Archive Page 2

Abundances and morphotypes of the coccolithophore Emiliania huxleyi in southern Patagonia compared to neighbouring oceans and Northern Hemisphere fjords

Coccolithophores are potentially affected by ongoing ocean acidification, where rising CO2 lowers seawater pH and calcite saturation state (Ωcal). Southern Patagonian fjords and channels provide natural laboratories for studying these issues due to high variability in physical and chemical conditions. We surveyed coccolithophore assemblages in Patagonian fjords during late spring 2015 and early spring 2017. Surface Ωcal exhibited large variations driven mostly by freshwater inputs. High-Ωcal conditions (max. 3.6) occurred in the Archipelago Madre de Dios. Ωcal ranged from 2.0–2.6 in the western Strait of Magellan and 1.5–2.2 in the inner channel and was subsaturating (0.5) in Skyring Sound. Emiliania huxleyi was the only coccolithophore widely distributed in Patagonian fjords (> 96 % of total coccolithophores), only disappearing in the Skyring Sound, a semi-closed mesohaline system. Correspondence analysis associated higher E. huxleyi biomasses with lower diatom biomasses. The highest E. huxleyi abundances in Patagonia were in the lower range of those reported in Norwegian fjords. Predominant morphotypes were distinct from those previously documented in nearby oceans but similar to those of Norwegian fjords. Moderately calcified forms of E. huxleyi A morphotype were uniformly distributed throughout Patagonia fjords. The exceptional R/hyper-calcified coccoliths, associated with low Ωcal values in Chilean and Peruvian coastal upwellings, were a minor component associated with high Ωcal levels in Patagonia. Outlying mean index (OMI) niche analysis suggested that pH and Ωcal conditions explained most variation in the realized niches of E. huxleyi morphotypes. The moderately calcified A morphotype exhibited the widest niche breadth (generalist), while the R/hyper-calcified morphotype exhibited a more restricted realized niche (specialist). Nevertheless, when considering an expanded sampling domain, including nearby southeast Pacific coastal and offshore waters, even the R/hyper-calcified morphotype exhibited a higher niche breadth than other closely phylogenetically related coccolithophore species. The occurrence of E. huxleyi in naturally low pH–Ωcal environments indicates that its ecological response is plastic and capable of adaptation.

Continue reading ‘Abundances and morphotypes of the coccolithophore Emiliania huxleyi in southern Patagonia compared to neighbouring oceans and Northern Hemisphere fjords’

Temporal and spatial variabilities of chemical and physical parameters on the Heron Island coral reef platform

Globally, coral reefs are threatened by ocean warming and acidification. The degree to which acidification will impact reefs is dependent on the local hydrodynamics, benthic community composition, and biogeochemical processes, all of which vary on different temporal and spatial scales. Characterizing the natural spatiotemporal variability of seawater carbonate chemistry across different reefs is critical for elucidating future impacts on coral reefs. To date, most studies have focused on select habitats, whereas fewer studies have focused on reef scale variability. Here, we investigate the temporal and spatial seawater physicochemical variability across the entire Heron Island coral reef platform, Great Barrier Reef, Australia, for a limited duration of six days. Autonomous sensor measurements at three sites across the platform were complemented by reef-wide boat surveys and discrete sampling of seawater carbonate chemistry during the morning and evening. Variability in both temporal and spatial physicochemical properties were predominantly driven by solar irradiance (and its effect on biological activity) and the semidiurnal tidal cycles but were influenced by the local geomorphology resulting in isolation of the platform during low tide and rapid flooding during rising tides. As a result, seawater from previous tidal cycles was sometimes trapped in different parts of the reef leading to unexpected biogeochemical trends in space and time. This study illustrates the differences and limitations of data obtained from high-frequency measurements in a few locations compared to low-frequency measurements at high spatial resolution and coverage, showing the need for a combined approach to develop predictive capability of seawater physicochemical properties on coral reefs.

