Archive Page 2

The future of global catastrophic risk events from climate change

The nine planetary boundaries beyond which there is a risk of destabilization of the Earth system, which would threaten human societal development, April 2022 version. (Image credit: Stockholm Resilience Institute; plot annotated for clarification)

Four times since 1900, human civilization has suffered global catastrophes with extreme impacts: World War I (40 million killed), the 1918-19 influenza pandemic (40-50 million killed), World War II (40-50 million killed), and the COVID-19 pandemic (an economic impact in the trillions, and a 2020-21 death toll of 14.9 million, according to the World Health Organization).

These are the only events since the beginning of the 20th century that meet the United Nations’s definition of global catastrophic risk (GCR): a catastrophe global in impact that kills over 10 million people or causes over $10 trillion (2022 USD) in damage.

But human activity is “creating greater and more dangerous risk” and increasing the odds of global catastrophic risk events, by increasingly pushing humans beyond nine “planetary boundaries” of environmental limits within which humanity can safely operate, warns a recent United Nations report, “Global Assessment Report on Disaster Risk Reduction – Our World at Risk: Transforming Governance for a Resilient Future” (GAR2022) and its companion paper, “Global catastrophic risk and planetary boundaries: The relationship to global targets and disaster risk reduction” (see July post, “Recklessness defined: breaking 6 of 9 planetary boundaries of safety“).

These reports, endorsed by United Nations Secretary-General António Guterres, make the case that the combined effects of disasters, economic vulnerabilities, and overtaxing of ecosystems are creating “a dangerous tendency for the world to tend toward the Global Collapse scenario. This scenario presents a world where planetary boundaries have been extensively crossed, and if GCR events have not already occurred or are in the process of occurring, then their likelihood of doing so in the future is extreme … and total societal collapse is a possibility.”

Continue reading ‘The future of global catastrophic risk events from climate change’

No ‘safe space’ for 12 key ocean species on North American west coast

For the generations who grew up watching Finding Nemo, it might not come as a surprise that the North American West Coast has its own version of the underwater ocean highway – the California Current marine ecosystem (CCME). The CCME extends from the southernmost tip of California up through Washington. Seasonal upward currents of cold, nutrient-rich water are the backbone to a larger food web of krill, squid, fish, seabirds and marine mammals. However, climate change and subsequent changes in ocean pH, temperature and oxygen levels are altering the CCME — and not in a good way.

New research led by McGill University Biology professor Jennifer Sunday and Professor Terrie Klinger from the Washington Ocean Acidification Center within EarthLab at the University of Washington warns that climate impacts will significantly affect twelve economically and culturally important species make their home in the CCME over the next 80 years. The northern part of this region and areas that are closer to shore will have strongest responses within this setting to changing ocean conditions. The region can expect to see substantial loss in canopy-forming kelp, declining survival rates of red urchins, Dungeness crab and razor clams, as well as a loss of aerobic habitat for anchovy and pink shrimp.

Effects of changing climate are complex

Evaluating the biological effects of several environmental variables at once shows the complexities in climate sensitivity research. For example, while some anticipated environmental changes will boost metabolism and increase consumption and growth, accompanying changes in other variables, or even the same ones, could potentially decrease survival rates. Notably, physiological increases (such as in size, consumption or motility) are not always beneficial, especially when resources – such as food and oxygenated water – are limited.

Of all the climate effects modeled, ocean acidification was associated with the largest decreases in individual biological rates in some species, but the largest increases in others. This result emphasizes the need for continued research and monitoring to provide accurate, actionable information.

Continue reading ‘No ‘safe space’ for 12 key ocean species on North American west coast’

Biological sensitivities to high-resolution climate change projections in the California current marine ecosystem

