scholarly journals The origin and diversification of pteropods predate past perturbations in the Earth’s carbon cycle

2019 ◽  
Author(s):  
Katja T.C.A. Peijnenburg ◽  
Arie W. Janssen ◽  
Deborah Wall-Palmer ◽  
Erica Goetze ◽  
Amy Maas ◽  
...  

SummaryPteropods are a group of planktonic gastropods that are widely regarded as biological indicators for assessing the impacts of ocean acidification (OA). Their thin aragonitic shells are highly sensitive to acute changes in ocean chemistry. However, to gain insight into their potential to adapt to current climate change, we need to accurately reconstruct their evolutionary history and assess their responses to past changes in Earth’s carbon cycle. Here, we resolve the phylogeny and timing of pteropod evolution with a phylogenomic dataset incorporating 21 new species and new fossil evidence. In agreement with traditional taxonomy, we recovered the first molecular support for a division between sea butterflies (Thecosomata: mucus-web feeders) and sea angels (Gymnosomata: active predators). Molecular dating demonstrated that these two lineages diverged in the early Cretaceous, and that all main pteropod clades, including shelled, partially-shelled and unshelled groups, diverged in the mid to late Cretaceous. Hence, these clades originated prior to and subsequently survived major global change events, including the Paleocene Eocene Thermal Maximum (PETM), which is the closest analogue to modern-day ocean acidification and warming. Our findings indicate that aragonitic calcifiers have been resilient to extreme perturbations in the Earth’s carbon cycle over evolutionary timescales.

2020 ◽  
Vol 117 (41) ◽  
pp. 25609-25617 ◽  
Author(s):  
Katja T. C. A. Peijnenburg ◽  
Arie W. Janssen ◽  
Deborah Wall-Palmer ◽  
Erica Goetze ◽  
Amy E. Maas ◽  
...  

Pteropods are a group of planktonic gastropods that are widely regarded as biological indicators for assessing the impacts of ocean acidification. Their aragonitic shells are highly sensitive to acute changes in ocean chemistry. However, to gain insight into their potential to adapt to current climate change, we need to accurately reconstruct their evolutionary history and assess their responses to past changes in the Earth’s carbon cycle. Here, we resolve the phylogeny and timing of pteropod evolution with a phylogenomic dataset (2,654 genes) incorporating new data for 21 pteropod species and revised fossil evidence. In agreement with traditional taxonomy, we recovered molecular support for a division between “sea butterflies” (Thecosomata; mucus-web feeders) and “sea angels” (Gymnosomata; active predators). Molecular dating demonstrated that these two lineages diverged in the early Cretaceous, and that all main pteropod clades, including shelled, partially-shelled, and unshelled groups, diverged in the mid- to late Cretaceous. Hence, these clades originated prior to and subsequently survived major global change events, including the Paleocene–Eocene Thermal Maximum (PETM), the closest analog to modern-day ocean acidification and warming. Our findings indicate that planktonic aragonitic calcifiers have shown resilience to perturbations in the Earth’s carbon cycle over evolutionary timescales.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Matthew O. Clarkson ◽  
Timothy M. Lenton ◽  
Morten B. Andersen ◽  
Marie-Laure Bagard ◽  
Alexander J. Dickson ◽  
...  

AbstractThe Paleocene Eocene Thermal Maximum (PETM) represents a major carbon cycle and climate perturbation that was associated with ocean de-oxygenation, in a qualitatively similar manner to the more extensive Mesozoic Oceanic Anoxic Events. Although indicators of ocean de-oxygenation are common for the PETM, and linked to biotic turnover, the global extent and temporal progression of de-oxygenation is poorly constrained. Here we present carbonate associated uranium isotope data for the PETM. A lack of resolvable perturbation to the U-cycle during the event suggests a limited expansion of seafloor anoxia on a global scale. We use this result, in conjunction with a biogeochemical model, to set an upper limit on the extent of global seafloor de-oxygenation. The model suggests that the new U isotope data, whilst also being consistent with plausible carbon emission scenarios and observations of carbon cycle recovery, permit a maximum ~10-fold expansion of anoxia, covering <2% of seafloor area.


2012 ◽  
Vol 9 (11) ◽  
pp. 4679-4688 ◽  
Author(s):  
S. J. Gibbs ◽  
P. R. Bown ◽  
B. H. Murphy ◽  
A. Sluijs ◽  
K. M. Edgar ◽  
...  

