albright, Ph.D., Academy Curator of Invertebrate Zoology and founder of the Coral Regeneration Lab (CoRL). “While not as high-profile as threats like coral bleaching, ocean acidification will cause widespread destruction of marine environments by the end of this decade if we don’t take urgent action. To help policymakers identify what actions they should take, my collaborators and I asked ourselves, ‘What would a government have to do in order to have a comprehensive plan to safeguard both the environment and society from ocean acidification?'”

Ultimately, the researchers identified six aspects of effective ocean acidification policy, along with specific indicators for each, that policymaking bodies, from local governments to federal agencies, can use to evaluate and guide their own policies.

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Juvenile Dungeness crab foraging behavior and lipid composition is altered more by food quantity than seawater pH in a multi-stressor experiment

Published 29 March 2023 Science Leave a Comment
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Highlights

  • We fed juvenile crab a maintenance- or low-quantity diet at ambient or reduced pH.
  • Foraging behaviors changed depending on diet and pH exposure but pH sensing did not.
  • Crab fatty acid composition was altered due to diet and pH exposure.
  • Crab lipid and fatty acid concentrations did not change due to pH exposure.
  • Crab in regions with pH and food supply variability may be resilient to reduced pH.

Abstract

Increases in atmospheric, anthropogenic carbon are driving reductions in seawater pH, a process referred to as ocean acidification. Reduced seawater pH can influence behavior of marine animals, but little is currently known about how juvenile crustaceans will respond. We conducted lab experiments to improve our understanding of the consequences of pH exposure and food quantity on juvenile Dungeness crab (Metacarcinus magister, (Dana, 1852)) behavior and nutritional condition. To understand the foraging and pH sensing behavior of juvenile crab, and how this interacts with their nutritional status, we exposed recently settled second instar juveniles to either ambient pH or reduced pH for 42-d, crossed with either a ‘maintenance’- or low-quantity ‘challenge’ diet treatment. After the experimental exposure period, we introduced crab into foraging and sensing pH behavior experiments. In the foraging experiment, we placed crab in a behavior arena with unidirectional flow, where we measured the food discovery time and time allocation of activities in 300-s trials for all individual crab. Food quantity and pH exposure influenced both the speed with which juvenile crab identified and allocation of activities but there was no interactive effect of experimental factors. For our pH sensing experiment, we used a two-current flume plumbed with both ambient and reduced pH seawater. This flow-through flume provided a choice between the pH treatment waters and allowed us to measure the amount of time individuals spent on either side of the arena in 300-s trials. There was no effect of prior diet or pH exposure on the amount of time juvenile crab spent in either seawater pH condition. In addition to the behavior trials, we evaluated crab nutritional condition by quantifying the total lipid content of whole-body tissues and fatty acid profile composition of juvenile crab fed either the maintenance or low-quantity diet during the experimental pH exposure period. The proportional fatty acid profiles differed for crab based on their diet and pH exposure, with no interactive effects. However, we did not detect differences in the concentrations of key summary categories of fatty acids (e.g., saturated, monounsaturated, or polyunsaturated) based on pH exposure. Our results indicate that reduced food availability has a greater impact on juvenile Dungeness crab foraging behavior and nutritional condition than reduced seawater pH exposure representing the 0.3 pH unit decrease predicted by 2100.

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Are we ready for ocean acidification? A framework for assessing and advancing policy readiness

Published 29 March 2023 Science Leave a Comment
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Effective climate policy that addresses carbon dioxide emissions is essential to minimizing and addressing the impacts of ocean acidification (OA). Here we present a framework to assess the readiness of OA policy, using coral reefs as a focal system. Six dimensions encompass comprehensive preparation by ecosystems and societies for the impacts of OA and other anthropogenic hazards: (1) climate protection measures, (2) OA literacy, (3) area-based management, (4) research and development, (5) adaptive capacity of dependent sectors, and (6) policy coherence. We define standardized indicators, identify leading countries, and evaluate the case study of Australia, the country with the largest coral reef system. The framework provides a rubric for a government unit to self- assess strengths and weaknesses in policy preparedness and to prioritize future endeavors.

