Archive Page 116

Heavy metal mobility in contaminated sediments under seawater acidification

Published 24 May 2023 Science Closed
Tags: ,

Highlights

  • Long-term effects of acidification on heavy metal mobility
  • Variations in heavy metal distribution patterns in sediment–seawater systems
  • CO2 enrichment acidified the pH of the system.
  • Changes in effective heavy metals were obtained by diffusion gradient technique.

Abstract

The behavior of heavy metals in contaminated sediment is of ecological significance considering the change of pH caused by ocean acidification. This study investigated the mobility of Cd, Cu, Ni, Pb, Fe, and Mn under experimental conditions for seawater acidification via enrichment of CO2 gas at different reaction set-ups. The results indicated that the concerned metals behaved differently in the water compared to the sediment. The heavy metals were considerably transferred from sediment to seawater, and the resultant intensity was controlled by the degree of acidification and the chemical state of specific metals. Moreover, labile fractions of heavy metals in sediments were more susceptible to acidification than other fractions. These findings were observed and confirmed using real-time monitoring conducted via the diffusion gradient technique (DGT). Overall, the results of this study provided new insights into exploring the coupling risk of heavy metals with ocean acidification.

Continue reading ‘Heavy metal mobility in contaminated sediments under seawater acidification’

Elevated water CO2 can prevent dietary-induced osteomalacia in post-smolt Atlantic salmon (Salmo salar, L.)

Published 24 May 2023 Science Closed
Tags: , , , , , , , ,

Expansion of land-based systems in fish farms elevate the content of metabolic carbon dioxide (CO2) in the water. High CO2 is suggested to increase the bone mineral content in Atlantic salmon (Salmo salar, L.). Conversely, low dietary phosphorus (P) halts bone mineralization. This study examines if high CO2 can counteract reduced bone mineralization imposed by low dietary P intake. Atlantic salmon post-seawater transfer (initial weight 207.03 g) were fed diets containing 6.3 g/kg (0.5P), 9.0 g/kg (1P), or 26.8 g/kg (3P) total P for 13 weeks. Atlantic salmon from all dietary P groups were reared in seawater which was not injected with CO2 and contained a regular CO2 level (5 mg/L) or in seawater with injected CO2 thus raising the level to 20 mg/L. Atlantic salmon were analyzed for blood chemistry, bone mineral content, vertebral centra deformities, mechanical properties, bone matrix alterations, expression of bone mineralization, and P metabolism-related genes. High CO2 and high P reduced Atlantic salmon growth and feed intake. High CO2 increased bone mineralization when dietary P was low. Atlantic salmon fed with a low P diet downregulated the fgf23 expression in bone cells indicating an increased renal phosphate reabsorption. The current results suggest that reduced dietary P could be sufficient to maintain bone mineralization under conditions of elevated CO2. This opens up a possibility for lowering the dietary P content under certain farming conditions.

Continue reading ‘Elevated water CO2 can prevent dietary-induced osteomalacia in post-smolt Atlantic salmon (Salmo salar, L.)’

Ocean acidification increases inorganic carbon over organic carbon in shrimp’s exoskeleton

Published 23 May 2023 Science Closed
Tags: , , , , , ,

Highlights

  • PIC: POC ratio in shrimps’ exoskeleton may increase under future OA.
  • Hyper-calcification and increased respiration are possible in shrimps under OA releasing more CO2 into the water.
  • Increased PIC: POC ratio may impact the ecosystem functions as well as the carbon cycle.

Abstract

Ocean acidification (OA) may either increase or have a neutral effect on the calcification in shrimp’s exoskeleton. However, investigations on changes in the carbon composition of shrimp’s exoskeletons under OA are lacking. We exposed juvenile Pacific white shrimps to target pHs of 8.0, 7.9, and 7.6 for 100 days to evaluate changes in carapace thickness, total carbon (TC), particulate organic carbon (POC), particulate inorganic carbon (PIC), calcium, and magnesium concentrations in their exoskeletons. The PIC: POC ratio of shrimp in pH 7.6 treatment was significantly higher by 175 % as compared to pH 8.0 treatment. Thickness and Ca% in pH 7.6 treatment were significantly higher as compared to pH 8.0 treatment (90 % and 65 %, respectively). This is the first direct evidence of an increased PIC: POC ratio in shrimp exoskeletons under OA. In the future, such changes in carbon composition may affect the shrimp population, ecosystem functions, and regional carbon cycle.

