Dozens of dead dolphins have been found on Bulgaria's northern Black Sea coastline over the last week, and they probably died after being tangled up in fishing nets, according to authorities.
Twenty-nine dead dolphins were spotted Tuesday and Wednesday near the town of Shabla, . Another 26 were found 10 days ago in the same area, the government's environmental office in the port of Varna said.
The animals most likely died of suffocation after getting entangled in fishing nets, the office said in a statement. There were no signs of violence, illness or pollution.
The authorities do not suspect poaching, which was blamed for the deaths of 11 dolphins found dead on the coast of Bulgaria's northern neighbor Romania in April.
"We have never had so many dolphins entangled in fishing nets. They may have been in a group and some of them got trapped," said Atanas Cholakov, head of the state fishing agency in the northeast town of Dobrich.
Hunting the animals is forbidden in Bulgaria, as they are on the list of endangered species.
"We have no grounds to suspect illegal fishing ... You need at least 100 dolphins to be able to sell them and make a profit, plus penalties are very high," Cholakov said.