Cited by 49Aquatic Ecosystems and Phytoplankton DynamicsAnomaly Detection Techniques and ApplicationsWater Quality Monitoring Technologies

Machine learning for anomaly detection in cyanobacterial fluorescence signals

Open access
Almuhtaram, Husein, Zamyadi, Arash, Hofmann, Ron·2021·Water Research

Published version of a preprint

Abstract

Many drinking water utilities drawing from waters susceptible to harmful algal blooms (HABs) are implementing monitoring tools that can alert them to the onset of blooms. Some have invested in fluorescence-based online monitoring probes to measure phycocyanin , a pigment found in cyanobacteria, but it is not clear how to best use the data generated. Previous studies have focused on correlating phycocyanin fluorescence and cyanobacteria cell counts. However, not all utilities collect cell count data, making this method impossible to apply in some cases. Instead, this paper proposes a novel approach to determine when a utility needs to respond to a HAB based on machine learning by identifying anomalies in phycocyanin fluorescence data without the need for corresponding cell counts or biovolume. Four widespread and open source algorithms are evaluated on data collected at four buoys in Lake Erie from 2014 to 2019: local outlier factor (LOF), One-Class Support Vector Machine (SVM), elliptic envelope, and Isolation Forest (iForest). When trained on standardized historical data from 2014 to 2018 and tested on labelled 2019 data collected at each buoy, the One-Class SVM and elliptic envelope models both achieve a maximum average F1 score of 0.86 among the four datasets. Therefore, One-Class SVM and elliptic envelope are promising algorithms for detecting potential HABs using fluorescence data only.

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Crossref · 10.1016/j.watres.2021.117073

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Authors
Almuhtaram, H., Zamyadi, A., & Hofmann, R.
Affiliations
  • University of Toronto (CA)
  • Melbourne Water (AU)
Corresponding author
Almuhtaram, Husein
Venue
Water Research
Publisher
Elsevier BV
Published
2021-06
Volume
197
Pages
117073
ISSN
0043-1354 (ISSN-L)
OpenAlex
W3139251132
Cited by
49
References
75
Citations by year
2026: 7 · 2025: 8 · 2024: 11 · 2023: 8 · 2022: 8 · 2021: 7
FWCI
3.22
Type
journal article
Language
en
Open access
Locations
  • Water Research (publishedVersion)
  • PubMed (publishedVersion)
Funders
Natural Sciences and Engineering Research Council of Canada
Topics
  • Physical Sciences › Environmental Science › Environmental Chemistry › Aquatic Ecosystems and Phytoplankton Dynamics
  • Physical Sciences › Computer Science › Artificial Intelligence › Anomaly Detection Techniques and Applications
  • Physical Sciences › Environmental Science › Water Science and Technology › Water Quality Monitoring Technologies
Keywords
harmful algal blooms, cyanobacteria, phycocyanin fluorescence, anomaly detection, online monitoring, drinking water utilities, Lake Erie, one-class support vector machine, elliptic envelope, Isolation Forest, local outlier factor
MeSH terms
Machine Learning, Cyanobacteria, Environmental Monitoring, Fluorescence, Harmful Algal Bloom, Lakes

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