The California Current Marine Ecosystem is a highly productive system that exhibits strong natural variability and vulnerability to anthropogenic climate trends. Relating projections of ocean change to biological sensitivities requires detailed synthesis of experimental results. Here, we combine measured biological sensitivities with high-resolution climate projections of key variables (temperature, oxygen, and pCO2) to identify the direction, magnitude, and spatial distribution of organism-scale vulnerabilities to multiple axes of projected ocean change. Among 12 selected species of cultural and economic importance, we find that all are sensitive to projected changes in ocean conditions through responses that affect individual performance or population processes. Response indices were largest in the northern region and inner shelf. While performance traits generally increased with projected changes, fitness traits generally decreased, indicating that concurrent stresses can lead to fitness loss. For two species, combining sensitivities to temperature and oxygen changes through the Metabolic Index shows how aerobic habitat availability could be compressed under future conditions. Our results suggest substantial and specific ecological susceptibility in the next 80 years, including potential regional loss of canopy-forming kelp, changes in nearshore food webs caused by declining rates of survival among red urchins, Dungeness crab, and razor clams, and loss of aerobic habitat for anchovy and pink shrimp. We also highlight fillable gaps in knowledge, including specific physiological responses to stressors, variation in responses across life stages, and responses to multistressor combinations. These findings strengthen the case for filling information gaps with experiments focused on fitness-related responses and those that can be used to parameterize integrative physiological models, and suggest that the CCME is susceptible to substantial changes to ecosystem structure and function within this century.

Continue reading ‘Biological sensitivities to high-resolution climate change projections in the California current marine ecosystem’

Impact of growth phase, pigment adaptation and climate change conditions on the cellular pigment and carbon content of fifty-one phytoplankton isolates

Owing to their importance in aquatic ecosystems, the demand for models that estimate phytoplankton biomass and community composition in the global ocean has increased over the last decade. Moreover, the impacts of climate change, including elevated carbon dioxide (CO2), increased stratification and warmer sea surface temperatures, will likely shape phytoplankton community composition in the global ocean. Chemotaxonomic methods are useful for modeling phytoplankton community composition from marker pigments normalized to Chlorophyll a (Chl a). However, photosynthetic pigments, particularly Chl a, are sensitive to nutrient and light conditions. Cellular carbon is less sensitive so using carbon biomass instead may provide an alternative approach. To this end, cellular pigment and carbon concentrations were measured in fifty-one strains of globally relevant, cultured phytoplankton. Pigment-to-Chl a and pigment-to-carbon ratios were computed for each strain. For twenty-five strains, measurements were taken during two growth phases. While some differences between growth phases were observed, they did not exceed within-class differences. Multiple strains of Amphidinium carteraeDitylum brightwellii and Heterosigma akashiwo were measured to determine whether time in culture influenced pigment and carbon composition. No appreciable trends in cellular pigment or carbon content were observed. Lastly, the potential impact of climate change conditions on the pigment ratios was assessed using a multistressor experiment that included increased mean light, temperature and elevated pCO2 on three species: Thalassiosira oceanicaOstreococcus lucimarinus and Synechococcus. The largest differences were observed in the pigment-to-carbon ratios, while the marker pigments largely covaried with Chl a. The implications of these observations to chemotaxonomic applications are discussed.

Continue reading ‘Impact of growth phase, pigment adaptation and climate change conditions on the cellular pigment and carbon content of fifty-one phytoplankton isolates’

Microbial ecosystem responses to alkalinity enhancement in the North Atlantic subtropical gyre

In addition to reducing carbon dioxide (CO2) emissions, actively removing CO2 from the atmosphere is widely considered necessary to keep global warming well below 2°C. Ocean Alkalinity Enhancement (OAE) describes a suite of such CO2 removal processes that all involve enhancing the buffering capacity of seawater. In theory, OAE both stores carbon and offsets ocean acidification. In practice, the response of the marine biogeochemical system to OAE must be demonstrably negligible, or at least manageable, before it can be deployed at scale. We tested the OAE response of two natural seawater mixed layer microbial communities in the North Atlantic Subtropical Gyre, one at the Western gyre boundary, and one in the middle of the gyre. We conducted 4-day microcosm incubation experiments at sea, spiked with three increasing amounts of alkaline sodium salts and a 13C-bicarbonate tracer at constant pCO2. We then measured a suite of dissolved and particulate parameters to constrain the chemical and biological response to these additions. Microbial communities demonstrated occasionally measurable, but mostly negligible, responses to alkalinity enhancement. Neither site showed a significant increase in biologically produced CaCO3, even at extreme alkalinity loadings of +2,000 μmol kg−1. At the gyre boundary, alkalinity enhancement did not significantly impact net primary production rates. In contrast, net primary production in the central gyre decreased by ~30% in response to alkalinity enhancement. The central gyre incubations demonstrated a shift toward smaller particle size classes, suggesting that OAE may impact community composition and/or aggregation/disaggregation processes. In terms of chemical effects, we identify equilibration of seawater pCO2, inorganic CaCO3 precipitation, and immediate effects during mixing of alkaline solutions with seawater, as important considerations for developing experimental OAE methodologies, and for practical OAE deployment. These initial results underscore the importance of performing more studies of OAE in diverse marine environments, and the need to investigate the coupling between OAE, inorganic processes, and microbial community composition.

