| 1. |
- Eichsteller, Angelina, et al.
(författare)
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DNA Barcoding of Cold-Water Coral-Associated Ophiuroid Fauna from the North Atlantic
- 2022
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Ingår i: Diversity. - : MDPI AG. - 1424-2818. ; 14:5, s. 358-358
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Tidskriftsartikel (refereegranskat)abstract
- In this study we focus on the ophiuroid species associated with cold-water corals south of Iceland. The specimens were sampled with the ROV Phoca (GEOMAR) in three different areas, during the recent expedition MSM75 connected to the IceAGE_RR (Icelandic marine Animals: Genetics and Ecology_Reykjanes Ridge hydrothermal vent activity) project. In each area, several corals were sampled and the ophiuroid specimens identified to the species level. The integrative taxonomic approach, based on morphological characters and DNA barcoding with COI of the collected ophiuroids, revealed five species that live on corals: Ophiomitrella clavigera (Ljungman, 1865); Ophiomyxa serpentaria (Lyman, 1883); Ophiacantha cuspidata (Lyman, 1879); Ophiactis abyssicola (M. Sars, 1861); and Ophiolebes bacata Koehler, 1921. Some of the sampled deep-sea corals exclusively host the species O.clavigera. The collected species are therefore associated with different corals but do not demonstrate a species-specific distribution. The video data support the integrative taxonomy and confirm the ecological evidence.
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| 2. |
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| 3. |
- 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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| 4. |
- Simon-Lledó, Erik, et al.
(författare)
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Carbonate compensation depth drives abyssal biogeography in the northeast Pacific.
- 2023
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Ingår i: Nature ecology & evolution. - 2397-334X. ; 7, s. 1388-97
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Tidskriftsartikel (refereegranskat)abstract
- Abyssal seafloor communities cover more than 60% of Earth's surface. Despite their great size, abyssal plains extend across modest environmental gradients compared to other marine ecosystems. However, little is known about the patterns and processes regulating biodiversity or potentially delimiting biogeographical boundaries at regional scales in the abyss. Improved macroecological understanding of remote abyssal environments is urgent as threats of widespread anthropogenic disturbance grow in the deep ocean. Here, we use a new, basin-scale dataset to show the existence of clear regional zonation in abyssal communities across the 5,000km span of the Clarion-Clipperton Zone (northeast Pacific), an area targeted for deep-sea mining. We found two pronounced biogeographic provinces, deep and shallow-abyssal, separated by a transition zone between 4,300 and 4,800m depth. Surprisingly, species richness was maintained across this boundary by phylum-level taxonomic replacements. These regional transitions are probably related to calcium carbonate saturation boundaries as taxa dependent on calcium carbonate structures, such as shelled molluscs, appear restricted to the shallower province. Our results suggest geochemical and climatic forcing on distributions of abyssal populations over large spatial scales and provide a potential paradigm for deep-sea macroecology, opening a new basis for regional-scale biodiversity research and conservation strategies in Earth's largest biome.
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| 5. |
- Willems, Wim, et al.
(författare)
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Meiofauna of the Koster-area, results from a workshop at the Sven Lovén Centre for Marine Sciences (Tjärnö, Sweden)
- 2009
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Ingår i: Meiofauna Marina. - : Pfeil. - 1611-7557. ; 17, s. 1-34
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Tidskriftsartikel (refereegranskat)abstract
- During a two-week workshop held at the Sven Lovén Centre for Marine Sciences on Tjärnö, an island on the Swedish west-coast, meiofauna was studied in a large variety of habitats using a wide range of sampling tech- niques. Almost 100 samples coming from littoral beaches, rock pools and different types of sublittoral sand- and mudflats yielded a total of 430 species, a conservative estimate. The main focus was on acoels, proseriate and rhabdocoel flatworms, rotifers, nematodes, gastrotrichs, copepods and some smaller taxa, like nemertodermatids, gnathostomulids, cycliophorans, dorvilleid polychaetes, priapulids, kinorhynchs, tardigrades and some other flatworms. As this is a preliminary report, some species still have to be positively identified and/or described, as 157 species were new for the Swedish fauna and 27 are possibly new to science. Each taxon is discussed separately and accompanied by a detailed species list.
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