Seasonal dynamics and nutrient controls of biogenic silica in Baltic Sea surface microplankton and picoplankton communities
Churakova, Yelena ; Aguilera, Anabella ; Charalampous, Evangelia ; Conley, Daniel J. LU
; Lundin, Daniel
; Pinhassi, Jarone
and Farnelid, Hanna
(2025)
In Applied and Environmental Microbiology
91(5).
- Abstract
In recent years, new contributors to the marine silica cycle have emerged, including pico-sized phytoplankton (<2–3 µm in size) such as Synechococcus and picoeukaryotes. Their contribution and relevance to silica cycling are still under investigation. Field studies reporting the biogenic silica (bSi) standing stock in the pico-sized fraction are limited to silica-poor oligotrophic environments, and the mechanism of bSi accumulation in picoplankton remains unknown. We investigated the variability of bSi standing stocks in two size fractions (picoplankton, 0.22–3 µm and microplankton, >3 µm) in the dissolved silica-replete Baltic Sea via biweekly time series samplings spanning 2 years. Time series data showed that the large changes... (More)
In recent years, new contributors to the marine silica cycle have emerged, including pico-sized phytoplankton (<2–3 µm in size) such as Synechococcus and picoeukaryotes. Their contribution and relevance to silica cycling are still under investigation. Field studies reporting the biogenic silica (bSi) standing stock in the pico-sized fraction are limited to silica-poor oligotrophic environments, and the mechanism of bSi accumulation in picoplankton remains unknown. We investigated the variability of bSi standing stocks in two size fractions (picoplankton, 0.22–3 µm and microplankton, >3 µm) in the dissolved silica-replete Baltic Sea via biweekly time series samplings spanning 2 years. Time series data showed that the large changes in bSi standing stock in the Baltic Proper were primarily related to microplankton biomass and community composition. Meanwhile, picoplankton were, at times, surprisingly high contributors to total bSi year-round (up to 21.6%). Simultaneously, we performed microcosm incubation experiments with natural phytoplankton communities in each season to examine how nutrient additions affected bSi concentrations. In these experiments, increases in microplankton bSi were directly correlated to increases in diatom biomass, highlighting their influential role in the Baltic Sea silica cycle. Meanwhile, phosphorus additions triggered an increase in picoplankton bSi accumulation in all experiments. This uncovers a potential control of bSi accumulation in picoplankton, which can help identify the cellular mechanisms behind this process and uncover their role in silica cycling. The results link phytoplankton community composition and silica cycling, which is important for understanding the consequences of organism shifts due to climate change.
(Less)
- author
- Churakova, Yelena
; Aguilera, Anabella
; Charalampous, Evangelia
; Conley, Daniel J.
LU
; Lundin, Daniel
; Pinhassi, Jarone
and Farnelid, Hanna
- organization
- publishing date
- 2025-05
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- biosilicification, marine silica cycle, microcosm, time series
- in
- Applied and Environmental Microbiology
- volume
- 91
- issue
- 5
- publisher
- American Society for Microbiology
- external identifiers
-
- scopus:105006528295
- pmid:40293244
- ISSN
- 0099-2240
- DOI
- 10.1128/aem.00676-25
- language
- English
- LU publication?
- yes
- id
- e92b3310-372d-4a63-b858-30d1c7fbf6be
- date added to LUP
- 2025-08-04 11:00:41
- date last changed
- 2025-08-05 03:00:03
@article{e92b3310-372d-4a63-b858-30d1c7fbf6be,
abstract = {{<p>In recent years, new contributors to the marine silica cycle have emerged, including pico-sized phytoplankton (<2–3 µm in size) such as Synechococcus and picoeukaryotes. Their contribution and relevance to silica cycling are still under investigation. Field studies reporting the biogenic silica (bSi) standing stock in the pico-sized fraction are limited to silica-poor oligotrophic environments, and the mechanism of bSi accumulation in picoplankton remains unknown. We investigated the variability of bSi standing stocks in two size fractions (picoplankton, 0.22–3 µm and microplankton, >3 µm) in the dissolved silica-replete Baltic Sea via biweekly time series samplings spanning 2 years. Time series data showed that the large changes in bSi standing stock in the Baltic Proper were primarily related to microplankton biomass and community composition. Meanwhile, picoplankton were, at times, surprisingly high contributors to total bSi year-round (up to 21.6%). Simultaneously, we performed microcosm incubation experiments with natural phytoplankton communities in each season to examine how nutrient additions affected bSi concentrations. In these experiments, increases in microplankton bSi were directly correlated to increases in diatom biomass, highlighting their influential role in the Baltic Sea silica cycle. Meanwhile, phosphorus additions triggered an increase in picoplankton bSi accumulation in all experiments. This uncovers a potential control of bSi accumulation in picoplankton, which can help identify the cellular mechanisms behind this process and uncover their role in silica cycling. The results link phytoplankton community composition and silica cycling, which is important for understanding the consequences of organism shifts due to climate change.</p>}},
author = {{Churakova, Yelena and Aguilera, Anabella and Charalampous, Evangelia and Conley, Daniel J. and Lundin, Daniel and Pinhassi, Jarone and Farnelid, Hanna}},
issn = {{0099-2240}},
keywords = {{biosilicification; marine silica cycle; microcosm; time series}},
language = {{eng}},
number = {{5}},
publisher = {{American Society for Microbiology}},
series = {{Applied and Environmental Microbiology}},
title = {{Seasonal dynamics and nutrient controls of biogenic silica in Baltic Sea surface microplankton and picoplankton communities}},
url = {{http://dx.doi.org/10.1128/aem.00676-25}},
doi = {{10.1128/aem.00676-25}},
volume = {{91}},
year = {{2025}},
}