Oil spill in the Black Sea caused mass bird deaths
A vegetable oil spill in the Black Sea, which occurred as a result of a Russian strike in late December 2025, killed over a thousand birds.
This was reported by Ivan Rusev, head of the scientific department of the Tuzlivski Lymany National Nature Park.
According to him, environmentalists continue to record pollution on the coast, in particular in the Odessa Bay and within the territory of the national park. The oil spill occurred after the Russian troops struck the port infrastructure in the area of the port of Pivdenny on December 20, 2025, near the outlet of the Great Adzhaliysky Estuary into the Black Sea.
Rusev noted that due to low temperatures, a significant part of the oil quickly settled to the bottom, contaminating large areas of the benthos. During storms, these deposits rise back into the water, forming clots that clog the gills of fish and disrupt the breathing of other marine organisms.
According to scientists, more than 1,000 birds of various species, mostly terns, died in the Odessa Bay. Zoo staff and volunteers tried to save about 400 birds, but the survival rate remains critically low – an average of 15-20%, even with prolonged detention in warm rooms.
The ecologist explained that vegetable oil is extremely dangerous for birds: it glues feathers together and destroys their water-repellent layer. Because of this, birds cannot fly, quickly get wet and overheat. While cleaning their feathers, they swallow the oil, which leads to intoxication, liver damage and suppression of the immune system.
Against the backdrop of hypothermia, severe stress, and weakened immunity, hidden infections and parasites are activated, effectively killing the weakened birds. According to Rusev, the scale of the environmental problem is much greater than it seemed in the first weeks after the accident.
Oil and dead birds were also recorded on the 28th kilometer of the sandbank within the “Tuzlivsky Limans”. During the survey on January 27, ecologists discovered several spots with a total area of up to 5,000 square meters on the coast, about 15 kilometers long. The distance from this place to the accident area is about 150 kilometers.
Five species of dead birds were found on the coast, including the great crested grebe, the black-necked grebe, and the red-billed loon. Re-surveys after the storms showed that waves and sand had partially covered the oil slicks, and the remains of the birds could have been picked off by coastal predators.
In addition, during three days of surveys within the national park, not a single Black Sea seahorse was recorded. This may indicate its death due to chemical pollution and the peculiarities of the seabed relief in its habitat.