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Ocean acidification induces tissue-specific interactions with copper toxicity on antioxidant defences in viscera and gills of Asiatic hard clam Meretrix petechialis (Lamarck, 1818)

Published 29 March 2023 Science Leave a Comment
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Highlights

  • Cu and OA coexposures induce tissue-specific oxidative stress in clams.
  • OA exacerbates Cu toxicity and increases oxidative damage in tissues.
  • Gill is more vulnerable to oxidation than viscera with MDA and 8-OHdG as indicators.
  • PCAs usefully identify the contributions of biomarkers to antioxidant defences.
  • The results provide insights for assessing Cu toxicity under OA in wild bivalves.

Abstract

Toxicity of contaminants in organisms under ocean acidification (OA) has attracted increasing attention in ecotoxicological studies. This study investigated how pCO2-driven OA affected waterborne copper (Cu) toxicity in antioxidant defences in viscera and gills of Asiatic hard clam Meretrix petechialis (Lamarck, 1818). Clams were continuously exposed to Cu at ambient relevant (0/no metal exposure, 10 and 50 μg L−1) and polluted-high (100 μg L−1) concentrations in unacidified (pH 8.10) and acidified (pH 7.70/moderate OA and 7.30/extreme OA) seawater for 21 days. Following coexposure, metal bioaccumulation and responses of antioxidant defence-related biomarkers to OA and Cu coexposure were investigated. Results showed that metal bioaccumulation was positively correlated with waterborne metal concentrations but was not notably influenced by OA conditions. Both Cu and OA affected the antioxidant responses to environmental stress. Additionally, OA induced tissue-specific interactions with Cu on antioxidant defences, varying with exposure conditions. In unacidified seawater, antioxidant biomarkers were activated to defend against oxidative stress induced by Cu and prevented clams from lipid peroxidation (LPO or MDA), but failed to defend against DNA damage (8-OHdG). OA exacerbated Cu toxicity in antioxidant defences and increased LPO levels in tissues. Gills and viscera adopted adaptive antioxidant defence strategies to manage oxidative stress, with the former being more vulnerable to oxidative stress than the latter. MDA and 8-OHdG were sensitive to OA and Cu exposure, respectively, and were useful bioindicators for assessing oxidative stress. Integrated biomarker response (IBR) and PCA can reflect the integrative responses of antioxidant biomarkers to environmental stress and illuminate the contributions of specific biomarkers to antioxidant defence strategies. The findings provided insights for understanding antioxidant defences against metal toxicity in marine bivalves under OA scenarios, which is essential into managing wild populations.

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Boron based geochemical reconstructions of ocean pH and atmospheric CO₂ in the geological record

Published 29 March 2023 Science Leave a Comment
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The boron isotope proxy is a valuable tool for reconstructing ocean pH and atmospheric CO₂ in Earth’s history. Its use on foraminifera in deep sea sediment cores has helped shape our understanding of Cenozoic carbon cycling and climate change, yet most of the extreme examples of biotic and climatic change are in the geological record, where the proxy has seen limited use. The boron isotope proxy’s widespread usage is also hindered by the challenges involved in traditional methods for measuring it: gravity microcolumns require exacting laboratory conditions and are time intensive. Older samples may have more variable matrices which can also be a problem for a gravity column. In order to expand the boron isotope proxy into a wider variety of matrices, Chapter 3 presents a new batch method for the purification of boron from its sample matrix. Together with methodological improvements for measurement by MC-ICPMS discussed in Chapter 2, these developments allow for measurement of a wide variety of samples with uncertainties roughly half the size, procedural blanks an order of magnitude lower, and sample throughput ~3 times faster than previous methods. These developments are applied to the geological record in Chapters 4 and 5 for two of the most significant biotic and climatic changes in Earth’s history. Chapter 4 presents boron isotope data from the Triassic-Jurassic boundary, indicating a ≥ 0.34 unit drop in ocean pH coincident with the ‘main’ carbon isotope excursion, suggesting that the carbon isotope excursions associated with the end-Triassic mass extinction event were likely also associated with pulses of ocean acidification. Chapter 5 presents a boron isotope record through the Ordovician into the early Silurian, showing a substantial rise in ocean pH and likely fall in atmospheric CO₂ accompanying the large cooling trend and major radiation in biodiversity though the Ordovician. CO₂-driven cooling thus sets the stage for the glaciation thought to trigger the end-Ordovician extinction event, while rising CO₂ in the early Silurian would have driven climatic recovery. Together these results highlight the success of the application of the boron isotope proxy to carbon cycle perturbations in the rock record and reveal, for the first time, the changes in the CO₂ system associated with some of the most important events in Earth’s history. In summary, this thesis allows for more accurate and precise boron isotope analysis and a deeper understanding of some of the major environmental events of the Phanerozoic.

