Sentinel-3 satellite products for detecting Eutrophication and Harmful Algal Bloom events in the French-English CHANNEL

About The Project

S-3 EUROHAB will develop a web based Harmful Algal Bloom and Water Quality alert system that uses satellite data to improve the ways in which these parameters / phenomena are monitored. The system is being designed by scientists in collaboration with stakeholders, in particular marine managers and shellfishery end users.

The S-3 EUROHAB project will use data from the recently launched European satellite, Copernicus Sentinel 3, to track the biomass and spread of HABs in the Channel. In addition, the system will also be used to monitor water quality. The satellite data will then be used to create a web based alert system, the first of its kind in Europe, to alert marine managers and fishing 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.

S-3 EUROHAB infographic 2021


A example satellite image showing an algal bloom off the Devon and Cornwall coast

Harmful Algal Blooms (HABs) are caused by excessive growth of marine algae which release harmful toxins into the water that can kill fish, shellfish and even humans when they consume contaminated fish. As a result they can have an extremely damaging effect on the tourism and fishing industries. In the EU, the annual cost of HABs to these industries is estimated to be in excess of 918 million euros. Poor water quality can also affect our coastal regions, which can adversely affect a number of maritime industries. For example, eutrophication is the anthropogenic enrichment of water by nutrients causing accelerated growth of algae and a deterioration in water quality.

Current methods of tracking HABs are expensive, costing 2 million euros annually to monitor just 6% of the Channel area. S-3 EUROHAB’s methods will not only cost significantly less, but will also cover the whole Channel area. The alert system will also result in much faster response times to HABs, potentially helping to mitigate the blooms which will help to reduce the millions of pounds lost each year as a result of HABs in both France and the UK. 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 will be designed alongside marine managers and industry end users to enhance the marine monitoring of HAB’s in the French-English Channel region.

The project budget is partially funded by the Interreg France (Channel) England programme, by the European Regional Development Fund. The project is made up of 9 organisations, 5 from France (IREMER-Brest, IFREMER-Port-en-Bessin, IFREMER-Boulogne-sur-Mer, Comité Régional des Pêches de Basse Normandie Universite de Brest) and 4 from the UK (Plymouth Marine Laboratory, Environment Agency, University of Southampton, Devon and Severn Inshore Fisheries and Conservation Authority), and will run from November 2017 until October 2021.

Project Objectives

  1. 1.

    To create a cross-border monitoring network and data portal for assessing Good Environmental Status of the common waters between the French-English Channel.

  2. 2.

    To produce a Web based alert system for the detection of water quality and harmful algal blooms using the latest European Space Agency / Copernicus satellite data.

  3. 3.

    To conduct a socio-economic analysis of the impact of Harmful Algal Blooms in the French-English Channel.

Some key facts about the project...


Start Date

30 March 2017


End Date

31 December 2022


EDRF Contribution





For Users

S-3 EUROHAB will work with shellfishermen to develop new approaches to help manage harmful algal bloom and water quality related risks to their industry, to help minimise potential impacts on their business. Additionally, stakeholders and decision-makers from other sectors, for example, the tourism and recreational sectors, may be impacted by the presence of HABs.

The value of the South West UK shellfishery is €8.25M per yr, of which €2.9M is lost to Harmful Algal Blooms which could be saved by an alert system. The current costs of monitoring Harmful Algal Blooms in the French-English Channel is €2M per yr which cover 6% of the French-English Channel with the S-3 alert system the cost is €42K per yr for the entire French-English Channel.



Fishing community

Fishing community harbour. Photo: Gavin Tilstone

Web Alert System

basic data viewed in GIS portal

S-3 EUROHAB has produced a web based alert system for a selection of the most important Harmful Algal Bloom Species. Currently the system provides data covering;

  • Karenia - responsible for reducing oxygen in the water column
  • Phaeocystis - responsible for producing foam
  • Pseudo-nitzschia - responsible for Amnesic Shellfish Poisoning

Images in the portal are provided in near real time so data up to a few days ago should be available. For more information on the Web Alert System please see:


A video demonstration of the S-3 EUROHAB Harmful Algal Bloom web alert system is available here:https://youtu.be/dHWlAXrxMjM


