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08/17/2026 | Press release | Distributed by Public on 08/17/2026 13:44

Robotic Ocean Glider Reveals Giant Phytoplankton Chains in the Mediterranean Sea

Published Date

August 17, 2026

Article Content

Scientists at Scripps Institution of Oceanography at UC San Diego and the Mediterranean Institute of Oceanography in Marseille, France have discovered something surprising in the Mediterranean Sea: giant chains of phytoplankton.

To find them, Scripps biological oceanographer Mark Ohman, phytoplankton expert Karine Leblanc from Marseille, and SIO Visiting Scholars Sven Gastauer and Jeff Ellen used a special robot called the "Zooglider". Invented at Scripps in 2019, the Zooglider is a torpedo-shaped glider equipped with a high-tech camera called "Zoocam", a sonar device called "Zonar", and an underwater microphone. While most ocean tools disturb the water, the Zooglider glides silently, taking photos of marine life exactly as it exists in nature.

For years, researchers used nets and water bottles to collect samples. However, this study revealed a major problem: those traditional tools actually break the fragile phytoplankton chains, making them look much smaller than they really are. Thanks to the Zooglider's non-invasive camera, the team spotted chains over 10 millimeters long-far larger than anything seen in previous samples.

This discovery changes how scientists understand the ocean's food web. These giant chains are so large that most tiny sea animals, known as zooplankton, simply cannot eat them. Because they are too big to be eaten, these elongate diatoms (including Guinardia and Proboscia) and other algae may sink to the deep ocean floor, which changes how carbon and other nutrients move through the sea.

"This finding shakes up some historical perspectives," said Ohman.

The researchers believe these giant primary producers are likely found throughout the world ocean, but they have remained hidden until now. By using the Zooglider, scientists can finally see the true size of some of the ocean's smallest inhabitants.

This research was supported by the U.S. National Science Foundation, the Gordon and Betty Moore Foundation, and by the French Agence Nationale de la Recherche, as part of the BioSWOT-Med program.

Read the story in Limnology and Oceanography Letters: "Giant phytoplankton revealed by in situ imaging."

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