Continue reading ‘Microbial ecosystem responses to alkalinity enhancement in the North Atlantic subtropical gyre’

Research scientist 4 – moored carbon

The Carbon Group at UW CICOES (located at the Pacific Marine Environmental Laboratory [PMEL] at Sand Point in Seattle, WA) has an exciting opportunity to support the mission of cutting-edge research and technology development in ocean carbon monitoring (www.pmel.noaa.gov/co2/).

The primary mission of this project is to evaluate variability and long-term change in air-sea CO2 flux and ocean acidification by conducting sustained, highly-resolved autonomous measurements and further developing ocean observing technologies for expanding and improving these measurements.

RESPONSIBILITIES:

• Serves as co-lead on operational activities, including developing and coordinating standardization related to lab quality assurance (QA) activities and data quality control (QC), based on project research priorities. Drafts standard operating procedure documentation for public dissemination. Schedules, prepares, and leads regular team meetings on these topics as needed.
• Serves as one of the primary points of contact within the project for planning and carrying out autonomous observing field operations. Maintains communications with project personnel and external partners to ensure critical time-sensitive information is received and necessary actions are taken.
• Coordinates staffing schedules and designates staffing assignments for supporting deployment of autonomous observing platforms. Documents notes related to field operations and sensor performance.
• Supervises research scientists. Works with employees to establish goals and performance time lines. Mentors employees and serves as employee advocate. Conducts employee performance reviews.
• Contributes to the group’s data QC efforts on delayed-mode carbon and biogeochemical data, ensuring timely public access to observational data. This may include developing data QC reports for internal review, submission of data, consistency checks among several data archives and products, and evaluating and applying innovative approaches to data QC.
• Assists CICOES PIs with CICOES budgets and reports. Fields, directs, and/or responds to requests for marine carbon information, data, and graphics.
• Represents the project at internal (PMEL) and external forums such as meetings and working groups relevant to autonomous carbon observing

MINIMUM REQUIREMENTS:

Minimum 6 years of relevant experience and a Bachelor’s degree.

Equivalent education/experience will substitute for all minimum qualifications except when there are legal requirements, such as a license/certification/registration.

ADDITIONAL REQUIREMENTS:

• Demonstrated skill (at least 2 years of experience) with supervising employees.
• Knowledge of oceanographic operations related to autonomous equipment and platforms.
• Ability and interest to learn and/or apply programming languages, such as Python, MATLAB, and LabVIEW.

Application Process:
The application process for UW positions may include completion of a variety of online assessments to obtain additional information that will be used in the evaluation process.  These assessments may include Work Authorization, Cover Letter and/or others.  Any assessments that you need to complete will appear on your screen as soon as you select “Apply to this position”. Once you begin an assessment, it must be completed at that time; if you do not complete the assessment you will be prompted to do so the next time you access your “My Jobs” page. If you select to take it later, it will appear on your “My Jobs” page to take when you are ready. Please note that your application will not be reviewed, and you will not be considered for this position until all required assessments have been completed.

Continue reading ‘Research scientist 4 – moored carbon’

Spatial and temporal variability of the physical, carbonate and CO2 properties in the Southern Ocean surface waters during austral summer (2005-2019)

Highlights

  • Latitudinal and temporal variability of physical and carbonate parameters are studied south of Tasmania.
  • Physical and carbonate parameters are impacted by mesoscale activity in the STZ and north of SAR.
  • The region is a sink of CO2 during summer with a mean CO2 flux of −4.0 ± 2.8 mmol m−2 d−1.
  • New empirical relationships for AT and CT during austral summer are determined.
  • The increase in CT and decrease in pH linked to rising anthropogenic emissions.

