| 1. |
- Rahlff, Janina, et al.
(författare)
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Short-term responses to ocean acidification : effects on relative abundance of eukaryotic plankton from the tropical Timor Sea
- 2021
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Ingår i: Marine Ecology Progress Series. - : Inter-Reserch Science Publisher. - 0171-8630 .- 1616-1599. ; 658, s. 59-74
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Tidskriftsartikel (refereegranskat)abstract
- Anthropogenic carbon dioxide (CO2) emissions drive climate change and pose one of the major challenges of our century. The effects of increased CO2 in the form of ocean acidification (OA) on the communities of marine planktonic eukaryotes in tropical regions such as the Timor Sea are barely understood. Here, we show the effects of high CO2 (mean ± SD pCO2 = 1823 ± 161 μatm and pHT = 7.46 ± 0.05) versus in situ CO2 (504 ± 42 µatm, 7.95 ± 0.04) seawater on the community composition of marine planktonic eukaryotes after 3 and 48 h of treatment exposure in a shipboard microcosm experiment. Illumina sequencing of the V9 hypervariable region of 18S rRNA (gene) was used to study the eukaryotic community composition. Increased CO2 significantly suppressed the relative abundances of different eukaryotic operational taxonomic units (OTUs), including important primary producers, although the chlorophyll a concentration remained constant. OA effects on eukaryotes were consistent between total (DNA-based) and active (cDNA-based) taxa after 48 h, e.g. for the diatoms Trieres chinensis and Stephanopyxis turris. Effects of OA on the relative abundances of OTUs were often species- or even ecotype-specific, and the incubation selectively allowed for detection of the OA-sensitive OTUs that benefitted the most from incubation in a closed bottle, as containment effects on the community structure were evident after 48 h. Many OTUs were adversely affected by sudden decreases of seawater pH, suggesting high sensitivity to OA at the base of the tropical marine biodiversity and difficult-to-predict outcomes for food-web functioning in the future ocean.
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| 2. |
- Voskuhl, Lisa, et al.
(författare)
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Natural and oil surface slicks as microbial habitats in marine systems : A mini review
- 2022
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Ingår i: Frontiers in Marine Science. - : Frontiers Media S.A.. - 2296-7745. ; 9
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Forskningsöversikt (refereegranskat)abstract
- Natural and oil surface slicks are widespread phenomena at the air-water interface and represent visible surface films with distinct physicochemical and biological properties compared to non-slick surface films and underlying marine water. Both types of slicks have major functions in nourishing and dispersing surface-dwelling micro- and macroorganisms, contribute to particle generation and carbon cycling, and are known to accumulate pollutants. Despite these functions and the high frequency of slicks in the marine environment, slicks are little understood considering their microbial inhabitants and contributions of these organisms for natural and oil slick establishment, function, and ecology. Our mini review summarizes the current knowledge of microbial life in natural slicks, natural and anthropogenic oil slicks, including the major knowledge gaps and perspectives for future research. Overall, we aim for an increased awareness about the existence of natural slicks, the differentiation between natural and anthropogenic oil slicks and an improved reporting of slick events during sampling of surface film and seawater from the epipelagic zone.
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