Continue reading ‘Ocean acidification increases inorganic carbon over organic carbon in shrimp’s exoskeleton’

A low-cost virtual sensor for underwater pH monitoring in coastal waters

Published 23 May 2023 Science Closed
Tags: , ,

In coastal water monitoring, abrupt pH changes might indicate different pollution sources. Existing sensors for pH monitoring in coastal waters at low cost are mainly based on a glass membrane and a reference electrode. Virtual sensors are elements capable of measuring certain parameters based on data from other parameters or variables. The aim of this paper is to propose the use of a virtual pH sensor based on measuring different physical effects of H+ on the electromagnetic field generated by an inductor. Double inductors based on two solenoids of 40 and 80 spires are used as sensing elements. Samples with pH from 4 to 11 are used, and the effect of temperature is evaluated using samples from 10 to 40 °C. The induced voltage and the delay of the signal are measured for powering frequencies from 100 to 500 kHz. These data of delay, induced voltage, frequency, and temperature are included in a probabilistic neural network to classify these data according to the pH. The results indicate low accuracy for samples with a pH of 11. A second analysis, excluding these data, offered correctly classified cases of 88.9%. The system can achieve considerable high accuracy (87.5%) using data gathered at a single frequency, from 246 to 248 kHz. The predicted versus observed data is correlated with a linear model characterized by an R2 of 0.69, which is similar to the ones observed in other virtual sensors.

Continue reading ‘A low-cost virtual sensor for underwater pH monitoring in coastal waters’

Ocean acidification as a hyperobject: mediating acidic milieus in the anthropocene

Published 23 May 2023 Science Closed
Tags:

Through the usage of Timothy Morton’s hyperobjects (2013) as a heuristic, this essay aims to portray how Ocean Acidification can be read as a hyperobject affecting tropical seawaters and beyond. Furthermore, it illustrates how the arts and humanities, through their hermeneutical gaze, might help us grasp Ocean Acidification as a hyperobject and the wide array of other objects that act upon each other in such acidic oceanic waters. In this task, the article will close-read the Underwater Woman set of pictures by Christine Ren (2018) understanding the interpretation of art as a tool to reconnect cognition and emotion to move from the understanding of a crisis to the feeling of such crisis. Finally, it aims to shed light upon the implications arising from considering Ocean Acidification as a hyperobject. By connecting the theoretical, visual and political in the same narrative, this essay highlights the transformative potential of interpretation and thinking through hyperobjects. With this, the challenges of the Anthropocene are put at the forefront, situating specific events and problematics in a planetary scale.

Continue reading ‘Ocean acidification as a hyperobject: mediating acidic milieus in the anthropocene’

Long-term physiological responses to combined ocean acidification and warming show energetic trade-offs in an asterinid starfish

Published 22 May 2023 Science Closed
Tags: , , , , , , , , ,

While organismal responses to climate change and ocean acidification are increasingly documented, longer-term (> a few weeks) experiments with marine organisms are still sparse. However, such experiments are crucial for assessing potential acclimatization mechanisms, as well as predicting species-specific responses to environmental change. Here, we assess the combined effects of elevated pCO2 and temperature on organismal metabolism, mortality, righting activity, and calcification of the coral reef-associated starfish Aquilonastra yairi. Specimens were incubated at two temperature levels (27 °C and 32 °C) crossed with three pCO2 regimes (455 µatm, 1052 µatm, and 2066 µatm) for 90 days. At the end of the experiment, mortality was not altered by temperature and pCO2 treatments. Elevated temperature alone increased metabolic rate, accelerated righting activity, and caused a decline in calcification rate, while high pCO2 increased metabolic rate and reduced calcification rate, but did not affect the righting activity. We document that temperature is the main stressor regulating starfish physiology. However, the combination of high temperature and high pCO2 showed nonlinear and potentially synergistic effects on organismal physiology (e.g., metabolic rate), where the elevated temperature allowed the starfish to better cope with the adverse effect of high pCO2 concentration (low pH) on calcification and reduced skeletal dissolution (antagonistic interactive effects) interpreted as a result of energetic trade-offs.

