Tag: plankton

Just out – new paper on plankton phenology

Posted on by monikawinder

Here we analyzed 15 yr of monitoring data to identify trends and drivers of timing and magnitude of bloom-forming phytoplankton and diverse zooplankton taxa throughout the season in the central Baltic Sea.

We show that the timings of phytoplankton blooms advance, whereas crustacean zooplankton seasonal timings remain constant. This increasing offset with the spring bloom is linked to the decline of Pseudocalanus, a key copepod sustaining pelagic fish production. The majority of copepod and cladoceran taxa, however, are co-occurring with summer blooms. We also find new developing fall blooms, fueling secondary production later in the season. Our study highlights that response to climate change differs within and between functional groups, stressing the importance of investigating plankton phenologies over the entire annual cycle in pelagic systems.

See also SU’s press release:

English: Earlier spring bloom disrupt the balance of the Baltic Sea

Swedish: Allt tidigare algblomningar rubbar den känsliga balansen i Östersjön

The full article is available here: Plankton blooms over the annual cycle shape trophic interactions under climate change. Limnology and Oceanography Letters

Plankton succession in the central Baltic Sea from 2008 to 2022. Seasonal timing, peak magnitude and bloom duration of (a) total spring and summer phytoplankton and total copepod and cladoceran biomass, and (b) dominating phytoplankton and zooplankton taxa. Point positions (x-axis) correspond to the average peak timing (week), point sizes to the average peak magnitude (zooplankton: μg L−1; phytoplankton: μg C L−1) and the horizontal bars to the average initiation and termination (week) of their respective growing seasons.

New study shows that climate change affects the activation of plankton resting stages with consequences for community composition and trophic mismatch

Posted on by monikawinder

A large majority of plankton species overwinter as resting stage in the sediment. The resting life stage is, however, often overlooked in climate change research, although emergence of planktonic organisms originating from resting stages from the sediment is a key driver for pelagic population dynamic and community composition.

Here we ask to what extent the recruitment of plankton resting stages is affected by proposed climate change. For this, we investigated  phyto- and zooplankton recruitment from oxic sediments in the Baltic Sea in a controlled experiment under proposed temperature and light increase during the spring and summer. 

We find that emergence of resting stage differs between seasons and the abiotic environment. Phytoplankton recruitment from resting stages were high in spring with significantly higher emergence rates at increased temperature and light levels for dinoflagellate and cyanobacteria than for diatoms, which had highest emergence under cold and dark conditions. In comparison, hatching of copepod nauplii was not affected by increased temperature and light levels. These results show that activation of plankton resting stages are affected to different degrees by increasing temperature and light levels, indicating that climate change affects plankton dynamics through processes related to resting stage termination with potential consequences for bloom timing, community composition and trophic mismatch.

You can find the full article here:

Hedberg P, Olsson M, Höglander H, Bruchert V, Winder M (2024) Climate change effects on plankton recruitment from coastal sediments. Journal of Plankton Research. https://doi.org/10.1093/plankt/fbad060

Investigating recruitment of resting stages from Baltic Sea sediments. Foto: Per Hedberg.