For Science

Harmful Algal Blooms and Eutrophication are a common environmental problem in Europe. Both of these are currently monitored by coastal boat surveys and determination of phytoplankton species and associated toxins in water, fish and shellfish. If toxins exceed specified thresholds, large areas of the coast, shelf and estuaries are closed for harvest. Harmful Algal Blooms and Water Quality cannot be predicted and marine managers can only act on these events after they have happened. Current in situ monitoring under the Water Framework Directive only covers 3% of the total French-English Channel region. The monitoring sites are fixed and there is no current possibility of reactive sampling due to a lack of information. This limits the ability to track the dispersion of blooms from area to area, especially in the shelf waters of the Channel. The impacts of HABs are often worse on the French side of the Channel due to accumulation of phytoplankton caused by the prevailing currents and larger nutrient inputs to the coast from rivers.

The project is developing a cross-border data portal that includes both in situ monitoring data and data from the recently launched Copernicus Sentinel 3 (S-3) satellite available from the EU’s Earth Observation and Monitoring Programme. The data portal will be used to assess the principal drivers, dispersion and transport of key Harmful Algal Bloom species throughout the French-English Channel.

An early warning detection system

The data portal will also be used to develop a web based alert system to provide marine managers and the fish and shellfish industry with more detailed information on the whereabouts and potential dispersion of HABs in the Channel region. This will enable a quicker response time to closing certain areas affected by Harmful Algal Blooms for harvest, whilst allowing other areas to remain open, thus reducing the economic impacts on the industry. Other parameters that are useful for promoting the growth of spats to increase shellfish productivity will also be included in the alert system. A socio-economic survey of the cost of poor water quality and HABs and the benefit of using the web based alert system will be conducted.

S-3 EUROHAB Scientific Publications

McCluskey, E.; Brewin, R.J.W.; Vanhellemont, Q.; Jones, O.; Cummings, D.; Tilstone, G.; Jackson, T.; Widdicombe, C.; Woodward, E.M.S.; Harris, C.; Bresnahan, P.J.; Cyronak, T.; Andersson, A.J. On the Seasonal Dynamics of Phytoplankton Chlorophyll-a Concentration in Nearshore and Offshore Waters of Plymouth, in the English Channel: Enlisting the Help of a Surfer. Oceans 2022, 3, 125-146. doi: 10.3390/oceans3020011

Karasiewicz, S., Lefebvre, A. 2022. Environmental Impact on Harmful Species Pseudo-nitzschia spp. and Phaeocystis globosa Phenology and Niche. J. Mar. Sci. Eng. 2022, 10, 174. doi: 10.3390/jmse10020174 

Panton, A., Purdie, D. A. 2022. Dinophysis spp. abundance and toxicity events in South Cornwall, U.K.: Interannual variability and environmental drivers at three coastal sites. Harmful Algae, 112, 102169, doi: 10.1016/j.hal.2021.102169.

Tilstone, G.H.; Pardo, S.; Simis, S.G.H.; Qin, P.; Selmes, N.; Dessailly, D.; Kwiatkowska, E. Consistency between Satellite Ocean Colour Products under High Coloured Dissolved Organic Matter Absorption in the Baltic Sea. Remote Sens. 2022, 14, 89. doi: 10.3390/rs14010089

Lefran, A., Hernández-Fariñas, T., Gohin, F., Claquin, P. 2021. Decadal trajectories of phytoplankton communities in contrasted estuarine systems in an epicontinental sea, Estuarine, Coastal and Shelf Science, 258,: 107409, doi:10.1016/j.ecss.2021.107409.

Gohin, F., Van der Zande, D., Tilstone, G.H. et al. 2019.Twenty years of satellite and in situ observations of surface chlorophyll-a from the northern Bay of Biscay to the eastern English Channel. Is the water quality improving? Remote Sensing of Environment, 233, 111343. 

