Phytoplankton added a milky blue hue to the waters of the Black Sea and nearby waterways in spring and summer 2026. The Ocean Color Instrument (OCI) on NASA’s PACE satellite captured stunning images of the colorful waters, highlighting a massive seasonal shift visible from orbit.

More info here: https://science.nasa.gov/earth/earth-observatory/a-turquoise-tint-for-the-black-sea/