Continue reading ‘Temporal and spatial variabilities of chemical and physical parameters on the Heron Island coral reef platform’

Toward unified pH of saline solutions

Fluctuations of pH in coastal systems are generally surveyed through potentiometric pH measurements. A new concept of a unified pH scale was introduced with the great advantage of enabling comparability of absolute values, pHabs, pertaining to any medium. Using water as an anchor solvent, yielding pHH2Oabs, enables referencing the pHabs values to the conventional aqueous pH scale. The current work aims at contributing to implement pHH2Oabs to saline solutions. To this purpose, differential potentiometric measurements, with a salt bridge of ionic liquid [N2225][NTf2], were carried out aiming at overcoming problems related to residual liquid junction potentials that affect the quality of such measurements. The ability to measure pHH2Oabs with acceptable uncertainty was evaluated using Tris-Tris·HCl standard buffer solutions prepared in a background matrix close to the characteristics of estuarine systems (salinity of 20) as well as with NaCl solutions with ionic strength between 0.005 and 0.8 mol kg−1. The present study shows that for high ionic strength solutions, such as seawater, challenges remain when addressing the assessment and quantification of ocean acidification in relation to climate change. Improvements are envisaged from the eventual selection of a more adequate ionic liquid.

Continue reading ‘Toward unified pH of saline solutions’

Lithium elemental and isotope systematics of modern and cultured brachiopods: implications for seawater evolution

Lithium has proven a powerful tracer of weathering processes and chemical seawater evolution. Skeletal components of marine calcifying organisms, and in particular brachiopods, present promising archives of Li signatures. However, Li incorporation mechanisms and potential influence from biological processes or environmental conditions require a careful assessment. In order to constrain Li systematics in brachiopod shells, we present Li concentrations and isotope compositions for 11 calcitic brachiopod species collected from six different geographic regions, paralleled with data from culturing experiments where brachiopods were grown under varying environmental conditions and seawater chemistry (pH–pCO2, temperature, Mg/Ca ratio). The recent brachiopod specimens collected across different temperate and polar environments showed broadly consistent δ7Li values ranging from 25.2 to 28.1‰ (with mean δ7Li of 26.9 ± 1.5‰), irrespective of taxonomic rank, indicating that incorporation of Li isotopes into brachiopod shells is not strongly affected by vital effects related to differences among species. This results in Δ7Licalcite–seawater values (per mil difference in 7Li/6Li between brachiopod calcite shell and seawater) from −2.9‰ to −5.8‰ (with mean Δ7Licalcite–seawater value of −3.6‰), which is larger than the Δ7Licalcite–seawater values calculated based on data from planktonic foraminifera (~0‰ to ~−4‰). This range of values is further supported by results from brachiopods cultured experimentally. Under controlled culturing conditions simulating the natural marine environment, the Δ7Licalcite–seawater for Magellania venosa was −2.5‰ and not affected by an increase in temperature from 10 to 16 °C. In contrast, a decrease in Mg/Ca (or Li/Ca) ratio of seawater by addition of CaCl2 as well as elevated pCO2, and hence low-pH conditions, resulted in an increased Δ7Licalcite-seawater up to −4.6‰. Collectively, our results indicate that brachiopods represent valuable archives and provide an envelope for robust Li-based reconstruction of seawater evolution over the Phanerozoic.

Continue reading ‘Lithium elemental and isotope systematics of modern and cultured brachiopods: implications for seawater evolution’

Microbiome response differs among lines of Sydney rock oysters to ocean warming and acidification (video)

Elliot Scanes from the University of Technology Sydney talks to us about his FEMS Microbiology Ecology

Read this article: Microbiome response differs among selected lines of Sydney rock oysters to ocean warming and acidification | FEMS Microbiology Ecology | Oxford Academic (oup.com)

Continue reading ‘Microbiome response differs among lines of Sydney rock oysters to ocean warming and acidification (video)’

Understanding how a crab’s complex life cycle will respond to climate change

Research with implications for species under stress from a warming planet

A Dungeness crab scuttling across a boardwalk. The life cycle of the Dungeness crab offers lessons on potential effects of climate change for other species.
The life cycle of the Dungeness crab offers lessons on potential effects of climate change for other species (Adobe Stock).

