Highlights

• This work introduces a novel system for measuring light extinction in coastal waters. The automated system can remotely capture visual images of a Secchi disk at different depths. The photos enable continuous monitoring of algal blooms in a remote site from the office.
• This system employs image contrast theory and image analysis to determine the Secchi disk depth (SD) and light extinction coefficient. This method offers a new and cost effective method  to assess water transparency related to algal blooms and water quality.
• Enabling high-frequency and on-demand measurements of SD enhanced the ability to manage and respond to environmental changes significantly. This finding substantially improves over conventional methods, which are sparse and inadequate for capturing the dynamics of fast-changing phenomena like algal blooms.

Summary

The research presents a new automated system for measuring light extinction in coastal waters. It focuses on Secchi Disk Depth (SD), a key indicator in aquatic ecosystem monitoring. Traditional manual methods of measuring SD are limited and unable to track rapid changes during algal blooms.

The remotely controlled system uses visual images and image analysis to determine SD and light extinction coefficients.  The new system is a significantly advance over traditional methods by allowing high-frequency, on-demand SD measurements, vital for understanding and responding to harmful algal blooms. The simplicity and effectiveness of this system make it a valuable tool for environmental monitoring and management.  The paper also indicates the potential for future enhancements, such as AI integration, to increase automation and efficiency in monitoring efforts.

Y. Fan and J. H. W. Lee, “A remotely controlled automated field measurement system for light extinction in coastal waters,” Marine Pollution Bulletin, vol. 186, p. 114423, Jan. 2023, doi: .