Dolphins are dying in droves in the Black Sea, and Ukraine says it's evidence that Russia is committing a new kind of war crime

• Ukrainian officials have documented an uptick in dolphin and porpoise deaths near the Black Sea.
• They may use the data to build a case accusing Russia of environmental war crimes, NYT reported.
• Factors like maritime mines and pollutants from explosives likely contribute to the dolphin die-off.

As Russia's war against Ukraine rages on, Ukrainian officials have noticed an uptick in marine mammal deaths — and they want to use it as evidence to accuse Russia of ecocide and environmental war crimes.

That's according to The New York Times, which reported that there's been a significant increase in dead dolphins and porpoises washing ashore in the Black Sea.

What's causing massive dolphin die-offs

The Times reported that a number of factors related to the war could be contributing to marine mammal die-off including maritime mines, pollutants from explosives and fuel leaks, and toxic algae brought about by the presence of pesticides and heavy metals in the water.

The cacophony of sounds coming from Russian fighter jets, explosions, and rocket launches could also be a contributing factor, the report said. Noise from ships, sonar, and drilling is known to affect marine mammals' communication, ability to hear predators and prey, and navigation, according to the National Oceanic and Atmospheric Administration. 

In a peace plan he laid out last November, Ukrainian President Volodymyr Zelenskyy discussed the environmental damage Russia's war was causing.

"Due to the Russian aggression, 6 million domestic animals died," he wrote in the plan. "These are official numbers. At least 50,000 dolphins were killed in the Black Sea."

Currently, there are four acts that are considered international crimes that the International Criminal Court (ICC) oversees: genocide, crimes against humanity, war crimes, and crimes of aggression. Ukraine proposes to add a fifth act to the list: ecocide.