A1 Journal article (refereed)
Calibration of in situ chlorophyll fluorometers for organic matter (2020)

Kuha, J., Järvinen, M., Salmi, P., & Karjalainen, J. (2020). Calibration of in situ chlorophyll fluorometers for organic matter. Hydrobiologia, 847(21), 4377-4387. https://doi.org/10.1007/s10750-019-04086-z

JYU authors or editors

Publication details

All authors or editors: Kuha, Jonna; Järvinen, Marko; Salmi, Pauliina; Karjalainen, Juha

Journal or series: Hydrobiologia

ISSN: 0018-8158

eISSN: 1573-5117

Publication year: 2020

Volume: 847

Issue number: 21

Pages range: 4377-4387

Publisher: Springer

Publication country: Netherlands

Publication language: English

DOI: https://doi.org/10.1007/s10750-019-04086-z

Research data link: https://doi.org/10.17011/jyx/dataset/62634

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/73751


Organic matter (OM) other than living phytoplankton is known to affect fluorometric in situ assessments of chlorophyll in lakes. For this reason, calibrating fluorometric measurements for OM error is important. In this study, chlorophyll (Chl) fluorescence was measured in situ in multiple Finnish lakes using two sondes equipped with Chl fluorometers (ex.470/em.650–700 nm). OM absorbance (A420) was measured from water samples, and one of the two sondes was also equipped with in situ fluorometer for OM (ex.350/em.430 nm). The sonde with Chl and OM fluorometers was also deployed continuously on an automated water quality monitoring station on Lake Konnevesi. For data from multiple lakes, inclusion of water colour estimates into the calibration model improved the predictability of Chl assessments markedly. When OM absorbance or in situ OM fluorescence was used in the calibration model, predictability between the in situ Chl and laboratory Chl a assessments was also enhanced. However, correction was not superior to the one done with the water colour estimate. Our results demonstrated that correction with water colour assessments or in situ measurements of OM fluorescence offers practical means to overcome the variation due to OM when assessing Chl in humic lakes in situ.

Keywords: water quality; organic material; colour of water; chlorophyll; fluorescence

Free keywords: automated monitoring; chlorophyll a; fluorescence; organic matter; optical sensors; water colour

Contributing organizations

Ministry reporting: Yes

Reporting Year: 2020

JUFO rating: 1

Last updated on 2021-07-07 at 21:35