Scientists are worried over mass dolphin deaths in the Black Sea, which could be a result of the noise pollution caused by the ongoing war in Ukraine. There are about 20 Russian navy vessels in the Black Sea, which appear to be driving the dolphins south towards the Turkish and Bulgarian shores –where they get caught in the fishing nets or stranded.

The Turkish Marine Research Foundation (TÜDAV) has reported an increase in the deaths of common dolphins (Delphinus delphis) off the coast of Turkey. TÜDAV said over 80 dolphin deaths have been registered since late February. Half got entangled in fishing nets and eventually drowned, while it’s still unknown how the other half died.

Bayram Öztürk, chair of TÜDAV, told The Guardian that acoustic trauma could be one of the possibilities behind the dolphins’ deaths. However, he urged caution as we don’t yet what a high concentration of low-frequency sonars could do to marine life. “We’ve never seen these many ships and this much noise for such an extended time,” he added.

The low-frequency sonar of submarines and warships in the area could be interfering with dolphins’ echolocation, the researchers believe. Unable to navigate, dolphins then can’t identify prey and starve. Scientists have also suggested they could get confused and panic, swimming into rocks or onto the shore. Some could also be swimming into mines or killed by live fire.

Threats on dolphins

TÜDAV said an investigation into the causes and scope of the dolphin deaths could take months or even years, as much of the coastline is inaccessible to researchers because of the war. However, the foundation is already arguing that these deaths and other war-related environmental problems may create a biodiversity crisis in the area.

“A war occurring in a semi-closed sea like the Black Sea affects the wildlife negatively in many ways,” TÜDAV said this week in a media statement. “This sea is already a place where overfishing is evident, negative effects of climate change are seen and land-based pollutants and eutrophication (food increase in seawater) occur.”

Wetlands and biosphere reserves biodiversity are the most vulnerable in face of the war, TÜDAV, especially in the Sea of Azov, Danube Delta, and Gulf of Odessa. For the organization, the endangering of bird and fish species that breed, feed, migrate and lay eggs in the same place where bombings and gunshots happen daily is inevitable.

Scientific groups have recently been raising the alarm over growing war-related pollution in the Black Sea, caused by oil spills from sunken ships, chemical runoff from ammunition, and sabotaged infrastructure. Researchers and organizations even signed an open letter in March to express their concern over the environmental consequences of the war.

TUDAV suggested the creation of a regional monitoring program to study the effects of war on the marine, atmospheric, and earth systems and living life in the Black Sea. Just like the bombing of archaeological sites, hospitals, and religious buildings shouldn’t be allowed, sensitive ecosystems in the area such as wetlands should also be better protected.