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Projected increase in carbon dioxide drawdown and acidification in large estuaries under climate change

Published 28 March 2023 Science Leave a Comment
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Most estuaries are substantial sources of carbon dioxide (CO2) to the atmosphere. The estimated estuarine CO2 degassing is about 17% of the total oceanic uptake, but the effect of rising atmospheric CO2 on estuarine carbon balance remains unclear. Here we use 3D hydrodynamic-biogeochemical models of a large eutrophic estuary and a box model of two generic, but contrasting estuaries to generalize how climate change affects estuarine carbonate chemistry and CO2 fluxes. We found that small estuaries with short flushing times remain a CO2 source to the atmosphere, but large estuaries with long flushing times may become a greater carbon sink and acidify. In particular, climate downscaling projections for Chesapeake Bay in the mid-21st century showed a near-doubling of CO2 uptake, a pH decline of 0.1–0.3, and >90% expansion of the acidic volume. Our findings suggest that large eutrophic estuaries will become carbon sinks and suffer from accelerated acidification in a changing climate.

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The clam before the storm: a meta analysis showing the effect of combined climate change stressors on bivalves

Published 28 March 2023 Science Leave a Comment
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Impacts of a range of climate change on marine organisms have been analysed in laboratory and experimental studies. The use of different taxonomic groupings, and assessment of different processes, though, makes identifying overall trends challenging, and may mask phylogenetically different responses. Bivalve molluscs are an ecologically and economically important data-rich clade, allowing for assessment of individual vulnerability and across developmental stages. We use meta-analysis of 203 unique experimental setups to examine how bivalve growth rates respond to increased water temperature, acidity, deoxygenation, changes to salinity, and combinations of these drivers. Results show that anthropogenic climate change will affect different families of bivalves disproportionally but almost unanimously negatively. Almost all drivers and their combinations have significant negative effects on growth. Combined deoxygenation, acidification, and temperature shows the largest negative effect size. Eggs/larval bivalves are more vulnerable overall than either juveniles or adults. Infaunal taxa, including Tellinidae and Veneridae, appear more resistant to warming and oxygen reduction than epifaunal or free-swimming taxa but this assessment is based on a small number of datapoints. The current focus of experimental set-ups on commercially important taxa and families within a small range of habitats creates gaps in understanding of global impacts on these economically important foundation organisms.

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The influence of ocean acidification and warming on responses of Scylla serrata to oil pollution: an integrated biomarker approach

Published 28 March 2023 Science Leave a Comment
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Graphical abstract

Highlights

  • The OAW conditions reduce tolerance capacity of crabs to acute pollution stress.
  • A greater degree of stress was experienced in oil exposure under OAW conditions.
  • Augmented antioxidant and detoxification enzyme activity was noted.