Abstract

In situ measurements of sea surface temperature (SST), salinity (SSS), Total Alkalinity (AT) and Total Carbon (CT) were obtained during austral summer (mid-February to mid-March) from 2005 to 2019 in the Southern Ocean (SO), along a transect between Hobart, Tasmania and Dumont d’Urville French Antarctic Station. The studied transect is divided in four regions from North to South: the Subtropical Zone (STZ), the Subantarctic Region (SAR), the Antarctic Region (AAR) and the Coastal Antarctic Zone (CAZ). Latitudinal distribution of measured SST, SSS, AT, CT as well as calculated pH, CO2 parameters (seawater fugacity of CO2 (fCO2sw), difference between seawater and atmospheric fugacity (ΔfCO2), CO2 flux (FCO2)) and satellite-derived Chlorophyll a (Chl-a) are discussed. We show that the variability of physical and carbonate parameters in the STZ and north of the SAR are related to the mesoscale activity. In the CAZ, the freshwater inputs from sea-ice melting strongly impact the variability of all parameters. The comparison between physical and carbonate parameters highlights that AT and CT are directly related to the latitudinal variability of SST and SSS. Study of the CO2 parameters shows that the transect is a sink of CO2 during February and March, with a mean FCO2 of −4.0 ± 2.8 mmol m−2 d−1. The most negative values of FCO2 are found in the STZ and SAR north of 50°S and in the AAR south of 62°S, where biological activity is high. New simple empirical relationships are developed for AT from SST and SSS and for CT using SST, SSS and atmospheric fCO2 (fCO2atm) for the austral summer in the studied area. Using high resolution SSS and SST from the SURVOSTRAL program, trends of AT and CT are determined in the SAR and the AAR from 2005 to 2019. SST, SSS and AT increase over this period in the SAR, which might be explained by the southward migration of the Subtropical Front. In the AAR, no clear trend is detected. CT increases by 1.0 ± 0.2 and 0.8 ± 0.3 μmol kg−1 y−1 in the SAR and AAR respectively. The trend in the AAR is attributed to the increase in anthropogenic CO2 emissions in the atmosphere while, in the SAR, hydrographic changes also contribute to the increase. Using the coefficient associated with fCO2atm in the equation of CT, we estimate the impact of atmospheric CO2 increase on CT at 1.18 ± 0.14 μmol kg−1 y−1 and 1.07 ± 0.13 μmol kg−1 y−1 in the SAR and AAR respectively. Decreases in pH are observed in both regions (−0.0018 ± 0.0001 and −0.0026 ± 0.0003 per year in the SAR and AAR respectively), indicating the sensitivity of surface waters in the area towards the development of ocean acidification processes under rising anthropogenic emissions.

Continue reading ‘Spatial and temporal variability of the physical, carbonate and CO2 properties in the Southern Ocean surface waters during austral summer (2005-2019)’

Limits and CO2 equilibration of near-coast alkalinity enhancement

Ocean Alkalinity Enhancement (OAE) has recently gained attention as a potential method for negative emissions at gigatonne scale, with near-coast OAE operations being economically favorable due to proximity to mineral and energy sources. In this paper we study critical questions which determine the scale and viability of OAE: Which coastal locations are able to sustain a large flux of alkalinity at minimal pH and ΩArag (aragonite saturation) changes? What is the interference distance between adjacent OAE projects? How much CO2 is absorbed per unit of alkalinity added? How quickly does the induced CO2 deficiency equilibrate with the atmosphere?

Using the LLC270 (0.3deg) ECCO global circulation model we find that the steady-state OAE rate varies over 1–2 orders of magnitude between different coasts and exhibits complex patterns and non-local dependencies which vary from region to region. In general, OAE in areas of strong coastal currents allow the largest fluxes and depending on the direction of coastal currents, neighboring OAE sites can exhibit dependencies as far as 400 km or more. We found that within relatively conservative constraints set on ∆pH or ∆Omega, most regional stretches of coastline are able to accommodate on the order of tens to hundreds of megatonnes of negative emissions within 300 km of the coast. We conclude that near-coastal OAE has the potential to scale globally to several GtCO2/yr of drawdown with conservative pH constraints, if the effort is spread over the majority of available coastlines.

Depending on the location, we find a diverse set of equilibration kinetics, determined by the interplay of gas exchange and surface residence time. Most locations reach an uptake-efficiency plateau of 0.6–0.8mol CO2 per mol of alkalinity after 3–4 years, after which there is little further CO2 uptake. The most ideal locations, reaching an uptake of around 0.8 include north Madagascar, San Francisco, Brazil, Peru and locations close to the southern ocean such as Tasmania, Kerguelen and Patagonia, where the gas exchange appears to occur faster than the surface residence time. Some locations (e.g. Hawaii) take significantly longer to equilibrate (up to 8–10 years), though can still eventually achieve high uptake. If the alkalinity released advects into regions of significant downwelling (e.g. around Iceland) up to half of the OAE potential can be lost to bottom waters.

