GLOBAL OCEAN ACIDIFICATION DURING THE LATE PERMIAN- LATE TRIASSIC AS INFERRED FROM CARBONATE CALCIUM ISOTOPE

2019 ◽  
Author(s):  
Feihong Ye ◽  
◽  
Laishi Zhao ◽  
Ying Cui ◽  
Lei Zhang
Keyword(s):  
Ocean Acidification ◽  
Global Ocean ◽  
Late Triassic ◽  
Late Permian ◽  
Calcium Isotope

CALCIUM ISOTOPE EVIDENCE OF AN EPISODE OF OCEAN ACIDIFICATION ACROSS THE SMITHIAN-SPATHIAN BOUNDARY

2018 ◽  
Author(s):  
He Zhao ◽  
◽  
Feifei Zhang ◽  
Thomas J. Algeo ◽  
Zhong Qiang Chen ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Calcium Isotope ◽  
Isotope Evidence

scholarly journals Quantifying the influence of CO<sub>2</sub> seasonality on future ocean acidification

2015 ◽  
Vol 12 (8) ◽  
pp. 5907-5940
Author(s):  
T. P. Sasse ◽  
B. I. McNeil ◽  
R. J. Matear ◽  
A. Lenton
Keyword(s):  
Ocean Acidification ◽  
North Pacific ◽  
Dissolved Inorganic Carbon ◽  
Marine Ecosystem ◽  
Global Ocean ◽  
Saturation State ◽  
The North ◽  
Data Limitations ◽  
The Future ◽  
The North Pacific

Abstract. Ocean acidification is a predictable consequence of rising atmospheric carbon dioxide (CO2), and is highly likely to impact the entire marine ecosystem – from plankton at the base to fish at the top. Factors which are expected to be impacted include reproductive health, organism growth and species composition and distribution. Predicting when critical threshold values will be reached is crucial for projecting the future health of marine ecosystems and for marine resources planning and management. The impacts of ocean acidification will be first felt at the seasonal scale, however our understanding how seasonal variability will influence rates of future ocean acidification remains poorly constrained due to current model and data limitations. To address this issue, we first quantified the seasonal cycle of aragonite saturation state utilizing new data-based estimates of global ocean surface dissolved inorganic carbon and alkalinity. This seasonality was then combined with earth system model projections under different emissions scenarios (RCPs 2.6, 4.5 and 8.5) to provide new insights into future aragonite under-saturation onset. Under a high emissions scenario (RCP 8.5), our results suggest accounting for seasonality will bring forward the initial onset of month-long under-saturation by 17 years compared to annual-mean estimates, with differences extending up to 35 ± 17 years in the North Pacific due to strong regional seasonality. Our results also show large-scale under-saturation once atmospheric CO2 reaches 486 ppm in the North Pacific and 511 ppm in the Southern Ocean independent of emission scenario. Our results suggest that accounting for seasonality is critical to projecting the future impacts of ocean acidification on the marine environment.

scholarly journals The Effects of Combined Ocean Acidification and Nanoplastic Exposures on the Embryonic Development of Antarctic Krill

2021 ◽  
Vol 8 ◽  
Author(s):  
Emily Rowlands ◽  
Tamara Galloway ◽  
Matthew Cole ◽  
Ceri Lewis ◽  
Victoria Peck ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Southern Ocean ◽  
Ocean Acidification ◽  
Antarctic Krill ◽  
Gravid Female ◽  
Limb Bud ◽  
Global Ocean ◽  
Plastic Pollution ◽  
Atlantic Sector ◽  
Scotia Sea