Continue reading ‘Long-term physiological responses to combined ocean acidification and warming show energetic trade-offs in an asterinid starfish’

Epistemic discourses and conceptual coherence in students’ explanatory models: the case of ocean acidification and its impacts on oysters

Published 22 May 2023 Science Closed
Tags:

Engaging students in epistemic and conceptual aspects of modeling practices is crucial for phenomena-based learning in science classrooms. However, many students and teachers still struggle to actualize the reformed vision of the modeling practice in their classrooms. Through a discourse analysis of 150 students’ explanatory models (as social semiotic spaces) from 14 classes, we propose a qualitative framework that investigates conceptual coherence and epistemic discourses to achieve a gapless explanation of scientific phenomena. Our framework draws attention to four critical components of students’ explanatory models: (a) key ideas based on evidence, (b) the discourse modalities of how evidence is presented, (c) scientific representations from the cultures of scientific disciplines, (d) systems thinking approaches directly and indirectly related to oceans and marine ecosystems. Our results indicate that students struggled to construct cohesive explanatory models that communicated all key ideas and the relationships among them, with the majority of student-developed models in our study categorized as ‘insufficiently’ cohesive (lacking key ideas and the relationships among them), and only a small percentage of the models considered ‘extensively’ cohesive (all key ideas attended to, as well as the relationships among them).

Continue reading ‘Epistemic discourses and conceptual coherence in students’ explanatory models: the case of ocean acidification and its impacts on oysters’

Carbon dioxide mineralization by electrode separation for quick carbon reduction and sequestration in acidified seawater

Published 22 May 2023 Science Closed
Tags: , , , ,

Aiming to sequestrate the excessive carbon dioxide and convert the acidified seawater, an improved method of carbon dioxide mineralization is developed based on electrode separation mechanism and extra oxygen-supplying technique. By electrode separation the neutralizations of the anodic acidity and the cathodic alkalinity, as well as the precipitation and the dissolution of calcium carbonate (CaCO3), are prevented. In addition, the extra-supplied oxygen prevents the evolution of hydrogen, which enhances the electric conductivity of the porous cathode and the deposition of CaCO3. A series of indoor physical experiments were conducted and the results show that the acidified seawater was successfully converted to alkaline in 72h. The speed of carbon mineralizing sequestration is significantly enhanced by supplying extra oxygen. The carbon dioxide mineralization speed increases with the immerse ratio of the aerator due to the more reacted oxygen and the less hydrogen evolution, which gives more porous space in the cathode for more conductive seawater and more deposition of CaCO3. The extra-supplied oxygen increases the CaCO3 -deposition by 100-214% under excessive atmospheric- CO2 conditions and 117-200% under normal atmospheric- CO2 conditions, respectively. This method has an application potential for quick conversion of locally acidified seawater in emergent circumstances.

Continue reading ‘Carbon dioxide mineralization by electrode separation for quick carbon reduction and sequestration in acidified seawater’

High and diurnally fluctuating carbon dioxide exposure produces lower mercury toxicity in a marine copepod

Published 19 May 2023 Science Closed
Tags: , , , , , , , ,

Highlights

  • Elevated pCO2 decreased Hg accumulation in Hg-treated T. japonicus.
  • Fluctuating elevated pCO2 further decreased Hg bioaccumulation.
  • Hg exposure caused energy depletion and oxidative stress in T. japonicus.
  • Elevated pCO2 initiated compensatory response in copepods to decrease Hg toxicity.
  • Fluctuating elevated pCO2 presented more immune defense related genes/processes.