For many marine animals, like the Dungeness crab, seasonality and timing are components of complex life cycles, where disruptions can have serious implications for the population. Understanding how climate change will impact each life stage is no small undertaking when considering all variables and moving parts in a changing environment. Despite these challenges, this information is vital for sustainable fishery management and to inform new conservation strategies.

A team of researchers from the University of Washington, the National Oceanic and Atmospheric Administration (NOAA), Simon Fraser University, and the University of Connecticut Department of Marine Science including Ph.D. student Halle Berger, Assistant Professor Catherine Matassa, and Assistant Professor Samantha Siedlecki, looked at the Pacific Northwest portion of the Dungeness crab fishery, which spans from Alaska down to Southern California. In a paper published this week in AGU Advances, they determined which life stages are most vulnerable, and to which stressors.

This research is part of a regional vulnerability assessment and collaboration funded by the NOAA Ocean Acidification Program. It also investigates environmental justice issues, says Siedlecki,

“Tribal communities in the Pacific Northwest identify Dungeness as both culturally and economically important species for their way of life. Species are moving but of course tribal communities don’t have the option of moving their land in response. The tribal communities are very interested and motivated to think about ways they can sustain the fishery.”

This assessment looked at three stressors all resulting from future carbon emissions: ocean acidification (OA), low oxygen levels (hypoxia), and warming temperatures. Berger explains that they integrated several layers of information to create a realistic model to study the consequences of stressors at different times throughout the life stages, from eggs, to larvae, to juveniles, to adults.

Continue reading ‘Understanding how a crab’s complex life cycle will respond to climate change’

Seasonality and life history complexity determine vulnerability of Dungeness crab to multiple climate stressors

Abstract

Scaling climate change impacts from individual responses to population-level vulnerability is a pressing challenge for scientists and society. We assessed vulnerability of the most valuable fished species in the Northwest U.S.—Dungeness crab—to climate stressors using a novel combination of ocean, population, and larval transport models with stage-specific consequences of ocean acidification, hypoxia, and warming. Integration across pelagic and benthic life stages revealed increased population-level vulnerability to each stressor by 2100 under RCP 8.5. Under future conditions, chronic vulnerability to low pH emerged year-round for all life stages, whereas vulnerability to low oxygen continued to be acute, developing seasonally and impacting adults, which are critical to population growth. Our results demonstrate how ontogenetic habitat shifts and seasonal ocean conditions interactively impact population-level vulnerability. Because most valuable U.S. fisheries rely on species with complex life cycles in seasonal seas, chronic and acute perspectives are necessary to assess population-level vulnerability to climate change.

Plain Language Summary

The release of carbon dioxide (CO2) into the atmosphere by human activities is altering ocean conditions including pH, oxygen, and temperature. One way to understand how these changing conditions will affect ecologically, economically, and culturally important marine species is to scale individual responses from laboratory experiments to population-level impacts. In this study, we assessed the vulnerability of Dungeness crab, one of the most valuable fisheries in the NW USA, to stressful conditions based on the predicted habitat exposure and response of each life stage (eggs, larvae, juveniles, and adults). The degree of vulnerability was determined by the seasonality of the ocean conditions in combination with the crab’s complex life cycle. This approach revealed that Dungeness crab life stages and populations will be more vulnerable to low pH, low oxygen, and high temperature in the future (year 2100) under an aggressive CO2 emissions scenario. Based on these results, we recommend that fishery managers incorporate changing conditions into their decision-making to protect vulnerable life stages in areas prone to stressful conditions (e.g., adult crabs in hypoxic areas). Our approach can be adapted for many other economically and ecologically important marine species in order to inform conservation and management strategies.

Continue reading ‘Seasonality and life history complexity determine vulnerability of Dungeness crab to multiple climate stressors’

Biological effects of the antihypertensive losartan under different ocean acidification scenarios

Highlights

  • Losartan was quantified in samples of marine water (up to 7.63 ng/L) and sediment (up to 3.10 ng/g).
  • Sediment spiked with an environmental concentration of losartan affected lysosomal stability.
  • Losartan effects were pH dependent and pH effects were dependent on the concentration of losartan.
  • Ocean acidification exacerbates the negative effects of losartan in waterborne exposure.

