Response of a coastal Baltic Sea diatom-dominated phytoplankton community to experimental heat shock and changing salinity
- 62 Downloads
Climate change has been altering the ocean environment, affecting as a consequence the biological communities including microorganisms. We performed a mesocosm experiment to test whether biodiversity loss caused by one stressor would influence plankton community sensitivity to a subsequent stressor, as envisioned in Vinebrooke’s multiple stressor concept. A natural Baltic Sea diatom-dominated phytoplankton assemblage was used as a model system where we examined whether a preceding heat shock would affect the community’s response to changing salinity. Initially, the community was treated by a short-term temperature increase of 6 °C, which resulted in a loss of species compared to the control. Thereafter, the control and the heat-shocked communities were subject to a salinity change (− 5 psu, control, + 5 psu). The species Skeletonema dohrnii, Thalassiosira anguste-lineata, Thalassiosira nordenskioeldii, Chaetoceros socialis and Ditylum brightwellii were major components of the control and heat-shocked assemblages (> 80% of the total biomass). We examined the effect on species composition and biodiversity (morphospecies and operational taxonomic units (OTUs) related to phytoplankton) and on phytoplankton biomass. In addition, we explored the single species response of five dominant diatoms on these environmental perturbations. Our results showed that increased salinity significantly reduced the OTUs richness both in the control and the less diverse heated community as well as the phytoplankton biomass in the heated community. On the other hand, decreased salinity significantly increased species richness and phytoplankton biomass in both communities and OTUs richness in the control community. The five dominant diatoms reached their highest biomass under decreased salinity and responded negatively to increased salinity (lower biomass than ambient salinity). Contrary to Vinebrooke’s multiple stressor concept, there was no indication that the heat treatment had altered the community’s sensitivity to the salinity stress in our study system.
KeywordsClimate change Interactive effects 18S rRNA gene sequencing Mesocosms
We would like to thank the editor and the two reviewers for their constructive comments and suggestions that helped improve our manuscript. We are thankful to Prof. Konstantinos Ar. Kormas for providing the equipment to perform the nucleic acid extractions. We would like to thank T. Hansen, B. Gardeler and C. Meyer for technical support. The experiments are part of the BEN-Network (Non-random Biodiversity Experiments Network) initiated by A.M. Lewandowska (University of Helsinki, Tvärminne Zoological Station). Similar experiments using the same design are conducted on other marine sites.
Author contribution statement
NS, US, and MM-G designed the research and the experiment. NS and SG carried out the molecular and the bioinformatics analysis. NS carried out the experiment, the statistical analysis, and prepared the manuscript. NS, SG, JL-B, US, and MM-G revised the manuscript.
This research was implemented through IKY scholarships program and co-financed by the European Union (European Social Fund–ESF) and Greek national funds through the action entitled “Scholarships program for postgraduates studies-2nd Study Cycle” in the framework of the Operational Program “Human Resources Development Program, Education and Lifelong Learning” of the National Strategic Reference Framework (NSRF) 2014–2020. This project was partially supported by the Alabama Greece Initiative, The University of Alabama.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
Research involving human participants and/or animals
This article does not contain any studies with human participants or animals performed by any of the authors.
- Amann RI, Binder BJ, Olson RJ, Chisholm SW, Devereux R, Stahl DA (1990) Combination of 16S rRNA-targeted oligo-nucleotide probes with flow cytometry for analyzing mixed microbial populations. Appl Environ Microbiol 56:1919–1925Google Scholar
- Bužančić M, Gladan ZN, Marasović I, Kušpilić G, Grbec B (2016) Eutrophication influence on phytoplankton community composition in three bays on the eastern Adriatic coast. Oceanologia 4:302–316Google Scholar
- Gliwicz ZM, Siedlar E (1980) Food size limitation and algae interfering with food collection in Daphnia. Arch Hydrobiol 88:155–177Google Scholar
- Intergovernmental Panel on Climate Change (IPCC) (2014) Climate change 2014: impacts, adaptation and vulnerability. IPCC Working Group II contribution to the 5th assessment report of the International Panel on Climate Change. Cambridge University Press, CambridgeGoogle Scholar
- Intergovernmental Panel on Climate Change (IPCC) (2018) Summary for Policymakers. In: Global warming of 1.5°C. An IPCC special report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty. World Meteorological Organization, Geneva, SwitzerlandGoogle Scholar
- Pfannkuchen MD, Godrijan J, Smodlaka TM, Baričević A, Kužat N, Djakovac T et al (2018) The ecology of one cosmopolitan, one newly introduced and one occasionally advected species from the genus Skeletonema in a highly structured ecosystem, the northern Adriatic. Microb Ecol 75:674CrossRefGoogle Scholar
- Utermöhl H (1958) Zur Vervollkommnung der quantitativen Phytoplankton-Methodik. Mitt Int Ver Theor Angew Limnol 9:263–272Google Scholar