Lefebvre, A., Dezécache, C. 2020.Trajectories of Changes in Phytoplankton Biomass, Phaeocystis globosa and Diatom (incl. Pseudo-nitzschia sp.) Abundances Related to Nutrient Pressures in the Eastern English Channel, Southern North Sea. J. Mar. Sci. Eng., 8, 401; doi:10.3390/jmse8060401 

Gohin, F., Bryère, P., Lefebvre, A., Sauriau, P-G., Savoye, N., Vantrepotte, V., Bozec, Y., Cariou, T., Conan, P., Coudray, S., Courtay, G., Françoise, S., Goffart, A., Hernández Fariñas, T., Lemoine, M., Piraud., A., Raimbault., P.,  Rétho, M.2020. Satellite and In Situ Monitoring of Chl-a, Turbidity,and Total Suspended Matter in CoastalWaters: Experience of the Year 2017 along the French Coasts. J. Mar. Sci. Eng.,8, 665; doi:10.3390/jmse8090665 

Chenouf S., Merzereaud M., Perez Agundez J., Raux P., (2020). Determination of scallop production areas closures due to phycotoxins along the Eastern English Channel using data from REPHY and REPHYTOX monitoring networks. SEANOE. doi.org/10.17882/71912

Raux P., Perez J. and Chenouf S., (2020). Integrated management of Harmful Algal Blooms (HABs) along the French Channel area. A system approach to assess and manage socio-economic impacts of HABs, in Ph. Hess [Ed]. 2020. Harmful Algae 2018 – from ecosystems to socioecosystems. Proceedings of the 18th Intl. Conf. on Harmful Algae. Nantes. International Society for the Study of Harmful Algae. 214 pages. pp 195-197

Chenouf S., Perez Agundez J., Raux P., (2020). Methodology for the estimation of scallop production areas closures in the Eastern English Channel.

Chenouf, S., Perez-Agundez, J., Raux, P. 2019. Impacts of Harmful Algal Blooms (HABs) in the French Channel area. Focus on the great scallop (Pecten maximus) fishery of the Eastern Channel, Phycotox, C3.1, 3499

Raux, P., Chenouf, S., Perez-Agundez, J.  2018. Socio-economic analysis of Harmful Algal Blooms (HAB)’ impact in the French Channel area and support from Sentinel-3 satellite products for detecting HABs (S-3 EUROHAB). ICHA Conference Proceedings

Lefran, A., Hernández-Fariñas, T., Gohin, F., Claquin, P. 2021. Decadal trajectories of phytoplankton communities in contrasted estuarine systems in an epicontinental sea, Estuarine, Coastal and Shelf Science, 258,: 107409, https://doi.org/10.1016/j.ecss.2021.107409

Group Related Scientific Publications

Keys, M., Tilstone, G., Findlay, H. S., Widdicombe, C. E., Lawson, T. 2018. Effects of elevated CO2 and temperature on phytoplankton community biomass, species composition and photosynthesis during an autumn bloom in the Western English Channel, Biogeosciences 15, 3203–3222, https://doi.org/10.5194/bg-15-3203-2018

Tilstone, GH; Mallor-hoya, S; Gohin, F; Bel Couto, A; Sa, C; Gloela, P; Cristina, S; Airs, RL; Icely, J; Zuhlke, M; Groom, SB. 2017. Which Ocean Colour algorithm for MERIS in NW European coastal waters?. Remote Sensing of Environment, 189. 132-151. https://doi.org/10.1016/j.rse.2016.11.012;

Keys, M., Tilstone, G.H., Findlay, H., Widdicombe, C. 2017. Effects of elevated CO2 on phytoplankton community biomass and species composition during a spring Phaeocystis spp. bloom in the western English Channel, Harmful Algae, 67: 92-106 http://dx.doi.org/10.1016/j.hal.2017.06.005 ;

Barnes, M., Tilstone G.H., Smyth, T.J., Widdicombe C, Gloel J, Robinson C, Kaiser J, Suggett D. 2015. Drivers and effects of Karenia mikimotoi blooms in the western English Channel (1992-2010). Progress in Oceanography, 137: 456-469. doi:10.1016/j.pocean.2015.04.018;

Kurekin, A.A., Miller, P.I., Van der Woerd, H.J. 2014. Satellite discrimination of Karenia mikimotoi and Phaeocystis harmful algal blooms in European coastal waters: Merged classification of ocean colour data. Harmful Algae, 31; 163-176.

Downes-Tettmar, N., Rowland, S., Widdicombe, C., Woodward, E.M.S., Llewellyn, C. 2013. Seasonal variation in Pseudo-nitzschia spp. and domoic acid in the Western English Channel. Continental Shelf Research, 53: 40-49.