Continue reading ‘Limits and CO2 equilibration of near-coast alkalinity enhancement’

Assistant research scientist/faculty specialist position to support NOAA National Centers for Environmental Information

Department: UMD/ESSIC/CISESS

Starting Salary: Commensurate with experience

Closing Date: Wednesday, August 31, 2022

Duties:

The University of Maryland / Cooperative Institute for Satellite Earth System Studies (UMD/CISESS) is looking for a talented and self-motivated candidate to start a new and promising career supporting the research, development, and transition projects funded by the NOAA National Centers for Environmental Information (NCEI). Responsibilities include:

(a) Supporting ocean acidification data management and data product development;

(b) Generating gridded coastal and global ocean data products by using NCEI’s World Ocean Atlas tools (Fortran based);

(c) Support environmental data management activities for shipboard data owned and collected by OMAO, e.g., archival support, maintenance of existing OMAO specific products and services, and annual reporting.

The incumbent is encouraged to conduct collaborative research with NOAA scientists. This position requires occasional travel to both domestic and international destinations to present at meetings and conferences.  This is a multiple-year position with good potential for promotion, subject to annual performance evaluation and renewal.

Qualifications:

  • A master’s degree (or above) in oceanography and related physical sciences (including STEM)
  • Excellent skills with the FORTRAN, Python, and SQL programming
  • Proficient in verbal and written English, and presentation skills
  • U.S. citizenship or Permanent resident (Green Card holder) is required.

To Apply: Interested candidates should send a CV with a list of at least 3 professional references and a cover letter explaining how your qualifications meet the posted requirements to Liqing.Jiang@noaa.gov.

Continue reading ‘Assistant research scientist/faculty specialist position to support NOAA National Centers for Environmental Information’

‘There are no bright spots’: regionwide Dungeness crab catch rates see down season

The end of the summer Dungeness crab season is only a few days away and reports of low catch rates might have some fishermen in a crabby mood.

“On a regionwide level, there are no bright spots, and generally regionwide catch rates have been down,” said Joseph Stratman, the lead crab biologist of Region I for the Alaska Department of Fish and Game.

Stratman said he can’t identify any specific causes as to why regionwide catch rates are down, but said it’s not atypical to see this species’s numbers fluctuate from year to year, and it’s hard to predict how a may differ each given the format the department collects the estimated season prediction.

“All info from the fishing, we don’t know how things look until people do some fishing,” he said. “But from what I’ve heard, people weren’t catching a lot of crabs.”

But, studies by the Office of National Marine Sanctuaries National Oceanic and Atmospheric Administration suggest that Dungeness crab populations will likely face challenges as climate change continues to grow as more of a threat to ocean sustainability.

Ocean acidification has been linked to a projected decline over the next 50 years in Dungeness crab biomass, larval development rates and survival and an overall loss in economic revenue according to a case study published by the NOAA fisheries in collaboration with The National Marine Sanctuary Foundation and NOAA Ocean Acidification Program.

Continue reading ‘‘There are no bright spots’: regionwide Dungeness crab catch rates see down season’

Engineers will suck CO2 from the ocean

Chemical engineers at Brunel University London are developing a pilot plant to strip CO2 from seawater that will then suck emissions out of the atmosphere.

The SeaCURE plant will be built at the Sea Life centre in Weymouth where it will process 3,000 L of seawater per minute, removing an estimated 100 t/y of CO2. The three-year project has received £3m (US$3.6m) of UK Government funding and the plant is scheduled to begin operating in 2024.

Salman Masoudi Soltani, Senior Lecturer in Chemical Engineering at Brunel University, and his research group will work to design, model and optimise the solvent-based CO2 capture process. The team aims to file a patent for the process so was unable to share the specific details of the process but Soltani said the key steps involve lowering the pH of the seawater to extract CO2. This CO2 stream will then be purified for use by industry, for example in building materials, or locked away in geological storage.