Abstract

Since the last decade, several studies have reported the presence and effects of pharmaceutical residues in the marine environment, especially those of the antihypertensive class, such as losartan. However, there is little knowledge about the physiological effects of losartan in marine invertebrates regarding its behavior under possible coastal ocean acidification scenarios. The objective of this study was to evaluate biological effects on marine organisms at different levels of the biological organization caused by the compound losartan in water and sediment under coastal ocean acidification scenarios. Water and sediment samples were collected at five sites around the Santos Submarine Sewage outfall (SSO) and two sites around the Guarujá Submarine Sewage Outfall (GSO). Losartan was found in concentrations ranging from <LOD to 7.63 ng/L in water and from <LOQ to 3.10 ng/g in sediments. Statistical analysis showed interactive effects pH and losartan on the toxicity results. The water toxicity test with Echinometra lucunter embryos/larvae showed LOECs 50–100 mg/L, with values decreasing as the pH decreased. In the sediment assays, LOEC value for sea urchin embryo-larval development was 1.0 μg/g for all tested pHs. Regarding the lysosomal membrane stability assays with adult bivalves, a LOEC of 3000 ng/L was found for Perna perna in water exposure (both at pH 8.0 and 7.6). Effects for Mytella guyanensis were observed at environmentally relevant concentrations in sediment (LOEC = 3 ng/g at pH 8.0 and 7.6). This study demonstrated that coastal ocean acidification by itself causes effects on marine invertebrates, but can also increase the negative effects of losartan in waterborne exposure. There is a need to deepen the studies on the ecotoxicity of pharmaceutical residues and acidification of the marine environment.

Continue reading ‘Biological effects of the antihypertensive losartan under different ocean acidification scenarios’

Possible future scenarios for two major Arctic Gateways connecting Subarctic and Arctic marine systems: I. climate and physical–chemical oceanography

We review recent trends and projected future physical and chemical changes under climate change in transition zones between Arctic and Subarctic regions with a focus on the two major inflow gateways to the Arctic, one in the Pacific (i.e. Bering Sea, Bering Strait, and the Chukchi Sea) and the other in the Atlantic (i.e. Fram Strait and the Barents Sea). Sea-ice coverage in the gateways has been disappearing during the last few decades. Projected higher air and sea temperatures in these gateways in the future will further reduce sea ice, and cause its later formation and earlier retreat. An intensification of the hydrological cycle will result in less snow, more rain, and increased river runoff. Ocean temperatures are projected to increase, leading to higher heat fluxes through the gateways. Increased upwelling at the Arctic continental shelf is expected as sea ice retreats. The pH of the water will decline as more atmospheric CO2 is absorbed. Long-term surface nutrient levels in the gateways will likely decrease due to increased stratification and reduced vertical mixing. Some effects of these environmental changes on humans in Arctic coastal communities are also presented.

Continue reading ‘Possible future scenarios for two major Arctic Gateways connecting Subarctic and Arctic marine systems: I. climate and physical–chemical oceanography’

State of Hawai‘i ocean acidification action plan 2021 -2031

The State of Hawaiʻi Ocean Acidification Action Plan was developed by the Department of Land and Natural Resources (DLNR) Division of Aquatic Resources (DAR) with support from the Hawai‘i Department of Health, Hawai‘i Department of Agriculture, the State of Hawai‘i Climate Change and Mitigation Commission, the University of Hawai‘i – School of Ocean and Earth Science and Technology, University of Hawai‘i Sea Grant College Program, the International Alliance to Combat Ocean Acidification, and many other partners and stakeholders.

This Ocean Acidification Action Plan for the State of Hawai‘i is based feedback from state departments, local experts, and partners on local Hawai‘i issues, and from the International Alliance to Combat Ocean Acidification’s “Action Plan Toolkit”, which was developed through the West Coast Consortium, a partnership of the States of Washington, Oregon, California, and the province of British Columbia.

The State of Hawai‘i activities, projects, and programs that have related to ocean acidification are jointly done by a number of departments and partners. This plan outlines existing activities that State Departments and partners are involved in, as well as forecasting future needs for activities projects, and programs from collaborative partnerships. For this reason, there was effort to put a stand alone plan together as well as integrate ocean acidification and climate considerations into other state plans.