In aquatic environments, plastic pollution occurs concomitantly with anthropogenic climate stressors such as ocean acidification. Within the Southern Ocean, Antarctic krill (Euphausia Superba) support many marine predators and play a key role in the biogeochemical cycle. Ocean acidification and plastic pollution have been acknowledged to hinder Antarctic krill development and physiology in singularity, however potential multi-stressor effects of plastic particulates coupled with ocean acidification are unexplored. Furthermore, Antarctic krill may be especially vulnerable to plastic pollution due to their close association with sea-ice, a known plastic sink. Here, we investigate the behaviour of nanoplastic [spherical, aminated (NH2), and yellow-green fluorescent polystyrene nanoparticles] in Antarctic seawater and explore the single and combined effects of nanoplastic (160 nm radius, at a concentration of 2.5 μg ml–1) and ocean acidification (pCO2 ∼900, pHT 7.7) on the embryonic development of Antarctic krill. Gravid female krill were collected in the Atlantic sector of the Southern Ocean (North Scotia Sea). Produced eggs were incubated at 0.5 °C in four treatments (control, nanoplastic, ocean acidification and the multi-stressor scenario of nanoplastic presence, and ocean acidification) and their embryonic development after 6 days, at the incubation endpoint, was determined. We observed that negatively charged nanoplastic particles suspended in seawater from the Scotia Sea aggregated to sizes exceeding the nanoscale after 24 h (1054.13 ± 53.49 nm). Further, we found that the proportion of embryos developing through the early stages to reach at least the limb bud stage was highest in the control treatment (21.84%) and lowest in the multi-stressor treatment (13.17%). Since the biological thresholds to any stressors can be altered by the presence of additional stressors, we propose that future nanoplastic ecotoxicology studies should consider the changing global ocean under future climate scenarios for assessments of their impact and highlight that determining the behaviour of nanoplastic particles used in incubation studies is critical to determining their toxicity.

scholarly journals The calcareous nannofossil <i>Prinsiosphaera</i> achieved rock-forming abundances in the latest Triassic of western Tethys: consequences for the δ<sup>13</sup>C of bulk carbonate

2013 ◽  
Vol 10 (5) ◽  
pp. 7989-8025 ◽  
Author(s):  
N. Preto ◽  
C. Agnini ◽  
M. Rigo ◽  
M. Sprovieri ◽  
H. Westphal
Keyword(s):  
Global Ocean ◽  
Late Triassic ◽  
Calcareous Nannofossils ◽  
Calcareous Nannofossil ◽  
Western Tethys ◽  
Carbonate Sedimentation ◽  
History Of ◽  
Calcareous Plankton ◽  
Inorganic Carbon Cycle

Abstract. The onset of pelagic biomineralization marked a milestone in the history of the long term inorganic carbon cycle: as soon as calcareous nannofossils became major limestone producers, the pH and supersaturation state of the global ocean were stabilized (the so-called Mid Mesozoic Revolution). But although it is known that calcareous nannofossils were abundant already by the end of the Triassic, no estimates exist on their contribution to hemipelagic carbonate sedimentation. With this work, we estimate the volume proportion of Prinsiosphaera, the dominant Late Triassic calcareous nannofossil, in hemipelagic and pelagic carbonates of western Tethys. The investigated Upper Triassic lime mudstones are composed essentially of microspar and tests of calcareous nannofossils, plus minor bioclasts. Prinsiosphaera became a significant component of lime mudstones since the late Norian, and was contributing up to ca. 60% of the carbonate by the late Rhaetian in periplatform environments with hemipelagic sedimentation. The increasing proportion of Prinsiosphaera in upper Rhaetian hemipelagic lime mudstones is paralleled by a increase of the δ13C of bulk carbonate. We interpreted this isotopic trend as related to the diagenesis of microspar, which incorporated respired organic carbon with a low δ13C when it formed during shallow burial. As the proportion of nannofossil tests increased, the contribution of microspar with low δ13C diminished, determining the isotopic trend. We suggest that a similar diagenetic effect may be observed in many Mesozoic limestones with a significant, but not yet dominant, proportion of calcareous plankton.

Within- and among-genus components of size evolution during mass extinction, recovery, and background intervals: a case study of Late Permian through Late Triassic foraminifera

Paleobiology ◽  
2012 ◽  
Vol 38 (4) ◽  
pp. 627-643 ◽  
Author(s):  
Brianna L. Rego ◽  
Steve C. Wang ◽  
Demir Altiner ◽  
Jonathan L. Payne
Keyword(s):  
Mass Extinction ◽  
Extinction Risk ◽  
Maximum Size ◽  
Size Reduction ◽  
Late Triassic ◽  
Mass Extinctions ◽  
Late Permian ◽  
Biotic Recovery ◽  
Size Evolution ◽  
Selective Extinction

