A5056848002- Microbial Community Ecology and Physiology
- Marine and coastal ecosystems
- Aquatic Ecosystems and Phytoplankton Dynamics
- Protist diversity and phylogeny
- Aquatic Invertebrate Ecology and Behavior
- Marine Biology and Ecology Research
- Evolution and Genetic Dynamics
- Genetic diversity and population structure
- Marine Toxins and Detection Methods
- Genomics and Phylogenetic Studies
- Algal biology and biofuel production
- Environmental DNA in Biodiversity Studies
- Ocean Waves and Remote Sensing
- Coastal wetland ecosystem dynamics
- Marine and environmental studies
- Isotope Analysis in Ecology
- Methane Hydrates and Related Phenomena
Uppsala University
2021-2024
Université de Lille
2020-2021
Centre National de la Recherche Scientifique
2019-2021
Lund University
2014-2021
Laboratoire d’Océanologie et de Géosciences
2018-2021
The University of Texas at Austin
2017-2019
In temperate systems, phytoplankton spring blooms deplete inorganic nutrients and are major sources of organic matter for the microbial loop. response to exudates environmental factors, heterotrophic communities highly dynamic change their abundance composition both on spatial temporal scales. Yet, most our understanding about these processes comes from laboratory model organism studies, mesocosm experiments or single transects. Spatial-temporal studies examining interactions...
Abstract Aim To test if a phytoplankton bloom is panmictic, or whether geographical and environmental factors cause spatial temporal genetic structure. Location Baltic Sea. Method During four cruises, we isolated clonal strains of the diatom Skeletonema marinoi from 9 to 10 stations along 1132 km transect analysed structure using eight microsatellites. Using F ‐statistics Bayesian clustering analysis determined samples were significantly differentiated. A seascape approach was applied...
Recent studies show that both marine and limnic microalgal species often consist of several genetically distinct populations. This is also valid for the nuisance freshwater algae Gonyostomum semen, which originates from acidic, brown water swamp lakes, but can nowadays be found in clearer lakes with close to neutral pH. We hypothesized observed genetic differentiation among G. semen lake populations, reported earlier studies, connected adaptation local environmental conditions. In present...
Species invasion and range expansion are currently under scrutiny due to increasing anthropogenic impact on the natural environment. This is also true for harmful algal blooms, which have been reported increased in frequency. However, this research challenging ephemeral nature, small size mostly low concentrations of microalgae One such species nuisance microalga Gonyostomum semen (Raphidophyceae), has occurrence northern Europe recent decades. The question whether expanded its habitat or if...
Abstract Spatial and seasonal dynamics of microbial loop fluxes were investigated in contrasting productivity regimes the Indian sector Southern Ocean. Observations carried out late summer (February–March 2018; project MOBYDICK) revealed higher biomasses naturally iron‐fertilized surface waters Kerguelen island comparison to surrounding off‐plateau waters. Differences most pronounced for bacterial heterotrophic production (2.3‐fold), abundance nanoflagellates (HNF; 2.7‐fold). Independent...
Abstract In the Southern Ocean, diatom blooms have attracted a lot of attention, while other small nonsilicified phytoplankton groups been less studied. Here, (< 20 μ m, including diatoms and phytoplankton) are focused on in two contrasting areas: productive Kerguelen plateau its surrounding low productivity waters. To assess diversity spatial structuration phytoplankton, discrete plankton samples (0–300 m layer) size fractions 20–100 m) were analyzed with 18S rDNA amplicon sequencing...
Abstract Diatom blooms are often accompanied by an increase in parasitic chytrids that kill the host cells, which they infecting, and can contribute to decline of bloom. However, specificity range these currently poorly understood. Low would enable parasites opportunistically infect any diatom species, while specialisation on infecting specific high‐biomass species could result high prevalence rapid spread infection. We investigated such host–parasite interactions monitoring diverse spring...
Many recent studies have found genetically differentiated populations in microorganisms despite potentially high dispersal. We designed a study to specifically examine the importance of physical dispersal barriers, i.e. geographic distance and lack hydrological connectivity, restricting gene flow enhancing divergence limnic microorganisms. focused on nuisance microalga Gonyostomum semen, which has recently expanded Northern Europe into distinct populations. G. semen was sampled from six...
Priority effects occur when a species or genotype with earlier arrival has an advantage such that its relative abundance in the community population is increased compared later-arriving species. Few studies have dealt this concept context of within-species competition. Skeletonema marinoi marine diatom shows high degree genetic differentiation between populations over small geographical distances. To test whether historical events as priority may been important inducing these patterns...
Population genetic studies provide insights into intraspecific diversity and dispersal patterns of microorganisms such as protists, which help understanding invasions, harmful algal bloom development occurrence seafood poisoning. Genetic differentiation across geography has been reported in many microbial species indicating significant barriers among different habitats. Temporal less studied its frequency, drivers magnitude are poorly understood due to a lack integral studies. The toxic...
Aquatic habitats are usually structured by light attenuation with depth resulting in different microalgal communities, each one adapted to a certain regime their specific pigment composition. Several taxa contain pigments restricted phylogenetic group, making them useful as marker phytoplankton community studies. The nuisance and invasive freshwater microalga Gonyostomum semen (Raphidophyceae) is mainly found brown water lakes sharp vertical gradients intensity color. However, its...
The majority of microalgal species reproduce asexually, yet population genetic studies rarely find identical multi-locus genotypes (MLG) in blooms. Instead, identify large genotypic diversity most species. This paradox frequent asexual reproduction but low number hampers interpretations diversity. We present a computer model for estimating, the first time, distinct MLGs by simulating composition after defined exponential growth periods. simulations highlighted effects initial diversity,...
Colonization of new habitats through dispersal phytoplankton cysts might be limited, if resident populations outcompete invaders during germination. We reciprocally transferred Gonyostomum semen (Raphidophyceae) from three lakes into native and foreign waters originating the respective habitats. Germination rate germling growth were impacted by water origin, but there was no preference for water. semen's ability to germinate in different conditions explain its expansion northern Europe.
Although the majority of microalgal species reproduce asexually for large parts growth season, most population genetic studies have rarely found clones in blooms. Instead, identified intraspecific diversity species. This paradox frequent asexual reproduction but low number creates challenges when interpreting proportion and distinct genotypes natural populations. To estimate genotype richness, we created a computer model that simulates composition populations after defined period exponential...
Abstract The freshwater raphidophyte Gonyostomum semen forms extensive summer blooms in northern European humic lakes. development of these might be facilitated by a lack natural top-down control, as few zooplankton species are able to prey on large algal cells (up 100 μm) that expel trichocysts upon physical stress. In this study, we describe small ciliate (< 17 preys G. damaging the cell membrane until cytoplasm and organelles spill out. Sequencing clonal cultures tentatively identified...
The complex evolution of chloroplasts in microalgae has resulted highly diverse pigment profiles. Freshwater raphidophytes, for example, display a very different composition to marine raphidophytes. To investigate potential differences the evolutionary origin these two groups plastid genomes freshwater species Gonyostomum semen and Vacuolaria virescens were sequenced. exclusively sequence organelle genomes, manually isolated amplified using single-cell whole-genome-amplification. Assembled...