DAR held several webinars to share the recent scientific understand of ocean acidification in Hawai‘i and talk about the ways different states have built their Ocean Acidification Action Plans, and some pathways forward the State of Hawai‘i could take. COVID-19 changed the way that we were able to host meetings and workshops, and so DAR hosted meetings with the contributors with a focus on each Goal related to their expertise to develop objectives and actions. DAR brought the 5 overall goals developed to the State Climate Change and Mitigation Commission for approval as part of the plan development process.

This Ocean Acidification Action Plan is the first of an iterative planning document that provides a strategic vision for developing and coordinating action around ocean acidification and the ocean-climate nexus. The State’s actions will include ways to be understand, adapt, and mitigate, communicate, and network to combat the impacts of ocean acidification in Hawai‘i. In future years, more comprehensive progress reports will include updates of actions implemented by this plan, and edits or changes to suggested actions can be made.

It will be important for State Legislature to create a formal working group of State and County that can guide the implementation and updates to this plan.

Continue reading ‘State of Hawai‘i ocean acidification action plan 2021 -2031’

Plenary 4: ocean biogeochemical extremes and compound events

OA Week 2021, Plenary Session 4 OceanSODA – The Satellite Oceanographic Datasets for Acidification Project

Dr. Nicolas Gruber, Professor of Environmental Physics, Eidgenössische Technische Hochschule (ETH Zürich), Switzerland

Description:

The potential of satellite observed salinity for observing the surface water carbonate system was identified some time ago and this space-based capability, combined with established temperature observations from space, is now enabling the development of novel satellite observation-driven acidification and inorganic carbon assessments (eg Land et al., 2019; Gregor and Gruber, 2021; Green et al., 2021; Quilfen et al., 2021). The European Space Agency funded Satellite Oceanographic Datasets for Acidification project (OceanSODA) aimed to establish the role that satellite-based Earth Observations can play in supporting and expanding research and monitoring in ocean acidification. The project, now nearly complete, had two distinct foci, scientific advancement and downstream impact assessments. The scientific advancements have produced regional and global time-series data of the surface water carbonate conditions with well characterised accuracies. The downstream assessments included the characterization and analysis of how upwelling (of low pH waters), compound (heatwaves and high acidity) events, and large river outflows (of low pH waters) impact the carbonate system, and how these conditions could affect marine organisms and ecosystems. The project has also identified how satellite observations can be used for, and are critical for, observing Arctic carbonate system conditions. These capabilities and datasets are now beginning to be noticed by non-scientific user groups as they hold potential for guiding management and policy decisions. This plenary session will discuss how this work has evolved, highlighting the scientific advances, identify potential new scientific opportunities, and discuss how these capabilities are now being noticed by early adopters and stakeholders to support decision making, by considering a range of users from shellfish farmers through to regional resources managers advising US and Canadian state governors.

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

Continue reading ‘Plenary 4: ocean biogeochemical extremes and compound events’

Plenary 5: detection, attribution, & predictability of ocean acidification (text & video)

OA Week 2021, Plenary Session 5 Attribution & Blue Carbon

Dr. Scott Doney, Joe D. and Helen J. Kington Professor in Environmental Change, University of Virginia, USA

Description:

Uptake of anthropogenic carbon dioxide from the atmosphere by the surface ocean is leading to global ocean acidification, but regional variations in ocean circulation and mixing can dampen or accelerate apparent acidification rates. Excess nutrient pollution can also result in coastal acidification in estuaries and near shore regions. Both climate variability and nutrient pollution exacerbate the ecological press from rising atmosphere CO2 and can cause extreme acidification events that are detrimental to ecosystem health and fisheries.

