Rome, Jun 24 (IANS): The temperature of the Mediterranean Sea in May was 4 degrees Celsius higher than average over the 20-year period ending in 2005, as a marine heatwave hit the waters, a new report has revealed.

The CAREHeat Project report on Thursday said that the surface water temperature of the Mediterranean Sea in May hit a peak of more than 23 degrees Celsius.

This is likely to have a lasting impact in Italy, Xinhua news agency quoted the report as saying.

Italian research agencies the National Agency for New Technology, Energy and Sustainable Economic Development (ENEA) and the National Research Council (CNR) participated in the project.

According to environmental group Greenpeace, the increasing temperatures are having a major impact on marine biodiversity off Italy's coastline.

Some vulnerable species are disappearing from the sea around Italy, Greenpeace said, and are being replaced by species better suited to thrive in warm waters.

These new species are often alien to the area, creating dangerous knock-on impacts across the ecosystem.

The report came as Italy grapples with a land-based heatwave, exacerbated by a lack of rainfall.

This has sparked requests for states of emergency to be declared across much of central and northern Italy, and is endangering agricultural production in multiple areas.