Abstract

Coastal waters have experienced fluctuations in partial pressure of carbon dioxide (pCO2) and mercury (Hg) pollution, yet little is known concerning how natural pCO2 fluctuations affect Hg biotoxicity. Here, a marine copepod Tigriopus japonicus was interactively exposed to different seawater pCO2 (ambient 400, steady elevated 1000, and fluctuating elevated 1000 ± 600 μatm) scenarios and Hg (control, 2 μg/L) treatments for 7 d. The results showed that elevated pCO2 decreased Hg bioaccumulation, and it was even more under fluctuating elevated pCO2 condition. We found energy depletion and oxidative stress under Hg-treated copepods, while combined exposure initiated compensatory response to alleviate Hg toxicity. Intriguingly, fluctuating acidification presented more immune defense related genes/processes in Hg-treated copepods when compared to steady acidification, probably linking with the greater decrease in Hg bioaccumulation. Collectively, understanding how fluctuating acidification interacts with Hg contaminant will become more crucial in predicting their risks to coastal biota and ecosystems.

Continue reading ‘High and diurnally fluctuating carbon dioxide exposure produces lower mercury toxicity in a marine copepod’

Evidence for an effective defence against ocean acidification in the key bioindicator pteropod Limacina helicina

Published 19 May 2023 Science Closed
Tags: , , , , , , , ,

The pteropod Limacina helicina has become an important bioindicator species for the negative impacts of ocean acidification (OA) on marine ecosystems. However, pteropods diversified during earlier high CO2 periods in Earth history and currently inhabit regions that are naturally corrosive to their shells, suggesting that they possess mechanisms to survive unfavourable conditions. Recent work, which is still under considerable debate, has proposed that the periostracum, a thin organic coating on the outer shell, protects pteropods from shell dissolution. Here, we provide direct evidence that shows that damage to the L. helicina periostracum results in dissolution of the underlying shell when exposed to corrosive water for ∼8 d, while an intact periostracum protects the shell from dissolution under the same conditions. This important first line of defence suggests that pteropods are more resistant to OA-induced shell dissolution than is generally accepted.

Continue reading ‘Evidence for an effective defence against ocean acidification in the key bioindicator pteropod Limacina helicina’

Re-evaluation of carbonic acid dissociation constants across conditions and the implications for ocean acidification

Published 19 May 2023 Science Closed
Tags: , ,

Highlights

  • pHt should be measured directly rather than calculated from TA and DIC.
  • Uncertainty in the constants contributes up to 680 m of uncertainty in the aragonite saturation horizon depth.
  • Calculated pHt at pCO2 between ~500–800 μatm are particularly poor, suggesting an underestimation of future ocean acidification in models.
  • Evaluation of an unidentified or organic component of TA was inconclusive.

Abstract

With the increasing threat of ocean acidification and the important role of the oceans in the global carbon cycle, highly precise, accurate, and intercomparable determination of inorganic carbon system parameters is required. Thermodynamic relationships enable the system to be fully constrained using a combination of direct measurements and calculations. However, calculations are complicated by many formulations for dissociation constants (over 120 possible combinations). To address these important issues of uncertainty and comparability, we evaluated the various combinations of constants and their (dis)agreement with direct measurements over a range of temperature (−1.9–40 °C), practical salinity (15–39) and pCO2 (150–1200 μatm). The results demonstrate that differences between the calculations and measurements are significantly larger than measurement uncertainties, meaning the oft-stated paradigm that one only needs to measure two parameters and the others can be calculated does not apply for climate quality ocean acidification research. The uncertainties in calculated pHt prevent climate quality pHt from being calculated from total alkalinity (TA) and dissolved inorganic carbon (DIC) and should be directly measured instead. However, climate quality TA and DIC can often be calculated using measured pH and DIC or TA respectively. Calculations are notably biased at medium-to-high pCO2 values (~500–800 μatm) implying models underestimate future ocean acidification. Uncertainty in the dissociation constants leads to significant uncertainty in the depth of the aragonite saturation horizon (>500 m in the Southern Ocean) and must be considered when studying calcium carbonate cycling. Significant improvements in the precision of the thermodynamic constants are required to improve pHt calculations.

Continue reading ‘Re-evaluation of carbonic acid dissociation constants across conditions and the implications for ocean acidification’

GOA-ON webinar: multinational efforts in the search for a global solution for the production and certification of reference materials for measurements of the seawater carbonate system

Published 19 May 2023 Events , Presentations Closed

Date and time: 31 May 2023, 13:00 UTC

Moderator: Artur P. Palacz, International Ocean Carbon and Biogeochemistry Coordination Project (IOCCP)

Speakers: Maribel I. García-Ibáñez, Institut de Ciències del Mar (ICM), CSIC; Regina Easley, National Institute of Standards and Technology (NIST)

High-quality measurements of the seawater carbonate system allow us to quantify and understand the oceanic uptake of atmospheric carbon dioxide (CO2) and monitor ocean acidification. Those seawater carbonate system measurements rely on the availability of reference materials (RMs). The COVID-19 pandemic highlighted the fragility of the production system of the seawater RMs for the carbonate system, currently depending on one single laboratory. With that in mind, a new model for seawater RMs for the carbonate system, centered on regional hubs, is being discussed to create a more resilient system. The proposed new model for seawater RMs for the carbonate system requires unprecedented involvement of National Metrology Institutes (NMIs) on a global level. The integration of the new model into the global metrology landscape will help to produce the RMs that are comparable and metrologically traceable to the International System of Units.

Continue reading ‘GOA-ON webinar: multinational efforts in the search for a global solution for the production and certification of reference materials for measurements of the seawater carbonate system’

Call for public comments on scope and actions for the United States Ocean Acidification Action Plan

Published 19 May 2023 Program Closed

Deadline for public comments: 17 June 2023

The Department of State and National Oceanic and Atmospheric Administration (NOAA) will be accepting public comments on the proposed scope for the upcoming United States Ocean Acidification Action Plan (OA–AP). Drafting a national OA–AP is a commitment made by all members of the International Alliance to Combat Ocean Acidification (OA Alliance). The document will highlight our leadership in reducing carbon emissions, strengthening monitoring, research and coordination research efforts, and investing in adaptive measures.

Comments are due by June 17, 2023. Please note that all comments and suggestions may not be included in the final document.   

If you have questions about the United States OA–AP, contact Meaghan Cuddy at CuddyMR@state.gov or at (202) 340–3272.

…

Continue reading ‘Call for public comments on scope and actions for the United States Ocean Acidification Action Plan’

Short-term variation of pH in seawaters around coastal areas of Japan: characteristics and forcings

Published 18 May 2023 Science Closed
Tags: , ,

The pH of coastal seawater varies based on several local forcings, such as water circulation, terrestrial inputs, and biological processes, and these forcings can change along with global climate change. Understanding the mechanism of pH variation in each coastal area is thus important for a realistic future projection that considers changes in these forcings. From 2020 to 2021, we performed parallel year-round observations of pH and related ocean parameters at five stations around the Japanese coast (Miyako Bay, Shizugawa Bay, Kashiwazaki Coast, Hinase Archipelago, and Ohno Strait) to understand the characteristics of short-term pH variations and their forcings. Annual variability (~1 standard deviation) of pH and aragonite saturation state (Ωara) were 0.05–0.09 and 0.25–0.29, respectively, for three areas with low anthropogenic loadings (Miyako Bay, Kashiwazaki Coast, and Shizugawa Bay), while it increased to 0.16–0.21 and 0.52–0.58, respectively, in two areas with medium anthropogenic loadings (Hinase Archipelago and Ohno Strait in Seto Inland Sea). Statistical assessment of temporal variability at various timescales revealed that most of the annual variabilities in both pH and Ωara were derived by short-term variation at a timescale of < 10 days, rather than seasonal-scale variation. Our analyses further illustrated that most of the short-term pH variation was caused by biological processes, while both thermodynamic and biological processes equally contributed to the temporal variation in Ωara. The observed results showed that short-term acidification with Ωara < 1.5 occurred occasionally in Miyako and Shizugawa Bays, while it occurred frequently in the Hinase Archipelago and Ohno Strait. Most of such short-term acidified events were related to short-term low-salinity events. Our analyses showed that the amplitude of short-term pH variation was linearly correlated with that of short-term salinity variation, and its regression coefficient at the time of high freshwater input was positively correlated with the nutrient concentration of the main river that flows into the coastal area.

Continue reading ‘Short-term variation of pH in seawaters around coastal areas of Japan: characteristics and forcings’

Ocean acidification enhances primary productivity and nocturnal carbonate dissolution in intertidal rock pools

Published 18 May 2023 Science Closed
Tags: , , , , , , , , ,

Human CO2 emissions are modifying ocean carbonate chemistry, causing ocean acidification, and likely already impacting marine ecosystems. In particular, there is concern that coastal, benthic calcifying organisms will be negatively affected by ocean acidification, a hypothesis largely supported by laboratory studies. The inter-relationships between carbonate chemistry and marine calcifying communities in situ are complex and natural mesocosms such as tidal pools can provide useful community-level insights. In this study, we manipulated the carbonate chemistry of intertidal pools to investigate the influence of future ocean acidification on net community production (NCP) and calcification (NCC) at emersion. Adding CO2 at the start of the tidal emersion to simulate future acidification (+1500 μatm pCO2, target pH: 7.5) modified net production and calcification rates in the pools. By day, pools were fertilized by the increased CO2 (+20 % increase in NCP, from 10 to 12 mmol O2 m−2 hr−1), while there was no measurable impact on NCC. During the night, pools experienced net community dissolution (NCC < 0), even in present-day conditions, when waters were supersaturated with regards to aragonite. Adding CO2 in the pools increased nocturnal dissolution rates by 40 % (from −0.7 to −1.0 mmol CaCO3 m−2 hr−1) with no consistent impact on night community respiration. Our results suggest that ocean acidification is likely to alter temperate intertidal community metabolism on sub-daily timescales, enhancing both diurnal community production and nocturnal calcium carbonate dissolution.

Continue reading ‘Ocean acidification enhances primary productivity and nocturnal carbonate dissolution in intertidal rock pools’

Atmospheric carbon dioxide and changing ocean chemistry

Published 18 May 2023 Science Closed
Tags: , , ,

“They call it life, we call it pollution” is an infamous quote which ignores many facts about why carbon dioxide (CO2) poses a significant problem for the ocean. But before we get to this, let’s start at the beginning. All organisms on Earth require a particular set of elements for growth. In the case of plants, these elements are needed to synthesise organic matter in a process called primary production via photosynthesis, and in the case of animals, these elements are directly assimilated by either consuming plant material or by preying on other animals. In this respect, one of the key elements is carbon. Being the molecular backbone for a number of vital organic compounds such as sugars, proteins and nucleic acids (containing genetic information), carbon can be considered as the building block of life.

Continue reading ‘Atmospheric carbon dioxide and changing ocean chemistry’

Job opportunity: Laboratory Technician, Marine Science Center, Northeastern University

Published 18 May 2023 Jobs Closed

Location: Massachusetts, United States

Employment Type: Full Time

Job summary

The Ries Lab at Northeastern’s Marine Science Center is seeking a Laboratory Technician to maintain and operate all systems within its laboratories, exercise functional supervision over supporting research staff and students, order supplies and consumables, act as the lab compliance liaison, manage laboratory waste, maintain the chemical and gas inventory and the BIORAD/EHS webpage, train instrument users, calibrate and operate instruments, run samples for internal and external users, record and tabulate instrument usage, invoice, conduct basic organization and cleaning of the lab, assist with basic or applied research (both laboratory- and field-based), write SOPs, and manage, report, and archive experimental samples and data.

The successful applicant will be hard-working, discovery-driven, and intellectually curious. Applicants should have a solid foundation in carbonate biogeochemistry, geology, carbon sequestration, biomineralization, ocean acidification, and/or basic chemistry and possess strong writing and analytical skills. Appointment is for one year with the possibility of renewal in subsequent years pending availability of applicable funding.

Continue reading ‘Job opportunity: Laboratory Technician, Marine Science Center, Northeastern University’

Warmer and more acidic conditions enhance performance of an endemic low shore gastropod

Published 17 May 2023 Science Closed
Tags: , , , , , , ,

Changing ocean temperatures are predicted to challenge marine organisms, especially when combined with other factors, such as ocean acidification. Acclimation, as a form of phenotypic plasticity, can however, moderate the consequences of changing environments for biota. Our understanding of how altered temperature and acidification together influence species acclimation responses is, however, limited compared to responses to single stressors. This study investigated how temperature and acidification affected the thermal tolerance and righting speed of the Girdled Dogwhelk, Trochia cingulata (Linnaeus, 1771). Whelks were acclimated for two weeks to combinations of three temperatures (11°C: cold, 13°C: moderate and 15°C: warm) and two pH regimes (8.0: moderate and 7.5: acidic). We measured the temperature sensitivity of righting response by generating thermal performance curves from individual data collected at seven test temperatures and determined critical thermal minima (CTmin) and maxima (CTmax). We found that T. cingulata has a broad basal thermal tolerance range (∼38°C) and after acclimation to the warm temperature regime, both the optimal temperature for maximum righting speed and CTmax increased. Contrary to predictions, acidification did not narrow this population’s thermal tolerance but increased CTmax. These plastic responses are likely driven by the predictable exposure to temperature extremes measured in the field which originate from the local tidal cycle and the periodic acidification associated with ocean upwelling in the region. This acclimation ability suggests that T. cingulata has at least some capacity to buffer the thermal changes and increased acidification predicted to occur with climate change.

Continue reading ‘Warmer and more acidic conditions enhance performance of an endemic low shore gastropod’

Impacts of ocean acidification and warming on post-larval growth and metabolism in two populations of the great scallop (Pecten maximus L.) 

Published 17 May 2023 Science Closed
Tags: , , , , , , , , , ,

Ocean acidification and warming are key stressors for many marine organisms. Some organisms display physiological acclimatisation or plasticity, but this may vary across species ranges, especially if populations are adapted to local climatic conditions. Understanding how acclimatisation potential varies among populations is therefore important in predicting species responses to climate change. We carried out a common garden experiment to investigate how different populations of the economically important great scallop (Pecten maximus) from France and Norway responded to variation in temperature and pCO2 concentration. After acclimation, post-larval scallops (spat) were reared for 31 days at one of two temperatures (13°C and 19°C) under either ambient or elevated pCO2 (pH 8.0 and pH 7.7). We combined measures of proteomic, metabolic, and phenotypic traits to produce an integrative picture of how physiological plasticity varies between the populations. The proteome of French spat showed significant sensitivity to environmental variation, with 12 metabolic, structural and stress-response proteins responding to temperature and/or pCO2. Principal component analysis revealed seven energy metabolism proteins in French spat that were consistent with countering ROS stress under elevated temperature. Oxygen uptake in French spat did not change under elevated temperature, but increased under elevated pCO2. In contrast, Norwegian spat reduced oxygen uptake under both elevated temperature and pCO2. Metabolic plasticity seemingly allowed French scallops to maintain greater energy availability for growth than Norwegian spat. However, increased physiological plasticity and growth in French spat may come at a cost, as French (but not Norwegian) spat showed reduced survival under elevated temperature.

Continue reading ‘Impacts of ocean acidification and warming on post-larval growth and metabolism in two populations of the great scallop (Pecten maximus L.) ‘

‘Sea butterfly’ life cycle threatened by climate change may impact Southern Ocean ecosystem

Published 17 May 2023 Press releases Closed

The world’s oceans absorb approximately a quarter of all carbon dioxide (CO2) emissions. During absorption, CO2 reacts with seawater and oceanic pH levels fall. This is known as ocean acidification and results in lower carbon ion concentrations. Certain ocean inhabitants use carbon ion to build and sustain their shells. Pteropods, which are important components of the marine ecosystem, are among them.

Certain aspects about pteropods, including life cycles and population dynamics, are not well-studied. This is partly due to their size—some sea butterfly species measure less than a millimeter—and poor long-term survival in captivity. Now, a team of marine scientists has examined life cycles, abundance, and seasonal variability of shelled sea butterflies in the north-east Scotia Sea, a region undergoing some of the fastest climate change in the Southern Ocean.

“Decline in Antarctic Ocean pteropod populations could have cascading ramifications to the food web and carbon cycle,” said Dr. Clara Manno, a researcher at the British Antarctic Survey and corresponding author of the study published in Frontiers in Marine Science. “Knowledge about the life cycle of this keystone organism may improve prediction of ocean acidification impacts on the Antarctic ecosystem.”

…

Continue reading ‘‘Sea butterfly’ life cycle threatened by climate change may impact Southern Ocean ecosystem’

Subscribe

Search

  • Reset

OA-ICC Highlights

Resources