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

Continue reading ‘Plenary 5: detection, attribution, & predictability of ocean acidification (text & video)’

Plenary 5: seagrasses in warming and acidifying oceans: physiological responses (text & video)

OA Week 2021, Plenary Session 5 Attribution & Blue Carbon

Dr. Rushingisha George, Researcher, Tanzania Fisheries Research Institute (TAFIRI), Tanzania

Description:

As concentration of anthropogenic CO2 continues to increase in the atmosphere, both ocean warming and acidification will continue to increase globally. This can have both negative and positive impacts on the health and function of seagrasses, which are key primary producers and ecosystem engineers in the coastal zone. The key physiological processes (photosynthesis, calcification and respiration) of these plants operate over a wide range of climatic factors (temperature, CO2, dissolved oxygen etc.) and their response can serve to mitigate the impacts of ocean acidification on short-time scales. This talk will focus on the responses of seagrass physiological processes to elevated climatic factors (under both current and future conditions) in the water column, and how these responses affect the pH of the water column as well as on the effect of the tidal variability on pH of seagrass meadows and adjacent coastal habitats. Research findings show that seagrass physiological processes respond differently to elevated climatic factors and their interaction govern the pH of the system. The effect of physiological processes on pH of seagrass meadows of intertidal waters depend on the water level and percentage cover, and is highest during low spring tides. Photosynthetic uptake of dissolved inorganic carbon (DIC) can raise the mean pH of seagrass meadows, and adjacent mangrove and coral reef habitats to 5% above that of adjacent open ocean during daytime at high tide. These findings show that healthy seagrass meadows offer a huge potential to mitigate the impacts of ocean acidification, as their photosynthetic uptake of DIC have been shown raise the mean pH of seagrass meadows, and adjacent mangrove and coral reef habitats to 5% above that of adjacent open ocean during daytime at high tide. Therefore, reducing anthropogenic stressors such as eutrophication by land-based pollution sources, among others, will make seagrass meadows healthy and resilient to elevated water temperatures while mitigating the impacts of ocean acidification on temporal scales.”

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

Continue reading ‘Plenary 5: seagrasses in warming and acidifying oceans: physiological responses (text & video)’

Decrease in volume and density of foraminiferal shells with progressing ocean acidification

Rapid increases in anthropogenic atmospheric CO2 partial pressure have led to a decrease in the pH of seawater. Calcifying organisms generally respond negatively to ocean acidification. Foraminifera are one of the major carbonate producers in the ocean; however, whether calcification reduction by ocean acidification affects either foraminiferal shell volume or density, or both, has yet to be investigated. In this study, we cultured asexually reproducing specimens of Amphisorus kudakajimensis, a dinoflagellate endosymbiont-bearing large benthic foraminifera (LBF), under different pH conditions (pH 7.7–8.3, NBS scale). The results suggest that changes in seawater pH would affect not only the quantity (i.e., shell volume) but also the quality (i.e., shell density) of foraminiferal calcification. We proposed that pH and temperature affect these growth parameters differently because (1) they have differences in the contribution to the calcification process (e.g., Ca2+-ATPase and Ω) and (2) pH mainly affects calcification and temperature mainly affects photosynthesis. Our findings also suggest that, under the IPCC RCP8.5 scenario, both ocean acidification and warming will have a significant impact on reef foraminiferal carbonate production by the end of this century, even in the tropics.

Continue reading ‘Decrease in volume and density of foraminiferal shells with progressing ocean acidification’

Combined effects of low pH and high water temperature conditions on oxidative stress and cell damage in juvenile olive flounder Paralichthys Olivaceus

The use of fossil fuels by anthropogenic activities causes ocean acidification and warming, and the combined conditions of these two environments can negatively affect fish metabolism, growth, and survival. Additionally, it can affect the antioxidant enzyme activity and cell damage caused by lipid peroxidation. In this study, we explores the adaptive potential for future marine conditions by investigating the stress and antioxidant enzyme activity, and apoptosis of juvenile olive flounder in an environment where ocean acidification and warming coexist. We found that juvenile olive flounder had increased oxidative stress and apoptosis under both warming and combined warming, and acidification conditions. Additionally, the effect on acidification under warming conditions does not seem to exceed the effect of high temperature conditions, and it is considered that the effect of acidification at low water temperatures is greater.

