| 1. |
- Burdett, Heidi L., et al.
(författare)
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The effect of chronic and acute low pH on the intracellular DMSP production and epithelial cell morphology of red coralline algae
- 2012
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Ingår i: Marine Biology Research. - : Taylor & Francis. - 1745-1000 .- 1745-1019. ; 8:8, s. 756-763
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Tidskriftsartikel (refereegranskat)abstract
- The release of dimethylsulphoniopropionate (DMSP) by marine algae has major impacts on the global sulphur cycle and may influence local climate through the formation of dimethylsulphide (DMS). However, the effect of global change on DMSP/DMS (DMS(P)) production by algae is not well understood. This study examined the effect of low pH on DMS(P) production and epithelial cell morphology of the free-living red coralline alga Lithothamnion glaciale. Three pH treatments were used in the 80-day experiment: (1) current pH level (8.18, control), (2) low, chronic pH representing a 2100 ocean acidification (OA) scenario (7.70) and (3) low, acute pH (7.75, with a 3-day spike to 6.47), representing acute variable conditions that might be associated with leaks from carbon capture and storage infrastructure, at CO2 vent sites or in areas of upwelling. DMS(P) production was not significantly enhanced under low, stable pH conditions, indicating that red coralline algae may have some resilience to OA. However, intracellular and water column DMS(P) concentrations were significantly higher than the control when pH was acutely spiked. Cracks were observed between the cell walls of the algal skeleton in both low pH treatments. It is proposed that this structural change may cause membrane damage that allows DMS(P) to leak from the cells into the water column, with subsequent implications for the cycling of DMS(P) in coralline algae habitats.
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| 2. |
- Calosi, Piero, et al.
(författare)
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Will Life find a Way? Evolution of Marine Species Under Global Change
- 2016
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Ingår i: Evolutionary Applications. - : Wiley. - 1752-4571. ; 9:9, s. 1035-1042
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Tidskriftsartikel (refereegranskat)abstract
- Projections of marine biodiversity and implementation of effective actions for its maintenance in face of current rapid global environmental change are constrained by our limited understanding of species’ adaptive responses, including, transgenerational plasticity, epigenetics, natural selection. This special issue presents 13 novel studies, which employ experimental and modeling approaches to: (1) Investigate plastic and evolutionary responses of marine species to major global change drivers; (2) ask relevant broad eco-evolutionary questions, implementing well-designed multiple species and populations studies; (3) show the advantages of using advanced experimental designs and tools; (4) construct novel model organisms for marine evolution; (5) help identifying future challenges for the field, and (6) highlight the importance of incorporating existing evolutionary theory into management solutions for the marine realm. What emerges is that at least some populations of marine species are able to adapt to future global change conditions. However, marine organisms’ capacity for adaptation appears finite, due to evolutionary trade-offs and possible rapid losses in genetic diversity. This further corroborate the idea that acquiring an evolutionary perspective on how marine life will respond to the selective pressure of future global changes will guide us in better identifying which conservation efforts will be most needed, and most effective.
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| 3. |
- Ellis, Robert P., et al.
(författare)
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Does sex really matter? Explaining intraspecies variation in ocean acidification responses
- 2017
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Ingår i: Biology Letters. - : The Royal Society. - 1744-9561 .- 1744-957X. ; 13:2
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Tidskriftsartikel (refereegranskat)abstract
- Ocean acidification (OA) poses a major threat to marine ecosystems globally, having significant ecological and economic importance. The number and complexity of experiments examining the effects of OA has substantially increased over the past decade, in an attempt to address multi-stressor interactions and long-term responses in an increasing range of aquatic organisms. However, differences in the response of males and females to elevated pCO2 have been investigated in fewer than 4% of studies to date, often being precluded by the difficulty of determining sex non-destructively, particularly in early life stages. Herewe highlight that sex can significantly impact organismresponses to OA, differentially affecting physiology, reproduction, biochemistry and ultimately survival. What is more, these impacts do not always conform to ecological theory based on differential resource allocation towards reproduction, which would predict females to be more sensitive to OA owing to the higher production cost of eggs compared with sperm. Therefore, non-sex-specific studies may overlook subtle but ecologically significant differences in the responses of males and females to OA, with consequences for forecasting the fate of natural populations in a near-future ocean.
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| 4. |
- Kamenos, Nicholas A., et al.
(författare)
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Coralline algal structure is more sensitive to rate, rather than the magnitude, of ocean acidification
- 2013
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Ingår i: Global Change Biology. - : John Wiley & Sons. - 1354-1013 .- 1365-2486. ; 19:12, s. 3621-3628
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Tidskriftsartikel (refereegranskat)abstract
- Marine pCO2 enrichment via ocean acidification (OA), upwelling and release from carbon capture and storage (CCS) facilities is projected to have devastating impacts on marine biomineralisers and the services they provide. However, empirical studies using stable endpoint pCO2 concentrations find species exhibit variable biological and geochemical responses rather than the expected negative patterns. In addition, the carbonate chemistry of many marine systems is now being observed to be more variable than previously thought. To underpin more robust projections of future OA impacts on marine biomineralisers and their role in ecosystem service provision, we investigate coralline algal responses to realistically variable scenarios of marine pCO2 enrichment. Coralline algae are important in ecosystem function; providing habitats and nursery areas, hosting high biodiversity, stabilizing reef structures and contributing to the carbon cycle. Red coralline marine algae were exposed for 80 days to one of three pH treatments: (i) current pH (control); (ii) low pH (7.7) representing OA change; and (iii) an abrupt drop to low pH (7.7) representing the higher rates of pH change observed at natural vent systems, in areas of upwelling and during CCS releases. We demonstrate that red coralline algae respond differently to the rate and the magnitude of pH change induced by pCO2 enrichment. At low pH, coralline algae survived by increasing their calcification rates. However, when the change to low pH occurred at a fast rate we detected, using Raman spectroscopy, weaknesses in the calcite skeleton, with evidence of dissolution and molecular positional disorder. This suggests that, while coralline algae will continue to calcify, they may be structurally weakened, putting at risk the ecosystem services they provide. Notwithstanding evolutionary adaptation, the ability of coralline algae to cope with OA may thus be determined primarily by the rate, rather than magnitude, at which pCO2 enrichment occurs.
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| 5. |
- Kamenos, Nicholas A., et al.
(författare)
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Substratum-mediated heart rate responses of an invertebrate to predation threat
- 2006
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Ingår i: Animal Behaviour. - : Elsevier. - 0003-3472 .- 1095-8282. ; 71, s. 809-813
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Tidskriftsartikel (refereegranskat)abstract
- Although the relation between behaviour and stress in humans and other vertebrates is well documented, few comparable observations exist for invertebrates. We addressed this issue by considering the impact of the physical environment on cardiac activity in invertebrates exposed to predation and nonpredation threat scenarios. We used cardiac activity as a proxy of stress in juvenile queen scallops, Aequipecten opercularis, under predation threat by the common starfish, Asterias rubens. Stress levels were monitored in juvenile queen scallops exposed, and not exposed, to predation threat on a substratum known to act as a refuge (live maerl) as well as substrata known not to possess refuge potential (dead maerl, sand and no sediment). In the vicinity of known refuges, stationary scallops under predation threat had significantly lower cardiac activity than individuals in habitats lacking refuges. Scallops not under predation threat did not show significant differences in cardiac activity. These are probably habitat-mediated physiological responses to the presence of a predator and possibly to the availability of suitable attachment substrata. These findings have implications in terms of behavioural physiology in invertebrates.
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| 6. |
- 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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