OBSERVER: How Copernicus Helps Monitor the Health of Europe’s Coastal Waters

Europe’s coastal areas: vital but vulnerable

The EU has around 68,000 km of coastline[1]. To put this into perspective, this represents over three times the coastline of the United States.

Coastal areas are vital. For plants, animals, and other organisms, they offer unique ecosystems. For human populations, they are an important source of food, host agricultural activities and support trade and transport, as well as tourism – all of which generate income for millions of people.

In fact, according to ‘The EU Blue Economy Report 2021’ published by the European Commission, the ‘blue economy’ in Europe employed nearly 4.5 million people in 2018, generating around €650 billion in turnover and a gross value added of €176 billion. As such, it is an important driver of the European economy, in coastal communities and further afield.

A new tour of Europe’s coastlines

This reality underlines why the monitoring activities of the Copernicus Marine Service are so important and why the Service has recently launched an article series, entitled ‘Touring Europe’s Coastlines’.

Each article in the series, focuses on one key coastal area in Europe, exploring the challenges faced by different countries or cities. They showcase how the Copernicus Marine Service products derived from satellite and in situ data as well as produced by models — help to better understand and assess the health of coastal waters. In particular, the series highlights the added-value applications that can be developed using the Copernicus Marine Service's new High-Resolution Ocean Colour products, which are based on the processing of Copernicus Sentinel-2 data.

“Europe’s coastlines are full of interesting and fascinating stories. Our article series attempts to uncover some of these to shed light on European coasts, which are important areas for many of us, but sadly, also seriously affected by climate change,” says Pierre Bahurel, the CEO of Mercator Ocean International, the entity entrusted with implementing the Copernicus Marine Service. “The series shows how our monitoring efforts help users and policymakers alike all-around coastal areas in Europe.”

Algae monitoring in Belgium

Along the coast of Belgium, for example, eutrophication – an enrichment of water by excessive minerals and nutrients content – is causing algal blooms. In particular one species, Phaeocystis globosa, can be whipped up into a thick foam by the action of wind and waves when it dies. And this foam is not just a problem for the tourism industry, but in exceptional circumstances it can be even deadly. P. globosa also grows quickly, taking up many of the available nutrients and leaving other marine species struggling to survive. The case study ‘Belgium and foaming algae’ describes how data from the Copernicus Sentinel-2 and -3 satellites are being used to inform and empower the Belgian authorities in dealing with these challenges.

For a safe swim in Marseille

Another case study, ‘Safe Swimming in Marseille’ looks at bathing conditions in this port city of southern France. Situated on the Mediterranean Sea, Marseille’s beaches and warm waters attract many visitors, with more than five million tourists staying in the city in 2019[2]. However, these waters are occasionally affected by bacterial pollution. Microbes such as Escherichia coli and other coliform bacteria can enter rivers upstream, from sources such as sewage or animal faeces. They are then washed down to the ocean, where anyone participating in water sports will be at risk of ingesting the bacteria and falling ill. With Marseille only around 40 km from the mouth of the Rhône, this can be a significant hazard. Satellite observations provide information on the big picture, complementing in situ data, which alone are insufficient to guide local decision-makers, due to the highly dynamic nature of coastal waters.

Keeping an eye on Venice

Further east, water quality and flooding are significant challenges for the city of Venice, as highlighted by true-colour images captured by Sentinel-2, which shows suspended particles in the area. These types of images are used by the Copernicus Marine Service to create a set of ocean colour products that allow high-resolution monitoring of suspended particles. This approach is showcased in the third case study, ‘Water quality and flooding in Venice’, which describes how these tools and other satellite observations, as well as in situ observations and data produced by models provide early warnings of potential pollution episodes to support emergency and safety response missions.

You want to know more about Copernicus and the monitoring of Europe’s coastal waters? Stay tuned, as the tour of Europe’s coasts will continue throughout 2022, covering a wide range of destinations and topics!

[1] https://www.marseille-congres.com/en/choose-marseille/marseille-numbers

[2] https://www.eea.europa.eu/themes/water/europes-seas-and-coasts [figure includes UK]