SOFIA (Reuters) - Carcasses of dolphins are washing up on Bulgaria’s Black Sea beaches at a higher than normal rate, with a record 108 dead animals discovered this year, local authorities said on Thursday.

The cause of the deaths has yet to be determined, said Environment Minister Ivelina Vasileva after collecting information by regional centers, adding that 77 of the dead dolphins were found in the southern part of the country’s Black Sea coast.

Bulgarian Prime Minister Boiko Borissov on Thursday called for a special meeting with conservation organizations to try to find a solution to the record number of deaths and said on his official Facebook page that steps are being taken to ban fishing in areas populated by the protected species.

The number of dead dolphins in 2016 is significantly higher than the 56 found last year and the previous record of 74 in 2012.

Media reports of dead dolphins on Bulgarian beaches have been rife in recent years. In spite of repeated allegations, often with finger-pointing at fishermen, the cause has yet to be established conclusively.

There are three species of dolphins in the Black Sea off Bulgaria: the short-beaked common dolphin, the harbor porpoise and the common bottlenose dolphin. The dolphin population along Bulgaria’s black sea coast is about 15,000, according to environment ministry data.

The penalty for killing a dolphin is a fine of up to 20,000 levs ($11,270) and imprisonment for up to five years.