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Fridolfsson, Emil
Publications (8 of 8) Show all publications
Bunse, C., Israelsson, S., Baltar, F., Bertos-Fortis, M., Fridolfsson, E., Legrand, C., . . . Pinhassi, J. (2019). High Frequency Multi-Year Variability in Baltic Sea Microbial Plankton Stocks and Activities. Frontiers in Microbiology, 9, Article ID 3296.
Open this publication in new window or tab >>High Frequency Multi-Year Variability in Baltic Sea Microbial Plankton Stocks and Activities
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2019 (English)In: Frontiers in Microbiology, ISSN 1664-302X, E-ISSN 1664-302X, Vol. 9, article id 3296Article in journal (Refereed) Published
Abstract [en]

Marine bacterioplankton are essential in global nutrient cycling and organic matter turnover. Time-series analyses, often at monthly sampling frequencies, have established the paramount role of abiotic and biotic variables in structuring bacterioplankton communities and productivities. However, fine-scale seasonal microbial activities, and underlying biological principles, are not fully understood. We report results from four consecutive years of high-frequency time-series sampling in the Baltic Proper. Pronounced temporal dynamics in most investigated microbial variables were observed, including bacterial heterotrophic production, plankton biomass, extracellular enzyme activities, substrate uptake rate constants of glucose, pyruvate, acetate, amino acids, and leucine, as well as nutrient limitation bioassays. Spring blooms consisting of diatoms and dinoflagellates were followed by elevated bacterial heterotrophic production and abundances. During summer, bacterial productivity estimates increased even further, coinciding with an initial cyanobacterial bloom in early July. However, bacterial abundances only increased following a second cyanobacterial bloom, peaking in August. Uptake rate constants for the different measured carbon compounds varied seasonally and inter-annually and were highly correlated to bacterial productivity estimates, temperature, and cyanobacterial abundances. Further, we detected nutrient limitation in response to environmental conditions in a multitude of microbial variables, such as elevated productivities in nutrient bioassays, changes in enzymatic activities, or substrate preferences. Variations among biotic variables often occurred on time scales of days to a few weeks, yet often spanning several sampling occasions. Such dynamics might not have been captured by sampling at monthly intervals, as compared to more predictable transitions in abiotic variables such as temperature or nutrient concentrations. Our study indicates that high resolution analyses of microbial biomass and productivity parameters can help out in the development of biogeochemical and food web models disentangling the microbial black box.

Place, publisher, year, edition, pages
Frontiers Media S.A., 2019
Keywords
marine bacteria, phytoplankton, cyanobacteria, production, substrate uptake, enzyme activity, biogeochemistry
National Category
Microbiology Ecology
Research subject
Ecology, Microbiology; Ecology, Microbiology
Identifiers
urn:nbn:se:lnu:diva-80150 (URN)10.3389/fmicb.2018.03296 (DOI)000455948100001 ()2-s2.0-85064405301 (Scopus ID)
Available from: 2019-02-05 Created: 2019-02-05 Last updated: 2019-08-29Bibliographically approved
Ejsmond, M. J., Blackburn, N., Fridolfsson, E., Haecky, P., Andersson, A., Casini, M., . . . Hylander, S. (2019). Modeling vitamin B1 transfer to consumers in the aquatic food web. Scientific Reports, 9, 1-11, Article ID 10045.
Open this publication in new window or tab >>Modeling vitamin B1 transfer to consumers in the aquatic food web
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2019 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, p. 1-11, article id 10045Article in journal (Refereed) Published
Abstract [en]

Vitamin B-1 is an essential exogenous micronutrient for animals. Mass death and reproductive failure in top aquatic consumers caused by vitamin B-1 deficiency is an emerging conservation issue in Northern hemisphere aquatic ecosystems. We present for the first time a model that identifies conditions responsible for the constrained flow of vitamin B-1 from unicellular organisms to planktivorous fishes. The flow of vitamin B-1 through the food web is constrained under anthropogenic pressures of increased nutrient input and, driven by climatic change, increased light attenuation by dissolved substances transported to marine coastal systems. Fishing pressure on piscivorous fish, through increased abundance of planktivorous fish that overexploit mesozooplankton, may further constrain vitamin B-1 flow from producers to consumers. We also found that key ecological contributors to the constrained flow of vitamin B-1 are a low mesozooplankton biomass, picoalgae prevailing among primary producers and low fluctuations of population numbers of planktonic organisms.