Abstract

Anthropogenic activities primarily combustion of fossil fuel is the prime cause behind the increased concentration of CO2 into the atmosphere. As a consequence, marine environments are anticipated to experience shift towards lower pH and elevated temperatures. Moreover, since the industrial revolution the growing demand for petroleum-based products has been mounting up worldwide leading to severe oil pollution. Sundarbans estuarine system (SES) is experiencing ocean warming, acidification as well as oil pollution from the last couple of decades. Scylla serrata is one of the most commercially significant species for aquaculture in coastal areas of Sundarbans. Thus, the prime objective of this study is to delineate whether exposure under ocean warming and acidification exacerbates effect of oil spill on oxidative stress of an estuarine crab S. serrata. Animals were separately exposed under current and projected climate change scenario for 30 days. After this half animals of each treatment were exposed to oil spill conditions for 24 h. Oxidative stress status superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), lipid peroxidation (LPO level) and DNA damage (Comet assay) were measured. Augmented antioxidant and detoxification enzyme activity was noted except for SOD but failed to counteract LPO and DNA damage. The present results clearly highlighted the detrimental combined effect of OWA and pollution on oxidative stress status of crabs that might potentially reduce its population and affect the coastal aquaculture in impending years.

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Reef monitoring structure installed at Pulau Gaya

Published 28 March 2023 Media coverage , Web sites and blogs Leave a Comment
Edwin (second from left) presenting the award to Gillian.

 The Marine Ecology Research Centre (MERC) at Pulau Gaya completed installing and commissioning Autonomous Reef Monitoring Structure (ARMS) and Calcification Accretion Units (CAUs) on February 2.

The successful deployment was led by Professor Dato’ Dr Aileen Tan, director of the Centre for Marine and Coastal Studies (CEMACS), Universiti Sains Malaysia, Penang.

“This is the first step in a research collaboration between MERC and the Intergovernmental Oceanographic Commission (IOC) of UNESCO, following the protocol established by National Oceanic and Atmospheric Administration (NOAA),” said MERC’s project director Alvin Wong in a statement issued in conjunction with the award from the Malaysia Book of Records for the MERC – The First Ocean Acidification Monitoring Station for South China Sea held at Le Meridien on Monday.

The award was presented to ECHO Resorts owner, Gillian Tan by The Malaysia Book of Records Senior Record Consultant, Edwin Yeoh.

He added that this was also an effort to achieve the Sustainable Development Goal 14: Life below water.

“The research under the title ‘Research and Monitoring of the Ecological Impacts of Ocean Acidification on Coral Reef Ecosystems’ would improve the understanding of ocean acidification and the potential damaging effects of ocean acidification on marine resources and ecosystems,” he said.

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Effects of ocean acidification and warming on the specific dynamic action of California Grunion (Leuresthes tenuis) larvae

Published 27 March 2023 Science Leave a Comment
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Highlights

  • SDA was measured as the difference in metabolic rate of fed and non-fed fish.
  • SDA is ∼15% of the daily metabolic energy costs for California Grunion larvae.
  • OA conditions shifted the SDA response earlier.
  • Changes in SDA with climate can have downstream effects on larval growth.

Abstract

Ocean acidification (OA) and Ocean Warming (OW) are ongoing environmental changes that present a suite of physiological challenges to marine organisms. Larval stages may be especially sensitive to the effects of climate change because the larval phase is a time of critical growth and development. Of particular importance to growth is Specific Dynamic Action (SDA) – the energy used in digestion, absorption, and assimilation of food. Relatively little is known about the energetics of SDA for larval fishes and even less is known about how SDA may be affected by climate change. In this study we used feeding experiments and respirometry assays to characterize the functional form of SDA for California Grunion (Leuresthes tenuis). In a second set of experiments, we tested the independent and combined effects of ocean acidification and warming on SDA. Our first experiment revealed that an elevated metabolic rate was detectable within an hour of feeding, peaked at 3–6 h post feeding, and lasted about 24 h in total. Experiments testing the effects of acidification and warming revealed that temperature generally increased the maximum rate of postprandial respiration and the total amount of energy expended via SDA. In an experiment where feeding level was the same for fish held at different temperatures, elevated pCO2 increased the maximum rate of postprandial respiration and shortened the SDA response. However, in an experiment that allowed fish to consume more food at high temperatures, effects of pCO2 on SDA were minimal. The effects of OA on SDA may depend on a combination of temperature and food availability, and the disruption of SDA with OA may be part of a chain of events where digestion and assimilation efficiency are impaired with potential consequences for growth, survival, and population replenishment.