In April, the UN Intergovernmental Panel on Climate Change (IPCC) said large-scale deployment of CO2 removal technologies was unavoidable if net zero emissions are to be achieved. In a report published in 2019, it said CO2 removal technologies would need to remove 100bn–1,000bn t of CO2 over the course of the 21st Century to limit warming to 1.5°C. Technologies for direct air capture – or DAC – are already in commercial operation and interest is growing. Currently, the largest direct air capture and CO2 storage facility is operated by Climeworks in Iceland, which has a capacity to capture 4,000 t/y of CO2, showing the measure of the scaleup and scale-out challenge faced in achieving the IPCC projections. In May, the US Government pledged to invest US $3.5bn to develop four large-scale DAC hubs, each capable of capturing 1m t/y of CO2.

Continue reading ‘Engineers will suck CO2 from the ocean’

Stretching crust explains Earth’s 170,000-year-long heat wave

A team studied sediment cores drilled from the North Atlantic to shed light on the Paleocene-Eocene Thermal Maximum. Credit: Tom Gernon/University of Southampton

Fifty-six million years ago, Earth endured a heat wave that lasted 170,000 years. The event, known as the Paleocene-Eocene Thermal Maximum (PETM), ushered in a wave of evolutionary shifts. New research published in Nature Geoscience suggests a massive belch of carbon from deep below the northern Atlantic Ocean could have played a key role.

“[The PETM] was one of the most extreme global warming events in the recent geologic past,” said Thomas Gernon, a geologist at the University of Southampton. The warm spell raised sea surface temperatures roughly 5°C, acidified the oceans, and wiped out some deep-sea creatures.

What makes the PETM so unusual is its rapid onset, said James Zachos, a paleoceanographer at the University of California, Santa Cruz, who researches the event but was not involved in the new study. “The rate of [carbon] emissions had to be really high—almost the same order of magnitude as fossil fuel emissions.” That suggests multiple sources of carbon, he said.

Continue reading ‘Stretching crust explains Earth’s 170,000-year-long heat wave’

Low water pH depressed growth and early development of giant freshwater prawn Macrobrachium rosenbergii larvae

Macrobrachium rosenbergii is one of the shellfish species with high aquaculture value due to its increasing market demand. However, the comparatively low production volume compared to demand coupled with the rapid decline of the natural environment, consequently, drives the potential depletion of the wild population. The decrease in water pH related to anthropogenic pollution is one of the most critical factors affecting the early life performances of M. rosenbergii. Therefore, this study was designed to examine the effect of low water pH on feeding, growth and development of M. rosenbergii early life stages. Experimental water pH was set as neutral (7.7 ± 0.4); mild-acidic (6.4 ± 0.5) and acidic (5.4 ± 0.2) with triplication at a stocking density of 2 larvae/L for 30 days. As expected, M. rosenbergii larvae were highly sensitive to acidic pH with no larvae survived beyond 48 h of exposure. Feeding, survival and growth of larvae were adversely affected by mild-acidic pH exposure as compared to neutral pH. Larvae exposed to mild-acidic water pH experienced a prolonged larval period and only metamorphosed to the post-larval stage at day-30. Whilst under neutral water pH, larval that metamorphosed to post-larval was first observed on day-23. The negative impact of decreased pH, even in mild-acidic pH exposure, on the feeding, survival, growth and development of M. rosenbergii larvae highlights the urgency of periodic pH monitoring during M. rosenbergii larviculture.

Continue reading ‘Low water pH depressed growth and early development of giant freshwater prawn Macrobrachium rosenbergii larvae’

Microplastics can aggravate the impact of ocean acidification on the health of mussels: insights from physiological performance, immunity and byssus properties

Graphical abstract

Highlights

  • Ocean acidification reduced phagocytic activity and hence immunity of mussels.
  • The reduced phagocytic activity was associated with lowered energy budget.
  • Ocean acidification also reduced byssus strength, extensibility and production.
  • Microplastics can aggravate these negative effects of ocean acidification.
  • Mussels would be more prone to diseases and dislodgement in future oceans.

