Resurrection studies can answer some fundamental questions in aquatic ecology and evolutionary biology. For phytoplankton resting stages, longevity of thousands to millions of years has recently been reported. However, contamination during sediment sampling could distort these estimates, and this risk has not been systematically evaluated. Here we used 4.5 μm diameter microspheres to quantify contamination while reviving the resting stages of seven abundant estuarine diatom and cyanobacterial taxa. We observed a sharp decline in resting stages abundance from 106 (g wet sediment)−1 at the surface to < 0.8 (g wet sediment)−1 at 12.5 cm depth. Added microspheres (~ 4.5 × 107 cm−2) were translocated even deeper down the sediment and could well explain the vertical distributions and abundances of revived cells. Without this control, we could have claimed to have revived seven multi-decades to centennial-old taxa. Our findings suggest that improved contamination controls are needed for sediment core sampling of rare cells, microfossils, or DNA molecules.
The Captain and the crew of R/V Electra af Askö, Raphael Gollnisch, Johan Burman, and Kotaro Hirose for sediment sampling assistance. Adele Maciute gathered the oxygen microsensor data. Rickard Stenow shared an MPN script, which served as a template for the analysis. Björn Andersson's late supervisor and mentor, Anna Godhe, who sparked my curiosity about the hidden world of phytoplankton resting stages. Anna assisted in the 2017 sampling and was the PI for this project until she passed away in 2019. She did not get the chance to see any of the work we began together in its final published form, and she did not plan, participate, or view data from the 2020 experiments. Therefore, Anna was not included as a co‐author in this manuscript. The submitted manuscript benefited greatly from thoughtful comments from the editors James Cloern and Peter R. Leavitt, as well as two anonymous reviewers. This project was funded by the Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (FORMAS) grant number 2016–00594, and the Oscar and Lili Lamm Foundation grant number FO2018‐0042.
© 2022 The Authors. Limnology and Oceanography Letters published by Wiley Periodicals LLC on behalf of Association for the Sciences of Limnology and Oceanography.
- Geosciences, Multidisciplinary
- Climate Research
- environmental stressors
- metal pollution