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Credit: European Union, Copernicus Sentinel-X imagery

EU - Severe heatwave in Mediterranean Sea for 70 days, mass mortalities in marine life expected

The Mediterranean Sea is experiencing a heatwave, with water temperatures between the coasts of Italy and France soaring by more than 5 degrees Celsius (°C) over average. The sea has been reporting high sea surface temperatures since May 2022.

The data was shared by Copernicus Marine Services, which monitors the ocean worldwide.

The sea surface temperature in the Mediterranean Sea touched 27ºC in July.

“Many areas are above 26ºC and some pockets are close to 30ºC,” Francisco Pastor told Down To Earth (DTE). Pastor is a researcher at the meteorology and climatology department at Fundación Mediterranean Center for Environmental Studies (CEAM), a research centre.

These temperatures are similar to the sea surface temperatures in the late Cretaceous period. Sea temperatures ranged between 27ºC and 37ºC in several parts of the world in that period, according to a study.

Dinosaurs roamed the planet during the Cretaceous period, which lasted from about 145 to 66 million years ago.

Atmospheric carbon dioxide levels were about 2,000 parts per million by volume in that period. Average temperatures were roughly 5°C-10°C higher than today, according to EOS, a science news magazine.

Studies have shown that volcanic eruptions were linked to the rise in greenhouse gases in the Cretaceous period. Greenhouse gases released from human activities are being absorbed in the ocean right now, increasing the sea surface temperature.

A marine heatwave emerges when the sea surface temperature crosses a threshold for at least five consecutive days.

Satellite data showed high sea surface temperatures in May 2022 in the Mediterranean Sea. Over the past three months, the northwest Mediterranean experienced a marine heatwave for 70 days.

“This will likely lead to extensive mortality of plants and animals,” Jean-Pierre Gattuso wrote in a tweet. Gattuso is a research director at the Laboratoire d’Océanographie de Villefranche, French National Centre for Scientific Research and Sorbonne University, France.

The average sea surface temperature between 2003 and 2019 in the Mediterranean Sea was 19.7°C, a study found.

The region experienced multiple heatwave events. The most severe ones emerged in 2012, 2015 and 2017, another study that looked at data between 1982-2017 pointed out.

Pastor said he analysed marine heatwaves in the Mediterranean in the last 40 years, which will be published in a scientific journal.

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IMAGE:

The recent extreme temperatures in southwestern Europe have been affecting the Mediterranean Sea, where water temperatures have increased. Heatwaves, in fact, do not only impact life on land, but also impact marine ecosystems.  

This visualisation, based on data from the Copernicus Marine Environment Monitoring Service (CMEMS), displays the Sea Surface Temperature (SST) anomaly recorded on 19 June 2022. The data show an anomaly of up to +5°C along the coasts of Spain, France and Italy.

The Copernicus Marine Environment Monitoring Service provides open data and information on marine ecosystems which are key for the monitoring of the effects of climate change on marine environments.

This visualisation, based on data from the Copernicus Marine Environment Monitoring Service (CMEMS), displays the Sea Surface Temperature (SST) anomaly recorded on 19 June 2022. The data show an anomaly of up to +5°C along the coasts of Spain, France and Italy.This visualisation, based on data from the Copernicus Marine Environment Monitoring Service (CMEMS), displays the Sea Surface Temperature (SST) anomaly recorded on 19 June 2022. The data show an anomaly of up to +5°C along the coasts of Spain, France and Italy.

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