Place, publisher, year, edition, pages
Nature Publishing Group, 2019
National Category
Ecology
Research subject
Ecology, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-86979 (URN)10.1038/s41598-019-46422-2 (DOI)000474820900024 ()31296876 (PubMedID)2-s2.0-85068902332 (Scopus ID)
Available from: 2019-07-25 Created: 2019-07-25 Last updated: 2019-10-04Bibliographically approved
Fridolfsson, E., Bunse, C., Legrand, C., Lindehoff, E., Majaneva, S. & Hylander, S. (2019). Seasonal variation and species-specific concentrations of the essential vitamin B₁ (thiamin) in zooplankton and seston. Marine Biology, 166(6), 1-13, Article ID 70.
Open this publication in new window or tab >>Seasonal variation and species-specific concentrations of the essential vitamin B₁ (thiamin) in zooplankton and seston
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2019 (English)In: Marine Biology, ISSN 0025-3162, E-ISSN 1432-1793, Vol. 166, no 6, p. 1-13, article id 70Article in journal (Refereed) Published
Abstract [en]

Thiamin (vitamin B1) is mainly produced by bacteria and phytoplankton and then transferred to zooplankton and higher trophic levels but knowledge on the dynamics of these processes in aquatic ecosystems is lacking. Hence, the seasonal variation in thiamin content was assessed in field samples of copepods and in pico-, nano- and micro-plankton of two size classes (0.7–3 µm and > 3 µm) collected monthly in the Baltic Sea during 3 years and in the Skagerrak during 1 year. Copepods exhibited species-specific concentrations of thiamin and Acartia sp. had the highest carbon-specific thiamin content, at both locations. Even members of the same genus, but from different systems contained different levels of thiamin, with higher thiamin content per specimen in copepods from the Skagerrak compared to congeners from the Baltic Sea. Furthermore, our results show that the small plankton (0.7–3 µm) had a higher carbon-specific thiamin content compared to the large (> 3 µm). Additionally, there was a large seasonal variation and thiamin content was highly correlated comparing the two size fractions. Finally, there was an overall positive correlation between thiamin content in copepods and plankton. However, for periods of high thiamin content in the two size fractions, this correlation was negative. This suggests a decoupling between thiamin availability in pico-, nano- and micro-plankton and zooplankton in the Baltic Sea. Knowledge about concentrations of this essential micronutrient in the aquatic food web is limited and this study constitutes a foundation for further understanding the dynamics of thiamin in aquatic environments.

Place, publisher, year, edition, pages
New York, NY: Springer, 2019
National Category
Ecology
Research subject
Ecology, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-82081 (URN)10.1007/s00227-019-3520-6 (DOI)000467561000005 ()2-s2.0-85065572171 (Scopus ID)
Available from: 2019-04-23 Created: 2019-04-23 Last updated: 2019-11-15Bibliographically approved
Fridolfsson, E., Lindehoff, E., Legrand, C. & Hylander, S. (2018). Thiamin (vitamin B1) content in phytoplankton and zooplankton in the presence of filamentous cyanobacteria. Limnology and Oceanography, 63(6), 2423-2435
Open this publication in new window or tab >>Thiamin (vitamin B1) content in phytoplankton and zooplankton in the presence of filamentous cyanobacteria
2018 (English)In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 63, no 6, p. 2423-2435Article in journal (Refereed) Published
Abstract [en]

Top predators in several aquatic food webs regularly display elevated reproductive failure, caused by thiamin(vitamin B1)deficiency. The reasons for these low-thiamin levels are not understood and information about the transfer of thiamin from the producers (bacteria and phytoplankton) to higher trophic levels is limited. One main concern is whether cyanobacterial blooms could negatively affect thiamin transfer in aquatic systems. Laboratory experiments with Baltic Sea plankton communities and single phytoplankton species were used to study the effect of filamentous cyanobacteria on the transfer of thiamin from phytoplankton to zooplankton. Experiments showed that the thiamin content in copepods was reduced when exposed to elevated levels of cyanobacteria, although filamentous cyanobacteria had higher levels of thiamin than any other analyzed phytoplankton species. Filamentous cyanobacteria also had a negative effect on copepod egg production despite high concentrations of non-cyanobacterial food. Phytoplankton species composition affected overall thiamin concentration with relatively more thiamin available for transfer when the relative abundance of Dinophyceae was higher. Finally, phytoplankton thiamin levels were lower when copepods were abundant, indicating that grazers affect thiamin levels in phytoplankton community, likely by selective feeding. Overall, high levels of thiamin in phytoplankton communities are not reflected in the copepod community. We conclude that presence of filamentous cyanobacteria during summer potentially reduces the transfer of thiamin to higher trophic levels by negatively affecting phytoplankton and copepod thiamin content as well as copepod reproduction, thereby lowering the absolute capacity of the food web to transfer thiamin through copepods to higher trophic levels.

