Over 100 dolphins and other marine mammals have washed up dead along the Russian coast over the past month, according to local reports earlier this week. Initial investigations reveal that many of the marine animals, which include the aquatic mammals called cetaceans, died because of 'unintentional' fishing practices. The deaths have been linked to fishing nets, rope entanglement, and other anthropogenic factors.

The discoveries of dead dolphins and other marine animals in different parts of the world are an emerging ecological disaster. This phenomenon has been observed over the past several decades, a period when maritime activities have further increased.

While natural factors could also be responsible, most dolphin deaths and those of other large aquatic animals such as whales have been linked to vessel strikes or ship collisions.

Dolphin Deaths in Russia

Almost 140 dolphin deaths and other marine mammal fatalities have been reported for March 2023 by the non-profit organization Delfa, a dolphin rescue and research center. In a post on the messaging app Telegram, Delfa wrote that a total of 137 cetaceans died over the past month. Cetaceans are aquatic mammals that include dolphins, whales, and porpoises. They belong to the infraorder Cetacea under the order Artiodactyla.

The rescue center added that on March 31, it received information about 26 cetacean deaths after learning of 101 dolphin deaths in the last week alone. The said figure has been considered serious and alarming by the organization, which suggested that the marine mammal deaths may have been caused by fishermen attempting to get rid of their bycatch. Many bodies of the animals showed signs of deep scratches, missing fins or tails, or torn stomachs.

This is not the first time that mass dolphin deaths have occurred. With this, Delfa states that the high number of deaths could be connected to authorities increasing the fishing quota in 2024 for flounders in southern Russia's Caucasus region, as cited by local sources. If such a trend continues and no alternative solution is found, dolphins could be eradicated from the Black Sea, the organization warns.

Cetacean Deaths and Vessel Strikes

Cetacean deaths, as mentioned earlier, are sometimes caused by ship collisions or any other vessels large enough to either kill or cause injury to these aquatic mammals.

According to experts, vessel strikes are one of the leading causes of fatalities for the endangered North Atlantic right whales in the waters off North America. The most common signs of vessel strike for cetaceans include blunt force trauma and propeller injuries.

Meanwhile, other sources point out that fishing gear entanglement is the leading factor that threatens dolphins and whales around the globe. According to the World Wide Fund for Nature, the entanglement phenomenon is responsible for at least 300,000 cetacean deaths per year. In addition, plastic pollution is also an emerging threat to the marine animals.