Continue reading ‘Combined effects of low pH and high water temperature conditions on oxidative stress and cell damage in juvenile olive flounder Paralichthys Olivaceus’

Co‑occurrence of aquatic heatwaves with atmospheric heatwaves, low dissolved oxygen, and low pH events in estuarine ecosystems

Heatwaves are increasing in frequency, duration, and intensity in the atmosphere and marine environment with rapid changes to ecosystems occurring as a result. However, heatwaves in estuarine ecosystems have received little attention despite the effects of high temperatures on biogeochemical cycling and fisheries and the susceptibility of estuaries to heatwaves given their low volume. Likewise, estuarine heatwave co-occurrence with extremes in water quality variables such as dissolved oxygen (DO) and pH have not been considered and would represent periods of enhanced stress. This study analyzed 1440 station years of high-frequency data from the National Estuarine Research Reserve System (NERRS) to assess trends in the frequency, duration, and severity of estuarine heatwaves and their co-occurrences with atmospheric heatwaves, low DO, and low pH events between 1996 and 2019. Estuaries are warming faster than the open and coastal ocean, with an estuarine heatwave mean annual occurrence of 2 ± 2 events, ranging up to 10 events per year, and lasting up to 44 days (mean duration = 8 days). Estuarine heatwaves co-occur with an atmospheric heatwave 6–71% of the time, depending on location, with an average estuarine heatwave lag range of 0–2 days. Similarly, low DO or low pH events co-occur with an estuarine heatwave 2–45% and 0–18% of the time, respectively, with an average low DO lag of 3 ± 2 days and low pH lag of 4 ± 2 days. Triple co-occurrence of an estuarine heatwave with a low DO and low pH event was rare, ranging between 0 and 7% of all estuarine heatwaves. Amongst all the stations, there have been significant reductions in the frequency, intensity, duration, and rate of low DO event onset and decline over time. Likewise, low pH events have decreased in frequency, duration, and intensity over the study period, driven in part by reductions in all severity classifications of low pH events. This study provides the first baseline assessment of estuarine heatwave events and their co-occurrence with deleterious water quality conditions for a large set of estuaries distributed throughout the USA.

Continue reading ‘Co‑occurrence of aquatic heatwaves with atmospheric heatwaves, low dissolved oxygen, and low pH events in estuarine ecosystems’

W 2 professorship in marine ecology / adaptation to ocean extremes

Kiel University and GEOMAR Helmholtz Centre for Ocean Research Kiel aim to attract more qualified women to professorships.

The Faculty of Mathematics and Natural Sciences at Kiel University, Germany and GEOMAR Helmholtz Centre for Ocean Research Kiel jointly invite applications for a

W 2-Professorship in Marine Ecology / Adaptation to Ocean Extremes

to start at the earliest possible date.

Deadline for application: 10 November 2021.

APPLY

The Professorship is located at GEOMAR Helmholtz Centre for Ocean Research Kiel (www.geomar.de) and will lead the Research Unit, Experimental Ecology-Benthic Ecology“ within the Research Division, Marine Ecology“.

The ocean is by definition an extreme habitat, with large regions being oligotrophic, below the reach of sunlight, and sometimes even anoxic, yet life is thriving. New extremes, such as heat waves, upwelling of oxygen deficient waters, pollution, or ocean acidification are induced by human activity, adding to naturally occurring extremes. A key question is thus how marine life adapts to such spatially or temporarily extreme conditions.

The successful candidate will have already established a successful and internationally visible research line that addresses adaptation of marine life in its broadest sense to natural and anthropogenic challenges. This may address (but not exclusively):
• the analysis of contemporary or past evolutionary adaptation
• the restructuring or migration of communities
• the physiological and plasticity of reactions of species
• metabolic and biochemical adaptations

The Professorship is associated with a teaching position in the Kiel Master‘s program in Biological Oceanography. Relevant teaching experience is required. Non-German speaking applicants are expected to acquire German language skills and to teach courses in German after three years at the latest.

For further formal information, please refer to the recruitment requirements of § 61 of the Higher Education Act of the State of Schleswig-Holstein. More information can be found at http://www.berufungen.uni-kiel.de (in German).