Place, publisher, year, edition, pages
John Wiley & Sons, 2018
Keywords
Acartia sp., Baltic Sea, community composition, trophic transfer, micronutrient, copepod
National Category
Ecology
Research subject
Ecology, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-77174 (URN)10.1002/lno.10949 (DOI)000450233300009 ()2-s2.0-85050456969 (Scopus ID)
Projects
EcoChangeCentre for Ecology and Evolution in Microbial Model Systems - EEMiS
Funder
Swedish Research Council Formas, 215-2012-1319Ecosystem dynamics in the Baltic Sea in a changing climate perspective - ECOCHANGECarl Tryggers foundation The Royal Swedish Academy of Sciences
Available from: 2018-08-17 Created: 2018-08-17 Last updated: 2019-11-15Bibliographically approved
Legrand, C., Fridolfsson, E., Bertos-Fortis, M., Lindehoff, E., Larsson, P., Pinhassi, J. & Andersson, A. (2015). Interannual variability of phyto-bacterioplankton biomass and production in coastal and offshore waters of the Baltic Sea. Ambio, 44(supplement 3), S427-S438
Open this publication in new window or tab >>Interannual variability of phyto-bacterioplankton biomass and production in coastal and offshore waters of the Baltic Sea
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2015 (English)In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 44, no supplement 3, p. S427-S438Article in journal (Refereed) Published
Abstract [en]

The microbial part of the pelagic food web is seldom characterized in models despite its major contribution to biogeochemical cycles. In the Baltic Sea, spatial and temporal high frequency sampling over three years revealed changes in heterotrophic bacteria and phytoplankton coupling (biomass and production) related to hydrographic properties of the ecosystem. Phyto- and bacterioplankton were bottom-up driven in both coastal and offshore areas. Cold winter temperature was essential for phytoplankton to conform to the successional sequence in temperate waters. In terms of annual carbon production, the loss of the spring bloom (diatoms and dinoflagellates) after mild winters tended not to be compensated for by other taxa, not even summer cyanobacteria. These results improve our ability to project Baltic Sea ecosystem response to short- and long-term environmental changes.

Place, publisher, year, edition, pages
Springer, 2015
Keywords
Phytoplankton, Bacteria, Baltic Sea, Production, Climate change, Microbial foodwebs
National Category
Oceanography, Hydrology and Water Resources
Research subject
Natural Science, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-45554 (URN)10.1007/s13280-015-0662-8 (DOI)000362290800010 ()26022325 (PubMedID)2-s2.0-84937577225 (Scopus ID)
Projects
ECOCHANGE
Funder
Ecosystem dynamics in the Baltic Sea in a changing climate perspective - ECOCHANGESwedish Research Council Formas
Available from: 2015-07-25 Created: 2015-07-25 Last updated: 2018-01-11Bibliographically approved
Majaneva, S., Fridolfsson, E., Casini, M., Legrand, C., Lindehoff, E., Margonski, P., . . . Hylander, S.Deficiency syndromes in top predators associated with large-scale changes in the Baltic Sea ecosystem.
Open this publication in new window or tab >>Deficiency syndromes in top predators associated with large-scale changes in the Baltic Sea ecosystem
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(English)Manuscript (preprint) (Other academic)
National Category
Ecology
Research subject
Ecology, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-90122 (URN)
Available from: 2019-11-15 Created: 2019-11-15 Last updated: 2019-11-19Bibliographically approved
Israelsson, S., Bunse, C., Baltar, F., Bertos-Fortis, M., Fridolfsson, E., Legrand, C., . . . Pinhassi, J.Seasonal dynamics of Baltic Sea plankton activities: heterotrophic bacterial function under different biological and environmental conditions.
Open this publication in new window or tab >>Seasonal dynamics of Baltic Sea plankton activities: heterotrophic bacterial function under different biological and environmental conditions
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(English)Manuscript (preprint) (Other academic)
National Category
Microbiology Oceanography, Hydrology and Water Resources Environmental Sciences
Research subject
Ecology, Microbiology
Identifiers
urn:nbn:se:lnu:diva-69151 (URN)
Available from: 2017-12-11 Created: 2017-12-11 Last updated: 2018-02-26Bibliographically approved
Fridolfsson, E., Lindehoff, E., Legrand, C. & Hylander, S.Species-specific content of thiamin (vitamin B1) in phytoplankton and the transfer to copepods.
Open this publication in new window or tab >>Species-specific content of thiamin (vitamin B1) in phytoplankton and the transfer to copepods
(English)Manuscript (preprint) (Other academic)
National Category
Ecology
Research subject
Ecology, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-90121 (URN)
Available from: 2019-11-15 Created: 2019-11-15 Last updated: 2019-11-27Bibliographically approved
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