A child looks at the damaged pier in the Greek port of Zakynthos, following an earthquake near the island on Friday. A powerful 6.8-magnitude undersea earthquake struck early Friday off the Ionian Sea island of Zante, causing structural damage but no injuries, officials said. Photo: VCG

Environmental groups are urging Greece to halt seismic research in the Ionian Sea after several whales washed up this week, the World Wildlife Fund said Tuesday. 

Athens has allowed hydrocarbon exploration and exploitation rights off the island of Crete and in the Ionian Sea in recent years to the dismay of local activists.

Conservationists say the seismic research can cause hearing damage and stress to cetaceans. 

On Tuesday, 15 environmental groups urged a halt to the research after three Cuvier's beaked whales washed up alive at the island of Corfu since Sunday, according to WWF's Greece chapter. 

"Seismic research conducted in the area must stop immediately" until it is clear what caused the whales to wash up, said the letter, posted on WWF's website.

The letter's signatories, which included Greenpeace and Medasset, was addressed to Greek Prime Minister Kyriakos Mitsotakis and environment officials. 

According to marine wildlife experts, Cuvier's beaked whales live at depths of over 1,000 meters and are acutely sensitive to noise pollution from human activity.

The groups said a survey ship has been conducting research in the Ionian Sea since February 10.

The area has also seen additional traffic from rescue vessels after an Italian-flagged ferry caught fire northwest of Corfu on Friday.

An adolescent member of the dolphin-like species also beached itself on the coast of Athens in January. It died a few days later.

AFP