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Field development of Posidonia oceanica seedlings changes under predicted acidification conditions

Published 27 March 2023 Science Leave a Comment
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Ocean acidification has been consistently evidenced to have profound and lasting impacts on marine species. Observations have shown seagrasses to be highly susceptible to future increased pCO2 conditions, but the responses of early life stages as seedlings are poorly understood. This study aimed at evaluating how projected Mediterranean Sea acidification affects the survival, morphological and biochemical development of Posidonia oceanica seedlings through a long-term field experiment along a natural low pH gradient. Future ocean conditions seem to constrain the morphological development of seedlings. However, high pCO2 exposures caused an initial increase in the degree of saturation of fatty acids in leaves and then improved the fatty acid adjustment increasing unsaturation levels in leaves (but not in seeds), suggesting a nutritional compound translocation. Results also suggested a P. oceanica structural components remodelling which may counteract the effects of ocean acidification but would not enhance seagrass seedling productivity.

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OrgAlkCalc: estimation of organic alkalinity quantities and acid-base properties with proof of concept in Dublin Bay

Published 27 March 2023 Science Leave a Comment
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Highlights

  • Global Ocean Acidification Observing Network TA titration apparatus can be modified to perform organic alkalinity titrations.
  • Open-source software can be used to estimate the concentrations and acid-base properties of organic alkalinity.
  • Organic alkalinity poses a significant fraction of TA in Dublin Bay.

Abstract

The presence and influence of organic species is generally omitted in total alkalinity (TA) analysis. This has direct implications to calculated carbonate system parameters and to key descriptors of ocean acidification, especially in coastal waters where organic alkalinity (OrgAlk) can contribute significantly to TA. As titratable charge groups of OrgAlk can act as unknown seawater acid-base systems, the inclusion of the total concentration and apparent dissociation constants of OrgAlk in carbonate calculations involving TA is required to minimise uncertainty in computed speciation. Here we present OrgAlkCalc, an open-source Python based programme that can be used in conjunction with simply modified Global Ocean Acidification Observing Network (GOA-ON) TA titration apparatus to measure TA and OrgAlk, as well as return estimations of associated acid-base properties. The modified titration apparatus and OrgAlkCalc were tested using samples collected from the transitional waters of Dublin Bay, Ireland over a 8 month period (n = 100). TA values ranged from 2257 to 4692 μmol·kg−1 and indicated that freshwater inputs pose a significant source of carbonate alkalinity to Dublin Bay. OrgAlk values ranged from 46 to 234 μmol·kg−1 and were generally observed to be higher in more saline waters, with elevated levels in the Autumn/Winter period. The dissociation constants of two distinct OrgAlk charge groups were identified, with pK values in agreement with previously reported values for humic substances. The majority of OrgAlk charge group concentrations were associated with carboxyl-like charge groups.

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Open position: chief of section (Ocean Science)

Published 27 March 2023 Jobs Leave a Comment

Overview of the functions of the post

Under the authority of the Executive Secretary of Intergovernmental Oceanographic Commission and Assistant Director-General of UNESCO (ADG/IOC), the incumbent will lead, coordinate and organize the activities of the IOC Ocean Science Section (OSS).
The Ocean Science Section’s role is to support Member State-driven programmes in maintaining and strengthening the highest level of expertise in ocean sciences. It also helps to review the requirements and opportunities for the development of ocean sciences through international cooperation.

The incumbent will be driven by priorities and directions set by IOC Governing Bodies and his/her main tasks will be to shape the IOC UNESCO response to ocean science challenges and to advise Member States on a broad spectrum of emerging issues. The incumbent will facilitate formulation of the IOC UNESCO priorities, agendas, policies and design of knowledge-based products and ensure the technical accuracy of deliverables.

The incumbent will be preparing bi-annual work programme and budget of OSS and will supervise its team. The collective effort of the Section is on development of international ocean science and delivering scientific advice for ocean policy, including on issues of climate change and variability, ocean health and disaster risk reduction. The OSS supports expert groups on ocean acidification; ocean deoxygenation; multiple ocean stressors; ocean carbon research; global capacity in ocean science; the state of the Ocean; as well as task teams of the IOC-FAO Intergovernmental Panel on Harmful Algal Blooms, the Joint Steering Committee for the World Climate Research Programme, sponsored working groups of GESAMP. The Section implements projects related to the development and exploitation of ocean science. It engages scientific communities and partner organizations in global and regional activities towards achieving IOC objectives.

In particular, the incumbent will:

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Exploring the benefits of satellite remote sensing for oceanography

Published 27 March 2023 Web sites and blogs Leave a Comment

Satellite remote sensing is becoming increasingly important for oceanography. This technology provides researchers with a powerful tool to study the ocean from space, allowing them to observe and measure the ocean’s physical and biological characteristics.

The most common type of satellite remote sensing used in oceanography is passive microwave remote sensing. This technique uses microwaves to measure the brightness of the ocean’s surface, which can be used to determine sea surface temperature, sea surface height, and sea surface salinity. This data can then be used to monitor ocean currents, track storms, and study ocean circulation patterns.

Satellite remote sensing can also be used to measure ocean color. This technique uses the visible and near-infrared spectrum to measure the color of the ocean’s surface. This data can be used to measure the amount of chlorophyll in the water, which can be used to monitor the health of the ocean’s ecosystems.

Satellite remote sensing also provides researchers with a way to measure the amount of carbon dioxide in the ocean. This data can be used to study the effects of climate change on the ocean’s carbon cycle.

The benefits of satellite remote sensing for oceanography are numerous. It provides researchers with a way to observe and measure the ocean’s physical and biological characteristics from space. This data can be used to monitor ocean currents, track storms, and study ocean circulation patterns. It can also be used to measure the amount of chlorophyll in the water and the amount of carbon dioxide in the ocean. By utilizing satellite remote sensing, researchers can gain a better understanding of the ocean and its role in the global climate system.

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Analyzing the impact of satellite remote sensing on oceanography

The use of satellite remote sensing in oceanography has revolutionized the way scientists study the world’s oceans. By providing a wealth of data on the ocean’s physical and chemical properties, satellite remote sensing has enabled researchers to better understand the complex dynamics of the marine environment.

Satellite remote sensing technology has enabled researchers to map ocean currents, measure sea surface temperatures, and track the movement of pollutants. This data has been invaluable in understanding the impacts of climate change on oceanic ecosystems, as well as in predicting the future of the world’s oceans.

The ability to monitor the oceans from space has also allowed scientists to detect and monitor harmful algal blooms, which can have devastating effects on aquatic life. By providing a detailed picture of the ocean’s surface, satellite remote sensing has enabled researchers to identify areas of algal blooms and track their movement. This data has been used to develop strategies for mitigating the impacts of algal blooms on marine life.

In addition, satellite remote sensing has been used to study the effects of ocean acidification on coral reefs. By measuring changes in the ocean’s chemistry, researchers have been able to identify areas of acidification and track its progression. This data has been used to develop strategies for protecting coral reefs from the effects of acidification.

The use of satellite remote sensing in oceanography has revolutionized the way scientists study the world’s oceans. By providing a wealth of data on the ocean’s physical and chemical properties, satellite remote sensing has enabled researchers to better understand the complex dynamics of the marine environment and develop strategies for mitigating the impacts of climate change and ocean acidification.

