A1 Journal article (refereed)
How to reach optimal estimates of confidence intervals in microscopic counting of phytoplankton? (2021)

Salonen, K., Salmi, P., & Keskitalo, J. (2021). How to reach optimal estimates of confidence intervals in microscopic counting of phytoplankton?. Journal of Plankton Research, 43(6), 846-852. https://doi.org/10.1093/plankt/fbab062

JYU authors or editors

Publication details

All authors or editors: Salonen, Kalevi; Salmi, Pauliina; Keskitalo, Jorma

Journal or series: Journal of Plankton Research

ISSN: 0142-7873

eISSN: 1464-3774

Publication year: 2021

Publication date: 04/10/2021

Volume: 43

Issue number: 6

Pages range: 846-852

Publisher: Oxford University Press (OUP)

Publication country: United Kingdom

Publication language: English

DOI: https://doi.org/10.1093/plankt/fbab062

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/79233


Present practices in the microscopic counting of phytoplankton to estimate the reliability of results rely on the assumption of a random distribution of taxa in sample preparations. In contrast to that and in agreement with the literature, we show that aggregated distribution is common and can lead to over-optimistic confidence intervals, if estimated according to the shortcut procedure of Lund et al. based on the number of counted cells. We found a good linear correlation between the distribution independent confidence intervals for medians and those for parametric statistics so that 95% confidence intervals can be approximated by using a correction factor of 1.4. Instead, the recommendation to estimate confidence intervals from the total number of counted cells according to Lund et al. should be categorically rejected. We further propose the adoption of real-time confidence intervals during microscopic counting as the criterion to define how long counting should be continued. Then each sample can be counted in its individual way to reach the necessary reliability independent of highly different samples. Such a dynamic counting strategy would be the most significant development in the quality control of phytoplankton counting since the early pioneers established the present counting practices in the late 1950s.

Keywords: plankton; microalgae; counting; microscopy; estimating (statistical methods); statistical methods; confidence levels

Contributing organizations

Ministry reporting: Yes

Reporting Year: 2021

JUFO rating: 1

Last updated on 2022-14-09 at 11:46