| 1. |
- Bednarsek, Nina, et al.
(författare)
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Polar Ocean Acidification : LOSS OF RESOURCES FROM THE “OTHER” CO2 PROBLEM
- 2015
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Ingår i: Thresholds and Closing December. RISKS OF IRREVERSIBLE CRYOSPHERE CLIMATE CHANGE. The International Cryosphere Climate Initiative. ; , s. 19-22
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Although technically not “cryosphere” (which is frozen water), the Arctic Ocean, and Southern Ocean around Antarctica make up some of the world’s richest fisheries, with diverse marine ecosystems. These cold waters are however highly vulnerable to ocean acidification from increased carbon dioxide (CO2) in the atmosphere. We already are crossing important ocean acidification thresholds in these regions, with early impacts possibly observed on some polar ocean species. There is substantial risk that ocean acidification will damage ecosystems and weaken the food chain in these important resource waters, even should countries meet the stated 2 degree goal, which entails atmospheric CO2 levels peaking at 450ppm. However, CO2 concentrations associated with current INDCs in the 2.7–3.5 degree range are far higher still, anticipated to peak potentially above 600ppm. At such high levels, and because of the very long time scales required for acidity to decrease, there is high risk for irreversible impacts on biodiversity in the Arctic and Southern oceans, with consequences for polar and near-polar fisheries and human activities.
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| 2. |
- Briddon, Charlotte L., et al.
(författare)
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Acclimation to various temperature and pCO2 levels does not impact the competitive ability of two strains of Skeletonema marinoi in natural communities
- 2023
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Ingår i: Frontiers in Marine Science. - 2296-7745. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the long-term response of key marine phytoplankton species to ongoing global changes is pivotal in determining how oceanic community composition will respond over the coming decades. To better understand the impact of ocean acidification and warming, we acclimated two strains of Skeletonema marinoi isolated from natural communities to three pCO2 (400 μatm, 600 μatm and 1000 μatm) for 8 months and five temperature conditions (7°C, 10°C, 13°C, 16°C and 19°C) for 11 months. These strains were then tested in natural microbial communities, exposed to three pCO2 treatments (400 μatm, 600 μatm and 1000 μatm). DNA metabarcoding of the 16S and 18S gene for prokaryotes and eukaryotes respectively was used to show differences in abundance and diversity between the three CO2 treatments. We found there were no significant differences in acclimated S. marinoi concentrations between the three pCO2 treatments, most likely due to the high variability these strains experience in their natural environment. There were significant compositional differences between the pCO2 treatments for prokaryotes suggesting that indirect changes to phytoplankton-bacteria interactions could be a possible driver of bacterial community composition. Yet, there were no differences for eukaryotic community composition, with all treatments dominated by diatoms (but not the acclimated S. marinoi) resulting in similar biodiversity. Furthermore, strain-specific differences in community composition suggests interactions between prokaryotic and eukaryotic taxa could play a role in determining future community composition.
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| 3. |
- Thor, Peter, 1965, et al.
(författare)
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Contrasting physiological responses to future ocean acidification among Arctic copepod populations : Contrasting responses to ocean acidification
- 2018
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- Widespread ocean acidification (OA) is modifying the chemistry of the global ocean, and the Arctic is recognised as the region where the changes will progress at the fastest rate. Moreover, Arctic species show lower capacity for cellular homeostasis and acid-base regulation rendering them particularly vulnerable to OA. In the present study, we found physiological differences in OA response across geographically separated populations of the keystone Arctic copepod Calanus glacialis. In copepodite stage CIV, measured reaction norms of ingestion rate and metabolic rate showed severe reductions in ingestion and increased metabolic expenses in two populations from Svalbard (Kongsfjord and Billefjord) whereas no effects were observed in a population from the Disko Bay, West Greenland. At pHT 7.87, which has been predicted for the Svalbard west coast by year 2100, these changes resulted in reductions in scope for growth of 19% in the Kongsfjord and a staggering 50% in the Billefjord. Interestingly, these effects were not observed in stage CV copepodites from any of the three locations. It seems that CVs may be more tolerant to OA perhaps due to a general physiological reorganisation to meet low intracellular pH during hibernation. Needless to say, the observed changes in the CIV stage will have serious implications for the C. glacialis population health status and growth around Svalbard. However, OA tolerant populations such as the one in the Disko Bay could help to alleviate severe effects in C. glacialis as a species.
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