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UBC gene family and their potential functions on the cellular homeostasis under the elevated pCO2 stress in the diatom Phaeodactylum tricornutum

Published 24 March 2023 Science Leave a Comment
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Graphical abstract

Highlights

  • 18 PtUBCs were identified into 5 independent clades.
  • Cis-acting elements related to stress responses were characterized from PtUBCs.
  • PtUBC15, PtUBC16 and PtUBC7 might have a negative effect during the ERAD pathway.
  • The misfolded/ unfolded proteins might be degraded by the ERAD mechanism.

Abstract

Ocean acidification (OA) as a result of more and more anthropogenic CO2 release, has already been referred to a severe ecological environmental issue. OA would destroy the balance of ocean carbonate buffering system and have negative effects on marine primary producers. Diatom Phaeodactylum tricornutum is one of the most important primary producers in the ocean, and it is susceptible to the elevated pCO2 stress. Under the elevated pCO2 stress, endoplasmic reticulum-associated degradation (ERAD) and its important components Ubiquitin-conjugating enzymes (UBCs) are pivotal to sustain cellular homeostasis. However, systematic investigation regarding phylogenetic relationships of UBC gene family, expression profiles under the elevated pCO2 stress and their potential functions on the cellular homeostasis of P. tricornutum remain poorly understood. In this study, a genome-wide analysis of PtUBC gene family was performed. It was shown that 18 PtUBC genes were unevenly distributed to the 14 chromosomes of total 33 chromosomes in P. tricornutum. Phylogenetic analysis showed that 18 PtUBC proteins were divided into 5 groups and each of them contained different conserved motifs. Besides, lots of cis-acting elements related to diverse stress responses were identified from PtUBC genes. Remarkably, transcriptomic analysis revealed that 3 PtUBC genes (PtUBC15, PtUBC16 and PtUBC7) were downregulated under the exposure to elevated pCO2 level, while the other 15 PtUBC genes did not have significant expression. Meanwhile, the model of endoplasmic reticulum-associated degradation (ERAD) mechanism was displayed, explaining that the misfolded/ unfolded proteins under the elevated pCO2 stress would be accumulated and then degraded via the ERAD mechanism to sustain the cellular homeostasis. The downregulated PtUBC genes might have a negative effect on the ERAD mechanism. Overall, this study provided an important foundation for further understanding of possible functions of PtUBC genes, especially on the cellular homeostasis, and the regulatory mechanism of PtUBCs on the diatom response to different environmental stresses.

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Assessing synergies and trade-offs of diverging Paris-compliant mitigation strategies with long-term SDG objectives

Published 24 March 2023 Science Leave a Comment
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Highlights

  • The Paris Agreement and the Sustainable Development Goals (SDGs) are interlinked.
  • Mitigation strategies chosen will affect how SDGs interact.
  • Technological and nature-based mitigation pathways increase resource consumption.
  • Mitigation strategies relying on behavioural changes limit potential SDG trade-offs.
  • Anticipating interdependences supports the design of SDG and Paris-compatible policies.

Abstract

The Sustainable Development Goals (SDGs) and the Paris Agreement are the two transformative agendas, which set the benchmarks for nations to address urgent social, economic and environmental challenges. Aside from setting long-term goals, the pathways followed by nations will involve a series of synergies and trade-offs both between and within these agendas. Since it will not be possible to optimise across the 17 SDGs while simultaneously transitioning to low-carbon societies, it will be necessary to implement policies to address the most critical aspects of the agendas and understand the implications for the other dimensions. Here, we rely on a modelling exercise to analyse the long-term implications of a variety of Paris-compliant mitigation strategies suggested in the recent scientific literature on multiple dimensions of the SDG Agenda. The strategies included rely on technological solutions such as renewable energy deployment or carbon capture and storage, nature-based solutions such as afforestation and behavioural changes in the demand side. Results for a selection of energy-environment SDGs suggest that some mitigation pathways could have negative implications on food and water prices, forest cover and increase pressure on water resources depending on the strategy followed, while renewable energy shares, household energy costs, ambient air pollution and yield impacts could be improved simultaneously while reducing greenhouse gas emissions. Overall, results indicate that promoting changes in the demand side could be beneficial to limit potential trade-offs.

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