One of the best-recognized patterns in the evolution of organismal size is the tendency for mean and maximum size within a clade to decrease following a major extinction event and to increase during the subsequent recovery interval. Because larger organisms are typically thought to be at higher extinction risk than their smaller relatives, it has commonly been assumed that size reduction mostly reflects the selective extinction of larger species. However, to our knowledge the relative importance of within- and among-lineage processes in driving overall trends in body size has never been compared quantitatively. In this study, we use a global, specimen-level database of foraminifera to study size evolution from the Late Permian through Late Triassic. We explicitly decompose size evolution into within- and among-genus components. We find that size reduction following the end-Permian mass extinction was driven more by size reduction within surviving species and genera than by the selective extinction of larger taxa. Similarly, we find that increase in mean size across taxa during Early Triassic biotic recovery was a product primarily of size increase within survivors and the extinction of unusually small taxa, rather than the origination of new, larger taxa. During background intervals we find no strong or consistent tendency for extinction, origination, or within-lineage change to move the overall size distribution toward larger or smaller sizes. Thus, size stasis during background intervals appears to result from small and inconsistent effects of within- and among-lineage processes rather than from large but offsetting effects of within- and among-taxon components. These observations are compatible with existing data for other taxa and extinction events, implying that mass extinctions do not influence size evolution by simply selecting against larger organisms. Instead, they appear to create conditions favorable to smaller organisms.

Depositional Sequences in Northern Peru: New Insights on the Palaeogeographic and Palaeotectonic Reconstruction of Western Gondwana During Late Permian and Triassic

2021 ◽  
pp. jgs2020-186
Author(s):  
Emilio Carrillo ◽  
Roberto Barragán ◽  
Christian Hurtado ◽  
Ysabel Calderón ◽  
Germán Martín ◽  
...  
Keyword(s):  
Ocean Dynamics ◽  
Late Triassic ◽  
Northwestern Part ◽  
Mass Extinctions ◽  
Late Permian ◽  
Triassic Boundary ◽  
Subsidence Basin ◽  
Restricted Environment ◽  
Resources Distribution ◽  
Northern Peru

Late Permian to Early Jurassic strata in northern Peru allows us to carry out a seismo-stratigraphic, litho-tectonic and chemostratigraphic analysis connecting the Andean-Amazonian foreland basins of Huallaga, Ucayali, southern Marañón, and the Eastern Cordillera. This analysis and data integration from Ecuador to western Brazil and southern Peru and Bolivia, allow us to redefine the timing of the major documented tectonic phases and corresponding palaeogeographies of western Gondwana from the late Permian to Triassic. Three litho-tectonic sequences and four associated deformation stages are recognized: 1) A sequence, tectonic relaxation, during late Permian; 2) A-B intra-sequence, folding-and-thrusting attributed to a continuation in time of the Gondwanide Orogeny, during the Early to Middle Triassic; 3) B sequence, rifting, attributed to Gondwana breakup during the Middle and Late Triassic; and 4) C Sequence, thermal sag, during the Late Triassic. Evaporites and carbonates (A sequence) dominated a low subsidence basin with southern restricted marine inflow at the Permian-Triassic boundary. A novel palaeogeographic model for these evaporites suggests that this saline basin extended up to 50,000 km2 in a restricted environment area with a potential bullseye pattern. The last pulse of the Gondwanide Orogeny and associated fold and thrust belt (A-B intra-sequence) exhumed previous the sequence generating emerged areas with little to no sedimentation. Red beds (B sequence) characterize the rifting stage, representing the syn-depositional infill of continental grabens, likely extending to the Acre Basin in Brazil. Finally, during the thermal sag, a marine inflow likely from the northwestern part of Peru generated sedimentation of carbonates and evaporites (C Sequence) to the west and east of the Peruvian margin. This sediment differentiation was, in part, controlled by the existence of pre-existing grabens associated to the previous rifting stage. This interpretation, together with other evaporitic occurrences attributed here to a Late Triassic epoch in south and north Peru and west Brazil, suggest the existence of an evaporitic basin filling an undeformed area of probably ca. 170,000 km2. It is therefore suggestive of the existence of a Late Triassic (Norian to Rhaetian; 217 to 204 Ma) salt giant controlled by thermal sag in western Gondwana. Our results are of great relevance for any future interpretation related to mass extinctions, paleoclimatic analysis and ocean dynamics during the Permian and Triassic as well as natural resources distribution between Ecuador and Bolivia.

scholarly journals Coccolithophore populations and their contribution to carbonate export during an annual cycle in the Australian sector of the Antarctic zone

2018 ◽  
Vol 15 (6) ◽  
pp. 1843-1862 ◽  
Author(s):  
Andrés S. Rigual Hernández ◽  
José A. Flores ◽  
Francisco J. Sierro ◽  
Miguel A. Fuertes ◽  
Lluïsa Cros ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Ocean Acidification ◽  
Deep Ocean ◽  
Sediment Traps ◽  
Global Ocean ◽  
Field Observations ◽  
Scotia Sea ◽  
Allochthonous Species ◽  
Circumpolar Current ◽  
The Antarctic