Abstract

Ocean acidification may increase the risk of disease outbreaks that would challenge the future persistence of marine organisms if their immune system and capacity to produce vital structures for survival (e.g., byssus threads produced by bivalves) are compromised by acidified seawater. These potential adverse effects may be exacerbated by microplastic pollution, which is forecast to co-occur with ocean acidification in the future. Thus, we evaluated the impact of ocean acidification and microplastics on the health of a mussel species (Mytilus coruscus) by assessing its physiological performance, immunity and byssus properties. We found that ocean acidification and microplastics not only reduced hemocyte concentration and viability due to elevated oxidative stress, but also undermined phagocytic activity of hemocytes due to lowered energy budget of mussels, which was in turn caused by the reduced feeding performance and energy assimilation. Byssus quality (strength and extensibility) and production were also reduced by ocean acidification and microplastics. To increase the chance of survival with these stressors, the mussels prioritized the synthesis of some byssus proteins (Mfp-4 and Mfp-5) to help maintain adhesion to substrata. Nevertheless, our findings suggest that co-occurrence of ocean acidification and microplastic pollution would increase the susceptibility of bivalves to infectious diseases and dislodgement risk, thereby threatening their survival and undermining their ecological contributions to the community.

Continue reading ‘Microplastics can aggravate the impact of ocean acidification on the health of mussels: insights from physiological performance, immunity and byssus properties’

Webinar registration: management guidance for the use of ocean and coastal acidification regional model outputs in the northeast

Description: As capabilities for biogeochemical forecast modeling improve, it is important to understand how stakeholder and end users might engage with and use potential model outputs. Here, we present the results of stakeholder focus groups with oyster growers who use upweller systems, mussel growers and water quality specialists who actively monitor nearshore water quality. We draw stakeholder-derived insights into how outputs from biogeochemical forecast models might be most effectively used in the NECAN region. 

This presentation is the result of research funded by the National Oceanic and Atmospheric Administration’s National Centers for Coastal Ocean Science Competitive Research Program and the NOAA Ocean Acidification Program under award NA18NOS4780178 to the Northeastern Regional Association of Coastal Ocean Observing Systems.

Time: Aug 2, 2022 01:00 PM in Eastern Time (US and Canada)

Registration: Link

Continue reading ‘Webinar registration: management guidance for the use of ocean and coastal acidification regional model outputs in the northeast’

Elevated pCO2 induced physiological, molecular and metabolic changes in Nannochloropsis oceanica and its effects on trophic transfer

The rise of dissolution of anthropogenic CO2 into the ocean alters marine carbonate chemistry and then results in ocean acidification (OA). It has been observed that OA induced different effects on different microalgae. In this study, we explored the physiological and biochemical changes in Nannochloropsis oceanica in response to increased atmospheric carbon dioxide and tested the effect of ocean acidification (OA) on the food web through animal feeding experiments at a laboratory scale. We found that the levels of C, N, C/N, Fv/Fm, and photosynthetic carbon fixation rate of algae cells were increased under high carbon dioxide concentration. Under short-term acidification, soluble carbohydrate, protein, and proportion of unsaturated fatty acids in cells were significantly increased. Under long-term acidification, the proportion of polyunsaturated fatty acids (PUFAs) (~33.83%) increased compared with that in control (~30.89%), but total protein decreased significantly compared with the control. Transcriptome and metabonomics analysis showed that the differential expression of genes in some metabolic pathways was not significant in short-term acidification, but most genes in the Calvin cycle were significantly downregulated. Under long-term acidification, the Calvin cycle, fatty acid biosynthesis, TAG synthesis, and nitrogen assimilation pathways were significantly downregulated, but the fatty acid β-oxidation pathway was significantly upregulated. Metabolome results showed that under long-term acidification, the levels of some amino acids increased significantly, while carbohydrates decreased, and the proportion of PUFAs increased. The rotifer Brachionus plicatilis grew slowly when fed on N. oceanica grown under short and long-term acidification conditions, and fatty acid profile analysis indicated that eicosapentaenoic acid (EPA) levels increased significantly under long-term acidification in both N. oceanica (~9.48%) and its consumer B. Plicatilis (~27.67%). It can be seen that N. oceanica formed a specific adaptation mechanism to OA by regulating carbon and nitrogen metabolism, and at the same time caused changes of cellular metabolic components. Although PUFAs were increased, they still had adverse effects on downstream consumers.

Continue reading ‘Elevated pCO2 induced physiological, molecular and metabolic changes in Nannochloropsis oceanica and its effects on trophic transfer’

The effects of acidification on arsenic concentration and speciation in offshore shallow water system

Highlights

  • Acidification simulation experiments were conducted in lab scale tanks.
  • Effects of acidification on speciation and transportation of arsenic were studied.
  • Acidification could cause more DIAs transport into overlying water from sediments.
  • Acidification would be favorable to the existence of As3+ in overlying waters.