Continue reading ‘W 2 professorship in marine ecology / adaptation to ocean extremes’

Plenary 4: introduction by Ms. Isabella Lövin, former Swedish Deputy Prime Minister

OA Week 2021, Plenary Session 4 OceanSODA – The Satellite Oceanographic Datasets for Acidification Project

Isabella Lövin, Former Deputy Prime Minister and Minister for Environment and Climate, Sweden

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

Continue reading ‘Plenary 4: introduction by Ms. Isabella Lövin, former Swedish Deputy Prime Minister’

Plenary 4: recent advances in studying ocean acidification from space (text & video)

OA Week 2021, Plenary Session 4 OceanSODA – The Satellite Oceanographic Datasets for Acidification Project

Dr. Jamie Shutler, Associate Professor in Earth Observation, University of Exeter, UK

Description:

The potential of satellite observed salinity for observing the surface water carbonate system was identified some time ago and this space-based capability, combined with established temperature observations from space, is now enabling the development of novel satellite observation-driven acidification and inorganic carbon assessments (eg Land et al., 2019; Gregor and Gruber, 2021; Green et al., 2021; Quilfen et al., 2021). The European Space Agency funded Satellite Oceanographic Datasets for Acidification project (OceanSODA) aimed to establish the role that satellite-based Earth Observations can play in supporting and expanding research and monitoring in ocean acidification. The project, now nearly complete, had two distinct foci, scientific advancement and downstream impact assessments. The scientific advancements have produced regional and global time-series data of the surface water carbonate conditions with well characterised accuracies. The downstream assessments included the characterization and analysis of how upwelling (of low pH waters), compound (heatwaves and high acidity) events, and large river outflows (of low pH waters) impact the carbonate system, and how these conditions could affect marine organisms and ecosystems. The project has also identified how satellite observations can be used for, and are critical for, observing Arctic carbonate system conditions. These capabilities and datasets are now beginning to be noticed by non-scientific user groups as they hold potential for guiding management and policy decisions. This plenary session will discuss how this work has evolved, highlighting the scientific advances, identify potential new scientific opportunities, and discuss how these capabilities are now being noticed by early adopters and stakeholders to support decision making, by considering a range of users from shellfish farmers through to regional resources managers advising US and Canadian state governors.

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

Continue reading ‘Plenary 4: recent advances in studying ocean acidification from space (text & video)’

Plenary 4: studying changing carbonate chemistry in the Arctic Ocean using satellite observations (text & video)

OA Week 2021, Plenary Session 4 OceanSODA – The Satellite Oceanographic Datasets for Acidification Project

Ms. Hannah Green, PhD Student, University of Exeter and Plymouth Marine Laboratory, UK

Description: The potential of satellite observed salinity for observing the surface water carbonate system was identified some time ago and this space-based capability, combined with established temperature observations from space, is now enabling the development of novel satellite observation-driven acidification and inorganic carbon assessments (eg Land et al., 2019; Gregor and Gruber, 2021; Green et al., 2021; Quilfen et al., 2021). The European Space Agency funded Satellite Oceanographic Datasets for Acidification project (OceanSODA) aimed to establish the role that satellite-based Earth Observations can play in supporting and expanding research and monitoring in ocean acidification. The project, now nearly complete, had two distinct foci, scientific advancement and downstream impact assessments. The scientific advancements have produced regional and global time-series data of the surface water carbonate conditions with well characterised accuracies. The downstream assessments included the characterization and analysis of how upwelling (of low pH waters), compound (heatwaves and high acidity) events, and large river outflows (of low pH waters) impact the carbonate system, and how these conditions could affect marine organisms and ecosystems. The project has also identified how satellite observations can be used for, and are critical for, observing Arctic carbonate system conditions. These capabilities and datasets are now beginning to be noticed by non-scientific user groups as they hold potential for guiding management and policy decisions. This plenary session will discuss how this work has evolved, highlighting the scientific advances, identify potential new scientific opportunities, and discuss how these capabilities are now being noticed by early adopters and stakeholders to support decision making, by considering a range of users from shellfish farmers through to regional resources managers advising US and Canadian state governors.

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

Continue reading ‘Plenary 4: studying changing carbonate chemistry in the Arctic Ocean using satellite observations (text & video)’

  • Reset

Subscribe

OA-ICC Highlights


%d bloggers like this: