Algal Blooms

Eye in the sky

Satellite technology is the latest weapon in the battle against harmful algae

BY GAVIN TILSTONE

Scientists are working on improving the monitoring and prediction of harmful algal blooms (HABs) using satellite images which can provide a cost effective means of observing HABs over larger spatial and temporal scales to complement current marine monitoring efforts.

An EU INTERREG France Channel England Programme (FCE) project, launched in 2017, is using the latest satellite technology from the European Space Agency (Copernicus Sentinel-3) to improve the way water quality and harmful algal blooms are monitored in the English Channel.

Led by Plymouth Marine Laboratory (PML), this four-year project involves scientists from eight French and English organisations. The project, known as S-3 EUROHAB (“Sentinel-3 products for detecting EUtROphication and Harmful Algal Bloom events in the FrenchEnglish Channel”) is using data from the Copernicus Sentinel-3 satellite, to track the growth and spread of HABs and phytoplankton abundance related to water quality, in the French-English Channel.

The satellite data has been used to create a web-based alert system, the fi rst of its kind in Europe, to warn marine managers and fi shing industries of the growth of potentially damaging algal blooms. Data will also be gathered to help better understand why, how and when HABs occur as well as the economic costs associated with HABs and poor water quality and how the web-based alert system may reduce these costs.

Harmful algal blooms are caused by excessive growth of marine

“Current methods of tracking HABs are ineffi cient and expensive”

micro-algae, some of which produce harmful toxins that can kill fi sh, shellfi sh and even humans when they consume contaminated fi sh. As a result, these HABs can have an extremely damaging effect on the tourism and fi shing industries. In the EU, the annual cost of HABs to these industries is estimated to be in excess of €918m. Poor water quality can also affect our coastal regions, which can adversely affect a number of maritime industries.

Current methods of tracking HABs are ineffi cient and expensive, costing €2m annually to monitor just 6% of the Channel area. S-3 EUROHAB’s methods will not only cost signifi cantly less, just €42,000 annually, but will also mean the whole Channel area is covered. The alert system will also result in much faster response times to HABs, potentially helping to mitigate the blooms which will aid in reducing the millions of pounds lost each year due to HABs occurring on both the French and UK sides of the Channel.

Improvements to existing methods will be made using satellite ocean colour data and, in particular, the application of the latest technological advancement in, and recent launch of, the European Copernicus satellites. The project will use these satellite data to create a web-based HAB and water quality alert system that has been designed alongside marine managers and industry end users to enhance the marine monitoring of HABs in the French-English Channel region. The web alert system is now live and producing HAB risk alerts for shell fi shermen between France and the UK in the vicinity of the English Channel. The alerts are free to access online via the EUROHAB portal (see below).

The project budget will total €3.7m with 69% funded by the Interreg France (Channel) England programme, representing a European Regional Development Fund budget of €2.6m. The project is made up of nine organisations: fi ve from France (IREMER-Brest, IFREMER-Port-en-Bessin, IFREMER-Boulogne -sur-Mer, Comité Régional des Pêches de Basse Normandie Universite de Brest) and

Top: Dead fi sh fl oa� ng in algal bloom Above right: The latest European Space Agency satellite mission Sen� nel-3 that is designed to observe a suite of oceanographic parameters from space including algal blooms Right: Satellite image of a harmful algal bloom (red-orange-grey coloura� on) in the English Channel four from the UK (Plymouth Marine Laboratory, Environment Agency, University of Southampton, Devon and Severn Inshore Fisheries and Conservation Authority), and is running from November 2017 to October 2021.

To fi nd out more about S-3 EUROHAB or offer feedback on its activities, please visit the website www.s3eurohab.eu/portal/ where you can also access up to date alerts. FF

Gavin Tilstone is a Senior Scientifi c Offi cer at Plymouth Marine Laboratory.

HARMFUL algal bloom incidents are a major problem for aquaculture, and can lead to the deaths of thousands of fi sh at a time. Last year, for example, a HAB in Upper Loch Fyne led to large-scale mortalities at Scottish Salmon Company’s Quarry Point farm.

HABs are also a problem for the fi sh farming industry in Norway. The spring of 2019 saw the most serious algae problem for almost 30 years. It killed at least eight million salmon in the Nordland and Troms regions, leading to job losses, hitting communities hard and costing the industry hundreds of millions of kroner.

Farmed fi sh are particularly susceptible to HABs, since unlike their wild counterparts they are unable to swim away from toxic algae.

HABs are associated with warmer sea temperatures, and continuing global warming means toxic algae is likely to continue as a threat to sea life, wild and farmed.