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Tracking Blue-Green Algae in Lough Neagh with Earth Observation

Posted By:
Mallon Technology

30th Jan 2024

It has been an eventful summer for the UK’s largest freshwater lake, Lough Neagh, which has rarely been out of the news over fears for its future health following the significant presence of toxic blue–green algae that is threatening the local ecosystem and the business that operate on it.

Over the past summer, we have taken a closer look at Lough Neagh through an Earth Observation lens, exploring how the technology can identify, track and understand algae blooms that form in the lake. Mallon Colleague Micheal Foley has created the following images.

How Satellite Technology can help to Protect Lough Neagh’s Ecosystem

With Lough Neagh covering such a large area, it can be challenging to track and monitor the health of the entire lake. This is where Earth Observation and Remote Sensing technology has proven itself to be a valuable tool.

Using multiple satellite platforms such as Landsat 8, Landsat 9 and Sentinel–2 has dramatically enhanced our ability to observe and analyse environmental issues on a large scale perspective. The multispectral capabilities of these satellites enable researchers to detect changes in the water quality and identify the extent of algae blooms.

The image below shows two different views of Lough Neagh. These were captured by the Sentinel–2 satellite in September.

The first image is an RGB True Colour image of the lough. This is how the lough would look to us if we were to view it from space. The second image has data from the Chlorophyll–a parameter overlaid on the RGB image. The Chlorophyll–a parameter is available from the Sentinel–2 satellite and is a key indicator of algal presence. The additional data overlaid on the image makes it clear how widespread the algal blooms are across the lough, even in the late summer period. The red marks on the image indicate higher levels of Chlorophyll–a and can be viewed down the eastern side of the lough.

Lough Neagh True Colour Image & Chlorophyll-a Overlay

How can Earth Observation Help Lough Neagh?

As the image above shows, it is possible to identify and track algae blooms using Earth Observation imagery and data.  This can be done remotely, allowing for a complete picture of the entire lough to be created, saving resources and the need for manual checks.

By using Earth Observation techniques, the overall health of the lough can be tracked over time, helping to identify problem areas, seasonal changes and even the flow of any algal blooms.  Such insights can ultimately be used to monitor the health of the lough and provide crucial data that can lead to informed decisions that help mitigate the impact of algae blooms on aquatic ecosystems and introduce more sustainable water management practices.