A stranded dolphin on the Black Sea.rai36de/Getty Images 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-offsThe 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.An explosion in Khmelnytskyi, UkraineTwitterThe cacophony of sounds coming from Russian fighter jets, explosions, and rocket launches could also be a contributing factor, the report said.