Abstract. Late Paleocene and early Eocene hyperthermals are transient warming events associated with massive perturbations of the global carbon cycle, and are considered partial analogues for current anthropogenic climate change. Because the magnitude of carbon release varied between the events, they are natural experiments ideal for exploring the relationship between carbon cycle perturbations, climate change and biotic response. Here we quantify marine biotic variability through three million years of the early Eocene that include five hyperthermals, utilizing a method that allows us to integrate the records of different plankton groups through scenarios ranging from background to major extinction events. Our long time-series calcareous nannoplankton record indicates a scaling of biotic disruption to climate change associated with the amount of carbon released during the various hyperthermals. Critically, only the three largest hyperthermals, the Paleocene–Eocene Thermal Maximum (PETM), Eocene Thermal Maximum 2 (ETM2) and the I1 event, show above-background variance, suggesting that the magnitude of carbon input and associated climate change needs to surpass a threshold value to cause significant biotic disruption.


2012 ◽  
Vol 27 (1) ◽  
pp. 59-67
Author(s):  
Dusanka Indjic ◽  
Slavica Vukovic ◽  
Snezana Tanaskovic ◽  
Mila Grahovac ◽  
Tatjana Keresi ◽  
...  

In 2009, the sensitivity of 15 field populations of Colorado potato beetle (Leptinotarsa decemlineata Say.) - CPB was assessed to chlorpyrifos, cypermethrin, thiamethoxam and fipronil, four insecticides which are mostly used for its control in Serbia. Screening test that allows rapid assessment of sensitivity of overwintered adults to insecticides was performed. Insecticides were applied at label rates, and two, five and 10 fold higher rates by soaking method (5 sec). Mortality was assessed after 72h. From 15 monitored populations of CPB, two were sensitive to label rate of chlorpyrifos, one was slightly resistant, 11 were resistant and one population was highly resistant. Concerning cypermethrin, two populations were sensitive, two slightly resistant, five were resistant and six highly resistant. Highly sensitive to thiamethoxam label rate were 12 populations, while three were sensitive. In the case of fipronil applied at label rate, two populations were highly sensitive, six sensitive, one slightly resistant and six were resistant. The application of insecticides at higher rates (2, 5 and 10 fold), that is justified only in bioassays, provided a rapid insight into sensitivity of field populations of CPB to insecticides.


2011 ◽  
Vol 33 (3) ◽  
pp. 30-34
Author(s):  
Rod W. Wilson ◽  
Erin E. Reardon ◽  
Christopher T. Perry

Human activities, such as burning fossil fuels, are playing an important role in the rising levels of carbon dioxide (CO2) in the Earth's atmosphere1. The oceans may store a large portion of CO2 that we are releasing into the atmosphere, with up to 40% already taken up by the oceans. Although this absorption helps to offset some of the greenhouse effect of atmospheric CO2, it also contributes to ocean acidification, or a fall in the pH of sea water. The historical global mean pH of oceanic sea water is about 8.2, and this has already declined by 0.1 pH units (a 30% increase in H+ concentration) and is predicted to reach pH ~7.7 by the end of the century if current rates of fossil fuel use continue, leading to an atmospheric CO2 level of 800 p.p.m.1,2. Even this extreme potential fall in pH would still leave seawater above the neutral point (pH 7.0), so technically it is more accurate to say that the ocean is becoming less alkaline, rather than truly acidic (i.e. below pH 7.0). However, the magnitude is perhaps less important than the speed of pH change which is occurring faster than at any time during the previous 20 million years. Over this time, the average ocean pH has probably never fallen below pH 8.02,3. It is only during the last decade that the importance of ocean acidification has come to the forefront of concerns for scientists1,2. Consequences of these changes in global CO2 production are predicted to include elevated global temperatures, rising sea levels, more unpredictable and extreme weather patterns, and shifts in ecosystems1. In order to more fully understand the implications of ocean acidification, teams of researchers, including fisheries scientists, physiologists, geologists, oceanographers, chemists and climate modellers, are working to refine current understanding of the ocean carbon cycle.


Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7185
Author(s):  
Oliver Gould ◽  
Natalia Drabińska ◽  
Norman Ratcliffe ◽  
Ben de Lacy Costello

Mass spectrometry (MS) is an analytical technique that can be used for various applications in a number of scientific areas including environmental, security, forensic science, space exploration, agri-food, and numerous others. MS is also continuing to offer new insights into the proteomic and metabolomic fields. MS techniques are frequently used for the analysis of volatile compounds (VCs). The detection of VCs from human samples has the potential to aid in the diagnosis of diseases, in monitoring drug metabolites, and in providing insight into metabolic processes. The broad usage of MS has resulted in numerous variations of the technique being developed over the years, which can be divided into hyphenated and real-time MS techniques. Hyphenated chromatographic techniques coupled with MS offer unparalleled qualitative analysis and high accuracy and sensitivity, even when analysing complex matrices (breath, urine, stool, etc.). However, these benefits are traded for a significantly longer analysis time and a greater need for sample preparation and method development. On the other hand, real-time MS techniques offer highly sensitive quantitative data. Additionally, real-time techniques can provide results in a matter of minutes or even seconds, without altering the sample in any way. However, real-time MS can only offer tentative qualitative data and suffers from molecular weight overlap in complex matrices. This review compares hyphenated and real-time MS methods and provides examples of applications for each technique for the detection of VCs from humans.


2021 ◽  
Vol 9 ◽  
Author(s):  
Kuo Wang ◽  
Han Zhang ◽  
Gao-Feng Fan ◽  
Zheng-Quan Li ◽  
Zhen-Yan Yu ◽  
...  

Since preindustrial times, atmospheric CO2 content increased continuously, leading to global warming through the greenhouse effect. Oceanic carbon sequestration mitigates global warming; on the other hand, oceanic CO2 uptake would reduce seawater pH, which is termed ocean acidification. We perform Earth system model simulations to assess oceanic CO2 uptake, surface temperature, and acidification for Zhejiang offshore, one of the most vulnerable areas to marine disasters. In the last 40 years, atmospheric CO2 concentration increased by 71 ppm, and sea surface temperature (SST) in Zhejiang offshore increased at a rate of 0.16°C/10a. Cumulative oceanic CO2 uptake in Zhejiang offshore is 0.3 Pg C, resulting in an increase of 20% in sea surface hydrogen ion concentration, and the acidification rate becomes faster in the last decade. During 2020–2040, under four RCP scenarios, SST in Zhejiang offshore increases by 0.3–0.5°C, whereas cumulative ocean carbon sequestration is 0.150–0.165 Pg C. Relative to RCP2.6, the decrease of surface pH in Zhejiang offshore is doubled under RCP8.5. Furthermore, simulated results show that the relationship between CO2 scenario and oceanic carbon cycle is nonlinear, which hints that deeper reduction of anthropogenic CO2 emission may be needed if we aim to mitigate ocean acidification in Zhejiang offshore under a higher CO2 concentration scenario. Our study quantifies the variation characteristics of oceanic climate and carbon cycle fields in Zhejiang offshore, and provides new insight into the responses of oceanic carbon cycle and the climate system to oceanic carbon sequestration.


2021 ◽  
Author(s):  
Dorota Przepiórka ◽  
Barbara Matyjasiak ◽  
Agata Chuchra ◽  
Hanna Rothkaehl

&lt;p&gt;Mid-latitude trough (MIT) is the distinct structure observed in Earth&amp;#8217;s ionosphere at high latitudes especially at the nighttimes. The phenomenon is observed at both hemispheres. As it resides at the topside ionosphere in the sub-auroral region, its behaviour and properties are highly sensitive to the solar and geomagnetic activity. Generally as the geomagnetic activity is more pronounced the MIT is observed at lower latitudes, it also deepens and becomes much more distinct in comparison to the low magnetic activity periods. MIT responds as well to the rapid changes in geomagnetic conditions, as are the geomagnetic storms, mainly caused by the CMEs.&amp;#160;&lt;/p&gt;&lt;p&gt;Based on the observations gathered by DEMETER data between 2005 and 2010 years&amp;#160; we present a set of geomagnetic storm cases and how the MIT properties has been changing as the storm evolves. We also discuss how it corresponds to the current solar activity and their evolutionary history&amp;#160; described by a set of different parameters.&lt;/p&gt;


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