Abstract. The Southern Ocean is experiencing rapid and relentless change in its physical and biogeochemical properties. The rate of warming of the Antarctic Circumpolar Current exceeds that of the global ocean, and the enhanced uptake of carbon dioxide is causing basin-wide ocean acidification. Observational data suggest that these changes are influencing the distribution and composition of pelagic plankton communities. Long-term and annual field observations on key environmental variables and organisms are a critical basis for predicting changes in Southern Ocean ecosystems. These observations are particularly needed, since high-latitude systems have been projected to experience the most severe impacts of ocean acidification and invasions of allochthonous species. Coccolithophores are the most prolific calcium-carbonate-producing phytoplankton group playing an important role in Southern Ocean biogeochemical cycles. Satellite imagery has revealed elevated particulate inorganic carbon concentrations near the major circumpolar fronts of the Southern Ocean that can be attributed to the coccolithophore Emiliania huxleyi. Recent studies have suggested changes during the last decades in the distribution and abundance of Southern Ocean coccolithophores. However, due to limited field observations, the distribution, diversity and state of coccolithophore populations in the Southern Ocean remain poorly characterised. We report here on seasonal variations in the abundance and composition of coccolithophore assemblages collected by two moored sediment traps deployed at the Antarctic zone south of Australia (2000 and 3700 m of depth) for 1 year in 2001–2002. Additionally, seasonal changes in coccolith weights of E. huxleyi populations were estimated using circularly polarised micrographs analysed with C-Calcita software. Our findings indicate that (1) coccolithophore sinking assemblages were nearly monospecific for E. huxleyi morphotype B/C in the Antarctic zone waters in 2001–2002; (2) coccoliths captured by the traps experienced weight and length reduction during summer (December–February); (3) the estimated annual coccolith weight of E. huxleyi at both sediment traps (2.11 ± 0.96 and 2.13 ± 0.91 pg at 2000 and 3700 m) was consistent with previous studies for morphotype B/C in other Southern Ocean settings (Scotia Sea and Patagonian shelf); and (4) coccolithophores accounted for approximately 2–5 % of the annual deep-ocean CaCO3 flux. Our results are the first annual record of coccolithophore abundance, composition and degree of calcification in the Antarctic zone. They provide a baseline against which to monitor coccolithophore responses to changes in the environmental conditions expected for this region in coming decades.

scholarly journals Ocean acidification alters the material properties of Mytilus edulis shells

2015 ◽  
Vol 12 (103) ◽  
pp. 20141227 ◽  
Author(s):  
Susan C. Fitzer ◽  
Wenzhong Zhu ◽  
K. Elizabeth Tanner ◽  
Vernon R. Phoenix ◽  
Nicholas A. Kamenos ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Mytilus Edulis ◽  
Material Properties ◽  
Blue Mussel ◽  
Global Ocean ◽  
Mussel Shell ◽  
Multiple Stressor ◽  
Mussel Shells ◽  
Increasing Temperature ◽  
The Impact

Ocean acidification (OA) and the resultant changing carbonate saturation states is threatening the formation of calcium carbonate shells and exoskeletons of marine organisms. The production of biominerals in such organisms relies on the availability of carbonate and the ability of the organism to biomineralize in changing environments. To understand how biomineralizers will respond to OA the common blue mussel, Mytilus edulis , was cultured at projected levels of p CO 2 (380, 550, 750, 1000 µatm) and increased temperatures (ambient, ambient plus 2°C). Nanoindentation (a single mussel shell) and microhardness testing were used to assess the material properties of the shells. Young's modulus ( E ), hardness ( H ) and toughness ( K IC ) were measured in mussel shells grown in multiple stressor conditions. OA caused mussels to produce shell calcite that is stiffer (higher modulus of elasticity) and harder than shells grown in control conditions. The outer shell (calcite) is more brittle in OA conditions while the inner shell (aragonite) is softer and less stiff in shells grown under OA conditions. Combining increasing ocean p CO 2 and temperatures as projected for future global ocean appears to reduce the impact of increasing p CO 2 on the material properties of the mussel shell. OA may cause changes in shell material properties that could prove problematic under predation scenarios for the mussels; however, this may be partially mitigated by increasing temperature.

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