Shutler, J.D., Warren, M.A., Miller, P.I., Barciela, R., Mahdon, R., Land, P.E., Edwards, K., Wither, A., Jonas, P., Murdoch, N., Roast, S.D., Clements, O., Kurekin, A. Operational monitoring and forecasting of bathing water quality through exploiting satellite Earth observation and models: The Al- gaRisk demonstration service. Computers & Geosciences , 77: 87-96.

Project Partners


  • Primary Contact:
    • Gavin Tilstone
    • Principle Investigator
    • +44 1752 633 100
  • Primary Contact:
    • Francis Gohin
    • Research Investigator
    • +33 2 98 22 43 15
  • Primary Contact:
    • Dr. Duncan Purdie
    • Research Investigator
    • +44 23 8059 2263
  • Primary Contact:
    • Dr. Mike Best
    • Senior Marine Technical Advisor
    • 44 2030 256 117
  • Primary Contact:
    • Catherine Paul
    • Research Investigator
    • +33 2 33 43 32 92
  • Primary Contact:
    • Pascal Raux
    • Research Assistant
    • +33 2 90 91 56 30


  • 21 November 2017 - 22 November 2017
    S3 EUROHAB Kick-Off Meeting
    Jury's Inn, Plymouth
  • 10 May 2018
    UK Stakeholders' Meeting
    Exeter Racecourse, Devon
  • 16 May 2018
    French Stakeholders' Meeting
    Caen, France
  • 26 March 2021
    S-3 EUROHAB web alert system demo - Shellfishery organisations 1
    Online Web Demo
  • 23 April 2021
    S-3 EUROHAB web alert system demo - Research and monitoring organisations 1
    Online Web Demo
  • 28 April 2021
    Estuarine and Coastal Sciences catchment to coast along SW England
    Online Focus Meeting
  • 18 May 2021
    S-3 EUROHAB web alert system demo - Shellfishery organisations 2
    Online Web Demo
  • 02 June 2021
    S-3 EUROHAB web alert system demo - Shellfishery organisations 3
    Online Web Demo
  • 07 June 2021
    S-3 EUROHAB web alert system demo - Research and monitoring organisations 2
    Online Web Demo
  • 10 June 2021
    S-3 EUROHAB web alert system demo - Shellfishery organisations 4
    Online Web Demo
  • 16 June 2021
    Future Ocean Conference - Science under the surface
    Virtual event
  • 14 July 2021
    Sensors for Water Interest Group Conference, How can sensors protect our oceans?
    Virtual event
  • 07 September 2021 - 11 September 2021
    CSA 58 - EMECS 13: Estuaries and coastal seas in the Anthropocene – Structure, functions, services and management
  • 11 October 2021
    International Conference on Harmful Algae
    Virtual event
  • 14 October 2021
    CPER MARCO project meeting
    CCI Hauts-de-France
  • 03 November 2021
    COP26 - Presidency Event: Earth Information Day

Project Partner Meetings

  • 09 January 2018
    Data Portal Meeting
    Online via WebEx
  • 02 February 2018
    Progress Meeting
    Online via webEx
  • 01 March 2018
    Progress Meeting
    Online via webEx
  • 16 May 2018
    6 Month Progress Meeting
    IFREMER Port-en-Bessin, France
  • 06 November 2018 - 07 November 2018
    12 Month Progress Meeting
    University of Southampton, UK
  • 03 April 2019 - 04 April 2019
    18 Month Progress Meeting
    IFREMER, Boulogne, France
  • 11 September 2019 - 12 September 2019
    24 Month Progress Meeting
    Environment Agency, Exeter, UK
  • 25 March 2020 - 26 March 2020
    30 Month Progress Meeting
    CRPBN, Normandie, France
  • 04 November 2020
    36 Month Progress Meeting
    Zoom meeting
  • 26 May 2021
    42 Month Progress Meeting
    Zoom meeting
  • 01 November 2021
    48 Month Progress Meeting
    PML, Plymouth
  • 25 May 2022
    54 Month Progress Meeting
    UBO, Brest
  • 05 September 2022
    Final Symposium
    IFREMER, Brest, France