Abstract

The effects of acidification on speciation and transportation of arsenic in shallow seawater system were investigated based on data from acidification simulation experiments in lab scale tanks, in which enhanced levels of pCO2 corresponding to pHT were processed. The results showed that: (1) the concentration of DIAs (Dissolved inorganic arsenic), As5+ and As3+ in the overlying water increased with experimental CO2 enrichment; (2) while the ratio of As5+/As3+ decreased; (3) acidification could cause more DIAs transport into the overlying water from sediments or suspended particulate matters, and would be favorable to the existence of As3+. Thus, DIAs is available to microorganisms and can be taken in effectively by microorganisms in the shallow water system, resulting in toxic effects of As on microorganisms and thus the inhibition of the growth of microorganisms.

Continue reading ‘The effects of acidification on arsenic concentration and speciation in offshore shallow water system’

GreenChat episode 3 major contributors to unsustainability: part B (audio & video)

In this episode of GreenChat we discuss the major causes of ocean acidification, fresh water use and loss of biodiversity that impact sustainability. Co-Hosted by Dr. Suresh Mony and Mr. N Suresh.

Continue reading ‘GreenChat episode 3 major contributors to unsustainability: part B (audio & video)’

High vulnerability and a big conservation gap: mapping the vulnerability of coastal scleractinian corals in South China

Highlights

  • The first vulnerability map for scleractinian corals along the coast of South China was created.
  • An approach combining vulnerability components and habitat suitability models was developed.
  • 37.7 % of the potential coral habitats were highly vulnerable.
  • Only 21.6 % of the coral habitats were protected, indicating a large conservation gap.

Abstract

Scleractinian corals build the most complex and diverse ecosystems in the ocean with various ecosystem services, yet continue to be degraded by natural and anthropogenic stressors. Despite the rapid decline in scleractinian coral habitats in South China, they are among the least concerning in global coral vulnerability maps. This study developed a rapid assessment approach that combines vulnerability components and species distribution models to map coral vulnerability within a large region based on limited data. The approach contained three aspects including, exposure, habitat suitability, and coral-conservation-based adaptive capacity. The exposure assessment was based on seven indicators, and the habitat suitability was mapped using Maximum Entropy and Random Forest models. Vulnerability of scleractinian corals in South China was spatially evaluated using the approach developed here. The results showed that the average exposure of the study region was 0.62, indicating relatively high pressure. The highest exposure occurred from the east coast of the Leizhou Peninsula to the Pearl River Estuary. Aquaculture and shipping were the most common causes of exposure. Highly suitable habitats for scleractinian corals are concentrated between 18°N–22°N. Only 21.6 % of the potential coral habitats are included in marine protected areas, indicating that there may still be large conservation gaps for scleractinian corals in China. In total, 37.7 % of the potential coral habitats were highly vulnerable, with the highest vulnerability appearing in the Guangdong Province. This study presents the first attempt to map the vulnerability of scleractinian corals along the coast of South China. The proposed approach and findings provide an essential tool and information supporting the sustainable management and conservation of coral reef ecosystems, addressing an important gap on the world’s coral reef vulnerability map.

Continue reading ‘High vulnerability and a big conservation gap: mapping the vulnerability of coastal scleractinian corals in South China’

SDG-14: life below water

Global systems and processes that assure the supply of rainwater, drinking water and oxygen are regulated by oceanic temperature chemistry, currents and life. Pollution, diminished fisheries and the loss of coastal habitats all have negative impacts on the ocean’s sustainability. Such activities have severely impacted around 40% of the world’s oceans. SDG-14, Life Below Water, aims to conserve marine ecosystems by establishing regulations for removing pollutants from the sea, decreasing sea acidification and regulating the fishing sector to ensure sustainable fishing. As a result, the major incentive for this goal is to protect and utilise marine ecosystem services sustainably. This chapter presents the business models of 36 companies and use cases that employ emerging technologies and create value in SDG-14. We should highlight that one use case can be related to more than one SDG and it can make use of multiple emerging technologies.

Continue reading ‘SDG-14: life below water’

  • Reset

Subscribe

OA-ICC Highlights


%d bloggers like this: