Shallow Calcium Carbonate Cycling in the North Pacific Ocean

Global Biogeochemical Cycles, Journal Year: 2022, Volume and Issue: 36(5)

Published: May 1, 2022

Abstract The cycling of biologically produced calcium carbonate (CaCO 3 ) in the ocean is a fundamental component global carbon cycle. Here, we present experimental determinations situ coccolith and foraminiferal calcite dissolution rates. We combine these rates with solid phase fluxes, dissolved tracers, historical data to constrain alkalinity cycle shallow North Pacific Ocean. coccolithophores demonstrate nonlinear dependence on saturation state. Dissolution all three major calcifying groups (coccoliths, foraminifera, aragonitic pteropods) are too slow explain patterns both CaCO sinking flux regeneration Pacific. Using combination solid‐phase document significant signal seawater supersaturated for calcite. Driving ambient state oxygen consumption simultaneously explains profiles across entire N. basin. do not need invoke presence phases higher solubilities. Instead, biomineralization metabolic processes intimately associate acid (CO 2 base same particles, driving coupled remineralization organic . linkage likely occurs through due zooplankton grazing microbial aerobic respiration within degrading particle aggregates. coupling cycles acts as filter export inorganic deep ocean.

Language: Английский

---

Severe biological effects under present-day estuarine acidification in the seasonally variable Salish Sea

The Science of The Total Environment, Journal Year: 2020, Volume and Issue: 765, P. 142689 - 142689

Published: Oct. 6, 2020

Language: Английский

---

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

ICES Journal of Marine Science, Journal Year: 2023, Volume and Issue: 80(5), P. 1329 - 1341

Published: May 12, 2023

Abstract 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 they possess mechanisms survive unfavourable conditions. Recent work, which is still under considerable debate, proposed periostracum, a thin organic coating outer shell, protects from shell dissolution. Here, we provide direct evidence shows damage L. periostracum results dissolution underlying when exposed water ∼8 d, while intact same This first line defence suggests more resistant OA-induced than generally accepted.

Language: Английский

---

Recommendations for interpreting zooplankton metabarcoding and integrating molecular methods with morphological analyses

ICES Journal of Marine Science, Journal Year: 2021, Volume and Issue: 78(9), P. 3387 - 3396

Published: May 18, 2021

Abstract Metabarcoding of zooplankton communities is becoming more common, but molecular results must be interpreted carefully and validated with morphology-based analyses, where possible. To evaluate our metabarcoding approach within the California Current Ecosystem, we tested whether physical subsampling PCR replication affects observed community composition; composition resolved by comparable to morphological analyses digital imaging; pH neutralization ethanol ammonium hydroxide diversity. We found that (1) was important accurately resolve alpha diversity can decrease sensitivity rare taxa; (2) there were significant correlations between relative read abundance proportions carbon biomass for most taxonomic groups analyzed, such relationships showed better agreement dominant groups; (3) in had no effect on Together, these indicate appropriate replication, paired characterize structure biomass, methods are some extent indicative when absolute measures or not available.

Language: Английский

---

Degradation of Internal Organic Matter is the Main Control on Pteropod Shell Dissolution After Death

Global Biogeochemical Cycles, Journal Year: 2019, Volume and Issue: 33(6), P. 749 - 760

Published: May 6, 2019

Abstract The potential for preservation of thecosome pteropods is thought to be largely governed by the chemical stability their delicate aragonitic shells in seawater. However, sediment trap studies have found that significant carbonate dissolution can occur above saturation horizon. Here we present results from experiments conducted on two cruises Scotia Sea directly test whether breakdown organic pteropod body influences shell dissolution. We find timescales 3 13 days, oxidation matter within dead a stronger driver than aragonite state Three four days after death, became milky white and nano scanning electron microscope images reveal smoothing internal surface features increased porosity, both indicative These findings implications interpretation condition traps fossil record, as well understanding processes controlling particulate export ocean.

Language: Английский

---

Determining how biotic and abiotic variables affect the shell condition and parameters of <i>Heliconoides inflatus</i> pteropods from a sediment trap in the Cariaco Basin

Biogeosciences, Journal Year: 2020, Volume and Issue: 17(7), P. 1975 - 1990

Published: April 14, 2020

Abstract. Pteropods have been nicknamed the “canary in coal mine” for ocean acidification because they are predicted to be among first organisms affected by changing chemistry. This is due their fragile, aragonitic shells and high abundances polar subpolar regions where impacts of most pronounced. For pteropods used effectively as indicators acidification, biotic abiotic factors influencing shell formation dissolution modern need quantified understood. Here, we measured condition (i.e., degree which a has dissolved) characteristics, including size, number whorls, thickness, volume amount material) nearly 50 specimens pteropod species Heliconoides inflatus sampled from sediment trap Cariaco Basin, Venezuela, over an 11-month period. The traps potential altered at three stages: (1) when live water column associated with (2) dead decay organic matter and/or (3) closed cup alteration preservation solution. Shell was assessed using two methods: Limacina Dissolution Index (LDX) opacity method. method found capture changes only early stages dissolution, whereas LDX recorded much larger range. Because Basin supersaturated respect aragonite year-round, assume no occurred during life, there evidence that deteriorated length time trap. Light microscope scanning electron (SEM) images show majority happened while matter. samples collected September October temperatures were warmest degradation, both within column, likely greatest. hydrographic chemical properties vary seasonally movement Intertropical Convergence Zone (ITCZ). Shells H. varied thickness throughout year. There not strong correlation between whorls diameter, suggesting growth plastic. formed 40 % thicker 20 diameter nutrient-rich, upwelling times food supply abundant, indicating this aragonite-supersaturated basin controlled availability. study produces baseline dataset variability characteristics documents controls on captured via traps. methodology outlined assessing parameters establishes protocol generating similar records populations globally.

Language: Английский

---

Relationship between shell integrity of pelagic gastropods and carbonate chemistry parameters at a Scottish Coastal Observatory monitoring site

ICES Journal of Marine Science, Journal Year: 2019, Volume and Issue: unknown

Published: Sept. 6, 2019

Abstract Ocean acidification (OA), the anthropogenic carbon dioxide-induced changes in seawater carbonate chemistry, is likely to have a significant impact on calcifying plankton. Most planktonic studies OA are based “one-off” cruises focused offshore areas while observations from inshore waters scarce. This study presents first analysis shell integrity of pelagic gastropods (holoplanktonic pteropods and larvae otherwise benthic species) at Scottish Coastal Observatory monitoring site Stonehaven east coast Scotland. The archived specimens 2011 2013 was examined using Scanning Electron Microscopy relationship with (pH aragonite saturation, Ωarg) other environmental parameters investigated. Evidence dissolution detected all analysed taxa even though supersaturated respect aragonite. condition matched temporal pattern observed Ωarg, higher proportion associated decreasing suggesting that seasonality component chemistry might affect gastropods. differed significantly between adult stages pteropods, supporting hypothesis early-life would be more vulnerable OA-induced changes. Our data also suggest sensitivity may differ closely related taxonomic groups. strong interannual variability revealed by year-to-year Ωarg illustrates difficulty assessing plankton response field value time series studies.

Language: Английский

---

Archival records of the Antarctic clam shells from Marian Cove, King George Island suggest a protective mechanism against ocean acidification

Marine Pollution Bulletin, Journal Year: 2024, Volume and Issue: 200, P. 116052 - 116052

Published: Jan. 30, 2024

Language: Английский

---

Testing the impact of two key scan parameters on the quality and repeatability of measurements from CT scan data

Palaeontologia Electronica, Journal Year: 2020, Volume and Issue: unknown

Published: Jan. 1, 2020

Computed tomographic (CT) scanning is becoming a popular research tool across earth and life sciences.However, despite its prominence, there have not been systematic investigations into how CT scan parameters affect data quality reproducibility.Here we conduct two sets of trials to test exposure time, the number x-ray radiographs averaged per view, overall time data, assessed using signal contrast noise ratios repeatability measurements derived from these in this case calculated volume pteropod shells.We find that ratio shell increase variability decrease with increasing time.However, benefits increased diminish considerably at times 50 minutes or more.Furthermore, as increases, scans are greater risk being affected by sample movement, which can make unusable.By balancing image 50-minute be comparable to, better than, collected 75-minute scan.By selecting rather than scan, collection between 66 75%, maximizing both quantity collected.

Language: Английский

---

Sea butterflies in a pickle: reliable biomarkers and seasonal sensitivity of Limacina retroversa to ocean acidification in the Gulf of Maine

Conservation Physiology, Journal Year: 2024, Volume and Issue: 12(1)

Published: Jan. 1, 2024

Abstract The passive dissolution of anthropogenically produced CO2 into the ocean system is reducing pH and changing a suite chemical equilibria, with negative consequences for some marine organisms, in particular those that bear calcium carbonate shells. Although our monitoring these changes has improved, we have not developed effective tools to translate observations, which are typically saturation state, ecologically relevant predictions biological risks. One potential solution develop bioindicators: variables clear relationship environmental risk factors can be used assessment management. Thecosomatous pteropods group pelagic shelled gastropods, whose responses been suggested as bioindicators acidification owing their sensitivity both laboratory natural environment. Using five exposure experiments, occurring across four seasons running up 15 days, describe consistent between shell transparency duration exposure, well identify genes could further study. We clarify variations thecosome due seasonality, resolving prior uncertainties demonstrating range phenotypic plasticity. These biomarkers stress implemented ecosystem models programmes regions where found, whilst approach will serve an example other on how bridge gap point-based biologically assessments health.

Language: Английский

---