Conservation groups in Bulgaria are to hold an emergency meeting following an alarming spike in dolphin and porpoise deaths in the Black Sea. 

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Dolphin and porpoise strandings have spiked dramatically this year. Image: Green Balkans/used with permission 

According to media reports, 108 dolphins have been found dead along the country's Black Sea coast since January, twice the number found in all of 2015. Bulgaria's environment minister, Ivelina Vasileva, says the cause of the deaths remains unclear.

Dimitar Popov, a researcher with the conservation organisation Green Balkans, which monitors cetacean strandings in Bulgaria, confirms the recent spike. Juvenile porpoises appear to be the hardest hit, with unexplained mass die-offs occurring in August of 2015 and July of this year. According to Popov, 35 dead porpoises were found washed up on local beaches during just one weekend this month.

Save Koral, an NGO headed by Atanas Rusev, claims there were over 300 dolphin and porpoise deaths recorded for 2015. Rusev's investigations suggest that illegal fishing involving gillnets, which pose a particular problem for porpoises, are the most likely cause of cetacean deaths in the Black Sea.

Aside from entanglement in fishing gear, the marine mammals also face threats from pollution, habitat loss and injury from sea-going vessels, according to the Whale and Dolphin Conservation Fund. The region is home to three species of toothed cetacean: the harbour porpoise, the bottlenose dolphin and the short-beaked common dolphin, all of which are listed as either Endangered or Vulnerable within the Black Sea. 

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Green Balkans says 35 dead porpoises were found washed up on local beaches during just one weekend in July. Image: Green Balkans/used with permission 

Last Thursday, Bulgaria's prime minister Boiko Borissov called for a special meeting of conservation groups in order to address the situation. In a statement that appeared on his Facebook page, Borissov suggested that a crackdown on illegal fishing would be a likely solution to the problem.

Direct hunting of dolphins in the Black Sea decimated their populations in the 20th century, driving them close to extinction. Bulgaria hunted and killed hundreds of thousands from the 1950s through the 1980s, with nearly 56,000 killed in its waters in 1959 alone. Today, the country is one of 21 signatories to an international agreement (ACCOBAMS) created to "reduce threats to cetaceans in Mediterranean and Black Sea waters". 

In addition to the ACCOBAMS agreement, international and domestic legislation now makes it illegal to deliberately capture or kill dolphins in Bulgarian waters. Fishing activities in areas populated by cetaceans are also limited. Nearly a third of the region currently has a "Special Areas of Conservation" designation, which limits economic activities like fishing in order to protect vulnerable wildlife.

A recent report on the interaction between fisheries and cetaceans in the Black Sea found that while most local fishermen were aware of the protection afforded these animals, they also believed there were too many dolphins and porpoises in the region, and that "their numbers should be controlled". Such attitudes have been the focus of both government and NGO attention as investigations into the mass die-offs continue. 

Popov, however, cautions that it's too soon to point the finger of blame at the fishing industry. "There are several hypotheses about the increased deaths of juvenile porpoises, but up to now, none is confirmed," he tells Earth Touch News. The deaths could be attributed to disease, oil and gas exploration, or even NATO naval exercises conducted in the Black Sea in the summers of 2015 and 2016, he adds.

A lack of data and proper facilities for necropsies also makes it difficult to determine the cause of death for stranded animals. "By focusing on fisheries, the investigation of strandings based on necropsies will be put aside," Popov warns. 

With the possibility of extinction looming for some of the Black Sea's cetacean species, the upcoming meeting of conservation groups will hopefully shed much-needed light on the problem. Determining the ultimate cause of these deaths, however, might not be as straightforward as many are hoping. 


Top header image: Bas Kers, Flickr