A Turquoise Tint for the Black Sea
Bias ratings based on AllSides + Ad Fontes Media. Agreement % = sources covering this story. Always read multiple sources and think critically.
Phytoplankton added a milky blue hue to the waters of the Black Sea and nearby waterways in spring and summer 2026.
Article View more Images of the Day:Jun 24, 2026Jun 26, 2026Instruments:ISS — Digital CameraPACECollections:Astronaut PhotographyTopics:Water Blooms The Black Sea sits at the boundary between Europe and Asia and connects to the Mediterranean Sea via a chain of waterways. Its surface often appears dark, but each spring and summer it transforms into a striking expanse of swirling turquoise. The OCI (Ocean Color Instrument) on NASA’s PACE (Plankton, Aerosol, Cloud, ocean Ecosystem) satellite captured this image (above) of the colorful waters on June 22, 2026. The turquoise color is likely caused by coccolithophores, a type of phytoplankton covered with calcium carbonate plates that can give surface waters a milky-blue appearance.
These types of phytoplankton tend to dominate in late spring and early summer. Other times of the year, diatoms—a type of microscopic algae with silica shells—can become more prevalent, and they tend to darken the water rather than brighten it. The Bosphorus, the narrow strait running through Istanbul that connects the Black Sea with the Sea of Marmara, also turned turquoise.
An astronaut aboard the International Space Station photographed the strait on May 27, 2026 (below), about a month before the PACE image, capturing blooming phytoplankton as it traced currents on both sides of the waterway. (Note that north is oriented toward the bottom of the frame.) Though coccolithophores are microscopic, they become so abundant during a bloom that they become visible from space. This makes remote sensing a useful tool for researchers studying bloom dynamics in regions where direct sampling is limited.
Beyond their visibility, these blooms also contribute to the ocean’s carbon cycle. When they die, some of the carbon they’ve taken up sinks to the seafloor, where it can remain stored for long periods of time. NASA Earth Observatory image by Michala Garrison, using PACE data from NASA EOSDIS LANCE and GIBS/Worldview and the NASA Ocean Biology Distributed Active Archive Center OB.DAAC.
Astronaut photograph ISS074-E-619520 was acquired on May 27, 2026, with a Nikon Z9 digital camera using a focal length of 50 millimeters. It is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit at NASA Johnson Space Center. The image was taken by a member of the Expedition 74 crew.
The image has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth.
References & Resources NASA Earth Observatory (2022, June 28) Brilliant Color in the Black Sea. NASA Earth Observatory (2012, July 15) Carbon Eaters on the Black Sea. (2026) Prolonged Summer Coccolithophore Blooms in the Northeastern Black Sea: Anomaly or Emerging Trend?
You may also be interested in: Stay up-to-date with the latest content from NASA as we explore the universe and discover more about our home planet. An astronaut on the International Space Station was surprised to photograph a shower of light streaking through the darkness while… Article Color Off the Mid-Atlantic Coast 4 min read Something is brewing in shallow waters offshore of Delaware, New Jersey, Maryland, and Virginia.
Think About This
What questions does this story raise for you? Talk with your family: Why does this news matter? Who is affected? What might happen next? Is there anything you can do?
- Ask your child: “What do you think scientists discovered about turquoise tint? What part surprised you most?”
- Explore together: Search for “turquoise tint” on NASA Kids’ Club, DK Find Out, or National Geographic Kids for more kid-friendly facts.
- Critical thinking: Science findings can change as more research is done. Ask: “How would scientists test this? What would prove them wrong?”
KiddieDaily is built for families — balanced sources, no agenda, no ads. Always read the original source and think for yourself.
Original Sources
🔍 Want to verify this story? Check it on Google Fact Check Explorer →
More stories: Kid News · Archive · Fact Check