| 1. |
- Doyle, Darragh, et al.
(författare)
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Assessing the morphological impacts of long-term harvesting in intertidal gastropods using historical data and morphometric tools
- 2022
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Ingår i: Journal of Molluscan Studies. - : Oxford University Press (OUP). - 0260-1230 .- 1464-3766. ; 88:3
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Tidskriftsartikel (refereegranskat)abstract
- Size-selective harvesting of intertidal molluscs is a common practice. However, the effects of long-term traditional harvesting remain unclear. Changes in mean shell size are generally taken as evidence of changes in harvesting intensity. However, mean shell size is also influenced by environmental pressures, which may confound the analysis of size variation over time. In this study, we apply geometric morphometrics to historical data from two shell middens, in an attempt to classify Littorina littorea shells to their environmental origins, prior to carrying out shell size analysis. Using this method, shell shape was found to be consistent within and between the midden sites. Based on comparison with modern populations from shores of known wave exposure, the midden shells were found to be more consistent with sheltered shores, and to differ most from the very exposed shore sites, the latter of which are located adjacent to the midden remains. The mean shell size was significantly smaller in the more recent midden site. We hypothesize this reduction is caused by an increase in harvesting intensity over this period. It is also possible, given the very slight reduction in shell size, coupled with certain life-history traits of L. littorea, that the change in shell size was caused by slight differences in environmental conditions. The use of midden shells and morphometrics has the potential to provide an insight into previous environmental conditions and past harvesting practices, which may be used to inform current harvesting practices.
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| 2. |
- Doyle, Darragh, et al.
(författare)
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Microplastic exposure in aquatic invertebrates can cause significant negative effects compared to natural particles - A meta-analysis.
- 2022
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Ingår i: Environmental pollution (Barking, Essex : 1987). - : Elsevier BV. - 1873-6424 .- 0269-7491. ; 315
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Tidskriftsartikel (refereegranskat)abstract
- Many studies have now reported adverse effects of exposure to microplastics in aquatic organisms. Still, relatively few studies have compared the effects of MPs with those of natural particle controls, which makes it difficult to separate particle effects from chemical effects. In this study, we carry out a meta-analysis of 26 studies to compare the effects of MPs and natural particles on aquatic animals using three different endpoints - growth, reproduction, and mortality. This analysis showed that MPs have the capacity to induce more adverse effects on growth, reproduction, and mortality for some taxonomic groups. However, the effects of exposure to MPs are not consistent across each endpoint or between taxonomic groups. We were not able to clearly discern differing impacts resulting from exposure to specific polymer types or shapes, though more negative effects were associated with polylactic acid and polyethylene, as well as fragments as opposed to beads or fibres. Additionally, meta-regression indicated that larger MP sizes, higher experimental temperatures, and longer exposure periods were all generally associated with more adverse effects. Future studies should continue to make use of negative particle controls to allow for better risk assessment of microplastics and nanoplastics in aquatic ecosystems.
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| 3. |
- Doyle, Darragh, et al.
(författare)
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Transport and Barrier Functions in Rainbow Trout Trunk Skin Are Regulated by Environmental Salinity
- 2022
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Ingår i: Frontiers in Physiology. - : Frontiers Media SA. - 1664-042X. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- The mechanisms underpinning ionic transport and barrier function have been relatively well characterised in amphibians and fish. In teleost fish, these processes have mostly been characterised in the gill and intestine. In contrast, these processes remain much less clear for the trunk skin of fish. In this study, we measured barrier function and active transport in the trunk skin of the rainbow trout, using the Ussing chamber technique. The effects of epithelial damage, skin region, salinity, and pharmacological inhibition were tested. Skin barrier function decreased significantly after the infliction of a superficial wound through the removal of scales. Wound healing was already underway after 3 h and, after 24 h, there was no significant difference in barrier function towards ions between the wounded and control skin. In relation to salinity, skin permeability decreased drastically following exposure to freshwater, and increased following exposure to seawater. Changes in epithelial permeability were accompanied by salinity-dependent changes in transepithelial potential and short-circuit current. The results of this study support the idea that barrier function in rainbow trout trunk skin is regulated by tight junctions that rapidly respond to changes in salinity. The changes in transepithelial permeability and short circuit current also suggest the presence of an active transport component. Immunostaining and selective inhibition suggest that one active transport component is an apical V-ATPase. However, further research is required to determine the exact role of this transporter in the context of the trunk skin.
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| 4. |
- König Kardgar, Azora, 1994, et al.
(författare)
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Microplastics in aquaculture - Potential impacts on inflammatory processes in Nile tilapia
- 2024
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Ingår i: Heliyon. - 2405-8440. ; 10:9
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Tidskriftsartikel (refereegranskat)abstract
- Aquaculture is essential for meeting the growing global demand for fish consumption. However, the widespread use of plastic and the presence of microplastics in aquaculture systems raise concerns about their impact on fish health and the safety of aquaculture products. This study focused on the Nile tilapia (Oreochromis niloticus), one of the most important aquaculture fish species globally. The aim of this study was to investigate the effects of dietary exposure to a mixture of four conventional fossil fuel-based polymers (microplastics) on the health of adult and juvenile Nile tilapia. Two experiments were conducted, with 36 juvenile tilapia (10–40 g weight) exposed for 30 days and 24 adult tilapia (600–1000 g) exposed for 7 days, the former including a natural particle (kaolin) treatment. In the adult tilapia experiment, no significant effects on intestinal health (Ussing chamber method), oxidative stress, or inflammatory pathways (enzymatic and genetic biomarkers) were observed after exposure to the microplastic mixture. However, in the juvenile tilapia experiment, significant alterations in inflammatory pathways were observed following 30 days of exposure to the microplastic mixture, indicating potential adverse effects on fish health. These results highlight the potential negative impacts of microplastics on fish health and the economics and safety of aquaculture.
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| 5. |
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| 6. |
- Waldschläger, Kryss, et al.
(författare)
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Microplastics: What Can We Learn from Clastic Sediments?
- 2023
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Ingår i: Springer Water. - : Springer Nature. - 2364-6934 .- 2364-8198. ; , s. 105-116
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Microplastics research has gained momentum in the 21st century but lags behind the long-standing research on clastic sediment.An interdisciplinary review paper was conducted, comparing microplastics with natural sediments in terms of particle properties, transport processes, sampling techniques, and ecotoxicology. The paper identifies seven research goals to enhance our understanding of microplastics in freshwater environments while learning from sediment research. This extended abstract presents the core message of the review paper, emphasizing the need to improve descriptions of microplastic particles, understand their transport processes, develop standardized sampling methods, and study their ecotoxicological effects. The research goals outline specific tasks to achieve these objectives and emphasize the importance of comparing microplastics to sediments to gain insights into their toxicity. Addressing these research goals will contribute to a comprehensive understanding of microplastics and their impact on freshwater ecosystems. For detailed insights, the original paper should be consulted.
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